Introduction
Soil amendments aim to improve soil properties. This includes increase of the soil organic matter and of the nutrient pool,stimulation of beneficial microbial populations and/or suppression of pathogens and weeds. The desired outcome of all these
beneficial effects is the improvement of soil fertility and consequently of its productivity. Soil amendments are of particular importance inorganic farming; most often, they are composted organic materials of different origin.The biological process of composting is the most commonly used method for the fermentation of organic materials prior to their incorporation into the soil. The key element of this process is the production of a stable and mature end product suitable for use as soil amendment. In general, the composted organic material positively affects important soil features and processes, and has beneficial impacts on the environment surrounding agricultural systems (Hargreaves et al.,