Nitrogen mineralization and after-year effects of green manure on certain soils in Southeast Norway. N mineralization and after-year effects of green manure

abonos verdes agriculture biologique azote cereales cereals crop residues cultivo bajo cubierta vegetal engrais vert gramineas graminee grasses green manures leaching lessivage du sol mineralisation mineralization nitrogen noruega norway organic agriculture rendement rendimiento residuos de cosechas rotation culturale rotational cropping soil types tipos de suelos trifolium pratense type de sol underplanting vicia sativa yields