Interactions between N supply and N uptake by perennial ryegrass, 15N recovery and soil pH for four acid Scottish soils

abonos abonos nitrogenados absorption de substances nutritives acidez acidity amendement calcique amendement du sol ammonium fertilizers arcilla argile chaulage clay denitrification encalado engrais enmiendas calizas enmiendas del suelo fertilidad del suelo fertilizers leaching lessivage du sol lime liming liming materials lolium perenne mineral nutrients nitrate fertilizers nitrification nitrogen fertilizers nutrient uptake nutrientes minerales ph del suelo ph du sol soil amendments soil fertility soil organic matter soil ph urea uree