Effect of crop rotation, fertilization and tillage on mail soil properties and its water extractable organic matter

The excessive use of fertilizers and frequent and deep tillage are not considered good agricultural practices since they increase the production costs and reduce soil fertility. Water extractable organic matter (WEOM) is the fraction of soil organic matter responsible for nutrients transport and bioavailability. The aim of this work was to investigate the effect of a 2-year rotation of faba bean–wheat, cultivated for a decade, and the agricultural practices (conventional vs. no tillage, fertilization vs. no fertilization) on selected soil parameters and WEOM quality. Results showed that the soil organic carbon (SOC) and the total nitrogen (TN) content increased after the wheat and the faba bean, respectively. Plots managed with conventional tillage showed WEOM with higher OC content with respect to no tillage plots. A higher WEOM OC content was observed also in the fertilized plots. The WEOM of fertilized and faba bean plots derived from the decomposition of the native SOC, while the microbial community decomposition was the main origin of WEOM after wheat.