The effect of nitrogen (N) fertilizer on the development of maize kernels has yet to be fully explored.  MicroRNA-mRNA analyses could help advance our understanding of how kernels respond to N.  This study analyzed the morphological, physiological, and transcriptomic changes in maize kernels under different N rates (0, 100, 200, and 300 kg ha^–1).  The result showed that increasing N application significantly increased maize grains’ fresh and dry weight until N reached 200 kg ha^–1.  Higher levels of indole-3-acetic acid, cytokinin, gibberellin, and a lower level of ethylene were associated with increased N applications.  We obtained 31 differentially expressed genes (DEGs) in hormone synthesis and transduction, and 9 DEGs were regulated by 14 differentially expressed microRNAs (DEMIs) in 26 pairs.  The candidate DEGs and DEMIs provide valuable insight for manipulating grain filling under different N rates.

The fully mulched ridge–furrow (FMRF) system has been widely used on the semi-arid Loess Plateau of China due to its high maize (Zea mays L.) productivity and rainfall use efficiency.  However, high outputs under this system led to a depletion of soil moisture and soil nutrients, which reduces its sustainability in the long run.  Therefore, it is necessary to optimize the system for the sustainable development of agriculture.  The development, yield-increasing mechanisms, negative impacts, optimization, and their relations in the FMRF system are reviewed in this paper.  We suggest using grain and forage maize varieties instead of regular maize; mulching plastic film in autumn or leaving the mulch after maize harvesting until the next spring, and then removing the old film and mulching new film; combining reduced/no-tillage with straw return; utilizing crop rotation or intercropping with winter canola (Brassica campestris L.), millet (Setaria italica), or oilseed flax (Linum usitatissimum L.); reducing nitrogen fertilizer and partially replacing chemical fertilizer with organic fertilizer; using biodegradable or weather-resistant film; and implementing mechanized production.  These integrations help to establish an environmentally friendly, high quality, and sustainable agricultural system, promote high-quality development of dryland farming, and create new opportunities for agricultural development in the semi-arid Loess Plateau.

The MADS-box (DAM) gene PpDAM6, which is related to dormancy, plays a key role in bud endodormancy release, and the expression of PpDAM6 decreases during endodormancy release.  However, the interaction network that governs its regulation of the endodormancy release of flower buds in peach remains unclear.  In this study, we used yeast two-hybrid (Y2H) assays to identify a mitogen-activated protein kinase, PpMAPK6, that interacts with PpDAM6 in a peach dormancy-associated SSHcDNA library.  PpMAPK6 is primarily located in the nucleus, and Y2H and bimolecular fluorescence complementation (BiFC) assays verified that PpMAPK6 interacts with PpDAM6 by binding to the MADS-box domain of PpDAM6.  Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of PpMAPK6 was opposite that of PpDAM6 in the endodormancy release of three cultivars with different chilling requirements (Prunus persica ‘Chunjie’, Prunus persica var. nectarina ‘Zhongyou 5’, Prunus persica ‘Qingzhou peach’).  In addition, abscisic acid (ABA) inhibited the expression of PpMAPK6 and promoted the expression of PpDAM6 in flower buds.  The results indicated that PpMAPK6 might phosphorylate PpDAM6 to accelerate its degradation by interacting with PpDAM6.  The expression of PpMAPK6 increased with decreasing ABA content during endodormancy release in peach flower buds, which in turn decreased the expression of PpDAM6 and promoted endodormancy release.

    Molybdenum (Mo) is an essential trace element in plant nutrition and physiology. It affects photosynthesis and photosynthate accumulation, therefore also affecting fruit quality and nutritional content. This study assessed the effects of different sodium molybdate (Na₂MoO₄) concentrations on strawberry. Five different Mo concentrations were applied in this experiment, including 0, 67.5, 135, 168.75, 202.5 g ha^–1, respectively. The mineral concentration, including nitrogen (N), Mo, iron (Fe), copper (Cu), and selenium (Se) was assessed in strawberry fruit, as well as chlorophyll content, nutrition quality, taste and aroma. Results showed that net photosynthetic rate (P_n) and chlorophyll content for the strawberry plants increased with an increase in Mo concentration; and the contents of N, Mo, Fe, Cu, total soluble solids (TSS), titratable acidity (TA), sweetness, some sugars, organic acids, and some volatile compounds in the fruit all increased, as well. However, the Mo concentration did not significantly affect the concentrations of Se, sucrose, lactic acid, acetic acid, and some aroma compounds. Fruit sprayed with 135 g ha^–1 Mo exhibited the highest TSS and sweetness values, as well as the highest N and Fe concentrations among all the treatments. Pn value and chlorophyll content, fructose, glucose, sorbitol and total sugar contents in fruit supplied with 135 g ha^–1 Mo were also higher than that in other treatments. Fruit sprayed with a Mo concentration of 67.5 g ha^–1 exhibited significantly higher ascorbic acid (AsA) values than that of control. Ninety-seven volatile compounds were identified in fruit extracted by head-space solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Fruits sprayed with 135 g ha^–1 Mo had the highest concentrations of six characteristic aroma compounds, including methyl butanoate, γ-decalactone, ethyl butanoate, methyl hexanoate, γ-dodecalactone, and ethyl caproate.

