小叶锦鸡儿根瘤固氮活性的动态变化

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

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 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.