【摘要】 在山西土壤气候条件下，大豆主栽品种自然结瘤率达９４．６％，单株结瘤量为３７．１±１５．２个，日固氮量０．４４～１，５６ｍｇ，每公顷约固氮３０ｋｇ。单株固氮总活性高峰期随品种和栽培条件的不同有所变化，而单瘤固氮活性的高峰均在花期。土著根瘤茵的固氮强度与结瘤量无相关性，固氮量与单瘤固氮酶活则成显著正相关（ｒ＝０．７１Ｐ＜０．０５）。覆膜栽培和秸秆还田均具有良好的共生固氮生态效应。更多还原

【Abstract】 Under soil and climatic conditions of shanxi province,the field nodulation rate of themain soybean cultivars reached 94.6%,The number of nodules per plant was 37.1±15.2the amount of N₂-fixation was 0.44～1.56mg/day and about 30kg/hectare. Thepeak-peried of the total cativity of N₂-fixation per plant was varied with the differentsoybean cultivars and the various cultural conditions,but the peak of the N₂-fixation activi-ty per nodule appeatal at thc blooming stage。The N2一Flxatio n capacity is not correlativewith the number of nodules but the amount of N₂-fixation is obviously correlative with thenitrogenase activity of per nodule（=0.71 p <0.05）.There is a better ecological efficency ofsymibiotic N₂-fixation by rilm mulching and com stalks returened to the field.更多还原