In spring 2001, pastures were grazed at the ISU Rhodes Research and Demonstration Farm to determine the effects of grazing management on pasture productivity and phosphorus (P) content of forage. Treatments included an ungrazed control, summer hay harvest with winter stockpiled grazing, continuous stocking to a residual height of 2 inches, rotational stocking to a residual height of 2 inches, and rotational stocking to a residual height of 4 inches. Forage production was greatest in June and July, decreased in August, and had a slight rebound in September and October before going dormant in November. Phosphorus concentration of forage was at a maximum in May at 0.27% and decreased to 0.11% in November. Ungrazed paddocks had no net uptake of P during the grazing season, while forage harvest stimulated P uptake. Forage growth and P uptake in buffers were unaffected by pasture management strategies that occurred upslope.
Iowa State University
Haan, Mathew M.; Russell, James R.; Powers, Wendy J.; Mickelson, Steven K.; Ahmed, Syed I.; Kovar, John L.; and Schultz, Richard C., "Effects of Grazing Management on Pasture Production and Phosphorus Content of Forage (A Progress Report)" (2003). Beef Research Report, 2003. 12.