We used paddy soil to examine the effects of an increased nutrientsupply on CO2emissions and microbial biomass over a 60-day in-cubation. We hypothesized that 1) microbes in paddy soils that receivelow nutrient input would have a positive PE because they would beforced to acquire the required N, P, K, Ca, and S through SOM de-composition and would, therefore, increase soil CO2emissions, and 2)microbes in paddy soils that receive high nutrient input would have anegative PE because the microorganisms would switch from decom-posing SOM to utilizing the available nutrients (N, P, K, Ca, and S) tomeet their demand. Hence, soil CO2emissions would be reduced.