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    Effects of Incremental Seeding Rate Under Sub-Soiling During the Fallow Period on Nitrogen Absorption and Utilization, Yield and Grain Protein Content in Dryland Wheat
    XUE LingZhu, SUN Min, GAO ZhiQiang, WANG PeiRu, REN AiXia, LEI MiaoMiao, YANG ZhenPing
    Scientia Agricultura Sinica    2017, 50 (13): 2451-2462.   DOI: 10.3864/j.issn.0578-1752.2017.13.005
    Abstract256)   HTML2)    PDF (437KB)(347)       Save
    【Objective】The objective of these experiments is to clarify the effects of sub-soiling during the fallow period(SS) on soil water storage, explore the optimum seeding rate for constructing rational community of dryland wheat, and find out the best tillage and seeding technique, which could improve yield and quality coordinately. 【Method】 Field experiments were carried out from 2012 to 2014 in Wenxi, Shanxi province, with or without SS as the main plots and three seeding rates (67.5, 90, 112.5 kg·hm-2) as subplots. Soil water storage during the fallow period, community tiller amount of plants before winter, dry weight and nitrogen content in different organs of plant, the yield and its components were measured to assess effects of seeding rate under SS on plant nitrogen absorption and utilization, yield, and grain protein content. 【Result】 The soil water storage efficiency during the fallow period was improved by more than 60% under SS compared with CK. Plant community tiller amount before winter, dry weight and nitrogen accumulation in plant at wintering stage, pre-anthesis accumulated nitrogen translocation amount from leaf and glume+spike to grains and nitrogen accumulation in the whole plant after anthesis were significantly increased under SS compared with CK. Plant community tiller amount before winter, dry weight at wintering stage and pre-anthesis accumulated nitrogen translocation amount from vegetative organs to grains and the contribution of pre-anthesis accumulated nitrogen translocation amount from leaf and glume+spike to grains were increased with the increase of seeding rate under SS while no significant difference between the seeding rate of 90 kg·hm-2 and 112.5 kg·hm-2 was presented. Spike number and grain number per spike were significantly increased under SS compared with CK, meanwhile, the yield was improved by 26%-66% and 17%-34% in two growing years respectively. Grain protein content was decreased under SS compared with CK, however, no significant difference was observed between them under 90 kg·hm-2 condition. Spike number, 1000-grain weight and the yield were increased with the increase of seeding rate under SS, however, there was no significant difference between seeding rate of 90 kg·hm-2 and 112.5 kg·hm-2. In addition, the highest grain protein content and its yield were observed under the seeding rate of 90 kg·hm-2 under SS. Water use efficiency was significantly improved by 13%-22% and 9%-16% in two growing years, respectively, under SS compared with CK. Nitrogen uptake efficiency and nitrogen productive efficiency were significantly improved, and nitrogen use efficiency was significantly improved under the seeding rate of 67.5 kg·hm-2 and 90 kg·hm-2 condition under SS compared with CK. The highest water use efficiency was significantly observed under the seeding rate of 90 kg·hm-2 condition under SS. Nitrogen uptake efficiency and nitrogen productive efficiency were improved with the increase of seeding rate under SS, while nitrogen productive efficiency had no significant difference between the seeding rate of 90 kg·hm-2 and 112.5 kg·hm-2 treatments. Moreover, under the condition of SS combined with different seeding rates, the yield and grain protein yield have significant and very significant correlation with pre-anthesis accumulated nitrogen translocation amount from vegetative organs to grains after anthesis, especially with the glume + spike under the condition of more precipitation. And nitrogen accumulation after anthesis was more significantly correlated with the yield under the condition of more precipitation. 【Conclusion】 Sub-soiling during the fallow period plus the seeding rate of 90 kg·hm-2 was not only beneficial to form the strong seedlings before winter for dryland wheat, increase nitrogen accumulation of various organs at anthesis, promote pre-anthesis accumulated nitrogen translocation from leaf and glume + spike to grains, form the effective spike number, construct plant rational community of dryland wheat, and improve yield, water use efficiency, nitrogen uptake efficiency and nitrogen productive efficiency, and ultimately achieve the coordinated improvement of yield and grain protein content.
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    Effects of Different Planting Densities on Photosynthetic Characteristics and Yield of Different Variety Types of Spring Maize on Dryland
    XU ZongGui, SUN Lei, WANG Hao, WANG ShuLan, WANG XiaoLi, LI Jun
    Scientia Agricultura Sinica    2017, 50 (13): 2463-2475.   DOI: 10.3864/j.issn.0578-1752.2017.13.006
    Abstract321)   HTML3)    PDF (438KB)(485)       Save
    【Objective】Effects of different planting densities and different variety types of spring maize on physiological characteristics and yield in Weibei highland were investigated. The aim of this study was to determine the suitable maize varieties and their planting densities in dryland. 【Method】Field experiments were carried out by using spring maize cultivar Yuyu22, Zhengdan958, Xianyu335, and four planting density treatments including D1(52 500 plants/hm2), D2(67 500 plants/hm2), D3(82 500 plants/hm2) and D4(97 500 plants/hm2) were designed. The changes of photosynthetic characteristics, leaf area index(LAI), biomass yield and yield related traits of spring maize at different growth stages were observed.【Result】(1)Photosynthetic rate (Pn) and transpiration rate (Tr) decreased with the increase of planting density, while LAI increased. Pn decreased by 1.32 μmol CO2·m-2·s-1, Tr decreased by 0.297 mmol·m-2·s-1 and LAI increased by 0.181 for each increase in density of 10 000 plants/hm2. (2)The number of productive ear was remarkably increased with the increase of planting density, but the kernels per ear and 1 000-kernel weight were significantly decreased(P<0.05). The kernels per ear decreased by 45 and the 1 000-kernel weight decreased by 12 g for each increase in density of 10 000 plants/hm2. The yield of three maize varieties was the highest at D2 density. In treatment D2, the yield of Yuyu 22, Zhengdan 958, and Xianyu 335 were 10.52, 9.59, and 9.14 t·hm-2 in 2015, and 11.37, 9.73, and 9.77 t·hm-2 in 2016, respectively. The average yield of three maize varieties was increased by 21.9%, 19.5%, and 7.5%, respectively, within two years, when the density was increased from 52 500 plants/hm2 to 67 500 plants/hm2. The average yield of three maize varieties was decreased by 19.8%, 15.4%, and 7.7%, respectively, within two years, when the density was increased from 67 500 plants/hm2 to 97 500 plants/hm2. (3) The stem diameter, and ear length of spring maize decreased with the increase of planting density. The ear length decreased by 0.86 cm, the stem diameter decreased by 0.09 cm for each increase in density of 10 000 plants/hm2. The lodging rate of Yuyu 22 and Zhengdan 958 rather than Xianyu 335 increased with the decrease of stem diameter. (4)The harvest index varied greatly in two years, the average performance was 2015>2016, and the varieties showed that Xianyu 335>Zhengdan 958>Yuyu 22. Water use efficiency (WUE) and radiation use efficiency (RUE) were increased with the increase of planting density and then decreased.【Conclusion】The optimum planting density of different variety types of spring maize in Weibei dryland was different. Yuyu 22 was 72 500 plants/hm2, Zhengdan 958 was 74 000 plants/hm2, and Xianyu 335 was 73 200 plants/hm2. Yuyu 22 had high stability and high yield. The optimum planting density of different variety types of spring maize was 72 600-74 000 plants/hm2. Low density was recommended for thin planting varieties, and high density was recommended for close planting varieties.
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    Effects of Climate Change on Cropping Pattern and Yield of Summer Maize-Winter Wheat in Huang-Huai-Hai Plain
    SUN XinSu, LONG ZhiWei, SONG GuangPeng, CHEN ChangQing
    Scientia Agricultura Sinica    2017, 50 (13): 2476-2487.   DOI: 10.3864/j.issn.0578-1752.2017.13.007
    Abstract390)   HTML15)    PDF (1585KB)(749)       Save
    【Objective】Global climate is changing significantly characterized by warming. Exploring the influence of climate warming on winter wheat-【Method】 The meteorological data, phenological data and yield data of HHH during 1992-2013 were used to analyze the effect of climate change on summer maize-winter wheat system by the mathematical statistics analysis method. The meteorological information including the temperature and precipitation data were obtained from China Meteorological Administration. Climate change of HHH area during 1992-2013 were analyzed by monadic linear regression. Through the weighted average of phenological data, the growth period and stubbles changes of summer maize-winter wheat were analyzed. The summer maize-winter wheat yields during 1992-2013 were analyzed by monadic linear regression. What’s more, nonlinear regression analysis and panel data sensitivity analysis were used to analyze the effect of climate change on annual yield of summer maize-winter wheat.【Result】The temperature of HHH showed a rising trend while precipitation generally remained unchange in the 1992-2013, but the regional difference was obvious. Climate change significantly changed the summer maize and winter wheat planting system: The whole growth stages of winter wheat observably shortened by 2 to 5 days in different regions with sowing time delayed. Sowing time of maize showed a difference of southern delay but northern advance while mature time delayed in general. What’s more, there was no significant change of summer maize growth period in the whole area. Stubbles time of summer maize-winter wheat was postponed because of the change of growth period, which led to the waste of climatic resources and land resources. In recent years, the anniversary yields of summer maize and winter wheat showed a significant rising trend in HHH. Climate sensitivity analysis showed that the impact of low temperature, high temperature and average temperature on winter wheat yield was alike, the yield in Jiangsu and Shandong yield decreased while that in Hebei and Henan increased, which the minimum temperature showed a significant effect. In the whole HHH plain, summer maize yield was reduced in different degrees when temperature rising except Henan province because of the difference of temperature rise range and precipitation. There were regional difference of annual yield affected by climate changes due to the regional difference of precipitation. Effect of climate change on annual yield was different that yield in north was increased but decreased in south, so choosing appropriate summer maize varieties is meaningful to guarantee the annual yield. 【Conclusion】Global warming delayed the winter wheat sowing time and shortened winter wheat growing period. It also made summer maize growth period changed that is extended in the north but that is shortened in the south. The prolonged stubbles owing to the shortened growth period led to the waste of climatic resources and land resources. Actual anniversary yield showed a significantly increasing trend in recent years. Effect of increasing temperature and precipitation had regional differences. Generally speaking, temperature rise made maize yield reduced and wheat yield increased, while precipitation made maize yield in northern HHH increased and maize yield reduced in the southern HHH as well as wheat production decreased in different degrees.summer maize cropping system in Huang-Huai-Hai Plain (HHH) to provide a theoretical foundation for formulating reasonable counter measures.
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    Retrieval Effects of Remedial Fertilizer After Freeze Injury on Wheat Yield and Its Mechanism at Tillering Stage
    LI ChunYan, YANG Jing, ZHANG YuXue, YAO MengHao, ZHU XinKai, GUO WenShan
    Scientia Agricultura Sinica    2017, 50 (10): 1781-1791.   DOI: 10.3864/j.issn.0578-1752.2017.10.004
    Abstract264)   HTML3)    PDF (448KB)(554)       Save
    【Objective】Freeze injury in wheat often happens and affects wheat yield formation during the wintering stage. There was less study on the remedial measures to recover wheat yield after low temperature stress at wintering stage. Hence, effects of remedial fertilizer after low temperature stress on yield recovery in wheat at tillering stage and its mechanism were studied, which will provide a basis for anti-cultivation technology in wheat. 【Method】The spring wheat cultivar Yangmai16 was treated at -2℃/-6℃(day/night, 2012) and -2℃/-8℃ (day/night, 2013) for 24, 48 and 72 h, respectively, using artificial temperature-controlled phytotron system. Then the different remedial urea (N 46%) amounts of 75, 150 kg·hm-2 (2012) and 75, 120, 180 kg·hm-2 (2013) were all used at a time after low temperature stress. The degree and freezing injury proportion of wheat plant under low temperature stress and the changes of soluble sucrose, proline and endogenous hormone contents in the second leaves from the top on the 10th, 20th and 30th day after applying remedial fertilizer were investigated. Plant height and yield at maturity were also recorded. 【Result】The index of freezing injury increased from 0.2 to 0.5 under longer stress at tillering stage. The contents of soluble sugar, proline, abscisic acid (ABA) and zeatin riboside (ZR) in leaves of the treatment increased under longer stress. These parameters in the treatment without fertilizer amendment were higher than those in the treatment with fertilizer amendment on the 10th day after applying remedial fertilizer. The parameters reduced more rapidly with more applying fertilizer under the same duration time. The content of gibberellines (GA3) decreased gradually with longer stress at tillering stage. The contents of soluble sugar and proline, and the contents of ABA and ZR of these treatments using fertilizer after cold stress gradually declined on the 20th day after applying remedial fertilizer. While the change of GA3 contents was opposite to ABA and ZR contents. All these parameters reached the levels of the controlled plants in natural environment on the 30th day after applying remedial fertilizer. Wheat yield, the first and second basal internode length and plant height all lowered with longer cold stress. With increased fertilizer applying amount under the same treatment duration, the length of wheat plants were better restored and the loss of grain yield was lessened.【Conclusion】Cold injury wheat will recover growth after using the right urea amount scientifically in time depending on the cold index at tillering stage. Osmotic adjustment substance contents declining and hormone contents becoming balance, new tillers emergency and the basal internode length becoming longer were the main reason for increasing grain yield at tillering stage after applying the urea. At tillering stage, considering recovery effect and nitrogen partial factor productivity, 75 kg·hm-2 urea would be recommended for nitrogen amendment when wheat plants were damaged slightly and the cold index was about 0.2. When the cold index was about 0.36, 120 kg·hm-2 urea would be suggested. When the cold index was about 0.50, 180 kg·hm-2 urea was recommended for recovering wheat growth after severe cold damage.
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    A Hybrid Yield Estimation Model Based on the Trend Yield Model and Remote Sensing Correction Yield Model
    CHEN ChangWei, ZHU XiuFang, CAI Yi, GUO Hang
    Scientia Agricultura Sinica    2017, 50 (10): 1792-1801.   DOI: 10.3864/j.issn.0578-1752.2017.10.005
    Abstract283)   HTML5)    PDF (952KB)(792)       Save
    【Objective】 This paper analyzed the advantages and disadvantages of current crop yield estimation methods and proposed a novel hybrid yield estimation model which combines statistical yield estimation and yield estimation methods. 【Method】The model consists of three parts, trend yield estimate (Yt), remote sensing correction yield (Ys) and random error. The trend yield estimation was firstly calculated by using the polynomial regression method based on a long time series data of historical yield and then corrected by ARIMA model, which was set up by using the bias between the trend yield estimates and the historical yields. After that, a multiple linear regression model was set up to further reduce the estimation errors by using the bias between the trend yield estimates (Yt) and the reference yields as dependent variable and NDVI in critical growth period of crop as independent variables. In order to verify the feasibility and accuracy of the new hybrid estimation model, this paper estimated the yield of winter wheat in Beijing in 2015 based on three HJ Imagery obtained in winter wheat growing season, winter wheat yield of 30 sampling fields in 2015, and a nearly 30 years time series data of winter wheat yield (1985-2014) of Beijing. The estimation results from the hybrid yield estimation model was then compared with the true yield (2015 statistic winter wheat yield).【Result】The accuracy of winter wheat yield by using novel hybrid yield estimation model was 98.7% at city level and above 90% at country level. Except Fangshan(90.3%), the relative accuracy of yield estimation at the other countries was above 95%. The accuracy of winter wheat yield by using traditional trend yield model in Beijing was 94.75%, but the accuracy by using traditional trend yield model at country level was low, especially was lower 80% in Fangshan. ARIMA model was used for improving the accuracy of the traditional trend yield model. The accuracy of winter wheat yield improved in average by introducing the ARIMA model. For the remote sensing correction model established in this paper, using three remote sensing images for improving the accuracy was better, and this method improved the accuracy of winter wheat yield by 3.55%, especially the accuracy had a significant ascension in Fangshan and Pinggu.【Conclusion】The accuracy of winter wheat yield by using the novel hybrid estimation model is good at city level and county level. The model considers the change of time and spatial and can be used in crop yield estimation.