Keng stiffgrass is a grass weed that affects wheat-rice cropping systems in China.  The extensive reliance on acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides has resulted in keng stiffgrass developing resistance to these herbicides.  The objective of this research was to evaluate the resistance level of the putative resistant keng stiffgrass populations to ACCase-inhibiting herbicides and to identify their molecular resistance mechanism.  Whole-plant dose-response experiments demonstrated that SD-4 (R), SD-11 (R), and JS-25 (R) populations were highly resistant to fenoxaprop, clodinafop, and fluazifop, moderately resistant to diclofop, had low resistance to sethoxydim and pinoxaden, but were sensitive to clethodim.  Partial chloroplastic ACCase sequences showed that there were two copies of ACCase gene in keng stiffgrass, and all homoeologous genes were expressed.  The results of sequence analyses of the ACCase CT domain revealed an isoleucine-to-asparagine substitution at position 2041 in SD-4 (R) and SD-11 (R) populations, and a tryptophan-to-cysteine substitution at position 2027 in the JS-25 (R) population.  To our knowledge, this is the first report of Ile-2041-Asn and Trp-2027-Cys mutations in ACCase-resistant keng stiffgrass.  In addition, three robust (derived) cleaved amplified polymorphic sequence ((d)CAPS) markers have been developed to rapidly identify these mutations in the ACCase gene of keng stiffgrass.

Laboratory aerobic incubation was conducted for 161 d to study N mineralization and the changes of organic N fractions of nine different manures (3 chicken manures, 3 pig manures and 3 cattle manures) from different farms/locations. Results indicated that significant (P<0.01 or P<0.001) difference existed in N mineralization between manures. The rapid N mineralization in manures occurred during 56 to 84 d of incubation. First order exponential model can be used to describe N mineralization from chicken manures and pig manures, while quadratic equation can predict mineralization of organic N from cattle manures. An average of 21, 19 and 13% added organic N from chicken manure, pig manure and cattle manure was mineralized during 161 d of incubation. Amino acid-N was the main source of N mineralization. The changes of amino acid-N together with ammonium N could explain significantly 97 and 96% of the variation in mineralized N from manured soils and manures. Amino acid-N and ammonium N are two main N fractions in determining N mineralization potential from manures. Amino acid-N contributed more to the mineralized N than ammonium N.

High temperature stress (HT) is efficient in breaking endo-dormancy of perennial trees. The effects of HT (50°C) on the respiration of dormant nectarine (Prunus persica var. nectariana cv. Shuguang) vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway (PPP) and the cytochrome C pathway (CYT) were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle (TCA) in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway (ALT) fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.

Shuguang (Prunus persica var. nectariana cv. Shuguang) nectarine was used to study effects of photoperiod on keyenzymeactivities of respiration during dormancy induction. The dormancy status was determined with sprouting ability.Spectrophotometry was used to investigate activities of phosphohexose isomerase (PGI), malic dehydrogenase (MDH),and glucose-6-phosphate dehydrogenase (G6PDH). The results revealed that short day (SD) treatment promoted dormancyinduction while long day (LD) treatment postponed the process. During dormancy induction, PGI activities declined,MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDHactivities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LDtreatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with thedevelopment of dormancy induction.

Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture (CA) is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world’s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.

Characteristics of dormancy induction and alternative respiration pathway (also known as cyanide-resistant respiration) of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate (Vt) in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity (Valt) and activity (ρValt) of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Valt and ρValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of alternative respiration pathway in total respiration rate (ρValt/Vt). The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.