[Phosphate rock evaluation in Zea mays L. at the coast of Jalisco, Mexico]

anglais. Rainfed corn is cultivated on the red soils of Tequesquitlan and La Huerta, Jalisco, Mexico. Two field experiments were established in acid soils of this area, planting corn variety V-524 (Tuxpenito) fertilized with nitrogen, 3 sources of phosphorus, plus sulphur and calcium, in order to test the convenience of the use of finely ground phosphate rock, alone or with sulphur or calcium. The highest grain and dry matter yields were obtained when applying 300 to 400 kg P2O5 ha**-1 as phosphate rock from San Juan, BCS (SJPR). The SJPR applied alone did not overcome any of the treatments with SJPR + sulphur. The 300 kg elemental-sulphur-per-hectare level gave the highest significance of the 3 S levels studied, on grain as well as on dry matter yields. Triple calcium superphosphate (TSP) did not overyield any of the SJPR + S treatments; however, TSP produced grain and dry matter yields slightly higher than those obtained with the application of SJPR alone, and much higher than those receiving SJPR plus dolomite. Finally, SJPR gave slightly better yields than phosphate rocks from Zimapan, Hgo. and Morocco.

espagnol; castillan. En los suelos rojos de Tequesquitlan y La Huerta, Jalisco, se cultiva comercialmente el maiz en condiciones de temporal. Se establecieron 2 experimentos con maiz V-524 (Tuxpenito) que fueron fertilizados con nitrogeno, 3 fuentes de fosforo, azufre y calcio sobre la conveniencia del uso de roca fosforica finamente molida, sola o mezclada con azufre o calcio, en suelos acidos donde se cultiva maiz de temporal. Los mayores rendimientos de grano y materia seca se obtuvieron al aplicar de 300 a 400 kg de P2O5 ha**-1 como roca fosforica de San Juan, B.C.S. (RFSJ). La RFSJ sola no logro superar a ninguno de los tratamientos con RFSJ + azufre. De los 3 niveles estudiados de S, el de mayor significancia fue el de 300 kg de S elemental ha**-1, tanto en rendimiento de grano como de materia seca. El superfosfato de calcio triple no logro superar a ninguno de los tratamientos con RFSJ + S; sin embargo, el superfosfato supero ligeramente a los tratamientos con RF sola y, en mayor grado, a los tratamientos con RFSJ + dolomita, en rendimiento de grano y materia seca. Finalmente, la roca fosforica de San Juan supero ligeramente a las rocas fosforicas de Zimapan (Hgo.) y Marruecos.