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    Differences of Double-Cropping Late Rice in Yield, Growth Stage and Utilization of Temperature and Illumination in Different Latitudes of Jiangxi Province
    CHEN Bo, ZHOU NianBing, GUO BaoWei, SHU Peng, ZHANG HongCheng, HUO ZhongYang, CHENG FeiHu, HUA Jin, HUANG DaShan, CHEN ZhongPing, CHEN Heng, LIU YunFa, LIAO ShiLiang
    Scientia Agricultura Sinica    2017, 50 (8): 1403-1415.   DOI: 10.3864/j.issn.0578-1752.2017.08.005
    Abstract439)   HTML2)    PDF (458KB)(799)       Save
    【Objective】This study was conducted to clarify the differences of different-types of late rice in yield, growth period and the utilization of temperature and illumination in different latitudes of Jiangxi province, which would provide grounds and references for scientific selection of Japonica rice varieties in Jiangxi. 【Method】The yield, growth stage and utilization of temperature and illumination of double-cropping late rice were comparatively studied by using four kinds of rice varieties as test materials namely indica-japonica hybrid rice, japonica hybrid rice, japonica conventional rice and indica hybrid rice. The experiment was carried out in such three cities indicating latitude discrepancy as Leping (29.00°N, 117.12°E), Shanggao (28.27°N, 115.12°E)and Ganzhou (25.81°N, 114.96°E) in Jiangxi province.【Result】The yield of three-types of late japonica rice increased with the increasing latitudes. In the 2013 (2014), when the latitudes rose by one unit, the yield of indica-japonica hybrid rice, japonica hybrid rice, japonica rice and indica hybrid rice increased by 0.36 (0.32), 0.18 (0.22), 0.25 (0.20) t·hm-2, respectively. Both indica-japonica hybrid rice and japonica hybrid rice yield significantly higher than indica hybrid rice in the same latitude, and with the exception of Ganzhou, the yields of conventional japonica rice were significantly higher than indica hybrid rice. The three types of japonica rice at each experimental site could mature in safety. With the increasing latitude, the stage from seeding to elongation of each type rice lengthened noticeably and its whole growth period was extended. As shown in the extensions of stages from heading to mature, the whole growth periods of three types japonica rice were extremely noticeably longer than indica hybrid rice at the same experimental site. Utilization efficiency of light and temperature of the three types of Japonica rice showed such a trend as indica-japonica hybrid rice > japonica hybrid rice > japonica conventional rice > indica hybrid rice, therefore a conclusion could be drawn that the growth period was in direct proportion to utilization rate of temperature and light in terms of double cropping late rice maturing in safety. 【Conclusion】 Indica Rice to Japonica Rice” project in different latitudes in double cropping late rice area of Jiangxi could significantly increase yield, temperature and illumination resource utilization. Compared with indica hybrid rice in local area, growing indica-japonica hybrid rice, japonica hybrid rice and japonica conventional rice in Leping and Shanggao has advantages in yield and temperature and illumination resource utilization, while growing indica-japonica hybrid rice in Ganzhou has obvious advantages. “Indica Rice to Japonica Rice” may be the main way to increase the production in double cropping rice area.
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    Effects of Supplemental Irrigation Based on Soil Moisture Measurement on Flag Leaf Chlorophyll Fluorescence and Senescence Characteristics in Two Wheat Cultivars
    YAN LiXia, YU ZhenWen, SHI Yu, ZHAO JunYe, ZHANG YongLi
    Scientia Agricultura Sinica    2017, 50 (8): 1416-1429.   DOI: 10.3864/j.issn.0578-1752.2017.08.006
    Abstract316)   HTML2)    PDF (548KB)(505)       Save
    【Objective】This study investigated the effects of supplemental irrigation based on soil moisture measurement on flag leaf chlorophyll fluorescence and senescence characteristics in two wheat cultivars. 【Method】Under field conditions, the experiments were conducted in the growth seasons of 2013-2015 using the cultivars Jimai 22 (J22) and Tainong 18 (T18). Three treatments were applied, namely, no-irrigation during whole growth season (W0); an average relative soil water content of 65% in 0-40 cm soil layers at jointing and anthesis, respectively, by supplemental irrigation based on measured soil moisture (W1); and irrigation with 60 mm each at jointing and anthesis (W2, local supplemental irrigation practice). 【Result】W1 regulated the amount of irrigation at jointing and anthesis, maintained the relative water content of soil by 65% after irrigation, and prevented excessive or too low irrigation to create suitable soil moisture environment for wheat growth and development. On the 14, 21, and 28 day after anthesis, the electron transport rate, photochemical quenching of chlorophyll fluorescence, actual photochemical efficiency, and sucrose content of flag leaves were significantly higher under W1 than those under W2. The activity of sucrose phosphate synthase in flag leaves of W1 on 14 and 21 day after anthesis was significantly higher than that of W2. On the 14, 21, and 28 day after anthesis, the activities of superoxide dismutase and catalase in flag leaves in W1 were significantly higher than those in W2 for two cultivars. In addition, the MDA content in flag leaves was significantly lower than that of W2, and a high level of soluble protein content was maintained in flag leaves. During the two growing seasons, the grain yield, water use efficiency, and irrigation efficiency of W1 treatment for T18 and J22 were significantly higher than that of W2. Comparison among cultivars, on the 21, and 28 day after anthesis, the electron transport rate, photochemical quenching of chlorophyll fluorescence, actual photochemical efficiency, and sucrose content of flag leaves were significantly higher of T18 under W1 and W2 than those of J22. The activity of sucrose phosphate synthase in flag leaves of T18 on the 7, 14 and 21 day after anthesis was significantly higher than that of J22. On the 21, and 28 day after anthesis, the activities of superoxide dismutase and catalase in flag leaves of T18 were significantly higher than those of J22 in W1 and W2. In addition, the MDA content in flag leaves of T18 was significantly lower than that of J22, and a high level of soluble protein content was maintained in flag leaves. In the same growing season under the same treatment, no significant difference in total water consumption and water use efficiency was observed between T18 and J22. Grain yield and irrigation efficiency of T18 in W1 and W2 treatments were significantly higher than those of J22. However, the yield of T18 in W0 was significantly lower than that of J22. 【Conclusion】Supplemental irrigation based on soil moisture measurement (W1) could regulate the relative water content in soil to the targeted level at jointing and anthesis. W1 was suitable for two wheat varieties and effective in achieving both high yield and saving water. Under irrigation conditions, the yield potential of T18 was higher than that of J22. Under drought conditions, however, the sensitivity to moisture and yield of T18 were lower than those of J22.
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    Effects of 24-Brassinolide on the Fertility, Physiological Characteristics and Cell Ultra-Structure of Soybean Under Saline-Alkali Stress
    WU Yang, GAO HuiChun, ZHANG BiXian, ZHANG HaiLing, WANG QuanWei, LIU XinLei, LUAN XiaoYan, MA YanSong
    Scientia Agricultura Sinica    2017, 50 (5): 811-821.   DOI: 10.3864/j.issn.0578-1752.2017.05.004
    Abstract435)   HTML10)    PDF (10562KB)(525)       Save
    Objective】The aim of this experiment was to study the effects of exogenous EBR (24-epibrassinolide) on the growth indices, physiological characteristics and cellular ultrastructure of soybean under saline-alkali stress. 【Method】Soybean variety Heinong 44 was employed as the test material, and cultivated in 110 mmol·L-1 nutrient solution saline-alkali stress treatments for 3 d and 7 d to investigate the effects of 1.2 mg·L-1 exogenous EBR on the height and root growth, SOD, POD, and APX three kinds of antioxidant enzyme activities, relative electrical conductivity, superoxide anion (O2-) production rate, contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA), free proline concentration content, chlorophyll content of soybean leaves and the responses of cellular ultrastructure of soybean leaves and root tips under saline-alkali stress. 【Result】Under the condition of saline-alkali stress dealing with 3 d and 7 d, compared to the control, the three kinds of antioxidant enzyme activities of SOD, POD, and APX, free proline content, relative electrical conductivity, O2-production rate, contents of H2O2 and MDA all increased, the growth indices and chlorophyll content all decreased; the chloroplast and mitochondria cellular ultrastructure of soybean leaves suffered severe damages. The mitochondria and endoplasmic reticulum cellular ultrastructure of soybean root tips suffered severe damages, and vacuole was ruptured. Application of EBR under saline-alkali stress increased soybean plant height, root length, fresh mass of root by 6.45%, 9.60% and 19.85%, respectively. Application of EBR the activities of SOD, POD, and APX of soybean leaves in 3 d and 7 d treatments increased by 16.92% and 9.68%, 48.85% and 61.44%, 19.05% and 20.36%, respectively, relative electrical conductivity, O2-production rate, H2O2 and MDA contents significantly decreased by 19.58% and 28.26%, 28.06% and 40.92%, 28.62% and 31.21%, 31.03% and 37.17%, respectively, free proline content and chlorophyll content significantly increased by 3.67% and 15.96%, 13.34% and 16.87%, respectively. At the same time, the stability of soybean leaves and root tip cell ultrastructure were maintained and the aging of cells and disintegration were delayed.【Conclusion】The results suggested that application of exogenous EBR under saline-alkali stress could increase the antioxidant enzyme activities, free proline concentration and chlorophyll content, reduce the accumulation of reactive oxygen species(ROS), maintain the cell structure integrity, promote seedling growth and resulting in improving the tolerance of soybean seedlings to saline-alkali stress.
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    Photosynthetic Characteristics and Yield Components of Dwarf Sorghum Hybrid Liaoza 35
    HUANG RuiDong, GAO Yue, ZHOU YuFei, WU Qi, ZHANG Jiao, SHANG PeiPei, ZHANG Zhuang, GAO MingYue, HAN Yi, XU WenJuan
    Scientia Agricultura Sinica    2017, 50 (5): 822-829.   DOI: 10.3864/j.issn.0578-1752.2017.05.005
    Abstract401)   HTML13)    PDF (504KB)(475)       Save
    【Objective】Enhancing the mechanization level is now one of the most important goals in sorghum production. Important progress has been made in the dwarf sorghum hybrid breeding suitable for mechanization planting. The aim of this experiment is to investigate the photosynthetic characteristics and yield formation regularities of dwarf stalk sorghum hybrid, the results of the study will beneficial for the breeding and popularization of the new type sorghum hybrids. 【Method】 In this experiment, the newly bred dwarf sorghum hybrid Liaoza 35, suitable for mechanized production, was served as the main test material, with three planting densities (90 000 plants/hm2, 120 000 plants/hm2 and 150 000 plants/hm2), and the middle-high stalk sorghum hybrid Liaoza 19, the regional main cultivar with a similar growth duration, was used as the control (planting density was set as the suitable level of 105 000 plants/hm2), to explore the photosynthetic characteristics and yield formation regularities of the dwarf stalk sorghum hybrid through analysis of plant morphological, photosynthetic and ecological environment indexes and yield components of the sorghum population. 【Result】 At filling stage of the most flourishing population, with the increase of planting density, the dwarf sorghum Liaoza 35 showed significant reductions of light intensity, light transmittance, stomatal conductance and photosynthetic rate in the middle and lower parts of the canopy, and also significantly lower than those of the control hybrid Liaoza 19, but no significant difference in the above each index at the upper canopy between the two hybrid varieties. The electron transport rate (ETR), coefficient of photochemical quenching (qP) and the maximal photochemical efficiency (Fv/Fm) on the second leaf from the top of Liaoza 35 at flowering and filling stages showed a trend of decrease along with the increase of planting densities, while the initial fluorescence (Fo) showed a trend of increase, and all the fluorescence parameters of Liaoza 19 were better than those of Liaoza 35 on the condition of middle-high planting densities. Leaf area index increased with the increase of planting density, showing a trend of increase until anthesis and then gradual decline, with the fastest decline in the treatment of 150 000 plants/hm2, however, a considerable leaf area index was also maintained at the maturity stage of Liaoza 35; leaf SPAD values declined significantly at lower parts of the canopy. Under high planting density conditions, the morphological, photosynthetic and ecological environment indexes of Liaoza 35 performed poorly compared to Liaoza 19, which might be associated with its plant type: dwarf in height, but no corresponding reduction of leaf number and no noticeable changing of leaf angle. With the increase of planting density, Liaoza 35 gave higher biological yield and grain yield, with significant reduction of grains per panicle but no significant change in 1000-kernel weight. Liaoza 35 produced the highest grain yield, 9 923.5 kg·hm-2, at the planting density of 150 000 plants/hm2, and over-yielded the control Liaoza 19. 【Conclusion】 Reasonable increase of planting density is a key to promote the grain yield increase of dwarf sorghum. However, high planting density may induce negative impacts on the photosynthetic characteristics and dry matter production in the population canopy, thus it is important to make the negative impact on the individual plants less than the positive effect on the population performance through improving sorghum plant type and the better management of water, fertilizers and planting densities to coordinate the relationship between the sorghum population and individual plants.
