Annual Research & Review in Biology

The aim of this study was to evaluate the initial salinity and the type and amount of salt evacuated from soils of palomas, san luispotosí in a leaching process. These soils present primary and secondary salinization problems, induced by irrigation which affects their productive capacity. The study was conducted in a greenhouse and in the soils laboratory of the graduate college, from april to august 2010. Leaching of salts was done in soil columns that were applied with three soil-water extraction ratios, namely, 1≈0.2-0.6, 1:5 and 1:10, and the normal rates of leaching Q_a/Q_π =0 ,1.5 AND 3.0, where: q_a is the volume of water at which a soil reaches its saturation capacity, plus another equal volume, and so on. Qπ is the volume of water needed to make the soil reach its saturation capacity. This rate corresponds to volumes of water applied under field conditions of 1971.72 m³ ha^-1, 2,957.58m³ ha^-1, and 5915.16m³ ha-1, respectively. The initial salinity of each ratio was 69.03 mgha^-1, 153.59mg ha^-1 and 201.37mg ha^-1. The higher extraction ratio and rate of leaching applied, the higher the amount of soluble salts leached, and the lower the average residual salinity of 0-50 cm soil layer. At zero leaching level no leachate was obtained. The extraction ratio 1:10 and the rate of leaching g Q_a/Q_π =3.0, was significantly (p=0.05) outstanding. Under these conditions appreciable amount of salts were leached off the topsoil, especially nacl and na₂so₄ . The residual salinity of the 30 cm soil layer was 1.68 g salt 100 g^-1 of soil (109.48 mg ha^-1). This indicates desalination.