The implementation of a cover crop, is a practice which allows farmers to protect the soil and introduce a supply of nutrients to it, enhancing soil structure and supporting life in the soil. In annual crops, the soil is kept covered throughout the whole year, either by crops (commercial or those planted with the sole purpose of keeping the soil covered) or by the residues of the harvest of the previous year, which is left scattered on the ground.


Living or inert cover provides a protective armor on the ground, acting as a protective layer which prevents the direct impact of rainfall against the bare surface. By blocking impact, physical erosion is avoided and therefore soil loss, one of the most pressing problems of agriculture in Mediterranean environments is prevented. In addition, ground cover provides a physical barrier to surface runoff on slopes. Thus, soil loss caused by the erosive effects of water flowing on the surface, which creates trails and gullies, is avoided.

The presence of cover on the soil surface also provides a screen, protecting against the harshness of direct sunlight, reducing heat stress on it. The result of this protective action includes decreased evaporation of water held in the soil, administering maintenance of moisture levels. This is particularly relevant in irrigated crops, especially those established in areas with a Mediterranean climate, assuming an important role in preserving water and hence proving to be financially beneficial for the farmer.

In addition to the protective functions on the ground, another benefit of the application of this practice is the supply of nutrients and biomass to the soil. The residues from the previous year’s harvest are broken down and absorbed by the micro organisms that inhabit the ground, causing a recirculation of nutrients as well as increased organic matter in the soil profile.

Finally, the disposal of crop residues on the soil surface and the implantation of cover crops, provide shelter and food for a variety of wildlife, ranging from microscopic creatures to communities of steppe birds. This not only increases the biodiversity of the agricultural system, but also favors self-regulation, preventing the appearance of pests and promoting sustainability.