Sources and Rates of Phosphorus in a Cultivation System Integrating Crop and Pasture Production in the State of Parana
IPNI-2009-BRA-55
19 Feb 2010
2009 Annual Interpretive Summary
The integration of crop and pasture production within the same area is becoming popular in Brazil due to its agronomic advantages. Phosphorus is a key nutrient in these systems and soils in the state of Parana are generally low in bioavailable P. The main purpose of this project is to evaluate the effects of P rates and sources (water-soluble and water-insoluble) on soil quality, plant mineral nutrition, forage, grain, and meat yields in an integrated crop-livestock system under no-till. The soil at the site has been under no-till for 5 years. Treatments include three sources of P (triple superphosphate/TSP, magnesium thermophosphate/MTP, and Arad reactive rock phosphate/RP) and three rates of P (60, 120, and 180 kg total P2O5/ha), with all sources applied prior to seeding the winter crop. The trial also included a control, with no P applied, and three treatments supplying each source at 90 kg P2O5/ha applied prior to seeding the spring-summer crop.
The experiment was started in April 2009 and only the results for the autumn-winter crop are available. There was a clear response to P in black oats for all P sources. The TSP source applied at 120 kg P2O5/ha generated the highest dry matter yield. No effect on soil carbon storage has been observed to date. The site is now under corn cultivation. Brazil-55