[Nitrate leaching: suitable standards and problem crops]

absorption de substances nutritives accounting azote besoin nutritionnel contabilidad contenido mineral crop residues crops cultivos exceso de nutrientes leaching lessivage du sol losses from soil mineral content minerales minerals necesidades de nutrientes netherlands nitrate nitrogen normas norme nutrient balance nutrient excesses nutrient uptake nutrition des plantes nutritional requirements perte par le sol plant nutrition plante de culture residuos de cosechas soil sol standards suelo