Erosión y desertificación.-Impacto en el medio ambiente del cultivo de almendros en fuertes pendientes con dos cubiertas vegetales: Matorral y Leguminosa.

Abstract

ABSTRACT

Soil erosion is one of the main physical processes of land degradation in Spain. Several studies in the Mediterranean environment have demonstrated the positive effect of vegetation covers on the reduction of water erosion and their indirect improvement of the soil physical and chemical properties, essentially by the incorporation of organic matter.

Soil loss and surface runoff patterns over a four-year period were monitored in erosion plots from hillslope with two different cover-crop strips: (1) non-tillage with leguminous (Lens esculenta Moench) and (2) non-tillage with and a mixture of autochthonous thymes (Thymus baeticus Boiss. ex Lacaita, Thymus capitatus (L.) Hoffmanns & Link.,Thymus vulgaris L.) of 3 m width, in Lanjarón (Granada) on the south flank of the Sierra Nevada of southeast Spain. The erosion plots were located on the hillslope at 35% incline, at 580 m in altitude and with 144 m2 (24 m x 6 m) in area. The area selected for the experiment is the part of the rainfed orchard given entirely with almond (Prunus amygdalus Basch cv. Desmayo Largueta) trees, the planting grid were 6 x 7 m.

The cover-crop strips were tested in order to provide information on the erosional response. In the leguminous strips, runoff ranged from 51.5 to 29.5 mm yr-1 and erosion from 7.4 to 1.5 Mg ha-1 yr-1, while under thymes strips, runoff ranged from 7.8 to 1.4 mm yr-1 and erosion from 1.0 to 0.1 Mg ha-1 yr-1. According to the results the strips of thymes reduced the runoff and soil losses with respect to the Lens esculenta. Thus, cultivation of medicinal and aromatic shrub (medicinal, aromatic, culinary and mellipherous), on the slopes of almond orchard can provide a positive impact on the environment while representing an extraincome for local farmers.