The evaluation of soil properties under conservation tillage in amaize-wheat-soybean rotation on the Loess Plateau

The aim of this study was to determine how soil properties changed when conservation tillage was used in a maizewheatsoybean rotation on the Loess Plateau, China. The four tillage treatments were: t (conventional tillage), ts (conventional tillage with stubble retention), nt (no tillage) and nts (no tillage with stubble retention). Soil total C, organic C, total N and microbial biomass C and N in the 0-5 cm and the 5-10 cm layer was measured over a seven year period in each treatment. Soil organic C was significantly higher in the ts, nt and nts treatments, compared with that in the t treatment. Soil microbial biomass C and N in 0-5 cm layer was highest in the nts treatment among the treatment..Notill enhanced soil organic C accumulation in the top layer, tillage incorporated stubble distribution along the soil profile. The results showed that soil microbial biomass C was an indicator for short term run effects of conservation tillage, and soil organic C was an indicator for mid term run conservation tillage.