Fate of fertilizer-15N to a maize crop grown in Northern Zambia [oxisol, partitioning]

absorption de substances nutritives azote contenido de materia seca dry matter content fertilisation fertilizer application leaching lessivage du sol loam soils nitrate nitrates nitratos nitrogen nitrogen content nutrient uptake rendement rendimiento sandy soils sol sableux sol sablolimoneux suelo arenoso suelo franco technique des traceurs teneur en azote tracer techniques yields zambia zambie zea mays