Journal of Integrative Agriculture

Barley and Wheat Share the Same Gene Controlling the Short Basic Vegetative Period

Lü Rui-hua, XU Yan-hao, Rodger Boyd, ZHANG Xiao-qi, Sue Broughton, Michael Jones, LI Cheng-dao, CHEN Yao-feng

2013, 12(10): 1703-1711. DOI: 10.1016/S2095-3119(13)60351-2

Abstract ( ) PDF in ScienceDirect

Basic vegetative period (BVP) is an important trait for determining flowering time and adaptation to variable environments. A short BVP barley mutant is about 30 d shorter than its wild type. Genetic analysis using 557 F2 individuals revealed that the short BVP is governed by a single recessive gene (BVP-1) and was further validated in 2 090 F3 individuals. The BVP-1 gene was first mapped to barley chromosome 1H using SSR markers. Comparative genomic analysis demonstrated that the chromosome region of BVP-1 is syntenic to rice chromosome 5 and Brachypodium chromosome 2. Barley ESTs/genes were identified after comparison with candidate genes in rice and Brachypodium; seven new gene-specific markers were developed and mapped in the mapping populations. The BVP-1 gene co-segregated with the Mot1 and Ftsh4 genes and was flanked by the gene-specific markers AK252360 (0.2 cM) and CA608558 (0.5 cM). Further analysis demonstrated that barley and wheat share the same short BVP gene controlling early flowering.

Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

HAN Juan, JIA Zhi-kuan, HAN Qing-fang , ZHANG Jie

2013, 12(10): 1712-1721. DOI: 10.1016/S2095-3119(13)60342-1

Abstract ( ) PDF in ScienceDirect

The ridge and furrow rainfall harvesting (RFRH) system is used for dryland crop production in northwest of China. To determine the effects of RFRH using different mulching materials on corn growth and water use efficiency (WUE), a field experiment was conducted during 2008-2010 at the Heyang Dryland Experimental Station, China. Four treatments were used in the study. Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic film (PF), biodegradable film (BF) or liquid film (LF). A conventional flat field without mulching was used as the control (CK). The results indicated that the average soil water storage at depths of 0-200 cm were 8.2 and 7.3%, respectively higher with PF and BF than with CK. However, LF improved soil water storage during the early growth stage of the crop. Compared with CK, the corn yields with PF and BF were increased by 20.4 and 19.4%, respectively, and WUE with each treatment increased by 23.3 and 21.7%, respectively. There were no significant differences in corn yield or WUE with the PF and BF treatments. The net income was the highest with PF, followed by BF, and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha-1, respectively, compared with CK. BF and PF had similar effects in enhancing the soil water content, crop yield and net income. Therefore, it can be concluded that biodegradable film may be a sustainable ecological alternative to plastic film for use in the RFRH system in northwest of China.

Over-Expression of ScMnSOD, a SOD Gene Derived from Jojoba, Improve Drought Tolerance in Arabidopsis

LIU Xiao-fei, SUN Wei-min, LI Ze-qin, BAI Rui-xue, LI Jing-xiao, SHI Zi-han, GENG Hongwei, ZHENG Ying, ZHANG Jun , ZHANG Gen-fa

2013, 12(10): 1722-1730. DOI: 10.1016/S2095-3119(13)60404-9

Abstract ( ) PDF in ScienceDirect

Jojoba (Simmondsia chinensis) is mainly distributed in desert, and the molecular mechanisms of jojoba in response to abiotic stress still remain elusive. In this paper, we cloned and characterized a SOD gene from jojoba named as ScMnSOD, and introduced into Arabidopsis to investigate its functions of responding to drought stress. The transgenic Arabidopsis showed an improvement in drought tolerance. Moreover, under a water deficit condition, the accumulation of reactive oxygen species (ROS) was remarkably decreased in the transgenic lines compared to the WT. Furthermore, the ScMnSOD promoter was cloned to the 5´-upstream of GUS coding region in a binary vector, and introduced into Arabidopsis. And results showed that ScMnSOD expression can be induced by drought, salt, ABA, and low temperature. In conclusion, ScMnSOD plays an important role in drought tolerance which is, at least partially, attributed to its role in ROS detoxification.

