[Characteristics of soil fertility during soil fertilization from parent material of a Mollisol in Northeast China].

Based on a long-term field experiment located in the central region of Mollisol in Northeast China, we examined the changes of soil fertility and nutrient supply capacity of the newly-formed soils with pot experiment after 14-year different agricultural management practices from parent material (PM) (down to 2.0-3.0 m depth) of a Mollisol, and finally tried to optimize pre-ferential agricultural practices improving soil fertility of seriously eroded PM. After 14-year different agricultural practices, soil organic carbon, total nitrogen, stability of soil aggregate and other rela-ted soil nutrient contents improved compared with PM. Soil fertility level of the newly-developed soils significantly affected nutrient supply capacity for wheat in the pot experiment. Results from principal component analysis showed that soil fertility developed toward to the surface Mollisol after 14 years of different agricultural practices from PM. Surface soils with higher organic carbon inputs in arable soil with chemical fertilizer plus all aboveground biomass incorporated and those in no-tilled alfalfa soil were much approached to surface Mollisol, followed by arable soil with fixed amount of organic inputs and natural fallow soil, while soils without and with only chemical fertilizer were much closed to PM. Our results indicated that 14-year organic carbon inputs improved soil aggregate structure and the decomposition of organic carbon entering into soil, changed soil physical and biochemical properties, and hence caused maturing of soil fertility of PM. Straw returning, organic manure application, and planting alfalfa were recommended for improving soil fertility of eroded soil. These findings would give a better scientific basis for high-efficient fertilization and management practices in eroded Mollisol region.