水稻田中氮素化合物的来源,主要可分以下几个途径:(一)在大工厂的合成塔中生产工业氮肥;(二)将农付产品等废弃物和人畜粪便中的氮素归还田地;(三)在田地里生产生物氮肥,其中又可分为在輪作制中安排生产生物氮肥,以及在水稻栽培的同时同地进行生物氮肥的生产;(四)由灌溉水和降雨带入的少 The sources of nitrogen compounds in paddy fields can be divided into the following ways: (1) Production of industrial nitrogen fertilizers in the synthesis towers of large factories; (2) Return of agricultural products and other wastes and return of farmland manure to the fields; (Iii) Production of biological nitrogenous fertilizers in the fields, which can be divided into the production of biological nitrogenous fertilizers in the rotation system and the production of biological nitrogenous fertilizers at the same time as rice cultivation; (iv)