小叶锦鸡儿根瘤固氮活性的动态变化

对多年生小叶锦鸡儿不同生育期根瘤固氮能力、不同树龄小叶锦鸡儿根瘤固氮能力进行调查,结果表明:开花期固氮酶活性最高,此时土壤含氮量和植株含氮量最高;新瘤多发生于果后营养期,植株生物量的峰值出现在结实期;二年生和五年生植株的根瘤固氮能力强于三年、四年生植株,随生长年限的延长,植株生物量逐渐增大,含氮量呈小幅度下降趋势。

The Dynamics of Nitrogen Fixtion Ability to Root Nodule of Caragana microphylla Lam

The nitrogen fixation ability of root nodule is investigated at different development stage of Caragana microphylla Lam. and at different age of tree. The results were as follows: during plant development, the peak values of nitrogenase activity appeared in blooming stage. At this moment, nodule fresh weight was the most, plant N and soil N were the highest. And it is obviously higher than other stages; the peak values of plant biomass appeared in Fruit Bearing Stage; The nitrogen fixing ability of root nodule of biennial plant and 5-yr-old plant were stronger than triennial plant and 4-yr-old plant. Plant biomass had a trend to increase with growing age, but plant N had a little decreasing trend.