很久以来人们就十分重视氮素在植物营养中的重要作用。为保证高产稳产农田对氮素的需要,在积极利用生物氮源,建立高水平、高功效的氮素循环体系方面,国内外都积累了许多经验。一、生物氮在现代化农业中的意义农田生态系中氮素来源有两个途径,非生物途径主要是化肥工业——氮肥;生物途径是微生物的固氮作用;其他如厩肥,高杆还团的氮素主 For a long time people attach great importance to the important role of nitrogen in plant nutrition. In order to ensure the nitrogen demand of farmland with high and stable yield, many experiences have been accumulated both at home and abroad with regard to the active utilization of biological nitrogen sources and the establishment of high-level and highly-efficient nitrogen circulation systems. First, the significance of biological nitrogen in modern agriculture Farmland ecosystem sources of nitrogen in two ways, the main biological pathways are non-biological fertilizer industry - nitrogenous fertilizer; biological pathway is the nitrogen fixation of microorganisms; other such as manure, Main nitrogen