The contribution of nitrogen through microbial biomass to plant nitrogen uptake in upland soils with different physicochemical properties

absorption de substances nutritives arroz de secano azote biomasa biomass biomasse etapas de desarrollo de la planta microorganisme microorganismos microorganisms nitrogen nutrient uptake plant developmental stages riz pluvial soil chemicophysical properties sol de moyenne altitude suelo de altura technique des traceurs tracer techniques upland rice upland soils