氮磷肥对黑土玉米农田生态系统土壤微生物量碳、氮的影响

通过田间氮磷肥配施试验研究了氮磷配施对黑土玉米农田生态系统玉米不同生育时期微生物量碳、氮的影响。微生物量随玉米不同生育期的动态变化表明,氮磷肥对微生物量碳和微生物量氮的动态影响并不同步,微生物量碳和微生物量氮变化最显著的时期均是授粉期,但此时微生物量碳是最低的谷值,而微生物量氮是最高的峰值。不同氮磷配比对微生物量碳影响的回归分析表明,氮肥是影响微生物量碳的主导因素,无论是适量施用还是过量施用都是氮肥对微生物量碳的影响较大。不同氮磷配比对微生物量氮影响的回归分析表明,过量氮肥的施用减少了土壤微生物量氮的含量。磷肥无论高量和低量均能增加微生物量氮的含量,但随着施用量的增加对微生物量氮的正效应减小。氮磷配合施用可增加土壤的微生物量氮,由此可见无论单施氮肥还是单施磷肥,过量施用对微生物量氮的增加都是不利的,只有氮磷配合施用才是增加土壤微生物量氮的有效途径。

Effect of Fertilizing N and P on Soil Microbial Biomass Carbon and Nitrogen of Black Soil Corn Agroecosystem

A field experiment was conducted to study the effects by match fertilizer N and P on microbial biomass C and N of black soil agroecosystem. The result of the variation of microbial biomass in different growth periods shows that the effects of fertilizer N and P on microbial biomass C is not same as on microbial biomass N, incubation period is the most obviously varied period of microbial biomass C and N, the microbial biomass C is at its lowest but microbial biomass N is at its highest.The regression analysis indicated that fertilizer N is the main factor in affecting the microbial biomass C, It showed that the excessive use of fertilizer N decrease the content of microbial biomass N, and fertilizer P can increase the content of microbial biomass N though it was applied property or excessive, the effect decrease follow the increase of use the fertilizer P. The match of fertilize N and P can increase the microbial biomass N, so we can say that it is not a effective way in increase the quantity of microbial biomass N by applying fertilizer N or fertilizer P singly, the effective way to increase soil microbial biomass N is by match applying of N and P