|POPP, MICHAEL - University Of Arkansas|
|LINDSAY, KAREN - University Of Arkansas|
|WELCH, MELISSA - Beaver Watershed Alliance|
|ROARK, BECKY - Beaver Watershed Alliance|
|POTE, DAN - Retired ARS Employee|
|PENNINGTON, JOHN - Arkansas Cooperative Extension Service|
Submitted to: Agriculture Ecosystems and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2021
Publication Date: 8/17/2021
Citation: Popp, M., Lindsay, K., Ashworth, A.J., Moore Jr, P.A., Owens, P.R., Adams, T.C., Welch, M., Roark, B., Pote, D., Pennington, J. 2021. Economic and GHG emissions changes of aeration and gypsum application. Agriculture Ecosystems and the Environment. 321. Article 107616. https://doi.org/10.1016/j.agee.2021.107616.
Interpretive Summary: Soil compaction from poor grazing management, field operations using heavy equipment, and heavy rainfall can lead to increased nutrient runoff and decreased forage production. Also, nutrient runoff from agricultural fields receiving animal manures may pose risks to the health of surface waters. Therefore, Improved pasture management strategies are needed to ensure long-term ecological and economical use of abundantly available poultry litter as a source of valuable nutrients. Two potential strategies include pasture aeration, which involves machinery equipped with spikes that penetrate the soil surface leaving openings, and gypsum as a soil amendment (both practices are in tandem with surface poultry litter applications) and have been shown to reduce soil compaction and increase water infiltration. Therefore, researchers developed a decision support software to estimate benefits and costs of pasture best management practices along with break-even analysis using a partial budgeting framework; and, summarized survey findings to date about producer willingness to adopt aeration among those who have used freely available equipment. Results showed, gypsum, did not offer sufficient yield increases or nutrient runoff reductions to pay for itself. Pasture aeration, on the other hand, showed more promise as yield enhancement and nutrient runoff reductions were available. These results may aid in increased adoption of conservation agricultural practices that improve water quality and on-farm profitability.
Technical Abstract: Alternative pasture management strategies are needed to ensure long-term ecological and economical use of abundantly available poultry litter as a source of valuable nitrogen (N), phosphorus (P) and potassium (K). Practices evaluated included gypsum application, spreading poultry litter, pasture aeration, or combinations thereof, to assess relative profitability, greenhouse gas (GHG) emission and nutrient runoff effects. Specifically, default values for nutrient runoff along with an evaluation framework as provided in decision support software, as attached, assist with the selection of field activities to perform. While much of cost and price information is provided, the user has the opportunity to modify key parameters to conduct sensitivity analyses. Results indicate that pasture aeration using rented equipment requires relatively little yield improvement (< 5%) to offer greater profit while reducing runoff.