This study compared the responses of soil chemical and microbial indicators to the conservational tillage (CT) versus traditional tillage (TT) in a Haplic Cambisol in the North China Plain (NCP). These indicators included soil organic C (SOC), soil total N (STN), soil available P (SAP), cation exchange capacity (CEC), exchangeable Ca 2+ and Mg 2+, microbial biomass C (MBC), microbial biomass N (MBN), alkaline phosphomonoesterase (AP), beta-glucosidase, N-acetyl-beta-glucosaminidase (NAG), nitrate reductase (NR), protease, urease and the geometric mean of the assayed enzymes (GMea). Our results showed that almost all investigated parameters, except the contents of CEC, Ca 2+, Mg 2+ and the ratios of GMea/MBN and C/N, were significantly higher under the CT (no-till, NT and reduced-till, RT) than those under the TT, whilst the crop yield was not significantly affected by tillage treatments. Principle component analysis (PCA) showed that the first and second component explained 67.2% and 16.6% of the total variation, respectively. The first component was significantly correlated with GMea, MBC, MBN and beta-glucosidase, and effectively discriminated soils under the NT or RT from those under the TT. Our results indicated that the 6-year CT improved the quality of the Haplic Cambisol by enhancing its chemical and microbial properties, whilst GMea, MBC, MBN and beta-glucosidase were among the most effective indicators for monitoring these improvements.
