Agro-Ecosystems Indicators of Sustainability as
Affected by Cattle Density in Ranch Management Systems
USDA/NRI Agricultural Systems Grant
Project Investigators
Campbell, K.L.; Capece, J.C.; Mullahey, J.J.; Fanning,
M.D.; Graetz, D.A.; Holt, J.; McSorley, R.; Muchovej, R.M.; Portier, K.M.;
Roka, F.M.; Steinman, A.D.; Tanner, G.W.
Summary
In an effort to restore the sensitive ecosystems
of south Florida, large reductions in phosphorus discharges are required
from major land uses in the region. Beef cattle pastures cover large land
areas resulting in large collective contributions of phosphorus. An interdisciplinary
team has launched a project to develop sustainable environmentally-sensitive
cattle ranch management practices for the region. The project is using
a 16-plot, 1040-acre pasture array system to evaluate the effects of cattle
stocking rate on: (1) runoff water quality, (2) biological agro-ecosystem
indicators including animal performance, vegetation/forage quality, soil
nutrient dynamics, nematode biodiversity, and avian utilization, and (3)
ranch sustainability as predicted by economic models that integrate cow-calf
performance and other financial considerations. The goal of this project
is to provide information regarding the interrelationships and interactions
of the overall agro-ecosystem and its sustainability, including tools to
evaluate the performance of the overall system.
To test the effects of grazing intensity on water
quality and nutrient assimilation, this study will impose four cattle stocking
rates on both an improved pasture site and a native range site. Data collected
will be analyzed using standard statistical tools to test the hypothesis
that stocking rate has no effect on runoff water quality, nutrient assimilation,
or biological agro-ecosystem indicators. These studies complement the water
quality assessment, hydrologic modeling, and decision support system projects
already underway. Together, all of these complementary studies constitute
a holistic analysis of ranch agro-ecosystems as affected by cattle stocking
density.
Complete
Project Statement