Comparison of composted rockphosphate with various P-fertilizers in rice-wheat cropping system

abonos fosfatados ammonium phosphate caracteres de rendimiento composante de rendement crop yield cropping systems fosfato de amonio fosfato mineral nitrofosfatos nitrophosphate nitrophosphates oryza sativa phosphate d'ammonium phosphate fertilizers phosphate naturel rendement des cultures rendimiento de cultivos rock phosphate sistemas de cultivo superfosfato superphosphate triticum aestivum yield components