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    Timeliness Analysis of Crop Remote Sensing Classification One Crop A Year
    LIU HuanJun, YU ShengNan, ZHANG XinLe, GUO Dong, YIN JiXian
    Scientia Agricultura Sinica    2017, 50 (5): 830-839.   DOI: 10.3864/j.issn.0578-1752.2017.05.006
    Abstract393)   HTML11)    PDF (2219KB)(987)       Save
    【Objective】Crop type remote sensing identification is a basis of crop cultivated area and crop growth analysis and yield estimation, and it is a very important driving force to promote the rapid development of modern agriculture. At the same time, it is also a basis for macro-regulation and control of understanding of agricultural conditions by the departments of agriculture as well as other related ones. At present, most of the present researches about agricultural remote sensing are limited to moderate or low resolution remote sensing images, which affect the accuracy of vegetable information extraction. The accuracy of vegetation information extraction can be improved by using high resolution multi temporal remote sensing images and selecting suitable classification methods. Clearly understanding of the timeliness and optimal classification method of crop remote sensing classification, acquire crop spatial distribution data quickly and accurately, and to provide a basis for crop quantitative remote sensing monitoring are the aims of the study.【Method】Based on the 20 remote sensing images covering the whole growth period of 5-10 months in Hulin, Heilongjiang province in 2014, the 16 m resolution NDVI time series curves were built by using 20 images. Different crops had different NDVI time series curves during the whole growth period. The decision tree classification model was established. After analysis of the images through serial threshold division, assisted with background data and expert knowledge, the areas and distributions of the land use and land cover information were extracted. Twenty images were used in order to classify the crops and the optimal phase was defined. Taking the farmland range as the rule, various classification methods for crop classification were compared. And it was also compared with the crop classification without extracting the farmland range by using several common methods of crop classification. Meanwhile, various classification methods including the maximum likelihood method, Mahalanobis distance method, neural network method, minimum distance method, support vector machine, spectral angle classification, and crop classification of principal component analysis were compared, and the data from the insured blocks were employed for the accuracy verification.【Result】 (1) In early July, the end of July to early August, and the end of September are the 3 key phases of crop remote sensing classification in the study area during the first quarter of the year. (2) The decision tree classification method had the highest accuracy in extracting land use cover information, the overall accuracy of classification was up to 94.01%, Kappa coefficient was 0.79. (3) In early June and early July, 2 images combined with classification of crops, the overall of classification accuracy was up to 90.24%, Kappa coefficient was 0.87. The combination of early June and early July images could be used to solve the timeliness of crop classification. (4) Combined with the image of Sep 21st, the overall accuracy was further improved, and the classification accuracy of soybean was improved obviously, so the maximum likelihood method was the best classification method, and the jointing stage was the best phase.【Conclusion】It was concluded that remote sensing images can be used to accurately classify crops in early July. Results of this study have expanded the application value of remote sensing data in the field of agriculture. It has guiding significance for one crop a year of the crop fast classification.
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    Cited: Baidu(1)
    Analysis of Moisture State and Transverse Relaxation Characteristics of Grains During the Growth Process of Rice
    SHAO XiaoLong, WANG Nan, SHI XiaoZhuan, SHEN Fei, SONG Wei, ZHANG Qiang
    Scientia Agricultura Sinica    2017, 50 (2): 240-249.   DOI: 10.3864/j.issn.0578-1752.2017.02.004
    Abstract358)   HTML5)    PDF (503KB)(555)       Save
    【Objective】This paper is mainly to observe the changes of moisture state of grains during the growth process of rice after heading by LF-NMR, and investigate the effects of accumulation of starch and protein on the moisture state of kernels, which provides reference for formation regularity of rice qualities.【Method】The spikes of “Yueguang” organic rice were sampled at intervals for 63 days after heading (DAH), The 100-grain weight, hardness, moisture content, starch content and protein content were measured, separately, which were used to compare the changes of whole qualities of grains at different growth periods of rice after heading. The transverse relaxation parameters determined by LF-NMR were adopted to qualitatively and quantitatively analyze the moisture dynamics of grains. What’s more, the internal relationships between the formation process of rice qualities and moisture state of grains were discussed.【Result】Both the 100-grain weight and starch content for “Yueguang” organic rice increased most quickly within 7-14 DAH, and they were highly significantly and positively correlated with each other (P<0.01). Hardness was highly significantly and positively correlated with starch content and protein content, respectively (P<0.01), and negatively correlated with moisture content (P<0.01). Within 7-56 DAH, moisture content exponentially declined from 57.16% to 22.39%. With showing an S-shaped growth curve, starch content increased to 50.47 g/100g wet-basis within 42 DAH. Protein content linearly increased to the peak value of 6.56 g/100g wet-basis within 7-49 DAH. On the whole, the whole qualities of rice grains had been formed within 49 DAH. The inversion spectrum of LF-NMR data showed that part of water in the grains moved towards the direction of high mobility within 7 DAH. Within 7-21 DAH, when inversion curves of LF-NMR data gradually moved towards the left, T2b peak representing for “bound water" with least mobility occurred, followed by the differentiation phenomenon of T22 peak representing for capillary water. Four kinds of transverse relaxation times including T2b, T21, T22 and T23, gradually decreased with growth periods, which indicated that whole proton degree of freedom in the kernels dropped obviously. The peak ratio of “bound water” was more than peak ratio summation of capillary water and free water at 21 DAH. The moisture content and transverse relaxation parameters (T2b, T21, T22, T23, A2b, A22 and A23) of grains varied with growth periods highly significantly (P<0.01), which were also highly significantly (P<0.01) related to the accumulation of starch and protein. With endosperm cells filled with starch granules, most of water molecules in the grains were mainly surrounded by starch granules and formed hydrogen bonds with hydrophilic groups of starch, which resulted in the migration of moisture state towards the direction of “bound water”. According to principal component analysis of transverse relaxation signals, there were significant differences among the moisture state of rice grains for different growth periods within 42 DAH, followed by keeping steady.【Conclusion】It was found that during the grain-filling process of rice, the moisture state of grains was significantly related to the accumulation of starch and protein. The ratio of “bound water” gradually increased, and the ratios of capillary water and free water significantly decreased in the grains. LF-NMR can be adopted to effectively analyze the whole moisture dynamic changes of grains at different growth periods of rice after heading.
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    Effects of Alkaline Stress on Metabonomic Responses of Wheat (Triticum aestivum Linn) Leaves
    GUO Rui, ZHOU Ji, YANG Fan, LI Feng
    Scientia Agricultura Sinica    2017, 50 (2): 250-259.   DOI: 10.3864/j.issn.0578-1752.2017.02.005
    Abstract387)   HTML5)    PDF (1183KB)(695)       Save
    【Objective】 A pot experiment was conducted to investigate the alkaline stress in ion balance and metabolic profiles of wheat, to determine the physiological adaptive mechanisms of wheat in tolerance to alkali stress. 【Method】 In a pot experiment with control and alkaline stress (NaHCO3﹕Na2CO3=1﹕1), the growth and photosynthetic characters, ion and 73 key metabolites of wheat were studied. 【Result】The results showed that when alkaline stress intensity exceeded the capacity of wheat adjustment, Na+ accumulation in cells in a high-pH environment resulted in damage of the photosynthetic system, reduced photosynthetic pigments, inhibited the activity of photosystem II, and reduced high stomatal conductance and net photosynthetic rate. Alkaline stress caused massive influx of Na+, a decrease of inorganic negative charge and pH value homeostasis, thus resulting ionic unbalance and leading to a series of strain metabolic response. In addition, 73 metabolites were detected in different alkaline stress treatments according to GC-MS analysis, and these metabolites were sugars/polyols, organic acids, amino acids and others. Compared with the control sample, the response of 25 and 48 metabolites in moderate and severe alkaline stress treatments remarkably changed, respectively, in leaves of wheat seedlings. The results of one-way ANOVA analysis indicated that the changes of metabolites were more significant under high alkaline stress than that under moderate alkaline stress. The results revealed that alkaline stress caused an significant decrease in levels of 5 and 6 metabolites, which are involved in TCA cycle and glycolysis; it also caused amino acids (glutamate, alanine, γ-aminobutyric acid, aspartic acid) and sugars/ploys (fructose, sucrose, talose, myo-inositol) decreased dramatically. Meanwhile, alkaline stress induced organic acids accumulation in wheat, and it maybe a passive adaptive response to alkaline stress, and organic acids kept ionic balance and pH homeostasis. 【Conclusion】 The results suggested that alkaline stress caused systems alterations in metabolic networks including TCA cycle, glycolysis, calvin cycle, shikimic path way, metabolism of plasma membrane,GS/GOGAT cycle and GABA path way, implying alkaline stress not only had side effect on synthesis of sugars, amino acids, fats and proteins, but also inhibited the translation between C and N, thus resulted in nutrients deficiency and caused decrease of plant growth and development.
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    Effects of Drought Stress on Wheat Endosperm Starch Structure and Physicochemical Properties of Different Varieties
    SONG XiaoJun, ZHANG Min, WU XuePing, ZHAO Cheng, SHI Jian, ZHANG YuChun, LIU XiWei, CAI RuiGuo
    Scientia Agricultura Sinica    2017, 50 (2): 260-271.   DOI: 10.3864/j.issn.0578-1752.2017.02.006
    Abstract408)   HTML9)    PDF (524KB)(650)       Save
    【Objective】The objective of this experiment is to study the effects of drought stress on the composition, granule size distribution, pasting properties and crystal properties of wheat endosperm of different varieties, and reveal the intrinsic relationship between the structure and physicochemical properties of wheat starch. 【Method】The wheat cultivars Jingdong8(JD8), Henong825(HN825), Jimai585(JM585) and Nongda211(ND211) were used as the test materials, and irrigated and rainfed treatments were designed in research of the effects of drought stress on wheat endosperm starch structure and physicochemical properties. 【Result】Drought stress significantly inhibited the accumulation of starch in wheat endosperm, but it had no significant effect on the Am/Ap ratio of wheat starch. The granule volume, surface area and number distribution of wheat endosperm showed a bimodal curve. The effect of drought stress on starch grain size distribution of wheat endosperm was different due to the difference of genotype and grain size, in which it had a great influence on the surface area and the number distribution of starch granule size <5 μm. Drought stress didn’t change the crystal type of wheat endosperm starch, but significantly increased the crystallinity of starch, and the effects of drought stress on intensity of X-ray diffraction peak were different due to different cultivars and diffraction angles. Drought stress significantly increased trough viscosity and pasting temperature of starch, prolonged the pasting time, while significantly reduced the peak viscosity and breakdown, and there was a genotypic difference in final viscosity and setback. Correlation analysis showed a that the wheat endosperm starch crystallinity showed significant negative correlation with total starch and Am content, and a significant positive correlation with Ap content. The total starch content showed a significant positive correlation with peak viscosity. The Am content showed a significant positive correlation with peak viscosity and breakdown, and a negative correlation with the pasting temperature. The correlation between the Ap content and pasting parameters was not significant, while the Am/Ap ratio of wheat starch showed a significant negative correlation with the pasting time. The volume of <5 μm and <10 μm starch granule, respectively, showed a significant and an extreme significant negative correlation with final viscosity and setback, but the starch granule with diameter >15 μm was positively correlated with final viscosity and setback. The correlation between granule volume distribution and crystallinity of wheat was not significant. Wheat starch peak viscosity and breakdown, respectively, showed an extremely significant and significant negative correlation with crystallinity, but there was a significant positive correlation between the pasting temperature and crystallinity. 【Conclusion】Drought stress changed the wheat endosperm starch composition, granule size distribution, crystallinity and pasting parameters. There were significant correlations between wheat endosperm starch structure and physicochemical properties, indicating that the effects of drought stress on the structure of wheat starch, indirectly affected the physicochemical properties, therefore, the cultivation conditions could be adjusted to achieve the purpose of quality wheat production.
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    Effects of Micro Ridge-Furrow with Plastic Film Mulching and Bunching Seeding on Water Consumption Characteristics and Water Use Efficiency of Winter Wheat in Semiarid Areas of Northwest Loess Plateau
    HOU Hui-zhi, Gao Shi-Ming, ZHANG Xu-cheng, WANG De-gui
    Scientia Agricultura Sinica    2016, 49 (24): 4701-4713.   DOI: 10.3864/j.issn.0578-1752.2016.24.003
    Abstract463)   HTML2)    PDF (871KB)(796)       Save
    【Objective】Precipitation is inadequate in arid and semiarid areas of Northwest Loess Plateau. Especially, the invalid precipitation, which daily rainfall less than 10 mm, accounts for more than 50% in winter wheat growth period. Consequently, How to use this part of precipitation sufficiently is a key method to increase the rainfall use efficiency and yield stably of winter wheat in this area.【Method】The winter wheat cultivar Zhongliang was selected as test material, a field experiment was conducted from 2011 to 2015 on Northwest Loess Plateau (104°36′ E, 35°35′ N) . The designed four treatments were (1) micro ridge-furrow with whole field plastic film mulching and bunching seeding (PRF), (2) whole field soil plastic mulching and bunching seeding (PMS), (3) sand mulching and bunching seeding (SM), and (4) bunching seeding without mulching (CK). The seasonal soil water content in 0-200 cm soil profile, aboveground biomass, yield and its components of winter wheat were recorded; the wheat periodical water consumption in 0-200 cm soil profile, and water use efficiency had been calculated, to understand the effect of PRF on soil water storage, water consumption characteristics, yield and water use efficiency of winter wheat. 【Result】 The four-year average soil water storage of PRF at sowing and re-green stages was higher than PMS, SM, CK by 24.3, 38.8, 7.4 mm and 18.2, 26.9, 67.8 mm, respectively. PRF averagely increased wheat evapotranspiration from heading to filling stage by 36.0 mm than PMS. As compared with SM and CK, it increased by 12.1 mm and 16.7 mm, 40.8 mm and 37.6 mm from turning-green to heading and from filling to maturity, respectively. The aboveground biomass of PRF was higher than PMS by 2.2%-15.4% at seeding, heading, filling and maturing stages, the significant difference was observed at filling stage in 2011-2012, and at seedling and heading stages in 2014-2015. As compared with CK and SM, the aboveground biomass of PRF was significantly higher at the four growth stages. Spike number, grain number and 1000-grain weight were performed as PRF>PMS>SM in four experimental years, the significant difference was not observed among the three treatments, but significantly higher than CK. The yield of PRF was the highest among the four treatments, it reached 4 373.6-4 950.0 kg·hm-2,increased by 2.4%-12.7% than PMS, and a significant difference was observed in 2012-2013 and 2014-2015. It was significantly higher than SM (except for 2012-2013) and CK (increased by 35.8%-43.8%) in four experimental years. The water use efficiency of PRF increased by 0.4%-12.8% as compared with PMS, a significant difference was observed except for 2013-2014, it was also significantly higher than SM (except for 2014-2015) and CK (significantly increased by 8.1% -42.1%) in four experimental years. 【Conclusion】 PRFcoulduse small rainfall (daily rainfall amount <10 mm) efficiently, increased soil water storage in 0-200 cm profile at sowing and turning-green stages, improved wheat evapotranspiration at filling stage, increased spike number, weight and kilo-grain weight, resulted in the increment of grain yield and water use efficiency. Consequently, the micro ridge-furrow with whole field plastic film mulching and bunching seeding is the better cropping patterns for high yield and efficiency of winter wheat in semiarid areas of Northwest Loess Plateau.