Two Lycopene β-Cyclases Genes from Sweet Orange (Citrus sinensis L. Osbeck) Encode Enzymes With Different Functional Efficiency During the Conversion of Lycopene-to-Provitamin A

ZHANG Jian-cheng, ZHOU Wen-jing, XU Qiang, TAO Neng-guo, YE Jun-li, GUO Fei, XU Juan, DENG Xiu-xin

2013, 12(10): 1731-1747. DOI: 10.1016/S2095-3119(13)60366-4

Abstract ( ) PDF in ScienceDirect

Citrus fruits are rich in carotenoids. In the carotenoid biosynthetic pathway, lycopene β-cyclase (LCYb, EC:1.14.-.-) is a key regulatory enzyme in the catalysis of lycopene to β-carotene, an important dietary precursor of vitamin A for human nutrition. Two closely related lycopene β-cyclase cDNAs, designated CsLCYb1 and CsLCYb2, were isolated from the pulp of orange fruits (Citrus sinensis). The expression level of CsLCYb genes is lower in the flavedo and juice sacs of a lycopeneaccumulating genotype Cara Cara than that in common genotype Washington, and this might be correlated with lycopene accumulation in Cara Cara fruit. The CsLCYb1 efficiently converted lycopene into the bicyclic β-carotene in an Escherichia coli expression system, but the CsLCYb2 exhibited a lower enzyme activity and converted lycopene into the β-carotene and the monocyclic γ-carotene. In tomato transformation studies, expression of CsLCYb1 under the control of the cauliflower mosaic virus (CaMV) 35S constitutive promoter resulted in a virtually complete conversion of lycopene into β-carotene, and the ripe fruits displayed a bright orange colour. However, the CsLCYb2 transgenic tomato plants did not show an altered fruit colour during development and maturation. In fruits of the CsLCYb1 transgenic plants, most of the lycopene was converted into β-carotene with provitamin A levels reaching about 700 μg g-1 DW. Unexpectedly, most transgenic tomatoes showed a reduction in total carotenoid accumulation, and this is consistent with the decrease in expression of endogenous carotenogenic genes in transgenic fruits. Collectively, these results suggested that the cloned CsLCYb1 and CsLCYb2 genes encoded two functional lycopene β-cyclases with different catalytic efficiency, and they may have potential for metabolite engineering toward altering pigmentation and enhancing nutritional value of food crops.

Physicochemical and Sensory Properties of japonica Rice Varied with Production Areas in China

YANG Xiao-yu, LIN Zhao-miao, LIU Zheng-hui, Md A Alim, BI Jun-guo, LI Gang-hua, WANGQiang-sheng , WANG Shao-hua , DING Yan-feng

2013, 12(10): 1748-1756. DOI: 10.1016/S2095-3119(13)60338-X

Abstract ( ) PDF in ScienceDirect

Northeast of China and Jiangsu Province are major production areas of japonica rice in China. Rice from northeast of China is well-known for its good-eating and appearance quality, and that from Jiangsu Province is viewed as inferior. However, little is known concerning the difference in physicochemical and sensory properties of rice between the major two production areas. Analysis of 16 commercial rice samples showed marked differences in physicochemical properties, including chalky grain rate, contents of amylose and protein and pasting properties between the two main areas. Northeastern rice contained more shortchain amylopectin as compared with Jiangsu rice. However, Jiangsu rice is comparable to northeastern rice in terms of sensory quality including overall acceptability and textural properties of springiness, stickiness and hardness as evaluated by trained panel. Our results indicated the limitation of conventional index of physicochemical properties, and suggested the necessity of identification of new factors controlling rice sensory property. In addition, the taste analyzer from Japan demonstrates limitation in distinguishing the differences between northeastern and Jiangsu rice, and therefore needs localization to fit China.

