Phosphate Fertilizer for Pasture Maintenance in Southern Brazil

The study was conducted in the south of Brazil at the Brazilian Agricultural Research Enterprise, BMBRAPA. A winter-cultivated pasture stocked for 14 years with different stocking rates ended with different soil phosphorus (P) levels. To evaluate additional pho·sphate fertiliser response on this area, a pot experiment in the glasshouse was carried out. Levels of 0, 20, 40, 80 and 160 kg/ha of P20s were applied on a soil with 12.0, 12.5 and 17.0 ppm of available soil P, respectively, from low, medium and high stocking rates. White clover (Trifolium repens L.) was grown in pots of 2 kg of soil. Clover dry matter (DM) response increased with increasing available soil P as well as with increasing P20s applied. The lowest response of clover DM by applying P205 was at 17.0 ppm of available soil P. At 17.0 ppm of available soil P, 20 kg/ha of P 205 was sufficient to maintain clover DM production. Critical available soil P level, total P concentration in clover tissue, fertiliser maintenance level and phosphorus cycling throughout the grazing animal are discussed.