Soil Respiration, Microbial Biomass and Nutrient Availability in Soil After Addition of Residues with Adjusted N and P Concentrations

作     者：Trung Ta NGUYEN Petra MARSCHNER 

作者机构：School of Agriculture Food and Wine The University of Adelaide Adelaide 5005 (Australia) 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2017年第27卷第1期

页      面：76-85页

核心收录：

学科分类：07[理学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学] 090301[农学-土壤学] 

基　　金：supported by the Australian Research Council 

主　　题：C/N ratio C/P ratio microbial activity nutrient immobilisation nutrient mineralisation 

摘      要：Microbial activity and nutrient release are known to be influenced by organic matter properties,but it is difficult to separate the effect of C/N ratio from that of C/P ratio because in most plant residues both ratios are either high or *** incubation experiment was conducted to investigate the effects of reducing the C/N and C/P ratios of slowly decomposable plant residues(young eucalyptus leaves,mature wheat straw,and sawdust) to those of rapidly decomposable residues(young kikuyu shoots) on soil respiration,microbial biomass,and N and P *** C/N and C/P ratios of the former were adjusted to 15 and 89,respectively,by adding N as(NH_4)_2SO_4,P as KH_2PO_4 or both and residues were added at 10 g C kg-1 to a silt *** respiration was measured over21 d;microbial biomass C(MBC) and available N and P were measured on days 0,7,and *** to the unamended soil,addition of kikuyu increased cumulative respiration 20-fold,MBC concentration 4 to 8-fold,and available P concentration up to4-fold,whereas the increase in available N concentration was small and *** respiration and MBC concentration were low in the sawdust-amended soil and were not influenced by reducing the C/N and C/P *** respiration with original wheat and eucalyptus was 30%-40%of that with *** the C/N ratio alone or both C/N and C/P ratios increased cumulative respiration and MBC concentration 2-fold compared to the original wheat and eucalyptus,whereas reducing the C/P ratio had little *** the experiment,the available N concentration after addition of residues with reduced C/N ratio increased in the following order of eucalyptus wheat *** independently lowering the C/N and C/P ratios,microbial activity was more limited by C and N than ***,lowering the C/N ratio of very slowly decomposable sawdust had no effect on soil respiration and MBC concentration,suggesting that other properties such as concentration of poor