不同有机碳源对施入土壤中不同形态氮素固持的影响

Effects of Different Organic Carbons on Nitrate and Ammonium Immobilization by Soil Microbial Biomass in Soil

利用培养试验研究了供应不同有机碳源(小麦秸秆及葡萄糖)对施入土壤的不同形态氮素(铵态氮及硝态氮)转化的影响。结果表明,以难分解的小麦秸秆为碳源时,培养期间土壤微生物对施入的不同形态氮素的固持率较低,且微生物对铵态氮的固持率高于硝态氮。而以易降解的葡萄糖为碳源,土壤微生物对施入的不同形态外源氮的固持率较高,且对这两种形态氮素的固定能力几乎相当。如何采用施入不同性质的有机碳源来调节土壤氮素的固持与释放,以达到协调氮素供应,减少氮素损失,是值得研究的问题。

An incubation experiment was used to study the effects of supplying different organic carbon sources （wheat straw and glucose） on transformation of different forms of nitrogen （NH4^＋-N and NO3^--N） in soil. Results showed that when wheat straw, which was difficult to decompose, was used as organic carbon source, the nitrogen immobilized by soil microbial biomass was lower compared with using glucose as organic carbon; and the immobilization of ammonium by microbial biomass was much higher than that of nitrate. When glucose was supplied as energy source, the immobilization of the two forms of nitrogen, ammonium and nitrate, was significantly increased; and there were no significant differences in nitrogen immobilization for the two forms of nitrogen. It needs to study the effects of different organic carbon sources in adjusting the nitrogen immobilization and release in soil to control nitrogen supply, and reduce its losses.