山西土著花生根瘤菌的数量分布及其共生结瘤固氮特性

在山西土壤气候条件下，土著花生根瘤菌数量变化范围在每克土壤５０～１５０００个之间，其生态分布褐土高于潮土，晋南多于晋中、晋北。主栽花生品种的自然结瘤率达７６０％，单株结瘤量为２０９±１４７个，日固氮量０３８～１２２ｍｇ，每公顷固氮１０～３０ｋｇ。单株固氮总活性与单瘤固氮比活性的高峰出现有所不同，前者在荚果期，后者在盛花期。土著根瘤菌的固氮强度与结瘤量无相关性，覆膜栽培与增施磷肥均具有良好的共生固氮生态效应。

Quantitative Distribution of Native Peanut Rhizobia and Their Symbiotic Nodulation and Nitrogen Fixation Characteristics in Shanxi Province

Under soil and climatic conditions of Shanxi province, the soil contained 50～15 000 cell of indigenous peanut rhizobium per gram. The quantitative distribution of indigenous strains in cinnamon soil and the south of Shanxi province was more than the meadow soil and the middle and northern part. The field nodulation rate of the main peanut cultivars reached 76.0%. The number of nodules per plant was 20.9±14.7. The amout of N 2-fixation was 0.38～1.22mg/day and about 10～30kg/hm 2. The peak-peried of the total activity of N 2-fixation per plant appeared at the poding stage and the peak of the N 2-fixation activity per nodule appeared at blooming stage, the N 2-fixation capacity of indigenous population is not correlative with the number of nodules. There is a better ecological efficiency of symbiotic N 2-fixation by film mulching and application of phosphorus fertilizers.