|Williams, Mary - Mimi|
Submitted to: Agricultural Research Service Publication
Publication Type: Other
Publication Acceptance Date: 5/15/2007
Publication Date: 6/4/2007
Citation: Sigua, G.C., Coleman, S.W., Williams, M.J. 2007. Properly managed forage-based cow-calf operations in south Central Florida are environmentally friendly. USDA-Agricultural Research Service, STARS Field Day Book, Brooksville, Florida. p. 23-27.
Technical Abstract: Soil phosphorus levels in subtropical forage-based beef cattle pastures with bahiagrass (BG) and rhizoma peanut – mixed grass (RP-G) declined from 1988 to 2004. During the past 15 years, there was no buildup of Mehlich-1 extractable soil P and other crop nutrients despite annual nitrogen and phosphorus fertilization. Soil testing of pastures in the subtropics is vital and should be continued to measure the amounts of soil P and other crop nutrients that are available to BG and RP-G. It also is important to continue investigating alternative soil phosphorus tests that are better predictors of the loss and/or accumulation of phosphorus in terrestrial and aquatic ecosystems. Maintaining a balance between the amount of nutrients added to the soil as manure and fertilizer and the amount of nutrients removed by forages, hay, or livestock is critical for productive crop growth and water/environmental quality protection. If more nutrients are added than can be used for productive forage growth, nutrients may accumulate in the soil, creating high risk for runoff and water contamination. Higher depletion rates of phosphorus, potassium, calcium, and magnesium in RP-G field than in pastures with BG indicate that the former has greater nutritional demands. Therefore, results of this study have renewed the focus on improving fertilizer efficiency in subtropical beef cattle systems, and maintaining a balance of nutrients removed to nutrients added to ensure healthy forage growth and minimize nutrient runoff. Modern management of forage-based beef cattle pasture requires an integration of experimental and professional resource knowledge with science as solid foundation to provide a sound base for improvement in management practices. Further studies are needed to determine whether the environmental and ecological implications of grazing and haying in forage-based pastures are satisfied over the longer term. New knowledge is needed to identify pasture lands at risk of degradation and to prescribe treatments or management practices needed to protect the natural resources while maintaining an economically and environmentally viable operation.