Effects of cultivation management on soil chemical and biological fertility

The aim of this work was to evaluate the effect of 10 years of different cultivation managements (woody or vegetable crops) on chemical and biological soil fertility. The presence of perennial crop had a positive effect on soil chemical and biological fertility, as stressed by the increase of OM, K, Mg, Mn, microbial biomass and by the decrease of pH with a potential positive effect on ion availability. The cultivation of woody species has reduced NO3 --N and simultaneously increased NH4+-N which can be fixed in soil, absorbed and used by plants less expensively. Considering that organic farming guidelines recommend to invest at least 5% of the farm surface in natural areas (i.e. wood, edges), a long-term rotation including woody species may be a tool to increase soil fertility