[Seasonal variations of soil microbial biomass, respiration rate and CH4 emission in black earth rice fields].

The measurements of soil microbial biomass C,respiration rate and CH 4 emissions during one rice growth period in black earth rice fields showed that the soil microbial biomass C and respiration rate were depressed significantly by the application of slow releasing urea at the early stage of rice growth period (P0.05),but almost not affected by intermittent irrigation.The CH 4 emission was decreased by 32.5% in the intermittent irrigation treatments,but not significantly affected by the application of slow releasing urea,compared to the control.It was significantly related to soil microbial biomass C in slow releasing urea treatments.