| The effects of different fertilization on soil microbial biomass C,N,P and maize yield in light sierozem were investigated with a field experiment,which was continued for 4 years at Hongsibu irrigated area of Ningxia.The results showed that the fertilization treatments significantly increased the contents of microbial biomass C,N and P compared with control,but there were significant differences among different treatments.The best effect was found in the treatment of chemical fertilizers + sheep manure,the second was sheep manure,and the lowest was chemical fertilizers.Fertilization significantly increased maize yield in the following order: NP + sheep manure >NPZnK>NPZn>NP>N>sheep manure>control.There were significant differences between NP + sheep manure and N or sheep manure. The compound application of chemical fertilizers and sheep manure not only increased the contents of microbial biomass C,N and P but also raised the yield of maize,therefore,it was the best fertilization measure in the newly cultivated light sierozem.Significant positive correlation was found between soil microbial biomass C and organic C as well as total N,so soil microbial biomass C could be regarded as a biological indication to identify the quality change of newly cultivated soil. |