Nitrogen Concentration in Subtending Cotton Leaves in Relation to Fiber Strength in Different Fruiting Branches

ZHAO Wen-qing, LI Jian, GAO Xiang-bin, WANG You-hua, MENG Ya-li , ZHOU Zhi-guo

2013, 12(10): 1757-1770. DOI: 10.1016/S2095-3119(13)60336-6

Abstract ( ) PDF in ScienceDirect

Nitrogen (N) fertilizer experiments were conducted to investigate the optimal subtending leaf N concentration for fiber strength, and its relationship with activities of key enzymes (sucrose synthase and β-1,3-glucanase) and contents of key constituents (sucrose and β-1,3-glucan) involved in fiber strength development in the lower, middle and upper fruiting branches of two cotton cultivars (Kemian 1 and NuCOTN 33B). For each sampling day, we simulated changes in fiber strength, activity of sucrose synthase and β-1,3-glucanase and levels of sucrose and β-1,3-glucan in response to leaf N concentration using quadratic eqs.; the optimal subtending leaf N concentrations were deduced from the eqs. For the same fruiting branch, changes in the optimal leaf N concentration based on fiber development (DPA) could be simulated by power functions. From these functions, the average optimal subtending leaf N concentrations during fiber development for the cultivar, Kemian 1, were 2.84% in the lower fruiting branches, 3.15% in the middle fruiting branches and 3.04% in the upper fruiting branches. For the cultivar, NuCOTN 33B, the optimum concentrations were 3.04, 3.28 and 3.18% in the lower, middle and upper fruiting branches, respectively. This quantification may be used as a monitoring index for evaluating fiber strength and its related key enzymes and constituents during fiber formation at the lower, middle and upper fruiting branches.

The Effect of Plastic-Covered Ridge and Furrow Planting on the Grain Filling and Hormonal Changes of Winter Wheat

LIU Yang, HAN Juan, WEN Xiao-xia, WU Wei, GUO Qiang, ZENG Ai , LIAO Yun-cheng

2013, 12(10): 1771-1782. DOI: 10.1016/S2095-3119(13)60337-8

Abstract ( ) PDF in ScienceDirect

Although plastic-covered ridge and furrow planting (RF) has been reported to produce substantial increases in the grain weight of winter wheat, the underlying mechanism is not yet understood. The present study used two cultivars, Xinong 538 and Zhoumai 18, and RF and traditional flatten planting (TF, control) with the objective of investigating the effect of RF on wheat grain filling and the possible relationship of hormonal changes in the wheat grains under RF to grain filling. The results indicated that RF significantly increased the grain weight, although the effects on grain filling were different: RF significantly increased the grain-filling rate and grain weight of inferior grains, whereas RF had no significant effect on grainfilling rate and grain weight of superior grains. The ?nal grain weight of inferior grains under RF was 39.1 and 50.7 mg for Xinong 538 and Zhoumai 18, respectively, 3.6 and 3.4 mg higher than the values under TF. However, the final grain weight of superior grains under RF was only 0.6 and 0.8 mg higher than under TF for Xinong 538 and Zhoumai 18, respectively. RF significantly decreased the ethylene and gibberellic acid content in the inferior grains and increased the indole-3-acetic acid, abscisic acid and zeatin + zeatin riboside content in the inferior grains; however, no significant difference between RF and TF was observed for the hormonal content in the superior grains. Based on these results, we concluded that RF significantly modulated hormonal changes in the inferior grains and, thus, affected the grain filling and grain weight of the inferior grains; in contrast, RF had no significant effect on grain filling, grain weight and hormonal changes in the superior wheat grains.

