Livestock production leads to valuable outputs of organic resources (manure, slurry, wastewater, etc) that could be used to supply nutrients and avoid soil organic matter depletion in agricultural soils. Nevertheless, it is not always possible to link the excess of organic matter in animal waste to the demand of soil nutrients that exists in agricultural soils. This is also the case in the Basque Country (north of Spain). This province has a Mediterranean climate, although with the influence of the Atlantic area where the region is located.