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    Effect of Salt Stress on Physiological Reponses and the Expression of Key Genes Involved in Na+ Homeostasis of Soybean Seedlings
    NING Li-hua, ZHANG Da-yong, LIU Jia, HE Xiao-lan, WAN Qun, XU Zhao-long, HUANG Yi-hong, SHAO Hong-bo
    Scientia Agricultura Sinica    2016, 49 (24): 4714-4725.   DOI: 10.3864/j.issn.0578-1752.2016.24.004
    Abstract424)   HTML3)    PDF (1520KB)(511)       Save
    【Objective】In order to provide a reference for soybean cultivation, breeding and artificial regulation of salt stress, the physiological and molecular responses to different genotype soybean seedlings, especially the effects of salt stress on photosynthetic parameters, ions content and the expression of key genes involved in Na+ homeostasis of soybean seedlings were studied. Through comparison of the difference in response to salt stress, the study try to reveal the salt resistance mechanisms of different cultivated genotypic soybeans.【Method】The responses of photosynthetic characteristics and ion content of soybean seedlings were studied under salt stress. Salt tolerant cultivated soybean varieties (Y8D6008, Y8D6013) and salt sensitive cultivated soybean varieties (Y8D6132, Y8D6136) were incubated in the 1/2×Hoagland nutrient solution. NaCl was added to nutrient solution incrementally by 50 mmol·L-1 step per day to provide final concentrations of 150 mmol·L-1 for salt treatment at 1-compound leaf stage, and the treatment lasted for 7 days. The control plants were cultured with nutrient solution without adding NaCl. The response of soybean seedlings to NaCl stress was assessed by measuring the expression of key genes involved in Na+ homeostasis, photosynthetic parameters, and the ion content of soybean. 【Result】The growth of the four cultivated soybean seedlings was significantly inhibited by 150 mmol·L-1 NaCl stress. And salt stress significantly reduced soybean leaf SPAD value, net photosynthetic rate and transpiration rate. However, the inhibition of NaCl on growth and photosynthetic characteristics was more severe in salt sensitive cultivar than in salt tolerant cultivar. Moreover, 150 mmol·L-1 NaCl concentration reduced leaf intercellular CO2 concentration in salt tolerant cultivar, and increased it in salt sensitive cultivar. Thus, the reduction in net photosynthesis rate of salt tolerant cultivar caused by 150 mmol·L-1 NaCl stress was considered to be a result of stomatal restriction; but increased non-stomatal restriction resulted in more severe reductions in photosynthesis of salt sensitive cultivar. Under salt stress, the Na+ content was significantly increased in four cultivars seedlings, and the increase was more pronounced in salt sensitive soybean. In response to salt stress, the K+ content of leaves decreased, the magnitude of these changes was greater in salt sensitive cultivars than in salt tolerance cultivars. Compared with the controls, phosphorus (P) accumulation of salt sensitive soybean in leaves was significantly decreased by 150 mmol·L-1 NaCl treatment. While salt treatment had no significant influence on the P content in the leaves of salt tolerance cultivars. Correlation analysis showed that the relative net photosynthetic rate was strongly negatively correlated with relative Na+ content and positively correlated with relative K+ content and total phosphorus content. Six key genes, Na+ transporter genes (GmSALT3, GmSOS1, GmNcl1, GmNHX1), the gene of signal system for Na+ homeostasis (GmCIPK1), and the gene of energetic system for the operation of Na+ transporters (GmAVP1), involved in Na+ homeostasis were chosen for gene expression analyses. The expression of GmNcl1 was significantly induced by NaCl treatment and the expressions of GmNcl1 induced by salt stress of salt tolerance cultivars were lower than those of salt sensitive cultivars. The expression of GmNcl1 associated closely with salt tolerance features and Na+ content of four soybean cultivars. However, the expression of the rest five genes showned no association with Na+ content of four soybean cultivars.【Conclusion】Compared with the salt sensitive cultivars, salt tolerant cultivars effectively maintained a lower Na+ content, and a higher level of K+ and P contents in leaves to ensure a relatively high photosynthetic rate under salt stress condition. This may be one of the mechanisms to keep higher salt resistance in salt tolerant cultivar than in salt sensitive cultivar. In addition, GmNcl1 may associate with the salt tolerance characteristics of the soybean cultivars in this study.
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    Effects of Seed Maturity on Maize Hybrid Seed Vigor and F1 Yield
    LIU Guo-liang, ZHAO Ya-li, WANG Xiu-ling, LI Hong-ping, LI Chao-hai
    Scientia Agricultura Sinica    2016, 49 (22): 4342-4351.   DOI: 10.3864/j.issn.0578-1752.2016.22.007
    Abstract477)   HTML6)    PDF (3199KB)(560)       Save
    【Objective】 Investigations on the effects of seed maturity on maize (Zea mays L.) hybrid seed vigor and F1 production in corn seed production base along Hexi corridor in China are the bases of determining optimum harvest time of maize seed, protecting seed from the early frost and ensuring seed quality safety. 【Method】A field experiment combined with biochemical test were carried out with two maize hybrids, i.e. Yudan603 (partial dent maize variety, YD603) and Yudan606 (rigid grain maize variety, YD606). Ear samples were taken at an interval of 5 days after 40 days after pollination to test milk line development, grain water content, hundred-grain weight, standard germination, electrical conductivity, F1 field performance and production, and study the effects of maize seed maturity on seed vigor and F1 production.【Result】 There was a significant difference in the occurrence time and development process of milk line between the two hybrids YD603 and YD606. Compared with YD606, milk line of YD603 appeared earlier while disappeared later. On 40 days after pollination (DAP), the milk line position of YD606 was at 0.16, while that of YD603 had not yet appeared. On 65 DAP, both hybrids had a similar milk line position about 0.50, and the grain water content of YD603 was 31.66% and that of YD606 was 35.09%. On 40 DAP, grain water content of YD603 was higher than that of YD606. After 45 DAP, opposite changes in grain water content were found between YD603 and YD606. At physiological maturity, grain water contents of YD603 (75 DAP) and YD606 (80 DAP) were 26.71% and 27%, respectively. The germinating ability of F1 increased with the seed maturity and reached the maximum at physiological maturity. On 40 DAP, the seeds of two hybrids had partly germinating ability. YD603 reached physiological maturity on 75 DAP with a standard germination rate of 96.67%, while YD606 reached physiological maturity on 80 DAP with a standard germination rate of 98%. Seed simple vigor index of YD603 and YD606 also increased with the seed maturity, and reached the maximum values 5.89 and 8.70, respectively, on 65 DAP. Afterwards, seed simple vigor index of both hybrids decreased slightly. In accordance with standard germination rate, artificial accelerated aging germination rate of the two hybrids increased with the seed maturity. On 40 DAP, aging germination rates of YD603 and YD606 were only 58.33% and 58.33%, respectively, for the low seed maturity, while that were 90.00% (75 DAP), and 92.33% (80 DAP), respectively at physiological maturity. The field germination percentage, uniformity, dry matter accumulation and yield of F1 generation of two hybrids increased with the seed maturity improvement, and reached maximum value at physiological maturity without significant difference compared with those of 65 DAP, which suggested that good seedling quality and yield of F1 could be obtained when F1 seed was harvested on 65 DAP . 【Conclusion】The results suggested that the optimum harvest time of hybrid seed is on 65 DAP, when the seed milk line position was at 0.5 and seed moisture is between 30% and 35%. The harvest time is 15 days earlier than the conventional harvest time (milk line almost disappeared) in corn seed production base along Hexi corridor of Zhangye, which not only can provide more time for seeds air-drying to avoid frost damage, but also can ensure high-quality hybrid seeds.
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    Analysis of Temporal and Spatial Variation of Vegetation Phenology in the Loess Plateau
    LI Qiang, ZHANG Chong, REN Zhi-yuan
    Scientia Agricultura Sinica    2016, 49 (22): 4352-4365.   DOI: 10.3864/j.issn.0578-1752.2016.22.008
    Abstract436)   HTML6)    PDF (12067KB)(467)       Save
    【Objective】The Loess plateau is in the transitional region from wetness to dryness, from forest to grassland, from farming to animal husbandry, being the sensitive zone in climate change and agricultural development in China, the research on phenological feature of surface vegetation coverage in the region is of directive significance to agricultural production, environmental protection and ecological construction. Analysis of difference in phenological trends of vegetation in different time series and altitudes and hydrothermal conditions shall offer theoretical support and decision basis for current agricultural ecological environment improvement and sustainable development on loess plateau.【Method】Phenological feature values of vegetation on Loess Plateau every year were determined and phenological change trend was analyzed based on NDVI of ten-day values of SPOT VEGETATION from 1998 to 2012 and combined with harmonic analysis method and linear trend method.【Result】(1) From 1998 to 2012, the start of growing season advanced by 0.9 d on average every year and the end of growing season delayed by about 0.8 d on average every year, the length of growing season every year extended by 1.7 d on average under the joint action of advance at the start of growing season and delay at the end of growing season. (2) Hydrothermal condition on Loess Plateau has an immediate impact on phenological difference, the restrictive temperature for vegetation growth is 9,with the restrictive precipitation of 475 mm and 540 mm, respectively and restrictive altitude of 1 750 m. (3) The spatial partial correlation coefficients between the length trend of growing season of vegetation and altitude and air temperature are 0.0591and 0.0139 respectively, the spatial partial correlation coefficients between the length trend of growing season of vegetation and precipitation is -0.0174, therefore, the degree of correlation between three factors and the trend at the start of growing season is higher than that at the end of growing season.【Conclusion】The zones showing a significant and stable trend of phenological feature of vegetation on loess plateau are primarily distributed on plateau in the north of Shaanxi and Beishan in the middle of Shanxi. The phenological change in arid area and desert and grassland area in northwest is mainly subject to control by air temperature. The phenological change in semi-arid area and farming and grassland areas is mainly subject to control by precipitation. The phenological change in agricultural area in Fenwei Basin is subject to hydrothermal condition. Difference in hydrothermal condition has an insignificant impact on vegetation phenology in broad leaved forest zone. Altitude has an insignificant impact on change trend of vegetation phenology on loess plateau. The extension trend of growing season is on the increase with the increase of altitude and air temperature under the joint action of the start and end of growing reason, the shortening trend of growing season is on the increase with the increase of precipitation, the change characteristics of the same type of vegetations in terms of phenological trend based on the change of altitude, precipitation and air temperature are consistent, the change characteristics at the start of growing season have a greater influence on length change of growing season compared with that at the end of growing season.
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    Cited: Baidu(1)
    Enzyme Activities and Soil Nutrient Status Associated with Different Aggregate Fractions of Paddy Soils Fertilized with Returning Straw for 24 Years
    LI Wei-tao, LI Zhong-pei, LIU Ming, JIANG Chun-yu, WU Meng, CHEN Xiao-fen
    Scientia Agricultura Sinica    2016, 49 (20): 3886-3895.   DOI: 10.3864/j.issn.0578-1752.2016.20.003
    Abstract552)   HTML5)    PDF (505KB)(622)       Save
    【Objective】Paddy soils in subtropical China derived from Quaternary red clay are generally deficient in available nutrients, and fertilizers have long been identified as dominant contributors to increase of crop production. Therefore, a long-term experiment was set up in a paddy field that used to be a wasteland earlier to study the distribution of nutrients and enzyme activities in water stable aggregates under long term application of fertilizers, and the findings will provide a sound basis for rational application of fertilizers to ensure sustainable crop production. 【Method】Soil samples were collected from a 24-year long-term field experiment, which was established in 1990 in the Yingtan Red Soil Ecological Experiment Station. The experiment included four treatments: CK (without fertilization), SM (straw application plus manure), NSM (straw application plus manure and nitrogen fertilizer), NPKSM (straw application plus manure, nitrogen, phosphorus and potassium fertilizers). Undisturbed bulk soils were separated into five aggregate-size classes (>2 mm, 1-2 mm, 0.25-1 mm, 0.053-0.25 mm and <0.053 mm) by wet sieving. Three soil enzymes, invertase, urease, and phosphatase, in water-stable aggregates (WSA) and total nitrogen (TN), available phosphorus (AP), and soil organic C (SOC) were determined. 【Result】Application of fertilizers to infertile paddy soil significantly increased the percentage of macro aggregates (larger than 0.25 mm), decreased the percentage of micro aggregates (smaller than 0.25 mm), and increased the mean weight diameter (MWD) of WSA, which could improve soil structure. The combined application of straw, manure and inorganic fertilizer significantly increased the soil enzyme activities in each size fraction. NSM treatment had the largest impact on invertase and urease activities. NPKSM treatment had the most significant impact on acid phosphatase activity. Compared with the control, NSM treatment increased invertase activity in five size fractions by 20.3%-396.2%; urease increased by 58.6%-372.1%. In NPKSM treatment, acid phosphatase activity in five size fractions increased by 48.9%-94.5%. Compared with the control, SOC in each size fraction of NSM treatment increased by 31.6%-65.1%. Total N increased by 19.8%-51.9%. In NPKSM treatment, available phosphorus content in each of the size fractions increased by 7.4-10 times. Aggregated boosted trees (ABT) analysis showed that the relative influence of SOC on invertase was the largest, accounting for 40.6% of the variation; the composition of soil particle had the largest relative influence on the activity of urease, accounting for 44.9% of the variation. Soil AP had the largest contribution of 41% to the variation in the activity of acid phosphatase. Nonmetric multidimensional scaling (NMDS) analysis indicated that soil aggregates within NPKSM treatment differed from those in CK, SM and NSM treatments. However, SM and NSM treatments showed similar effect on soil fertility. 【Conclusion】The combined application of straw, manure, and inorganic fertilizer significantly increased the mean weight diameter (MWD) of WSA, the contents of SOC, TN, AP, and soil enzyme activities, which improved the soil structure and biological functions.
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    Effects of Lime Application Rates on Soil Acidity and Barley Seeding Growth in Acidic Soils
    HU Min, XIANG Yong-sheng, LU Jian-wei
    Scientia Agricultura Sinica    2016, 49 (20): 3896-3903.   DOI: 10.3864/j.issn.0578-1752.2016.20.004
    Abstract555)   HTML2)    PDF (1678KB)(540)       Save
    【Objective】The aim of this study was to assess the effects of lime on soil acidity and barley seedling growth in an acidic soil (pH 3.9), and to determine the suitable dosage of lime and thus providing scientific proof for acidic soil improvement and reasonable application rate. 【Method】 The trial was conducted at the experimental base of Huazhong Agricultural University. Soil incubation and pot experiments were used. The Ca(OH)2 titration method was employed to estimate the lime requirement, and six treatments were designed: no lime, 0.3 g·kg-1, 0.9 g·kg-1, 1.8 g·kg-1, 2.4 g·kg-1 and 4.8 g·kg-1 lime application rates. Samples were collected on 10, 20, 30, 40, 50, 60, 70 and 90 days after incubation to monitor the dynamic changes of soil pH, soil exchangeable acidity, exchangeable H+ and exchangeable Al3+. Barley was sowed on the 90th day and harvested after 2 weeks to assess the effects of liming rates on barley biomass, morphological parameters, and root activity. 【Result】 Soil incubation results demonstrated that lime application significantly improved soil pH, however the content of exchangeable acidity and exchangeable Al3+ were decreased significantly during the first 30 days. The content of potential acid decreased gradually with the increasing dosage of lime, therefore the content of soil exchangeable acid, exchangeable H+ and exchangeable Al3+ were zero in the treatment of 4.8 g·kg-1. From then on, due to the influences of soil buffer, low lime dosages (< 1.8 g·kg-1) showed no obvious effects on improving soil pH but significantly reduced soil potential acidity. The results of pot experiment showed that application of lime significantly enhanced barley growth through improving plant height, biomass and root development. Barely seedlings plant height, dry mass, total root length and surface area, and root activity improved with the lime application rate from 0 to 1.8 g·kg-1. Whereas, lime input decreased root average diameter. Barley growth was inhibited significantly when lime application rate was above 1.8 g·kg-1. The root activity in the treatment of 4.8 g·kg-1 was lower than that of 0.9 g·kg-1, the excess of lime application retarded the root growth. Thus, the optimum liming rate was 1.8 g·kg-1, which agreed with the lime requirement calculated using the Ca(OH)2 titration method. 【Conclusion】 Lime application is capable of neutralizing soil acidity and promoting barley seedling growth. Under the conditions of this study (soil pH 3.9), the appropriate liming rate was 1.8 g·kg-1 (4 t·hm-2). This rate was consistent with that from the Ca (OH)2 titration method, confirming that the approach adopted in this study is appropriate for determining the lime application rate.