Exogenous Nitric Oxide Involved in Subcellular Distribution and Chemical Forms of Cu2+ Under Copper Stress in Tomato Seedlings

DONG Yu-xiu, WANG Xiu-feng , CUI Xiu-min

2013, 12(10): 1783-1790. DOI: 10.1016/S2095-3119(13)60367-6

Abstract ( ) PDF in ScienceDirect

Nitric oxide (NO), a bioactive signaling molecule, serves as an antioxidant and anti-stress agent under abiotic stress. A hydroponics experiment was conducted to investigate the effects of sodium nitroprusside (SNP), a NO donor, on tomato seedlings exposed to 50 μmol L-1 CuCl2. The results show that copper is primarily stored in the soluble cell sap fraction in the roots, especially after treatment with Cu+SNP treatment, which accounted for 66.2% of the total copper content. The copper concentration gradually decreased from the roots to the leaves. In the leaves, exogenous NO induces the storage of excess copper in the cell walls. Copper stress decreases the proportion of copper integrated with pectates and proteins, but exogenous NO remarkably reverses this trend. The alleviating effect of NO is blocked by hemoglobin. Thus, exogenous NO is likely involved in the regulation of the subcellular copper concentrations and its chemical forms under copper stress. Although exogenous NO inhibited the absorption and transport of excess copper to some extent, the copper accumulation in tomato seedlings significantly increased under copper stress. The use of exogenous NO to enhance copper tolerance in some plants is a promising method for copper remediation.

Essential Oil from Inula britannica Extraction with SF-CO2 and Its Antifungal Activity

ZHAO Te, GAO Fei, ZHOU Lin, SONG Tian-you

2013, 12(10): 1791-1798. DOI: 10.1016/S2095-3119(13)60382-2

Abstract ( ) PDF in ScienceDirect

The aim of this study was to determine the extraction technique of supercritical fluid carbon dioxide (SF-CO2) for the essential oil from Inula britannica flowers and its antifungal activities against plant pathogenic fungi for its potential application as botanical fungicide. The effects of factors, including extraction temperature, extraction pressure, SF-CO2 flow rate, flower powder size, and time on the essential oil yield were studied using the single factor experiment. An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield. Adopting the optimum conditions, the maximum yield reached 10.01% at 40°C temperature, 30 MPa pressure, 60 mesh flower powder size, 20 L h-1 SF-CO2 flow rate, and 90 min extraction time. The antifungal activities of I. britannica essential oil using the SF-CO2 against the most important plant pathogenic fungi were also examined through in vitro and in vivo tests. Sixteen plant pathogenic fungi were inhibited to varying degrees at 1 mg mL-1 concentration of the essential oil. The mycelial growth of Gaeumannomyces graminis var. tritici was completely inhibited. The radial growths of Phytophthora capsici and Fusarium monilifome were also inhibited by 83.76 and 64.69%, respectively. In addition, the essential oil can inhibit the spore germination of Fusarium oxysporum f. sp. vasinfectum, Phytophthora capsici, Colletotrichum orbiculare, and Pyricularia grisea, and the corresponding inhibition rates were 98.26, 96.54, 87.89, and 87.35% respectively. The present study has demonstrated that the essential oil of I. britannica flowers extracted through the SF-CO2 technique is one potential and promising antifungal agent that can be used as botanical fungicide to protect crops.

Development of A Real-Time PCR Assay for Plasmodiophora brassicae and Its Detection in Soil Samples

