EFFECT OF TWO TILLAGE SYSTEMS ON STRUCTURAL SOIL PROPERTIES AND GRAIN YIELD OF DRY BEANS UNDER RAINFED CONDITIONS IN NORTH-CONTRAL MEXICO

摘要

Soil degradation and low precipitation patterns are among others limiting factors in rainfed bean production on semiarid lands of North-Central Mexico (1). Soil degradation involving conventional methods of soil tillage have shown negative influencesin grain yield of bean by modifying structural soil properties. Structural soil properties affected by conventional tillage are soil water transmission, retention and storage characteristics (2). Besides soil physical properties also textural soil characteristics influence rainfall reception and infiltration capacity. The infiltration rate is a function of total porosity, the relative proportion and continuity of macropores and the stability of aggregates (3). Rainfall shortage in growing season of beanis a recurrent phenomenon in semiarid North-Central Mexico. The occurrence of plant water stress as a consequence of lower soil moisture availability during flowering and seed maturation stages may cause a reduction in grain yield. Grain yield of bean under rainfed conditions may be enhanced by utilizing Improved (drought resistant) bean varieties in conjunction with both conservation tillage systems and reception and conservation of soil water techniques. The objective of this study was to analyze the combined effect of tillage systems and a rainwater harvesting in situ technique ("pileteo") on some structural soil properties and grain yield of bean.