Long-term comparison of rock phosphate with superphosphate on crop yield in two cereal-legume rotations

analyse de tissus application rates avena sativa crop yield dose d'application feuille foliar diagnosis fosfato mineral glycine max hojas illinois leaves medicago sativa ph phosphate naturel rendement des cultures rendimiento de cultivos rock phosphate rotation culturale rotational cropping soil chemicophysical properties superfosfato superphosphate tissue analysis zea mays