Water-quality effects of a mechanized subsurface-banding technique for applying poultry litter to perennial grassland q D.H. Pote a, * , T.R. Way b , K.R. Sistani c , P.A. Moore, Jr. d a USDA-ARS, Dale Bumpers Small Farms Research Center, 6883 South State Hwy. 23, Booneville, AR 72927, United States b USDA-ARS, National Soil Dynamics Laboratory, 411 South Donahue Dr., Auburn, AL 36832-5806, United States c USDA-ARS, Animal Waste Management Research Unit, 230 Bennett Lane, Bowling Green, KY 42104, United States d USDA-ARS, PPPSRU, 0-303 POSC, University of Arkansas, Fayetteville, AR 72701, United States article info Article history: Received 29 December 2008 Received in revised form 15 May 2009 Accepted 9 June 2009 Available online 7 July 2009 Keywords: Water quality Manure management Poultry litter Nutrient management abstract Poultry litter is known to be an excellent organic fertilizer, but the common practice of spreading litter on the surface of pastures has raised serious water-quality concerns and may limit potential benefits of litter applications. Because surface-applied litter is completely exposed to the atmosphere, runoff can trans- port nutrients into nearby streams and lakes, and much of the ammonium nitrogen volatilizes before it can enter the soil. Our previous research showed that a manual knifing technique to apply dry litter under a perennial pasture surface effectively prevented about 90% of nutrient loss with runoff from surface-applied litter, and tended to increase forage yield. However, this technique (known as subsurface banding) cannot become a practical management option for producers until it is mechanized. To begin that process, we tested an experimental single-shank, tractor-drawn implement designed to apply poultry litter in subsurface bands. Our objective was to compare this mechanized subsurface-banding method against conventional surface application to determine effects on nutrient loss with runoff from a perennial grassland treated with dry poultry litter. Early in the growing season, broiler litter was applied (6.7 dry-weight Mg ha 1 ) to each plot (except three control plots) using one of two application methods: surface broadcast manually or subsurface banded using the tractor-drawn implement. Simu- lated rainfall (5 cm h 1 ) generated 20 min of runoff from each plot for volume and analytical measure- ments. Results showed that subsurface-banded litter increased forage yield while decreasing nutrient (e.g. N and P) loss in runoff by at least 90% compared to surface-broadcast litter. Published by Elsevier Ltd. 1. Introduction Many family farms across the southeastern United States rely primarily on poultry production supplemented by beef cattle as their main source of income, especially in hilly areas that are not well suited for most other types of agricultural production. Poultry litter (manure mixed with bedding material) is a by-product of poultry production that provides a rich source of plant nutrients, and it is usually spread on beef pastures and hay fields to serve as organic fertilizer for perennial forages that dominate much of the agricultural landscape in this region. However, this common prac- tice of applying litter on the surface of pastures has raised serious water-quality concerns and may limit the potential benefits that poultry litter can provide. Because surface-applied litter is completely exposed to the atmosphere, rainfall runoff can transport nutrients into nearby streams and lakes (Westerman et al., 1983; McLeod and Hegg, 1984; Edwards and Daniel, 1993; Shreve et al., 1995), and much of the ammonia nitrogen volatilizes before it can enter the soil (Chapman and Snyder, 1992; Nathan and Malzer, 1994). Poultry producers need improved management options that protect water quality by decreasing losses from poultry litter, while making the valuable nutrients more available to crop plants. Placing fertilizer applications below the soil surface has been a successful technique for decreasing nutrient losses from some crop production systems. Baker and Laflen (1982) injected liquid inorganic P and NH 4 –N fertilizers 5 cm deep into a fallow sandy loam soil and observed that dissolved P and NH 4 –N concentrations in runoff were no higher than in runoff from control plots that received no fertilizers. Several researchers have also reported Abbreviations: DRP, dissolved reactive phosphorus; EC, electrical conductivity; GLM, general linear models; ICP, inductively coupled plasma spectrometer; TDS, total dissolved solids; TN, total nitrogen; TP, total phosphorus; TS, total solids; TSS, total suspended solids. q Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. * Corresponding author. Tel.: þ1 479 675 3834x344; fax: þ1 479 675 2940. E-mail address: dan.pote@ars.usda.gov (D.H. Pote). Contents lists available at ScienceDirect Journal of Environmental Management journal homepage: www.elsevier.com/locate/jenvman 0301-4797/$ – see front matter Published by Elsevier Ltd. doi:10.1016/j.jenvman.2009.06.006 Journal of Environmental Management 90 (2009) 3534–3539