Managing Cattle Operations to Protect Lakes and Rivers

Concerns about long-term effects of beef cattle browsing more than 11 million acres of Florida grazinglands led Agricultural Research Service (ARS) scientists to examine soil fertility changes in bahiagrass-based beef cattle pastures from 1988 to 2002. Analysis of data from that research shows that cattle can be managed in an environmentally safe way, despite the large quantities of waste the animals generate.

Forage-based livestock systems have been cited as a major cause of deteriorating water quality in Florida and other cattle-producing states. Phosphorus runoff from manure and fertilizers applied to enhance forage production can pollute rivers and lakes. However, very limited data have been available to quantify nutrient losses to adjacent bodies of water from pastures managed for grazing and hay production.

For this long-term monitoring study, the pastures were managed for spring grazing and late- summer haying. Soil scientist Gilbert C. Sigua and colleagues in the ARS Beef Cattle Research Unit in Brooksville, Fla., monitored changes in soil nutrients. The data they generated enabled them to predict soil chemical and physical changes likely under continuous forage-livestock cultivation, and to devise measures to manage them.