Soil organic matter pools under different system management and tillage level in a three-year crop rotation

The agricultural management and practices can strongly influence the soil organic C processes. Aims of this work have been: i) to detect changes in terms of amount and quality of both labile C pools and microbial biomass in response to man, agement (organic and conventional) and tillage (conventional and minimum); ii) to verify if these changes caused variations in the soil capacity to store organic C. Organic management resulted mainly to affect the labile C pools of soil organic matter, increasing both Soluble and living fractions, and without influencing total organic C. A 4 year period of organic management was not enough to stabilize C compounds. The deep tillage generated a strong soil disturbance reducing both microbial biomass C and N, and inducing a net loss of organic matter.