Soil Carbon and Nitrogen Transformations under Soybean as Influenced by Organic Farming

作者：Xiaoming Tian, Hua Fan, Foyi Zhang, Kecheng Wang, James A. Ippolito, Junhua Li, Zenghai Jiao, Yinan Li, Yingying Li, Jianping Su, W.T. Li, Maweu AN · 发表于：Agronomy Journal · 年份：2018 · DOI：10.2134/agronj2017.12.0687 · 被引用次数：10 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil Management and Crop Yield、Legume Nitrogen Fixing Symbiosis

Organic farming significantly increased or improved many soil properties, including the mean weight diameter of aggregates, soil organic matter, available N, soil microbial diversity, and soil C and N transformation rates. Soybean yield was also 13.7 % greater in the organic farming treatment than in conventional farming treatment. Organic farming increased soil Cu and Ni; however, their concentrations were still less than the allowable limits for organic production. Organic farming with composted manure application improved soil properties and altered the structure and function of the microbial community. The <0.25‐mm aggregate fraction had a major influence on microbially mediated C and N transformations and soybean yield. Organic farmers use natural inputs and ecological principles to produce crops in ways that protect soil, the environment, and human health. The objectives of this study were to determine (i) how organic farming with composted manure application affects soil properties under soybean and (ii) how soil C and N transformations in this system are related to soil microbial community structure, soil nutrient and heavy metal content, and soybean yield and quality. The results showed that three years of organic farming promoted soil aggregation and significantly increased aggregate associated C and N concentrations by 11.7 to 24.1% and 9.4 to 17.0%, respectively. Microbial biomass and species diversity (i.e., Shannon, Simpson, and Pielou indexes) were significa...