LI Jin-ping, LI Yan, SHI Yan-xia, XIE Xue-wen, Chai A-li , LI Bao-ju

2013, 12(10): 1799-1806. DOI: 10.1016/S1671-2927(00)9145

Abstract ( ) PDF in ScienceDirect

A SYBR Green I real-time PCR assay was developed to detect and quantify Plasmodiophora brassicae ribosomal DNA (rDNA) and internal transcribed spacer (ITS). A pair of primers PBF1/PBR1 was designed based on the conservative region of rDNA-ITS of P. brassicae. The positive plasmid pB12 was obtained and used as the template to create standard curve. The specificity, sensitivity, and reproducibility of real-time PCR were evaluated respectively. Naturally and artificially infested soil samples containing different concentrations of P. brassicae were detected. The results demonstrated that standard curve established by recombinant plasmid was shown a fine linear relationship between threshold cycle and template concentration. The melting curve was specific with the correlation coefficient of 0.995 and that the amplification efficiency was 93.8%. The detection limit of P. brassicae genomic DNA was approximately 40 copies per 25 μL. The sensitivity of the assay was at least 100-fold higher than conventional PCR. Only DNA from P. brassicae could be amplified and detected using this assay, suggesting the highly specific of this assay. The coefficient of variation was less than 3%, indicating the PCR method revealed high reproducibility. The detection limit in soil samples corresponded to 1 000 resting spores g-1 soil. Bait plants were used to validate the real-time PCR assay. This developed real-time PCR assay allows for fast and sensitive detection of P. brassicae in soil and should be useful in disease management and pest interception so as to prevent further spread of P. brassicae.

Impact Assessments of Transgenic cry1Ab Rice on the Population Dynamics of Five Non-Target Thrips Species and Their General Predatory Flower Bug in Bt and Non-Bt Rice Fields Using Color Sticky Card Traps

Akhtar Zunnu Raen, YE Gong-yin, LU Zeng-bin, CHANG Xue, SHEN Xiao-jing, PENG Yu-fa

2013, 12(10): 1807-1815. DOI: 10.1016/S2095-3119(13)60499-2

Abstract ( ) PDF in ScienceDirect

A 2-yr field study was conducted to assess the effects of transgenic japonica rice (KMD1 and KMD2) with a synthetic cry1Ab gene from Bacillus thuingiensis Berliner on population dynamics and seasonal average densities of five thrips species including Stenchaetothrips biformis (Bagnall), Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Haplothrips aculeatus (Fabricius), Haplothrips tritici (Kurd) and their general predatory flower bug, Orius similis Zheng as compared to the parental control rice line using the white, blue and yellow sticky card traps. Population dynamics and seasonal average densities of these five thrips species and their general predatory flower bug were not significantly affected by rice type. Additionally, the white sticky card trap was suggested to be the most suitable for monitoring the population of these five thrips species and their general predator. These results show that our tested Bt rice lines do not interrupt the population of non-target thrips species and their general predatory flower bug in the field, and also cannot result in more occurrence of these thrips species in the rice ecosystem.

Cloning, Tissue Distribution, and Transmembrane Orientation of the Olfactory Co-Receptor Orco from Two Important Lepidopteran Rice Pests, the Leaffolder (Cnaphalocrocis medinalis) and the Striped Stem Borer (Chilo suppressalis)

LIU Su, HUANG Yuan-jie, QIAO Fei, ZHOU Wen-wu, GONG Zhong-jun, CHENG Jia-an , ZHU Zeng-rong

2013, 12(10): 1816-1825. DOI: 10.1016/S2095-3119(13)60501-8

Abstract ( ) PDF in ScienceDirect

In insects, the sense of smell is mainly mediated by olfactory receptors (Ors). Olfactory co-receptor (Orco), which is coexpressed with the Ors in almost all olfactory receptor neurons (ORNs), is demonstrated to be an essential component in the insect olfactory system. It can be potential target for developing novel olfactory-disruption strategy to control insect pests. In this study, two full-length cDNA sequences encoding Orcos (CmedOrco and ChsupOrco) were cloned from two Lepidopteran rice pests, the rice leaffolder, Cnaphalocrocis medinalis and the rice striped stem borer, Chilo suppressalis. The amino acid sequences of CmedOrco and ChsupOrco showed high similarity to the previously identified Orcos from other insect species. Bioinformatic prediction and cellular immunofluorescence indicated that CmedOrco and ChsupOrco were both seventransmembrane proteins with intracellular N-termini and extracellular C-termini. mRNA expression levels of the two Orcos were much higher in male and female antennae than those in non-olfactory tissues, and the ChsupOrco transcripts reached a peak level in adults compared to other life stages. Our results provide a foundation from which it will be possible to elucidate the roles of Orco in moth olfaction and for the development of environment-friendly management strategies of these two rice insect pests.