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    Effect of Technique of Ridge Film Mulching and Furrow Seeding on Soil Erosion and Crop Yield on Sloping Farmland in Western Liaoning
    XIAO Ji-bing, SUN Zhan-xiang, JIANG Chun-guang, ZHENG Jia-ming, LIU Yang, YANG Ning, FENG Liang-shan, BAI Wei
    Scientia Agricultura Sinica    2016, 49 (20): 3904-3917.   DOI: 10.3864/j.issn.0578-1752.2016.20.005
    Abstract426)   HTML4)    PDF (431KB)(364)       Save
    【Objective】Western Liaoning is not only short and great variation in precipitation resource, but soil erosion in hilly area is mostly serious in Liaoning province. The sloping farmland is the main source of water and soil loss. Ridge film mulching and furrow seeding could collect natural precipitation and reduce soil erosion effectively, improve water and soil resources utilization availability. The purpose of this study is to make full use of the limited natural rainfall, protect water and soil resources of dry farming area and promote high and stable yield of crops.【Method】Two factors split plot design was used to examine the effects of different farming types on soil erosion, soil water and yield in sloping farmland and the study was carried out by runoff plots under natural rainfall from 2012 to 2015 in dry farming experimental area in Liaoning Academy of Agricultural Sciences at Fuxin. The runoff plot was 15 m and 6 m in length and width and the area was 60 m2. The main plot was a sloping land with slopes of 5°and 10°, and split plot was crop planting patterns, the designed patterns were traditional cultivation(CK, contour ridge and furrow planting, ridge and furrow were uncovered), ridge film mulching and furrow straw mulching(T1), ridge film mulching and furrow seeding(furrow was uncovered, T2). The study was repeated three times. Ridges and furrows of ridge film mulching and furrow seeding were in opposite arrangement, furrow width was 60 cm and ridge width was 40 cm, ridge height was 10-12 cm. The ridge was a rain collecting area. The furrow, which was planted with two lines of crop, was a planting area. The experimental crops were millet and maize and rotated.【Result】The ridge film mulching and furrow straw mulching and ridge film mulching and furrow seeding could effectively reduce and prevent water and soil erosion. In four years, the total runoff and total erosion amount of the CK were 512.7 m⊃3;·hm-2, 4 561.3 kg·hm-2and T1, T2 did not occur soil erosion under five-degree slope. The total runoff and total erosion amount of T1 were reduced by 81.71% and 96.17% and that of T2 were reduced by 56.92% and 95.15% compared with the CK, and that of T1 were reduced by 57.54% and 21.05% compared with T2, T1 and T2 would reduce the amount of lost nutrients in sediment compared with the CK under ten-degree slope. The results showed that runoff and erosion amount increased in accordance with increasing of gradient and the effect of anti-erosion of T1, T2 would weaken along with slope increasing. There was no significant difference between the five-degree slope and ten-degree on four years' average soil water, which had a reducing trend with slope increasing. The effect of T1, T2 on mean soil water reached very significant level as a whole compared with CK and mean soil water of T1, T2 was 1.68 and 1.45 percentage points higher than that of CK. The effect of T1, T2 on increasing moisture reached very significant level compared with CK to millet regardless of high flow year or dry year and that of T1, T2 on increasing moisture to maize was not significant in normal year and very significant in special dry year. There was no significant difference between five-degree slope and ten-degree slope in four years' average yield, which had a reducing trend with slope increasing. The effect of T1 on the average production reached very significant level increasing by 25.59% and 10.68% compared with CK and T2, and there was a significant difference between T2 and CK and the average production of T2 increased by 13.47% compared with CK. The effect of yield increasing of T2 was insignificant compared with CK and that of T1, which increased by 24.75% and 74.58%, was significant compared with CK for millet in 2012, 2014. The effect of T1, which the yield of maize increased by 11.29% and 54.39%, and T2, which increased by 5.05% and 51.81%, on the production reached very significant level compared with CK in 2013 and 2015. The effects of yield increasing of ridge film mulching and furrow straw mulching (millet, maize) and ridge film mulching and furrow seeding (maize) were particularly significant in dry year. 【Conclusion】 The effect of micro-rainwater-collecting planting mode by ridge film mulching and furrow seeding in dry sloping farmland on rainwater harvesting, water storage, soil moisture conservation and anti-erosion was definite after 4 years of study in semi-arid region in Liaoxi area. The technique could mitigate the negative impact of drought and soil erosion on crop growth and enriched the theoretical basis of the rain-harvesting agriculture of dry farming in the area. By application and dissemination of the technique, it could improve soil and water resources utilization, protect quality of cultivated land and promote overall grain production capability on sloping farmland and facilitate stable and high yield of crop and healthy and sustainable development of dry farming in the area. It could be seen that the ridge film mulching and furrow straw mulching would be suitable for dry sloping land in Western Liaoning from the point of anti-erosion, catchment, increasing soil moisture, increasing production. The study has filled the gaps in the study of this subject in western Liaoning and provided important references for development of the rain-harvesting agriculture of dry farming in the north of China.
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    Cited: Baidu(1)
    Synergistic Effects of Water-Saving Irrigation, Polymer-Coated Nitrogen Fertilizer and Urease/Nitrification Inhibitor on Mitigation of Greenhouse Gas Emissions from the Double Rice Cropping System
    LI Jian-ling, LI Yu-e, ZHOU Shou-hua, SU Rong-rui, WAN Yun-fan, WANG Bin, CAI Wei-wei, GUO Chen, QIN Xiao-bo, GAO Qing-zhu, LIU Shuo
    Scientia Agricultura Sinica    2016, 49 (20): 3958-3967.   DOI: 10.3864/j.issn.0578-1752.2016.20.010
    Abstract425)   HTML3)    PDF (490KB)(664)       Save
    【Objective】Optimization of water and nitrogen management measures has a great significance for rice yield improvement and greenhouse gas emission reduction in paddy fields. To establish water and fertilization management regimes with effects on yield promotion and greenhouse gas mitigation, a new water-saving irrigation technique, “thin and shallow alternate wetting drying”, was investigated in the double rice cropping system. Synergistic effects of water-saving irrigation and new types of nitrogen fertilizer on rice yield and greenhouse gas emissions were evaluated. 【Method】The study focused on double rice cropping system in the Jianghan Plain, Hubei province, Central China. Greenhouse gas emissions were observed from four different treatments: U+CI: urea with conventional traditional irrigation, as the control (CK); U+SI: urea with “thin and shallow alternate wetting drying” water-saving irrigation; CRU+SI: polymer-coated urea with “thin and shallow alternate wetting drying” water-saving irrigation; NU+HQ+SI: nitrapyrin crystal urea with hydroquinone and “thin and shallow alternate wetting drying” water-saving irrigation. Measurements were taken using the automatic static chamber-GC (gas chromatography) method. CH4 and N2O emissions, and total CO2-eq (CH4+N2O, on a 100a horizon) of each treatment were analyzed. Rice yield per plot and greenhouse gas intensity (GHGI) were calculated after harvesting. 【Result】The “thin and shallow alternate wetting drying” water-saving irrigation technique diminished CH4 emission fluxes during the early and late rice seasons, especially at the reproductive stage, resulted in lower CH4 emissions for U+SI compared to U+CI (P<0.01). The reduction in CH4 emissions in the late rice season was greater than in the early rice season. By using water-saving irrigation techniques, pronounced differences in CH4 emissions were identified among polymer-coated urea, nitrapyrin crystal urea with hydroquinone and urea treatments. Total CH4 emissions during two rice seasons from CRU+SI and NU+HQ+SI were 60% and 73% of emissions from the U+SI treatment, respectively. “Thin and shallow alternate wetting drying” water-saving irrigation increased N2O emissions in paddy fields. Compared to U+CI, the U+SI treatment significantly increased N2O emissions in the early and late rice seasons by 34% and 39%, respectively (P<0.05). Compared to urea, N2O emissions from nitrapyrin crystal urea with hydroquinone and polymer-coated urea treatments were decreased. The effect of nitrapyrin crystal urea with hydroquinone on the control of N2O emissions was superior to that of the other two nitrogen fertilizers. A trade-off was identified between CH4 and N2O emissions under “thin and shallow alternate wetting drying” irrigation, but the effect on the reduction of CH4 emissions was greater than the increase in N2O emissions. Overall, “thin and shallow alternate wetting drying” irrigation can reduce total greenhouse gas emissions, with the strength of the mitigation effect depending on the type of nitrogen fertilizer used. Polymer-coated urea had the greatest mitigation effect, reducing total CO2-eq emissions by 49%, followed by nitrapyrin crystal urea with hydroquinone (46%) and urea (28%). Furthermore, polymer-coated urea and nitrapyrin crystal urea with hydroquinone were more beneficial for rice yield promotion and decreased greenhouse gas intensity of rice production. 【Conclusion】The results suggest that “thin and shallow alternate wetting drying” water-saving irrigation has good effects on yield maintenance and GHG abatement. The combined application of water-saving irrigation and polymer-coated urea or nitrapyrin crystal urea with hydroquinone could further increase rice yield and reduce greenhouse gas emissions. Thus, these water and nitrogen management measures deserved wider extension in order to simultaneously increase grain yield and decrease global warming effects.
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    Cited: Baidu(3)
    Effects of Types of Controlled Released Nitrogen and Fertilization Modes on Yield and Dry Mass Production
    XING Xiao-ming, LI Xiao-chun, DING Yan-feng, WANG Shao-hua, LIU Zheng-hui, TANG She, DING Cheng-qiang, LI Gang-hua, WEI Guang-bin
    Scientia Agricultura Sinica    2015, 48 (24): 4892-4902.   DOI: 10.3864/j.issn.0578-1752.2015.24.004
    Abstract512)   HTML11)    PDF (389KB)(668)       Save
    【Objective】This experiment seeks to investigate the effects of different types of controlled released nitrogen and fertilization modes on the yield, characteristics of photosynthesis and dry mass production. 【Method】 Local japonica rice of Wuyunjing 24 mechanical transplanting. Four N fertilizer types (urea, slow-release fertilizer blend, polymer-coated urea, sulfur-coated urea) and two fertilization modes, the base-tiller nitrogen fertilizer and single fertilization were conducted in Danyang, Jiangsu province, China, in 2013 and 2014, seven treatment including single fertilization of slow-release fertilizer blend(B-BSRB), single fertilization of polymer-coated urea(B-PCU), single fertilization of sulfur-coated urea(B-SCU), base-tiller nitrogen fertilizer of slow-release fertilizer blend(BT-BSRB), base-tiller nitrogen fertilizer of polymer-coated urea(BT-PCU), base-tiller nitrogen fertilizer of sulfur-coated urea(BT-SCU) and conventional split fertilization (CK). 【Result】 The yield of different types of controlled released nitrogen showed that, slow-release fertilizer blend >polymer-coated urea > sulfur-coated urea. The dry matter weight of the population, Leaf area index and photosynthetic potential of different controlled released nitrogens at the growth period showed that slow-release fertilizer blend > polymer-coated urea > sulfur-coated urea. Dry matter accumulation, its proportion of distribution and crop growth rate at the jointing stage showed slow-release fertilizer blend >polymer-coated urea > sulfur-coated urea, while at the maturity stage showed slow-release fertilizer blend> sulfur-coated urea> polymer- coated urea. All of them showed a trend of base-tiller nitrogen fertilizer treatment > single fertilization treatment. The yield of slow-releasing blending fertilizer with the base-tiller nitrogen fertilizer treatment (BT-BSRB) was 11.6 and 10.1 t hm-2 in 2013 and 2014, respectively. Compared to conventional fertilization (CK), the yield of BT-BSRB increased by 9.4、12.2%, respectively.【Conclusion】Polymer-coated urea and sulfur-coated urea were a poor application on japonica rice, while slow-release fertilizer blend can significantly increase japonica rice yield and photosynthetic material production.
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    Cited: Baidu(13)
    Effects of Spraying Uniconazole on Lodging Resistance of Culm and Yield in Common Buckwheat
    LIU Xing-bei, WU Dong-qian, WANG Can, HU Dan, YANG Hao, SHE Heng-zhi, RUAN Ren-wu,YUAN Xiao-hui, YI Ze-lin
    Scientia Agricultura Sinica    2015, 48 (24): 4903-4915.   DOI: 10.3864/j.issn.0578-1752.2015.24.005
    Abstract494)   HTML2)    PDF (479KB)(748)       Save
    【Objective】Common buckwheat (Fagopyrum esculentum M.) has been praised as one of the green foods of human beings in the 21st century. Lodging is an important factor which limiting common buckwheat yield and quality worldwide, so exploring the effects of spraying uniconazole of different concentrations on culm could provide a theoretical basis for lodging resistance cultivation of common buckwheat. 【Method】 The field experiments were conducted as a randomized block design in 2013 and 2014 at the Xiema Experimental Station, Southwest University, China. Ningqiao 1, a moderate lodging resistance cultivar of common buckwheat, was used in this study. 0 mg·L-1 (CK), 25 mg·L-1 (T1), 50 mg·L-1 (T2), 75 mg·L-1 (T3), and 100 mg·L-1 (T4) uniconazole were sprayed at the rate of 100 mL·m-2 on common buckwheat leaf surfaces at the four-leaf stage. The culm snapping resistance, lodging index, culm morphology characteristics, and culm anatomical structure were measured and analyzed at the anthesis stage, filling stage, and maturity stage, respectively. The lodging behavior and yield were investigated at the maturity stage.【Result】The culm snapping resistance, culm wall thickness, and vascular bundle area increased and then decreased from the anthesis stage to maturity stage, and their maximum values appeared in the filling stage. The lodging index, plant height, culm gravity height, culm fresh weight, basal 2nd internode length, basal 2nd internode diameter, mechanical tissue thickness, and vascular bundle number increased from the anthesis stage to the maturity stage. The basal 2nd internode dry weight, filling degree, and mechanical tissue layer number increased from the anthesis stage to the filling stage, but then changes were not obvious. The yield, culm snapping resistance, basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness, culm wall thickness, vascular bundle number, and vascular bundle area increased with the increase of the concentration of uniconazole in the condition of CK-T3 treatments, while decreased with the increase of the concentration of uniconazole in the condition of T3-T4 treatments. The lodging percentage, lodging index, plant height, culm gravity height, culm fresh weight, and basal 2nd internode length decreased with the increase of the concentration of uniconazole in the condition of CK-T3 treatments, while it increased with the increase of the concentration of uniconazole in the condition of T3-T4 treatments. Compared with the control, the yield under the T1, T2, T3 and T4 treatments increased by 2.3%, 6.5%, 21.3%, and 11.3%, respectively, and the lodging percentage decreased by 17.9%, 40.7%, 84.0%, and 60.5%, respectively. There were significant differences in culm snapping resistance, lodging index, culm morphological structure, and culm anatomical structure among different treatments of uniconazole concentration. Plant height, culm gravity height, culm fresh weight, basal 2nd internode length , lodging index, lodging percentage were significant and negatively correlated with the yield. However, the basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness , culm wall thickness, vascular bundle area, vascular bundle number and culm snapping resistance are significantly and positively correlated with the yield. The culm snapping resistance, basal 2nd internode diameter, basal 2nd internode dry weight, filling degree, mechanical tissue layer number, mechanical tissue thickness, culm wall thickness, vascular bundle number, and vascular bundle area showed a trend of T3>T4>T2>T1>CK, while the lodging index, plant height, culm gravity height, culm fresh weight, and basal 2nd internode length showed a trend of CK>T1>T2>T4>T3.【Conclusion】In this research, when uniconazole was sprayed 75 mg·L-1, the culm structure could be optimized effectively, the culm quality improved, the lodging risk decreased and the yield of common buckwheat was enhanced. The result would lay a foundation of lodging resistance cultivation of common buckwheat.
