论文部分内容阅读
Ecological stoichiometry provides the possibility for linking microbial dynamics with soil carbon (C),nitrogen (N),and phosphorus (P) metabolisms in response to agricultural nutrient management.To determine the roles of fertilization and residue ret with respect to ecological stoichiometry,we collected soil samples from a 30-year field experiment on residue ret (maize straw) at rates of 0,2.5,and 5.0 Mg ha-1 in combination with 8 fertilization treatments:no fertilizer (F0),N fertilizer,P fertilizer,potassium (K) fertilizer,N and P (NP) fertilizers,N and K (NK) fertilizers,P and K (PK) fertilizers,and N,P,and K (NPK) fertilizers.We measured soil organic C (SOC),total N and P,microbial biomass C,N,and P,water-soluble organic C and N,KMnO4-oxidizable C (KMnO4-C),and carbon management index (CMI).Compared with the control (F0 treatment without residue ret),fertilization and residue ret significantly increased the KMnO4-C content and CMI.Furthermore,compared with the control,residue ret significantly increased the SOC content.Moreover,the NPK treatment with residue ret at 5.0 Mg ha-1 significantly enhanced the C∶N,C∶P,and N∶P ratios in the soil,whereas it significantly decreased the C:N and C:P ratios in soil microbial biomass.Therefore,NPK fertilizer application combined with residue ret at 5.0 Mg ha-1 could enhance the SOC content through the stoichiometric plasticity of microorganisms.Residue ret and fertilization increased the soil C pools by directly modifying the microbial stoichiometry of the biomass that was C limited.