豆科作物摄取空中氮素的能力早已为人所知,但豆科作物究竟能从空气中固定多少氮这个问题至今仍研究得不够。以往有关固氮数量的概念,主要是建立在室内试验的基础上,在生产上不可无条件地推广。鉴于大面积种植豆科作物,农业生产的广泛化学化,以及测定方法的多样性, The ability of leguminous crops to ingest nitrogen in the air has long been known, but the question of how much leguminous crops can fix nitrogen in air is still not well studied. In the past, the concept of the amount of nitrogen fixation was mainly based on laboratory tests and was unconditionally promoted in production. In view of the widespread chemicalization of leguminous crops for agricultural production and the diversity of methods of measurement,