Changes in Soil Enzyme Activity By No-Tillage and Conventional-Tillage Practice Activities in the Cultivation of Soybean in Upland Soil.

Land treatments affect nutrient cycling, fertility, and other chemical, microbiological, and biochemical processes in soils. Soil enzymes have been suggested as potential indicators of soil quality because of their relationship to soil biology, ease of measurement, and rapid response to changes in soil management. This study has been carried out to determine the effects of conventional tillage and no-tillage on soil enzyme activities in the cultivation of soybean in the sandy loam soils in Cheongju, Republic of Korea that is located in the temperate climate zone. In this study we investigated the activities of three enzymes (Cellulase, Dehydrogenase and Urease) and the soil microbial biomass C by No-tillage (NT) and Conventional-tillage (CT) practice from March to September in 2015. The activities of cellulase, dehydrogenase and urease were significantly (P < 0.05) higher at no-tillage (NT) compared to conventional tillage (CT) practices. The cellulase activities in the soil were correlated with soil microbial biomass C. Organic matter contents seemed to affect the soil enzyme activities. Dehydrogenase activities were 38.2% higher in NT than in CT and were directly proportional to soil temperature. Dehydrogenase activities were significantly (P < 0.05) correlated with the soil microbial biomass C. Urease activities were high after application of fertilizer and its activities were 22.5% higher in NT than in CT. The study results appeared that the disturbances by tillage practice induced the changes in soil properties, which affected soil microbial activities.