Oxidative Stress and Role of Natural Plant Derived Antioxidants in Animal Reproduction

ZHONG Rong-zhen , ZHOU Dao-wei

2013, 12(10): 1826-1838. DOI: 10.1016/S2095-3119(13)60412-8

Abstract ( ) PDF in ScienceDirect

The experimental knowledge on the role of oxidative stress, and beneficial and detrimental effects of plant derived antioxidants in male and female animal reproduction are reviewed in this article. Free radical-induced oxidative stress in animal reproduction causes great loss to livestock industry. Antioxidant therapy has been implicated to be effective in preventing diseases resulted from oxidative stress. Considering the advantages of lower side effects of natural antioxidants than those of synthetic antioxidants, plants or their extracts have been extensively utilized in animals. Although many advances have been gained on application of plant derived antioxidants in alleviating oxidative stress, debatable issues still exist. Because many opposite effects were observed even using plant extracts containing similar bioactive substances in the same animal species. Therefore, plant derived antioxidants, like free radicals, are “double-edged swords” in animal reproduction, representing that they may exhibit beneficial or detrimental effects in animal reproduction, including spermatogenesis, semen functions, estrous cycles, ovulation, ovary functions, endometrium, embryo development, and pregnancy. Besides dose-dependent manner as an explanation of plant extracts’ dual function, future studies are needed to investigate the mechanism of double-edged actions of plant derived antioxidants in different animal reproduction systems.

ALK Family Inhibitor A83-01 Promotes the Proliferation of Mouse Male Germline Stem Cells (mGSCs) Under Serum- and Feeder-Free Conditions

YU Meng, WANG Long, HU Yue, LIAN Zhi-min , HUA Jin-lian

2013, 12(10): 1839-1846. DOI: 10.1016/S2095-3119(13)60413-X

Abstract ( ) PDF in ScienceDirect

A83-01 is a selective inhibitor of the TGF-β type I receptor ALK, which inhibits the TGF-β-induced epithelial-to-mesenchymal transition (EMT) via the inhibition of Smad2 phosphorylation. Previous studies have showed that A83-01 promoted somatic cellular reprogramming significantly. Male germline stem cells (mGSCs), as an alternative resource of pluripotent stem cells derived adult testis, have promising valuable in clinic medicine and regeneration, however, the derivation of mGSCs was complex and difficult. What the role A83-01 plays in promoting the proliferation of mGSCs is still unknown. In this study, combined with A83-01 and knockout serum replacement (KSR) medium, we obtained a relatively feeder- and serum-free system for mGSCs culturing in vitro and the optimal concentration of A83-01 was 0.25 μmol L-1. After continuous culturing, the proliferation efficiency of undifferentiated mGSCs and differentiation capacity of mGSC were examined as well. Results showed that, A83-01 dramatically increased the number of mGSCs and AP positive colonies, and the mitosis index according to the BrdU assay. A83-01 could also increase the expression of pluripotent markers including Oct4, Klf4, Nanog and c-Myc, analyzed by real-time quantative PCR. mGSCs cultured in the optimal feeder-and serum-free system combined with A83-01 could form embryoid bodies (EBs), which consisted of three embryonic layers detected by immunofluorescence and RT-PCR. Remarkably, the results demonstrated 0.25 μmol L-1 A83-01 could promote the proliferation of mouse mGSC colonies and maintain their undifferentiated status under feeder- and serum-free systems.

