Water quality in an irrigated sandy soil: ridge tillage in rotated corn and soybean compared with full-width tillage in continuous corn

alachlor alachlore alacloro atrazina atrazine calidad del agua continuous cropping cultivo continuo culture continue glycine max irrigated soils labor en caballones leaching lessivage du sol minnesota nitrate nitrates nitratos ridge tillage rotation culturale rotational cropping sandy soils sol sableux suelo arenoso suelo irrigado travail du sol en billon water quality zea mays