Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/4/2010
Publication Date: 3/1/2011
Citation: Watts, D.B., Way, T.R., Torbert III, H.A. 2011. Subsurface application of poultry litter and its influence on nutrient losses in runoff water from permanent pastures. Journal of Environmental Quality. 40(2):421-430.
Interpretive Summary: Recently, an experimental implement has been developed at the USDA-ARS National Soil Dynamics Laboratory (NSDL) to subsurface band poultry litter in soil. Use of this implement to subsurface apply poultry litter in soil can potentially reduce the negative impact that N and P loss from poultry litter has on water quality. Thus, a rainfall simulation study was performed using high rainfall rates to evaluate how subsurface applying poultry litter in a bermudagrass pasture would impact nutrient loss in surface water runoff at two field sites containing soil from the Piedmont and Coastal Plain regions of the Southeastern US. Subsurface banding of poultry litter was compared to surface applied poultry litter, inorganic fertilizer, and a non-fertilized control. Subsurface banding poultry litter reduced the impact of N and P loss in surface water runoff to levels observed in the non-fertilized pasture. Thus, this study shows that subsurface banding poultry litter in soil can reduce N and P loss compared to common fertilization practices.
Technical Abstract: Environmental pressure to reduce nutrient losses from agricultural fields has increased in recent years. To abate this nutrient loss to the environment, better management practices and new technologies need to be developed. Thus, research was conducted to evaluate if subsurface banding poultry litter (PL) would reduce nitrogen (N) and phosphorus (P) loss in surface water runoff using a four-row prototype implement. Rainfall simulations were conducted to create a 40 min runoff event in an established bermudagrass (Cynodon dactylon L.) pasture on soil types common to the Coastal Plain and Piedmont Region. The Coastal Plain soil type was a Marvyn loamy sand (Fine-loamy, kaolinitic, thermic Typic Kanhapludults) and the Piedmont soil type was a Hard Labor loamy sand (Fine, kaolinitic, thermic Oxyaquic Kanhapludults). Treatments consisted of surface and subsurface applied PL at a rate of 9 Mg ha-1, surface broadcast applied commercial fertilizer (CF; urea and triple super phosphate blend) at the equivalent N (330 kg N ha-1) and P (315 kg N ha-1) content of PL, and a non-fertilized control. The greatest loss for inorganic N, total N, dissolved reactive P and total P occurred with the surface broadcast treatments, with CF contributing to the greatest loss. Nutrient losses from the subsurface banded treatment reduced N and P in surface water runoff to levels of the control. Subsurface banding of PL reduced concentrations of inorganic N 91 %, total N 90 %, DRP 86 %, and total P 86 % in runoff water compared to surface broadcasted PL. These results show that subsurface band-applied PL can greatly reduce the impact of N and P loss to the environment compared to conventional surface applied PL and CF practices.