Macroscopic Features of Nitrogen Transformation and Cycling in the Agroecosystem in China and It‘s Implications to Ecological Agriculture Characteristics of ammonia volatilization and nitrous oxide emission of different fermentation beds in pig pens Biological factors influencing nitrogen transformation in wheat fields of lime concreted black soils and their response to different nitrogen supplications Effect of biochar on nitrogen forms and related microorganisms of rhizosphere soil of seedling maize Effects of transgenic BADH soybean on nitrogen transformation in saline-alkaline soil