Experimental Approach    Two large experimental pasture arrays (see figure) were established at the Buck Island Ranch to examine the effects of stocking rate on nutrient content in pasture stormwater runoff (see previous data summary table).  In central Florida, ranchers often have two major pasture systems. Summer pastures are planted in bahia grass or other exotic grasses and are fertilized often.  Winter pastures generally are dominated by native grasses and may not be fertilized. MAERC has constructed 16 pastures plots (8 summer pastures and 8 winter pastures) each as a separate hydrologic unit.  Summer and winter pastures are 50 and 80 acres, respectively.  These pasture arrays will also allow for experiments on fertilization rates, grazing schemes, and other variables.

Research Herds    The experimental design will evaluate four stocking rates (see table) in two pasture types (with two herds at each rate). Stocking rates are 35, 20, 15, and no cow/calf pairs.  Each test herd will occupy summer pastures (see map) during May–November and winter pastures (see map) during November–April/May.  Each study animal will remain with the same herd for the life of the project.  The 140 "Braford" cows (4–9 yrs. old) in this study will be selected randomly from one of the commercial herds at Buck Island Ranch.  During the study, replacement females will be selected from the same herd.

Component Investigations    Effects of the Cattle Stocking Rate Treatments are being measured by scientists from a range of perspectives under the sponsorship of several grants and contracts:

• Hydrology and Water Quality
• DEP Data Collection/Analysis Project (with reports)
• Project Tasks Management & Status  (No Frames)
• Current Weather Information
• Hydrologic Instrumentation and Measurements
• Water Quality Sampling Methods (SOP)
• Water Quality QAPP
• Water Flow Measurement and Sampling Site Photos
• June 14, 1999 MOU meeting presentation and summary
• Telemetry Meeting Notes (Nov. 12, 1998)
• Annual UF-CNR water quality report
• Data Management Meeting Notes  (Sep. 1, 1998)
• Animal Science
• Cow-calf Performance
• Beef Cattle Water Quality
• National Cattlemen's Beef Association Water Quality Guide
• Soil Science
• Pilot soil sampling locations
• Wildlife
• Ranch Economics
• Nematology
• Vegetation (Range Science)

1. ABS Info:Wildlife, Water Quality, and Florida's Beef Cattle Ranches(general project description)
2. SFWMD/ABS: Grant: Instrumentation Installation Grant (project completed)
3. DEP Project: Data Collection & Analysis Project Grant (water quality project)
4. USDA Grant: Agro-ecology Project USDA Grant and Reference List (related research)
5. USDA Grant Reports
    1998 CRIS: Annual Project Report
    1998 Summary: Non-technical Progress Report
    1999 CRIS: Annual Project Report
    1999 Summary: Non-technical Progress Report
6. UF CNR: 1997 UF-Center for Natural Resources report
7. New DEP-319 Proposal: Fiscal Year 2000 Project Proposal and Abstract