The Finding and Phylogenetic Evolution Analysis of Bovine Piroplasms in the Ras?n Area of North Korea

JIA Li-jun, ZHANG Shou-fa, CAO Shi-nuo, QIAN Nian-chao, YU Long-zheng , XUAN Xue-nan

2013, 12(10): 1847-1854. DOI: 10.1016/S2095-3119(13)60377-9

Abstract ( ) PDF in ScienceDirect

The objective of this study was to investigate the epidemiology of bovine Piroplasms infections in the Ras?n area of North Korea. The survey was carried out by light microscopic examination of Giemsa-stained blood smears, PCR, and phylogenetic evolution analysis of 128 blood samples collected from the Ras?n area. The results showed that the infection rates of the small and large parasites were about 2.5 and 1.5% on average, respectively, in all Theileria sergenti and Babesia ovatapositive blood smears by microscopic examination of blood smears. The detection rate of T. sergenti Giemsa-stained smears was 43.75%, while that with PCR was 67.97%. The detection rate of B. ovata Giemsa-stained smears was 49.21%, while that with PCR was 71.88%. The sequence and phylogenetic analysis of DNA showed 98.84% homology between the 18S rRNA gene sequences of T. sergenti isolates from North Korean and that of Yanbian state from China, indicating the closest genetic relationship between both of them. Moreover, 100% homology was shown between the 18S rRNA gene sequence of B. ovata isolates from North Korea and the published sequence AY081192 of GenBank, indicating the closest genetic relationship between both of them. This survey confirmed that Ras?n is the endemic area of T. sergenti and B. ovata in North Korea.

Changes in Phosphorus Fractions and Nitrogen Forms During Composting of Pig Manure with Rice Straw

Lü Dui-an, YAN Bai-xing, WANG Li-xia, DENG Zhi-qiang, ZHANG Yu-bin

2013, 12(10): 1855-1864. DOI: 10.1016/S2095-3119(13)60400-1

Abstract ( ) PDF in ScienceDirect

The study was conducted to reveal P fractions and N forms changing characters during composting of pig manure with rice straw. During composting, the NH4 +-N concentration decreased and reached at a relatively low value (<400 mg kg-1) in the final compost, while the NO3 --N concentration increased. Total N losses mainly occurred during thermophilic phase due to the high temperature, the high NH4 +-N concentration and the increase of pH value. Labile inorganic P was dominated in the pig manure and initial compost mixture. During composting, the proportion of labile inorganic P of total extracted P decreased, while the proportion of Fe+Al-bound P, Ca+Mg-bound P and residual P increased. The evolutions of the proportion of labile inorganic P, Fe+Al-bound P and Ca+Mg-bound P were well correlated with the changes of pH value, organic matter and C/N ratio. Therefore, composting could increase the concentration of N and P and decrease the presence of NH4 +-N and labile P fractions which might cause environmental issues following land application.

Compositional and Structural Difference of Fulvic Acid from Black Soil Applied with Different Organic Materials: Assessment After Three Years

LI Jian-ming , WU Jing-gui

2013, 12(10): 1865-1871. DOI: 10.1016/S2095-3119(13)60397-4

Abstract ( ) PDF in ScienceDirect

Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture. A pot experiment was conducted at Jilin Agricultural University, Jilin Province in northeast China to discover the influence of herb residue, animal excrement, woody residue, animal remnant on fulvic acid (FA) composition and structure using differential thermal analysis-thermogravimetric (DTA-TG), fourier transform infrared spectroscopy (FTIR) and elemental analysis. DTA-TG showed the range of peak temperature in the first exothermic reaction increased following the trend: CK>herb residue>animal excrement>woody residue=animal remnant, and the most weight loss was observed in animal excrement. Moreover, the second exothermic reaction of CK- and animal excrement-FA was presented as double peaks, the order of weight loss in that area was animal remnant>CK>woody residue>animal excrement>herb residue. According to FTIR, herb residue displayed higher adsorption intensity at 2 950, 1 420, 1 240 and 1 030 cm-1, animal excrement was in reverse. At the same time, herb residue- and animal excrement-FA had an absorption peak at 1 720 cm-1, while other organic materials didn’t have this peak. As elemental analysis showed, FA isolated from various treatments was significantly distinct. It was clearly shown from our results that FA composition and structure in amended soils may be affected in different ways and at various extents on dependence of the nature and origin of amendment.

