Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/28/2010
Publication Date: N/A
Technical Abstract: Recent assessments of water quality status have identified eutrophication as one of the major causes of water quality “impairment” around the world. In most cases, eutrophication has accelerated by increased inputs of phosphorus and/or nitrogen due to intensification of crop and animal production systems since the early 1990’s. As animal-based agriculture has evolved to larger production in subtropical region of United States, the problems associated with manure handling, storage and disposal have grown significantly. Little information exists regarding possible magnitudes of nutrient losses from pastures that are managed for both grazing and hay production and how these might impact adjacent bodies of water. Trends in water quality parameters and trophic state index (TSI) of lakes associated with beef cattle operations are being investigated. Overall, there was no spatial or temporal build up of soil nutrients despite the annual application of fertilizers and daily in-field loading of animal waste. Our results indicate that when nutrients are not applied in excess, cow-calf systems are slight exporters of nutrients through removal of cut hay. Water quality in lakes associated with cattle production was “good” (30-46 TSI) based upon the Florida Water Quality Standard. Our results indicate that properly managed livestock operations contribute negligible loads of nitrogen and phosphorus to shallow groundwater and surface water. Therefore standard practices that include cattle rotation and recommended fertilizer application offer little potential for negatively affecting the environment.