Assessing impact of forage-based cattle operation on phosphorus and other crop nutrient loads in subtropical beef cattle pastures

Authors: Sigua, Gilbert

Submitted to: University of Florida Cooperative Extension Service Institute of Food and Agriculture Science
Publication Type: Other
Publication Acceptance Date: 5/2/2005
Publication Date: 6/14/2005
Citation: Sigua, G.C. 2005. Assessing impact of forage-based cattle operation on phosphorus and other crop nutrient loads in subtropical beef cattle pastures. University of Florida Cooperative Extension Service Institute of Food and Agriculture Science 2004 Annual Research Reports.

Interpretive Summary:

Technical Abstract: Beef cattle production contributes over $300 million to Florida’s economy and ranks sixth among agricultural commodities. Florida beef production is predominantly cow-calf production and occupies large areas of grazing lands, which have traditionally thought to be environmentally friendly. However in the Lake Okeechobee watershed, soluble-phosphorus (P) fertilizers applied to beef cattle pastures, as well as beef cattle manure, have been suggested as a significant source of P loading, and efforts to reduce the impact have cost cattlemen millions. Florida’s grazing lands have considerable variability in soils, climate, and growing season, which not only affect the types of forage that can be grown but also the overall environmental and biodiversity management. The role of how pasture management (stocking rate, grazing system, etc.) and fertilizer application affect nutrient dynamics and water quality are issues of increasing importance to environmentalists, ranchers, and public officials in the State. Nutrient dynamics in various agro-animal-ecosystems are continually evolving in response to changing management practices. A major area where knowledge is lacking relates to the pathways and rates of movement of nutrients deposited in urine and dung through various soil pools and back to the plant, or adversely into surface or ground water. Beef cattle producers throughout the United States need better forage management systems to reduce input costs and protect environmental quality. Dr. Sigua evaluated the effects of grazing and haying on soil P dynamics (levels and changes) in subtropical beef cattle pastures with bahiagrass (Paspalum notatum) and rhizoma peanut (Arachis glabrata) with or without phosphorus fertilization from 1988 to 2002 to determine how management practices affected soil P levels in deep sand pastures of central Florida.