Soil Microbial Community Composition During Natural Recovery in the Loess Plateau, China

XIAO Lie, LIU Guo-bin, XUE Sha,ZHANG Chao

2013, 12(10): 1872-1883. DOI: 10.1016/S2095-3119(13)60399-8

Abstract ( ) PDF in ScienceDirect

This study aimed to determine the characteristics of soil microbial community composition and its relationship with soil chemical properties during natural recovery in the Loess Plateau. The soil microbial community composition was analyzed by comparing the soil microbial phospholipid fatty acids (PLFAs) of eight croplands abandoned for 1, 3, 5, 10, 13, 15, 20, and 30 yr in the Dunshan watershed, northern Loess Plateau, China. The results showed that soil organic carbon, total nitrogen, soil microbial biomass carbon, and soil microbial biomass nitrogen significantly increased with the abandonment duration, whereas the metabolic quotient significantly decreased. The Shannon richness and Shannon evenness of PLFAs significantly increased after 10 yr of abandonment. Gram-negative, Gram-positive, bacterial, fungal, and total PLFAs linearly increased with increased abandonment duration. Redundancy analysis showed that the abandonment duration was the most important environmental factor in determining the PLFA microbial community composition. The soil microbial PLFAs changed from anteiso- to iso-, unsaturated to saturated, and short- to long-chain during natural recovery. Therefore, in the Loess Plateau, cropland abandonment for natural recovery resulted in the increase of the soil microbial PLFA biomass and microbial PLFA species and changed the microbial from chemolithotrophic to a more heterotrophic community.

Economic Growth, Demographic Change and Rural-Urban Migration in China

ZHONG Fu-ning, LI Qing, XIANG Jing , ZHU Jing

2013, 12(10): 1884-1895. DOI: 10.1016/S2095-3119(13)60597-3

Abstract ( ) PDF in ScienceDirect

Is China able to maintain fast growth after three decades? This paper tries to answer this question by: 1) arguing that factors contributed to sustained long-run growth at supply side; 2) focusing on contributions of demographic dividend especially that of rural-urban migration; and 3) analyzing rural demographic change with information collected through village-wide household survey. Policy alternatives to realize remaining potential demographic dividend are proposed based on the analysis of changing rural demographic structure.

Productivity Growth in China’s Agriculture During 1985-2010

LI Zhou, ZHANG Hai-peng

2013, 12(10): 1896-1904. DOI: 10.1016/S2095-3119(13)60598-5

Abstract ( ) PDF in ScienceDirect

This paper made an empirical analysis of China’s agricultural growth path and influential factors using the province-level panel data of agricultural inputs and outputs during 1985-2010. The findings indicate that the increase in agricultural inputs and TFP contributed 40.6 and 55.2% to the agricultural output growth, respectively; China’s agriculture had jumped out of the pattern which output growth was mainly driven by increasing input. Of the total inputs, chemical fertilizer had the most important contribution to the output growth, followed by mechanical inputs. The contribution of land and labor was negative. China’s agricultural output growth belonged to the type of induced technology innovation. China’s agricultural TFP growth had characteristics of fluctuations over time and unbalanced between regions, but the gap between the eastern, the middle, and the western regions has been narrowed.

Human Capital of Family and Social Mobility in Rural Areas - Evidence from China

ZHANG Jin-hua, YU Mei-lian, WU Fang-wei , CHEN Wei

2013, 12(10): 1905-1915. DOI: 10.1016/S2095-3119(13)60599-7

Abstract ( ) PDF in ScienceDirect

This research focuses on the impact of family’s human capital on social mobility in China’s rural community. Empirical research is conducted based on data from surveying a typical rural community in the past 20 yr. The study indicates that social mobility in rural area is active in the past 20 yr, and the human capital of family, represented by primary labor’s education level, has played an essential role in mobility of low social class. Meanwhile, socio-economic development and the change of supply and demand in labor market dims the signaling role of degree education, but the impact of occupational training is increasingly remarkable. Therefore, the change from sole degree education to multi-leveled education including occupational education and training is a main way for China’s rural families in low class to realize social mobility.

Archive

About JIA

Editorial board

For authors