Effects of N and P fertilizers on common bean (Phaseolus vulgaris L.) grown in a P-fixing Nicaraguan mollic andosol

abonos nitrogenados absorption de substances nutritives andosol andosoles andosols crop yield developing countries ensayos de variedades essai mycorrhizae nitrogen fertilizers nutrient uptake phaseolus vulgaris plant response pruebas rendement des cultures rendimiento de cultivos respuesta de la planta root nodulation superfosfato superphosphate trials tropical zones urea uree variety trials zona tropical zone tropicale