Phosphorus fertilization and plant-available phosphorus in relation to risk of eutrophication

abonos fosfatados bovin cattle compost composts disponibilidad de nutrientes eutrophication eutrophisation farmyard manure fosforo fraccionamiento fractionation fractionnement fumier ganado bovino grosseur des particules noruega norway nutrient availability particle size phosphate fertilizers phosphore phosphorus soil sorption sorption du sol