EFECTOS DEL RODILLO AIREADOR Y EL FUEGO EN LAS PROPIEDADES FÍSICAS E HIDROLÓGICAS DEL SUELO EN MATORRALES DE COAHUILA, MÉXICO.

Since the XVI century, the Chihuahuan desert has been a grazing area. This area has ecological and economical significance for the country; however, overgrazing has caused changes in the physical and hydrological properties of the soil. These changes were evaluated on microphyllus desert scrublands (MDM) and rosette desert scrublands (MDR) in Coahuila, Mexico. The rehabilitation techniques were an aerator roller during 2004, 2008 and 2011, and natural fires. The hypothesis was that both techniques promote the increase of the soil's organic matter (MOS), water infiltration, and decrease soil compaction. A bifactorial experimental design was used which consisted of 10 treatments: 1) control (MDMt and MDRt); 2) aerator roller, applied in 2004 (MDMRA04 and MDRRA04); 3) 2008 (MDMRA08 and MDRRA08); 4) 2011 (MDMRA11 and MDRRA11); and, 5) burned area, 2011 (MDMIN11 and MDRIN11). The following variables were analyzed: useful water (AU), coefficient of permeability, electrical conductivity, apparent density, water infiltration on the soil, soil organic matter, soil reaction, mechanical resistance to penetration, and soil texture. Five treatments were applied on both types of vegetation, and the analysis of variance showed significant differences in all the variables, except for the AU percentage. The RA11 and IN11 treatments' MOS content doubled on both types of vegetation, with regard to the content observed on the control treatments. Permeability decreased by 5, 82, 45, 48, and 12 %, on the MDMRA04, MDMRA08, MDMRA11, MDRRA08, and MDRIN11 treatments, respectively, and increased by 6 and 2 % on the MDMIN11 and MDRRA04 treatments, in relation to control. During the first 3 years, the aerator roller increased MOS and decreased soil compaction. Therefore using the aerator roller is a periodic management option depending on the soil variables' state, in relation with its use. [ABSTRACT FROM AUTHOR]