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    Risk Assessment and Zoning of the Main Meteorological Disasters for Maize in Northeast China
    GAO Xiao-rong, WANG Chun-yi, ZHANG Ji-quan, WEN Xu
    Scientia Agricultura Sinica    2014, 47 (24): 4805-4820.   DOI: 10.3864/j.issn.0578-1752.2014.24.004
    Abstract498)   HTML3)    PDF (5944KB)(732)       Save
    【Objective】Northeast China, one of China’s key grain production bases, witnessed unstable maize yield caused mainly by such meteorological disasters as chilling, drought and flood, and risk assessment of the main meteorological disasters threatening maize in Northeast China at different growth stages and the whole growth period will provide a scientific basis for regional agricultural production planning and meteorological disaster prevention and alleviation. 【Method】Based upon the theory of natural disaster risk and the formation mechanism of agro-meteorological disaster risk, the established risk assessment index system and the risk assessment model of growth stages and the whole growth period aiming at the main meteorological disasters threatening maize in Northeast China were used to assess four elements (hazard of the natural disasters as chilling, drought and flood, exposure and vulnerability of the disaster-affected body and the disaster prevention and mitigation capacity of human beings) at four growth stages, namely sowing to seven-leaf, seven-leaf to tasseling, tasseling to milky ripening and milky ripening to maturation. After that, risk of the main meteorological disasters in each growth stage and of the whole growth period was assessed and zoning of the assessment result was identified in the system cluster analysis. 【Result】 Generally the hazard of chilling damage increases from west to east and are in zonal distribution at each growth stage. In early stages, areas with medium or high values of the hazard of chilling are in Changbai Mountain area and Southeast Heilongjiang; at later stages, the areas with medium or high values of the hazard of chilling are mostly in Changbai Mountain area and southeast and north of Heilongjiang research area. Generally the hazard of drought increases from east to west or from southeast to northwest and are in zonal distribution at each growth stage. While the hazard of flood present obvious regional differences at each growth stage with Southeast Liaoning being an area easy to be affected by flood. Of the four growth stages, it is less likely to have flood at the stage of sowing to seven-leaf in the research area. At the subsequent three stages, the areas with high hazard of flood are mainly in Southeast Liaoning. At the stage of sowing to seven-leaf, the main meteorological disaster risk are in zonal distribution from northeast to southwest: areas with low or medium risk values are in central Northeast China while those with medium or high values are mostly in west and east of Northeast China. At the stage of seven-leaf to tasseling, the main meteorological disaster risk increases from northeast to southwest: areas with low or medium risk values are mainly in Heilongjiang and central and northeast of Jilin, while those with medium or high values are in the west of Northeast China, Southeast Jilin and south and east of Liaoning. At the stages of tasseling to milky ripening, milky ripening to maturation and even the whole growth period, the main meteorological disaster risk increases from east to west and the areas with medium or high risk values are mostly in the western part of Heilongjiang research area, west Jinlin and a large part of Liaoning. At the sowing to seven-leaf stage, the areas with high risk of the main meteorological disasters are in Qinggang, Dongning, Baicheng, Qian’an and Changbai, and most areas face medium risk. At the seven-leaf to tasseling stage, the high risk areas are in Southeast Liaoning’s Kuandian, Xiuyan and Zhuanghe; in the first two growth stages, the high risk regions are distributed sporadically or cover a relatively small area. In tasseling to milky ripening, milky ripening to maturation and the whole growth period, the high risk regions expand and are stretched in the west of Heilongjiang research area, west Jilin and east Liaoning’s Kuandian and Xiuyan.【Conclusion】The risk of the main meteorological disasters, namely chilling, drought and flood, threatening maize in Northeast China at each growth stage and of its whole growth period, are distributed in different patterns. At the first two growth stages, the high risk regions cover a relatively small area; at the last two growth stages and in the whole growth period, the high risk regions expand and are stretched in the west of Heilongjiang research area, west Jilin and east Liaoning’s Kuandian and Xiuyan.
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    Cited: Baidu(13)
    Analysis of Physiological Characteristics about ABA Alleviating Rice Booting Stage Drought Stress
    GUO Gui-hua, LIU Hai-yan, LI Gang-hua, LIU Ming, LI Yan, WANG Shao-hua, LIU Zheng-hui, TANG She, DING Yan-feng
    Scientia Agricultura Sinica    2014, 47 (22): 4380-4391.   DOI: 10.3864/j.issn.0578-1752.2014.22.004
    Abstract520)   HTML5)    PDF (554KB)(854)       Save
    【Objective】The objective of the study is to reveal the drought tolerance mechanisms of different rice varieties and the physiological mechanisms about ABA reliving rice drought stress.【Method】Japonica drought tolerance rice Zaoyuxiangjing and conventional japonica rice Nanjing44 were pot planted until booting stage, and 150 mg·kg-1 of abscisic acid (ABA) was sprayed on leaf to study the influence on rice antioxidant enzyme activity (SOD, CAT), membrane lipid peroxidation (MDA) content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), chlorophyll and soluble sugar(SS)content, biomass accumulation, yield per pot and yield components. Finally, their different biological and physiological drought resistance and response to ABA treatment were compared.【Result】During drought stress, rice maintained higher SOD and CAT activities, leading to a lower MDA content to a certain extent. They synthesized higher soluble sugar content to maintain cell osmotic adjustment. The leaf net Pn decreased consistently. Gs also showed a downward trend with increasing water stress, and Tr consistented with the Gs. Chlorophyll a synthesis was inhibited, and the content decreased. The result showed that dry matter accumulation and yield per pot were decreased significantly compared with CK. Two varieties showed significant differences in response to drought stress, and Zaoyuxiangjing was more drought resistant than Nanjing44. When ABA treated, Pn and dry matter accumulation were reduced in short time. While SOD activity was further improved, leading to reduction of MDA accumulation. Meanwhile, exogenous ABA induced stomatal closure during drought stress and reduced transpiration rate, the excessive water consumption was reduced and water use efficiency was improved, thus having a significant protective effect on rice, reduced the metabolic function of drought on rice physiological damage, and accelerated functional recovery after rehydration, keeping higher content of chlorophyll a to prevent leaf premature. The effect of ABA treatment was more significant on Zaoyuxiangjing. Its Pn, Gs and Tr recovered quickly after rehydration and a significant increase in chlorophyll a content. ABA also promoted its soluble sugar synthesis and dry matter accumulation more faster under drought stress, then improved its grains of per panicle, filled grain rate, 1000-grain weight and grain yield per pot significantly. ABA effect was weaker on Nanjing44 because of its general drought resistance. Nanjing44 was susceptible to drought stress, less sensitive to ABA, slow physiological and growth characteristics recovery. Although ABA significantly increased Nanjing 44 grains per panicle, filled grain rate and 1000-grain weight, it did not significantly increase the yield per pot.【Conclusion】The short-term “dormancy” effect on rice of ABA could relieve the physiological metabolic function damage of riceunder booting stage stress effectively, promote its functional recovery after rehydration, and mitigate the effects of drought on yield. There were differences in the response to ABA between different drought resistance varieties. The stronger drought resistance variety was more sensitive to ABA and displayed better result to exogenous ABA.
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    Effects of Whole Field Soil-Plastic Mulching on Spring Wheat  Water Consumption, Yield, and Soil Water Balance in Semiarid Region
    HOU Hui-zhi, Lü Jun-feng, GUO Tian-wen, ZHANG Guo-ping, DONG Bo, ZHANG Xu-cheng
    Scientia Agricultura Sinica    2014, 47 (22): 4392-4404.   DOI: 10.3864/j.issn.0578-1752.2014.22.005
    Abstract480)   HTML6)    PDF (2164KB)(614)       Save
    【Objective】The main limiting factors which affect spring wheat productivity on Northwest Loess Plateau are drought, rainfall dynamics could not meet spring wheat water needs, and low temperature in spring. How to conserve the rainwater in soil efficiently, and use it at the spring wheat growth stage, is the most important method to increase spring wheat yield in this area. The aim of the study is to reveal the effect of whole field soil plastic mulching (i.e. the whole soil surface firstly mulched by plastic, and then spread around 1cm thick soil on plastic surface) on spring wheat seasonal water consumption, yield, water use efficiency and the soil water recharge in fallow period, further to assess its effect on inter annual soil water balance in semiarid region on Northwest Loess Plateau. 【Method】The spring wheat (Triticum aestivum Lunchun 27) selected as test material, a field experiment was conducted from 2011 to 2013 on the Dingxi Experimental Station of Gansu Academy of Agricultural Sciences (104°36′ E, 35°35′ N) , which located on northwest Loess plateau. The designed three treatments are whole field soil plastic mulching and bunch seeded (FMS), whole field mulching and bunch seeded (FM), and uncovered and bunch seeded (CK). The seasonal soil water content, spring wheat biomass, yield and spring wheat yield components were recorded, as well as the rainwater fallow efficiency, evapotranspiration, water use efficiency, harvest index, and reproduction allocation index were calculated.【Result】The evapotranspiration among the three treatments were not differed significantly in 2011 and 2012, but the evapotranspiration of FMS was significantly higher than CK in 2013. From seeding to jointing stage, the FMS and FM significantly increased spring wheat evapotranspiration by 27.2% and 9.6% in dry year, 52.2% and 44.6% in wet year, respectively, as compared with CK. The evapotranspiration of FMS and FM was not significantly different at each spring wheat growth stage. However, the evapotranspiration of FMS shown an increasing trend in wet year (i.e. 2012 and 2013) as compared with FM, especially, this trend was more obvious in 2013. In fallow period, the soil water from 0 to 80 cm soil profile of FMS and FM was recharged by 25.4 mm and 18.3 mm, lower than CK by 2.2 and 9.3 mm. However, in 80-200 cm soil profile, the soil water of FMS and FM recharged by 78.0 mm and 71.0 mm, higher than CK by 30.0 mm and 23.1 mm, respectively. In the three years experimental period, the 0-200 cm profile soil water storage of FMS, FM and CK was increased by 23.8, 22.5 and 12.4mm, as compared with before sowing in 2011. The rainwater fallow efficiency of FMS was 30.5%-52.6%, higher than CK by 12.8%-109.5%, than FM by 4.5%-40.9%, spike grain number and kilo grain weight of FMS were significantly higher than CK (P<0.05). Harvest index and reproductive allocation index of FMS was 0.42-0.49 and 0.59-0.67, averagely increased by 32.54% and 35.37% than CK, respectively. The spring wheat yield and water use efficiency of FMS reached 1 750-3 180 kg·hm-2 and 5.5-11.5 kg·hm-2·mm-1, increased by 40%-220% and 27%-239% than CK, respectively. Especially, the increased extent of yield and water use efficiency was higher in dry year than that in wet year. The yield and water use efficiency of FMS were increased by 26.2% and 28.2% in the dry year (2011), and by 20.9% and 14.8% in wet year (2013), as compared with FM, the significant difference were observed. It indicated that the FMS could significantly increased spring wheat yield in wet year, and adapted drought environment in dry year, resulted in sustainable higher yield, as compared with FM.【Conclusion】FMS efficiently increased soil water storage before spring wheat sowing and early spring wheat growth stage, as well as increased spring wheat water consumption from seedling to booting stages, caused the increment of grain number per spike and reproductive allocation index, expanded sink capacity by increasing spring wheat spike grain number and kilo grain weight, resulted in higher yield and water use efficiency than FM and CK treatments. Additionally, FMS recharged the soil water from 0 to 200 cm at fallow period completely, so it is beneficial to sustain the soil water balance through years.
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    Study on Endosperm Development and Morphological Features of Starch Granules in Waxy Wheat Shannuo 1 and Non-Waxy  Wheat Xinong 1330
    YU Jing, RAN Cong-fu, LI Xue-jun, SHAO Hui, LI Li-qun
    Scientia Agricultura Sinica    2014, 47 (22): 4405-4416.   DOI: 10.3864/j.issn.0578-1752.2014.22.006
    Abstract384)   HTML8)    PDF (3881KB)(491)       Save
    【Objective】 The aim of this research is to study the endosperm development and morphological features of starch in waxy wheat Shannuo 1 and non-waxy wheat Xinong 1330, which will provide a theoretical basis for quality improvement of wheat breeding. 【Method】 Two wheat cultivars, Shannuo 1 (waxy wheat) and Xinong 1330 (non-waxy wheat) were used as materials in this paper. The development of endosperm cells were observed by optical microscope. In order to preserve the endosperm structure, the developing grains (5, 8, 12, 15, 18, 21, 25 and 28 d after fertilization) were immersed in glutaraldehyde and osmic acid after transected by freezing in liquid nitrogen. Before embedded with Epon812, samples were washed with phosphate buffer and dehydrated individually in a graded acetone solution. The semi-thin slices were obtained by Leica ULTRACUT slicer. Images were taken by optical microscope after stained by 1% toluidine. The cross sections of Shannuo 1 and Xinong 1330 grains and starch samples which isolated from the two wheat varieties were placed on an aluminum specimen holder, and sputter-coated with a thin ?lm of gold under vacuum condition. Samples were observed with a JEOL scanning electron microscope (JSM-6360LV, JEOL, Japan). Particle size distribution of the starch samples was measured by MASTERSIZER-2000 laser particle analyzer (Malvern UK company). All measurements were performed in triplicates. Analysis of variance (ANOVA) was performed using LSD’s test to compare treatment variations at a signi?cance level of P<0.05 with DPS software. The data figures were performed by Sigmaplot 12.0 software. 【Result】 The results indicated that the endosperm cells of waxy wheat Shannuo 1 were smaller and developed slower than those of non-waxy wheat Xinong 1330 during grain development. In the early period of the endosperm development, the starch granules of Shannuo 1 and Xinong 1330 could be stained well by toluidine. However, in the late period of the grain development, the starch granules of Shannuo 1 could also be stained well, but Xinong 1330 can not. Compared with Xinong 1330, the endosperm of Shannuo 1 contained less protein matrix and the combination between protein and starch granules was much looser. The shape of B type starch granules of Shannuo 1 was irregular polygon, while that of Xinong 1330 was spherical. There was no significant difference in the shape of A type starch granules between Shannuo 1 and Xinong 1330. The size distribution of starch granules varied between waxy and non-waxy wheat. Volume distribution of Shannuo 1 starch granules showed a typical four-peak distribution, while that of Xinong 1330 showed a bimodal distribution. Granule surface area distribution of both cultivars indicated a typical three-peak distribution. The number distribution of granules in waxy and non-waxy starch was a typical unimodal distribution.The percentage of starch granules of Shannuo 1 and Xinong 1330 was nearly identical. In contrast, the percentage of the volume and the surface area of Shannuo 1 differed significantly from those of Xinong 1330. For A (>10 μm) type starch granules, the percentage of the volume and the surface area of Shannuo 1 were both lower than those of Xinong 1330. While for B (<10 μm) type starch granules, those of Shannuo 1 were higher than those of Xinong 1330. The volume, surface area and number of SB (<1 μm) type starch granules of Shannuo 1 were lower than those of Xinong 1330 by 1.11%, 11.60% and 9.28%, respectively, whereas the LB (1-10 μm) type starch granules of Shannuo 1 were higher than those of Xinong 1330 by 8.27%, 15.88% and 9.27%, respectively. A minority LA (>53 μm) type starch granules was found in Shannuo 1, but not in Xinong 1330. 【Conclusion】 In conclusion, the development of endosperm and the morphological features of starch granules of waxy wheat Shannuo 1 were significantly different from those of non-waxy wheat Xinong 1330 during grain development. The starch granules of LB type had considerable effects on the B type starch granules size distribution of Shannuo 1 and Xinong 1330.
