Nitrate leaching to a shallow mid-Atlantic coastal plain aquifer as influenced by conventional no-till and low-input sustainable grain production systems

aquifers azote cero-labranza cultivo intercalado cultivos de invierno culture d'hiver culture intercalaire feed legumes glycine max groundwater table intercropping labranza leaching leguminosas forrajeras lessivage du sol losses from soil low input agriculture maryland nappe souterraine nitrate nitrates nitratos nitrogen physiographic soil types relay cropping rotation culturale rotational cropping tillage travail du sol triticum triticum aestivum vicia winter crops zea mays zero tillage