Effects of the application of pig slurry on some physico-chemical and physical properties of calcareous soils

The effects of adding pig slurry to two calcareous soils containing different levels and types of clay were studied over a period of two years. Doses up to 1000 m3 ha−1 year−1 were used and the evolution of some physico-chemical (cationic exchange capacity and pH) and physical (porosity and water holding capacity) properties was studied. The exchange capacity increased as more slurry was added when the soil had a low clay content, giving rise to a good correlation between the values for organic carbon and exchange capacity. In soils of a higher clay content, the increase in exchange capacity was not so significant. pH decreased with the addition of slurries, possibly due to the liberation of exchangeable ammonium and its subsequent nitrification.Peer reviewe