[Exploratory experiments of agronomic components of the maize-bean system, under minimal and conventional tillage in the Opico-Quetzaltepeque area, Department of La Libertad, El Salvador]

compound fertilizers conception control de insectos control de malezas culture multiple design diabrotica ferme pilote fertilizantes compuestos fincas experimentales haricot commun insect control kidney beans labranza lutte anti-insecte lutte anti-mauvaise herbe multiple cropping pilot farms tillage travail du sol weed control zea mays