|ANDERSON, KELSEY - University Of Arkansas|
|POPP, MICHAEL - University Of Arkansas|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/7/2018
Publication Date: N/A
Technical Abstract: Producers in Northwest Arkansas need alternative management practices to ensure long-term sustainable and economical use of poultry litter, an abundant source of valuable nitrogen (N) and phosphorus (P). Project objectives were to identify the efficacy of best management practices (BMPs; i.e., pasture aeration and subsurface litter incorporation) to reduce nutrient runoff compared to poultry litter surface applications from small watersheds under rainfed conditions. Watersheds (0.23 ha each) were assigned a treatment [pasture aeration, litter incorporation, or surface application of litter (control)] on a Leadvale (fine-silty, siliceous, thermic Typic Fragiudult) silt loam under grazed conditions. Poultry litter was applied annually to all plots at variable rates (2.3-3.6 Mg ha-1) from 2007-2011. Over the 5-yr study period, runoff loads of NO3-N, total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) varied per conservation management treatment (P=0.05). Specifically, NO3-N, TN, SRP, and TP loads were reduced 51, 46, 28, and 34% following pasture aeration and by 81, 74, 58, and 61% from subsurface applying poultry litter, relative to surface poultry litter applications, respectively. However, conservation management practices did not reduce (P=0.05) runoff loads of ammonium (NH4+), total suspended solids (TSS), and total organic carbon (TOC) relative to surface poultry litter applications. Overall, subsurface banding poultry litter and pasture aeration are promising BMPs for improving forage yields and water quality while reducing non-point pollution in watersheds with nutrient imbalances.