The effect of phosphorus and mulching on the efficiency of phosphorus use and productivity of wheat grown on a mountain Alfisol in the Western Himalayas

abonos fosfatados alfisols cubrimiento del suelo economia economics economie efficiency eficacia fosforo inde india lantana camara luvisol luvisoles luvisols malezas mauvaise herbe mulch mulches mulching paillage phosphate fertilizers phosphore phosphorus pinus roxburghii polietileno polyethylene productividad productivity rendement rendimiento soil types tipos de suelos trigo triticum aestivum type de sol uses usos utilisation weeds wheats yields