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    Study on Spatial Differences of Late Frost Injury to Winter Wheat and Its Reasons at Field Scale
    WU Yong-feng, HU Xin, ZHONG Xiu-li, Lü Guo-hua, REN De-chao, SONG Ji-qing
    Scientia Agricultura Sinica    2014, 47 (21): 4246-4256.   DOI: 10.3864/j.issn.0578-1752.2014.21.010
    Abstract421)   HTML1)    PDF (684KB)(513)       Save
    【Objective】At the field scale, the study was conducted to investigate spatial differences of late frost injury to winter wheat and their influences on yields. The reasons for the spatial differences were discussed, which might provide a priori knowledge for predicting late frost damage and regulating influence factors.【Method】A frost-prone farmland in Shangqiu was selected as the study area where a winter wheat cultivar Aikang58 was sowed. Natural frost occurred in April 7, 10 and 21, 2013, when the winter wheat was in the periods from middle jointing to booting stage. At maturity, ear number and actual yield per square meter, and soil fertilities were respectively measured based on one hundred sampling points (the interval between samples is 5 m). Four indexes, such as dead ear rate (DER), injured ear rate (IER), injured ear index (IEI) and yield loss rate (YLR), were established to evaluate late frost damage. Their spatial differences and relations with ear number and actual yield were estimated using multiple linear stepwise regression method, geo-statistics method, cluster method, ANOVA and multiple comparison methods. In order to reveal the reasons for the spatial differences, late frost indexes related to developmental progressions of winter wheat and soil fertility factors were measured at early returning green stage. 【Result】 Through the stepwise regression, DER was found to be the only factor affected ear number and showed a negative effect. Factors, including IEI, DER and IER, all showed negative effects on actual yield. Of all the factors, IEI was the most powerful (its direct path coefficient reached -0.453) to actual yield. DER, IER and IEI were the factors impacted YLR and all showed positive effects, indicating that YLR increased with their increments. DER showed the most influence (its direct path coefficient was up to 0.626) on YLR. Late frost damage had a positive spatial autocorrelation (P<0.05). Sampling points with similar frost damage degrees tended to the clustering distribution in the local space. Of all the damage evaluation indexes, YLR showed the strongest clustering distribution (Moran’s I=0.5538). The result of frost damage divisions indicated that ear number and actual yield significantly decreased (P<0.05) with deepening frost injuries. The index DER showed the biggest increase (the amplitude reached 271.3%), followed by IER (36.4%) and IEI (31.8%). They comprehensively led to a sharp rise of YLR (132.1%). Sampling points with the most severe frost injury almost showed a contiguous distribution. Developmental progression of winter wheat and soil nitrogen in the turn-green stage showed obviously spatial differences and had a certain spatial correlation with late frost damage. A significant difference (P<0.05) was found between total nitrogen, hydrolysable nitrogen, available phosphorus, available potassium and organic matter and the frost evaluation indexes. As soil nutrient content reduced, frost damage had a deepening trend. After the green up, the persistent drought made the soil water content decreased rapidly, further exacerbating the extent of frost damage. 【Conclusion】 At the field scale, the spatial differences of ear number and actual yield influenced by late frost damage were obvious. The spatial pattern of frost damage was significantly related to the developmental progress of winter wheat and soil nitrogen at returning-green stage, indicating that it maybe has an opportunity to predict frost damage risks early and regulating influence factors in the fine scale.
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    A Risk Assessment System of the Main Meteorological Disasters for Maize in Northeast China
    GAO Xiao-rong, WANG Chun-yi, ZHANG Ji-quan, WEN Xu
    Scientia Agricultura Sinica    2014, 47 (21): 4257-4268.   DOI: 10.3864/j.issn.0578-1752.2014.21.011
    Abstract667)   HTML2)    PDF (469KB)(992)       Save
    【Objective】 Agricultural production is often threatened by several meteorological disasters. Presently, the risk assessment of agro-meteorological disasters often focuses on the influence of single meteorological disaster on disaster-affected body, not exactly reflecting the comprehensive risks faced by agriculture under real meteorological conditions. Meteorological disasters occurred at different crop growth stages have different influences on the final crop yield. In this paper, maize in Northeast China is used as an example to study risk assessment method and technology aiming at meteorological disasters at different crop growth stages. 【Method】 The whole growth period of maize in Northeast China was divided into four growth stages, namely sowing to seven-leaf, seven-leaf to tasseling, tasseling to milky ripening and milky ripening to maturation, and chilling, drought and flood are regarded as the three main meteorological disasters. Then with data on maize development record, meteorology, soil, crop sown area and yield, etc., and in accordance with the theory of natural disaster risk, the formation mechanism of agro-meteorological disaster risk and the “Four Elements” causing natural disaster risk, namely the natural disaster risk in certain area is caused by four factors, including hazard of the natural disaster, exposure and vulnerability of the disaster-affected body and the disaster prevention and mitigation capacity of human beings, the four elements for Northeast China’s maize of each growth stage were comprehensively analyzed, and risk assessment indices were selected thereby. Multi-indexes method for environment causing the disaster was adopted to select indices on meteorology, crops, physical geography, etc. in order to fully reflect hazard of the main meteorological disasters of each growth stage; assessment indices were selected according to the connotation of exposure and vulnerability of disaster-affected body; based on the relative lag situation of disaster prevention and mitigation, variation coefficient of yield was used to comprehensively reveal the preventing and mitigating capability, and a fairly complete index system of the main meteorological disasters risk assessment was developed. Owing to multiple and complicated factors causing agro-meteorological disasters and the fuzziness and uncertainty of such indices, analytic hierarchy process (AHP) was used to judge the weights of “Four Elements” and the hazard factors for each growth stage. The main meteorological disasters risk assessment model for each growth stage was established using natural disasters risk index method. The main meteorological disasters hazard assessment model was built by adopting synthetic weighted mark method, and the weight coefficients were determined by the ratio of the frequency of the three main meteorological disasters in each growth stage, reflecting the relative seriousness of the main meteorological disasters. 【Result】Based on the risk assessment of the main meteorological disasters in each growth stage, the model of the main meteorological disasters risk assessment of the whole growth period was established using synthetic weighted mark method, and the weight coefficients of risk indices for each growth stage were determined according to correlation relationship between yield reduction rate and the main meteorological disasters risk indices. A fairly complete index system of the main meteorological disasters risk assessment based on the crop growth stages was established, the models of the main meteorological disasters risk assessment and of hazard assessment for each growth stage were developed, and the model of the main meteorological disasters risk assessment for the whole crop growth period was also constructed. Multiple agro-meteorological disaster risk assessment technology system based on Northeast China’s maize growth stages was established basically. 【Conclusion】The analysis of hazard indices and yield reduction rate in the key development stage of the research stations in the typical widespread disaster years and of the representative stations in the typical disastrous years in Northeast China showed that the main meteorological disasters hazard indices were well selected.
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    Characteristics of Air Moisture and the Effects of High Air Moisture at Booting Stage on Grain Yield of Wheat in Jianghan Plain
    WANG Xiao-yan, ZHAO Xiao-yu, CHEN Hui-fu, WANG Xiao-ling, XIONG Qin-xue
    Scientia Agricultura Sinica    2014, 47 (19): 3769-3779.   DOI: 10.3864/j.issn.0578-1752.2014.19.005
    Abstract408)   HTML1)    PDF (679KB)(846)       Save
    【Objective】 Jianghan Plain is one of the most important wheat producing areas in Hubei Province, and high relative air moisture is a major limitation on wheat grain yield. Under the conditions of global climate change, relative air moisture increased as well as air temperature. This research was carried out to study the effect of increasing relative air moisture on wheat grain yield, in order to provide a theoretical basis for promoting wheat production in Jianghan Plain. 【Method】The research was carried out based on the analysis of air moisture characteristics in Jianghan Plain from 1983-2013. During the experiment, air moisture was increased to 100% by artificial chamber for 10 days at booting stage of wheat, and the normal air moisture treatment was used as CK, samples were taken at 5 d, 10 d after high air moisture control, and 5 d, 15 d after recovery from all treatments. The effects of high air moisture on photosynthetic characteristics, SPAD value in flag leaf and top 3rd leaf, course of leaf senescence, root activity, plant height, and accumulation of dry matter, grain yield and yield components were studied. 【Result】Air moisture from 1983 to 2013 in Jianghan Plain fluctuated with a 2-5-year circle, and the average air moisture was over 80% during booting stage in most of the years. The air moisture at booting stage in Jianghan Plain in 2011-2012 and 2012-2013 was high, and averaged 77.4% and 79.1%, respectively. Increasing air moisture at booting stage decreased SPAD value in flag leaf and top 3rd leaf, and the difference was not significant at 5 d later, but significant at 10 d later. When air moisture returned to normal, there was a difference in leaf SPAD value between high air moisture treatment and CK, but still inferior to CK. The effects of high air moisture on photosynthetic rate in flag leaf was in agreement with SPAD value. High air moisture reduced photosynthetic rate in flag leaf and removing high air moisture treatment, the difference between high air moisture treatment and CK reduced. Increased air moisture to 100%, MDA content in flag leaf and top 3rd leaf increased, suggesting that high air moisture quickened senescence in leaf. Further analysis showed that root activity reduced as well. Removing high air moisture treatment, the difference of MDA in leaf and root activity between CK and high air moisture treatment reduced, but was still significant, which mean the effects of high air moisture on the above index was not reversal. With the increasing of relative air moisture, the amount of dry matter and grain yield decreased. Compared with CK, at maturity, dry matter of high air moisture treatment decreased by 5%, and grain yield decreased 10.0%, respectively. For further analysis, the decrease of grain yield was attributed to spike weight and grain amount per spike, decreased by 6.0% and 4.2%, respectively, at maturity compared to CK. 【Conclusion】Under the conditions of this experiment, high air moisture at booting stage decreased SPAD value and photosynthetic rate in flag leaf, quickened membrane peroxidating, reduced root activity, and induced to the decrease of biomass and grain yield decreased as well.
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    Remote Sensing Prediction of Winter Wheat Protein Content Based on Nitrogen Translocation and GRA-PLS Method
    LI Zhen-hai, XU Xin-gang, JIN Xiu-liang, ZHANG Jing-cheng, SONG Xiao-yu, SONG Sen-nan, YANG Gui-jun, WANG Ji-hua
    Scientia Agricultura Sinica    2014, 47 (19): 3780-3790.   DOI: 10.3864/j.issn.0578-1752.2014.19.006
    Abstract425)   HTML3)    PDF (489KB)(704)       Save
    【Objective】Prediction of grain protein content (GPC) can provide effective decision-making supporting information for acquisition and processing of high quality wheat. The objective of the study is to demonstrate the feasibility of remote sensing monitoring of wheat grain protein content based on nitrogen translocation theory, and its expansibility between regional and annual level. 【Method】Field experiments of four winter wheat cultivars by four nitrogen applications in Beijing during 2012-2013 growing seasons were carried out for model building. Firstly, the two main sources of grain nitrogen accumulation and their relationships were analyzed based on nitrogen translocation theory and agronomy parameters modeling. The nitrogen remobilization from vegetative organs to grain was considered as the key point, while the nitrogen uptake from the root absorption during grain filling stage was simply calculated as the nitrogen remobilization from vegetative organs to grain multiplied by a factor. Mechanism of predicting GPC with leaf nitrogen content (LNC) at the flowering stage was clarified through integrating agronomy parameters modeling. Meanwhile, the temperature factor was considered. Secondly, twenty-four vegetative indices were selected according to the good relationship between vegetative indices and leaf nitrogen content, and remote sensing estimating of LNC was established by using grey relational method and partial least squares method (GRA-PLS). Therefore, a prediction model of GPC with remote sensing was established. 【Result】The results showed that the selected five vegetative indices according to grey relational grade were mND705, NDVIcanste, Readone, DCNI and NDCI. For the LNC estimating, the determination coefficient (R2) and corresponding to root mean square error (RMSE) of modeling and validation results were 0.859, 0.257% and 0.726, 0.063%, respectively. Estimation of LNC has good robustness by using GRA-PLS method. The R2 and RMSE of predicted and measured GPC of modeling and validation results were 0.726, 1.30% and 0.609, 1.19%, respectively. The results indicated that it was available to estimate GPC by integration model of nitrogen translocation theory and GRA-PLS method. 【Conclusion】The integration model with explanatory and expansibility could explain the theory of “why the LNC is used to predict GPC”, achieved prediction of grain protein content between regional and annual levels, and had a wide range of potential applications.
