氮肥对玉米籽粒发育的影响还未得到充分研究。microRNAs与mRNAs联合分析有助于加深我们对氮素调控玉米籽粒发育的理解。在本研究中，我们分析了不同施氮量（0 kg ha^-1、100 kg ha^-1，200 kg ha^-1和300 kg ha^-1）下玉米籽粒的形态、生理和转录组变化。结果表明，增加施氮显著增加了玉米籽粒的鲜重和干重，但施氮量超过200 kg ha^-1时，籽粒的鲜重和干重没有显著增加。总体来说，生长素、细胞分裂素和赤霉素的含量随着施氮量的增加而增加，而乙烯的含量降低。我们在激素合成和传导过程中获得了31个差异表达基因（DEGs），其中9个DEGs由14个差异表达microRNAs（DEMIs）调节，共形成26个表达对。本研究中候选的DEGs和DEMIs为不同施氮量下的玉米籽粒发育提供了有价值的见解。

全覆膜沟垄栽培技术促进降雨利用效率和玉米产量提高，已在黄土高原半干旱区大面积推广应用，然而，玉米高产出导致土壤养分和水分耗竭，从而影响该技术的可持续性，因此，有必要进一步对该技术进行优化，确保其可持续发展。本文综述了全覆膜沟垄栽培技术的发展、增产机制、负面影响、优化措施及其相互关系。我们提出以粮饲兼用玉米替代普通玉米，秋季覆膜或地膜冬留春揭，少免耕结合秸秆还田，轮作或间作冬季油菜(Brassica campestris L.)、谷子(Setaria italica)或胡麻(Linum usitatissimum L.)，氮肥减量，有机肥代替部分化肥，使用生物降解或耐候性薄膜以及机械化化生产。这些措施的整合有助于构建环境友好、优质和可持续的覆膜栽培技术体系，促进旱作农业高质量发展，为黄土高原半干旱区农业发展带来新的机遇。

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.

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.