Grazing Management Effects on Surface Runoff from Pastures Fertilized with Broiler Litter

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Repeated heavy applications of broadcast broiler litter can increase nutrient nmoff from pastures. Rotational stocking of cattle, as compared to continuous stocking, may be useful in decreasing surface nutrient runoff because of better manure . distribution and more uniform forage accumulation to act as filters and trap nutrients. The objective of this study was to measure phosphorus runoff from six 0.75- ha (6-8% slope) endophyte-infected tall fescuecommon bermudagrass pastures that were fertilized with 13 to 15 Mg (dry weight) ha-1 yr-1 broiler litter. Runoff was analyzed for dissolved reactive P (DRP) and total Kjeldahl P (TKP). Grazing method had no effect (P>0.10) on surface runoff quality or quantity. The average flow weighted concentration of DRP for both stocking treatments was 5.1 mg P L-1 for the first year and 8.2 mg P L-1 for the second year {P<0.10). The flow weighted concentration of TKP was 6.8 mg P L-1 for the first year and 12.8 mg P L-1 for the second year (P