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    Cited: Baidu(4)
    Optimization of Samples Layout in Spatial Sampling Schemes    for Estimating Winter Wheat Planting Acreage
    WANG Di, CHEN Zhong-xin, ZHOU Qing-bo, LIU Jia
    Scientia Agricultura Sinica    2014, 47 (18): 3545-3556.   DOI: 10.3864/j.issn.0578-1752.2014.18.003
    Abstract477)   HTML1)    PDF (2737KB)(519)       Save
    【Objective】 Sample layout is one of the key factors in spatial sampling schemes for estimating crop planting acreage. Optimization of sample layout plays an important role in improving the representativeness of samples versus population and the accuracy of population extrapolation, decreasing the cost of survey sampling. In this study, focusing on the problem that the formulation of samples layout in the spatial sampling scheme for crop acreage estimation was not reasonable (e.g. samples units are  not all independent of each other, when simple random sampling method was used to formulate samples layout; sampling intervals are not able to be reasonably defined, when systematic sampling method was used in the design of samples layout), the author tried to propose a optimal formulation of samples layout to improve the efficiency of the spatial sampling scheme further.【Method】Mengcheng County in Anhui Province, China was chosen as the study area, winter wheat planting acreage as the study object, and square girds as the shape of sampling units. Geostatistics, “3S” techniques (Remote Sensing, Geographic Information Systems and Global Positioning techniques) and traditional sampling methods were used in this study. Firstly, 8 kinds of sampling unit sizes were formulated, and then the study area was split by the sampling units with these 8 kinds of sizes to construct the sampling frame. The winter wheat acreages in all sampling units were calculated based on the spatial distribution data of winter wheat in 2009 and 2010(derived by ALOS AVNIR-2 and Landsat5 TM image, respectively). Secondly, in order to build the Variogram theoretical model of winter wheat planting acreage proportion within the sampling unit (WPS), simple random sampling method was used to draw the initial samples. Spatial correlation and variability of sampling units were analyzed, and spatial correlation threshold was quantitatively determined by the Variogram theoretical model. Thirdly, the equi-spaced pattern (sampling intervals were identical in vertical and horizontal directions, and spatial correlation threshold of samples was chosen as the sampling interval) was used to reasonably formulate the samples layout, following the principle that samples units were independent of each other in the traditional sampling methods. Finally, the population extrapolation accuracy, stability and sampling cost were estimated according to the samples that the spatial layout were reasonably formulated. In order to evaluate the design efficiency of samples layout, relative error, coefficient of variation (CV) and sampling size were selected as the indices, and simple random sampling method as the control treatment. 【Result】The experimental results demonstrate that, the variability of WPS increased with sampling unit size increasing. CV of WPS varies from 32.75% to 43.46% under 8 kinds of sampling unit size levels; There was an intense spatial correlation among all of WPS within a certain range, and the spatial correlation was mainly dominated by structural factors (climate, topography, soil type). Spatial correlation thresholds of WPS increase with sampling unit size increasing; The relative error and CV of population extrapolation that samples layout was optimized were obviously less than those of simple random sampling method at the same sample size, while sampling unit size was small (500m×500m-2 000m×2 000m); Compared those of simple random sampling method, although the relative error and CV were not decreased after optimized design of sample layout, there was an obvious decreasing in sample size, when sampling unit size was larger (2 500m×2 500m-4 000m×4 000m).【Conclusion】In this way, this research can provide a solution for improving the efficiency of spatial sampling scheme to estimate crop planting acreage.
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    Developing trend, basic principles and research orientation of conservation tillage
    Scientia Agricultura Sinica    2007, 40 (12): 2702-2708.   DOI: 10.3864/j.issn.0578-1752.at-2006-8415
    Abstract1316)      PDF (242KB)(1318)       Save
    Based on the analysis of characteristic and development trends of conservation tillage in the world, the concept of conservation tillage (CT) was defined as an integrative technology system, which will reduce soil erosion and protect ecological environment in agricultural system. The key technologies of CT include the technology of minimum tillage and no-tillage, the technology of micro-topographical alteration and the technology of surface coverage. The principles of CT are to achieve “lower soil disturbances”, “less bareness”, “less pollution”, “moderate moisture”, “moderate roughness” and to maintain sustainable productivity of farmland. According to the concept and principles of CT, the research orientations and the key technologies suited for different regions in China of CT were put forward to build a China characteristic CT system.
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    Spectral character of cotton single leaf infected with verticillium wilt and severity level of disease estimation
    Bin CHEN Ke-Ru WANG Fang-Yong WANG Hai-Zhen TAN Guo-Qing LIU Jiang-Lu CHENG
    Scientia Agricultura Sinica    2007, 40 (12): 2709-2715.   DOI: 10.3864/j.issn.0578-1752.at-2006-8603
    Abstract1173)      PDF (428KB)(1323)       Save
    【Objective】In order to elucidated characteristics of spectrum of cotton leaf infected with verticillium wilt and estimated its severity level (SL)to provide theoretic foundation for further monitoring cotton verticillium wilt at large scale using airborne and airspace remote sensing. 【Method】 The spectrum reflectance of cotton single leaf infected with verticillium wilt was measured in cotton disease garden and cotton field in different growth phase, meanwhile, SL of single leaf infected with verticillium wilt was investigated. The methods of first derivative spectral were used estimate accurately disease of cotton with Verticillium wilt when compared with the reflectance spectrum of different single leaf infected of verticillium wilt. 【Result】The results indicated that Spectral characteristic of cotton leaf infected with verticillium wilt had better regularity with the increase of SL in different periods and varieties. Spectral reflectance increased significantly at visible light region (400~700nm) and near-infrared region (700~1300nm) with the increase of the SL ,and specially signification at blue- violet to red regions(525~680nm) when SL got 25%, cotton leaf of verticillium wilt could be used as a watershed and diagnosed index in early time. There were evident different characteristics of first derivative spectra in these disease leave, it changed significantly in red edge ranges(680~780nm) in different disease level, derivative spectra of red edge swing decreased, and red edge position equal moved to the blue. The thesis indicated that 434~724nm and 909~1600nm were selected out as sensitive bands region to SL of single leaf. Some inversion models for estimating cotton leaf diseased level of verticillium wilt all reached the best significantly level.【Conclusion】The results suggested that different characteristics of spectrum of cotton leaf infected with verticillium wilt were obvious. The model in which the first derivative spectra at 723nm could invert accurately the cotton leaf SL., and it may be used to forecasting the position of cotton leaf infected with verticillium wilt in quantitatively.
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    Study on adaptation and introduction possiablity of winter rapeseed in dried and cold areas in Northwest China
    Scientia Agricultura Sinica    2007, 40 (12): 2716-2726.   DOI: 10.3864/j.issn.0578-1752.au-2007-00060
    Abstract1474)      PDF (402KB)(1081)       Save
    Abstract:【Objective】The studies were conducted for studying on feasibility of expanding winter rapeseed northwards into dry,cold regions in Northwest China and screening of the winter type rapeseeds cultivars adaped to this area.【Method】Field experiments were carried out in 2001-2006 at 10 locations in northwest China’s Gansu Province where latitude ranged 35°30’-39°46’N, elevation ranged 1477-2300 m, precipitation ranged 92.0-630 mm, and annual average temperature ranged 5.9-8.7 oC.【Result】The 40 Brassica napus cultivars or breeding lines tested did not survive the local winter. All the 15 B. rapa materials tested, all of which were native of northwest China, had >70% overwintering rates at most locations. At Jiuquan, the northernmost location , only the ultra winter-hardy lines MXW-1 and DQW-1 survived the winter. The B. rapa winter rapeseed had desirable agronomic characteristics and outyielded spring rapeseed and flax. Its early maturity maximized the multiple crop index and increased unit land cash return. 【Conclusion】As a winter cover crop, it may eliminate a dust source that furnishes the damaging sand storms in northern China. It is not only possible but also beneficial economically, environmentally and ecologically to grow winter rapeseed in the dried and cold regions in northwest China.
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    Low molecular weight organic acids in rhizosphere and their effects on cadmium accumulation in two cultivars of amaranth
    Scientia Agricultura Sinica    2007, 40 (12): 2727-2733.   DOI: 10.3864/j.issn.0578-1752.at-2006-8531
    Abstract1501)      PDF (488KB)(1160)       Save
    【Objective】 To examine whether low- molecular weight organic acids (LMWOAs) in root exudates of amaranth play a role in Cd hyperaccumulation, we compared the amounts and composition of LMWOAs collected from two cultivars of amaranth,Zibeixian ,a low Cd accumulator,and Tianxingmi,a high Cd accumulator. 【Method】 Plants were grown hydroponically and three treatment (Cd 0、1 and 2.5 mg/L ) were later imposed for 1 wk before collection of LMWOAs. 【Result】 With the increase of solution Cd concentration, the biomass and its components of Zibeixian decreased dramatically, while those of Tianxingmi remained stable. In all treatment, total amount of LMWOAs in rhizosphere of Tianxingmi were significantly higher than that in Zibeixian,and the content of LMWOAs in two cultivars followed the same tendency, i.e. citric>malic>acetic>propinonic>butyric, and citric acid and malic acid predominated the composition of LMWOAs. The percent distribution of total LMWOAs of Zibeixian was very similar to Tianxingmi. With the increase of solution Cd supply, the content of LMWOAs in rhizosphere increased dramatically for both two cultivars, and the increment of LMWOAs of Tianxingmi was found to be greatly higher than that of Zibeixian. 【Conclusion】Therefore, Cd accumulation in amaranth was highly related to the total amount of LMWOAs in rhizosphere,and the differential increment of LMWOAs in the rhizosphere induced by Cd exposure may played an important role for Cd bioaccumulation by the high and low Cd accumulating cultivars of amaranth.
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    Cited: Baidu(1)
    Effect of Free-air CO2 Enrichment (FACE) on Grain Filling Properties of Rice
    Scientia Agricultura Sinica    2007, 40 (11): 2443-2451.   DOI: 10.3864/j.issn.0578-1752.at-2006-8295
    Abstract1470)      PDF (323KB)(1127)       Save
    【Objective】 In order to investigate the effect of atmospheric CO2 concentration ([CO2]) on grain-filling properties of rice. 【Method】Using the unique free-air CO2 enrichment (FACE) system in China, a japonica rice cv. Wuxiangging 14 was grown at ambient or elevated (ca 200 μmol mol-1 above ambient) [CO2] under three levels of N: low (LN, 150 kg hm-2), medium (MN, 250 kg hm-2) and high N (HN, 35 kg hm-2). Grain filling dynamic at different positions of rice panicle was investigated. The Richards equation was used to describe grain filling processes. 【Result】(1) Under LN condition, FACE treatment increased grain weight significantly, averaging 9.9%, 7.0% and 7.7% for grains on upper, middle and low parts of the panicle, respectively. However, no effect of FACE was observed under HN and MN conditions. (2) In general, FACE treatment enhanced the initial relative growth power (GR0/W0) of grains on different parts of the panicle. (3) FACE treatment greatly increased the maximum grain-filling rate (MRm), averaging 38.6%, 24.3% and 38.6% for LN-, MN- and HN-plants, respectively, with CO2-induced increase being larger for upper grains than middle and low ones on the panicle. In addition, the mean grain-filling rate (MGR) was enhanced due to FACE by 38.9%, 47.7% and 44.1% for LN-, MN- and HN-plants, respectively. (4) Overall, grains of FACE plants had later time to reach maximum growth rate, heavier grain weight at time when the growth rate is maximum and shorter mean grain-filling duration as compared with those of ambient plants. As for different grain-filling stages, FACE treatment obviously prolonged the duration of early grain-filling stage, while the duration of middle and late grain-filling stages showed the opposite trends.【Conclusion】These data indicated that FACE treatment increased the GR0/W0, GRm and MGR, prolonged the duration of early grain-filling stage with a shortening of duration of middle, late and whole grain-filling stages. FACE treatment greatly increased grain weight of different panicle positions under LN condition, whereas no significant changes were observed under MN and HN conditions.
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    Gray Relational Grade Analysis of Agronomical Characters and Physi-biochemical Indexes Related to Drought Tolerance in Wheat
    Scientia Agricultura Sinica    2007, 40 (11): 2452-2459.   DOI: 10.3864/j.issn.0578-1752.at-2006-8460
    Abstract1266)      PDF (421KB)(1467)       Save
    【Objective】This paper aims to probe the relationship between agronomical characters and physi-biochemical indexes of wheat cultivar with its drought tolerance. 【Method】 12 indexes, including 5 agronomical characters and 7 physi-biochemical indexes that measured in 65 wheat cultivars grown at drought shelf and no-irrigation conditions, were analyzed using gray relational grade analysis method. 【Result】 Gray correlation degrees facilitating to identify the drought tolerance of wheat were calculated between each index and its drought resistance index, they were ranked as follows by their contribution to drought tolerance: stomata conductance (γ=0.7995), photosynthetic rate (γ=0.7909), transpiration rate (γ=0.7556), soluble sugar content (γ=0.7467), MDA content (γ=0.7336), dissociative proline content (γ=0.7267), spike length (γ=0.7102), number of kernel per spike (γ=0.7095), 1000-kernel weight (γ=0.7005), water potential (γ=0.6959), tiller (γ=0.6951), plant height (γ=0.6866). And the clustering analysis based on the weighted drought index of cultivars could finely represent their breeding and application areas. Species that have the best drought resistance among the 65 species are: Luohan 6, Xiaoyan 6, Jinmai 47, Shanmai 168 etc. 【Conclusion】 The result indicates that the physi-biochemical indexes related to leaf stomata have the closest relationship with the drought resistance of wheat, and these indexes are significantly influenced under water stress, thus have the greatest relation degree with drought resistance index, so the physi-biochemical indexes including stomata conductance, photosynthetic rate and transpiration rate should be used for the assistant selection of drought tolerance to improve the selection efficiency.
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    Canopy and Yield Characteristics of Super-High-Yielding Soybean Liaodou14
    Scientia Agricultura Sinica    2007, 40 (11): 2460-2467.   DOI: 10.3864/j.issn.0578-1752.at-2006-8319
    Abstract1245)      PDF (489KB)(1006)       Save
    Abstracts: 【Objective】Super-high-yielding soybean had certain advantages in plant type characteristics. This study investigated the morphological and physiological characteristics of super-high-yielding soybean Liaodou14. 【Method】Comparative analysis of plant type characteristics were carried out through multi-year experiments with super-high-yielding soybean Liaodou14 and general soybean Liaodou11 as varieties. 【Result】The chlorophyll content and photosynthetic rate of L14 from seedling to full podding were not superior to L11, but higher obviously after full podding. When the photosynthetic rate of different nodes was tested, it was found that the difference of photosynthetic rate between upper layer and lower layer was smaller and the leaves of lower layer senesced slower for super-high-yielding soybean. The distribution of petiole length and LSI (leaf shape index) of L14 were more reasonable, which made it intercept more sunlight at higher LAI. The LAI and photosynthetic rate of L14 maximized later than L11, but had a longer duration and descended slower in late stage. The accumulation of biological yield of L14 was smaller before podding, but higher than L11 after podding. After podding, L14 transported more photosynthetic products to pods, which made it got higher HI. 【Conclusion】The main reason why super-high-yielding soybean L14 got higher yield was that from full podding to late pod-filling, it had better canopy structure, maintained higher LAI and photosynthetic potential and had higher photosynthetic productivity.
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    Tobacco plants transformed with Sweet Pepper positive GPAT Gene Alleviate Photoinhibition Under High Temperature
    Scientia Agricultura Sinica    2007, 40 (11): 2468-2473.   DOI: 10.3864/j.issn.0578-1752.at-2006-8440
    Abstract1355)      PDF (415KB)(1122)       Save
    The saturated extent of MGDG, SQDG, DGDG and PG in thylakoid membrane of tobacco plants transformed with sweet pepper positive GPAT gene increased entirely, remarkably in MGDG with increasing by 16.2%. Under high temperature stress (48℃), ΦPSⅡ and Fv/Fm of wild type tobacco plants decreased by 42.3% and 21.3%, but only decreased by 24.2% and 13.7% in transgenic tobacco, which indicated that the transformed tobacco plants maintained higher actual photochemistry efficiency of PSII and lower photoinhibition under high temperature. The increase in saturated extent of thylakoid membrane lipids raised the temperature inducing phase separation and enhanced the stability of PSⅡunder high temperature.
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