Evaluating water quality benefits of manureshed management in the Susquehanna River Basin

Authors: SAHA, ARGHAJEET - Pennsylvania State University; SAHA, GOURAB - Pennsylvania State University; CIBIN, RAJ - Pennsylvania State University; Spiegal, Sheri; Kleinman, Peter; Veith, Tameria - Tamie; WHITE, CHARLES - Pennsylvania State University; DROHAN, PATRICK - Pennsylvania State University; Tsegaye, Teferi

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2022
Publication Date: 11/5/2022
Citation: Saha, A., Saha, G., Cibin, R., Spiegal, S.A., Kleinman, P.J., Veith, T.L., White, C., Drohan, P., Tsegaye, T.D. 2023. Evaluating water quality benefits of manureshed management in the Susquehanna River Basin. Journal of Environmental Quality. 52(2):328-340. https://doi.org/10.1002/jeq2.20429.
DOI: https://doi.org/10.1002/jeq2.20429

Interpretive Summary: With fertilizer prices at historic high, there is unprecedented interest in improving the use of manure from animal production facilities as a substitute for commercial fertilizers in crop production. With better use of manure fertilizer resources, opportunity also exists to reduce the impacts of manure on environmental outcomes such as water quality. As part of the Long-Term Agroecosystem Research network, researchers at Penn State University and USDA’s Agricultural Research study quantified water quality benefits of “manureshed” nutrient management with the Susquehanna River Basin of the Chesapeake Bay Watershed. They found that better distribution of manures across the Basin would result in 3-25% reduction in nutrient pollution from the Basin, improving the health of the Chesapeake Bay.

Technical Abstract: 'Manureshed’ management supports the sustainable use of manure resources by balancing matching areas of crop demand (nutrient sinks) with livestock manure generation (nutrient sources). This study quantifies potential water quality benefits of manureshed-based nutrient management through scenario-based analyses in the Susquehanna River Basin (SRB) using Soil and Water Assessment Tool (SWAT). Five manureshed management scenarios were developed and compared with a baseline “business-as-usual” scenario. The scenarios included, (i) Business43 as-usual scenario which assume manure is less transportable, which means some areas have excess manure application than crop demand, (ii) Watershed nutrient balance scenarios which assume excess manure from surplus areas are transportable and manure is applied based on crop nutrient demand, (ii) Watershed nutrient balance avoiding runoff prone areas scenarios that assume manure is transportable and not applied in vulnerable landscapes. Each manure management scenario was evaluated under two application rates considering crop nitrogen demand (N-based) and phosphorus demand (P-based). P-based manuresheds were more effective in water quality improvements than the N-based for the case study watershed. P-based watershed nutrient balance scenarios simulated 3% and 25% reduction in TN and TP from baseline scenario at the watershed outlet. The N- and P-based scenarios with no manure application in runoff prone areas simulated 3% and 6% reduction in TN loss, and 4% and 25% reduction in TP loss respectively from the baseline scenario. The manureshed management scenarios were more effective in improving local stream waters quality in livestock intensive regions than the watershed outlet in this case study.