An overview of the effectiveness of agricultural conservation practices for water quality improvement

Authors: YUAN, YONGPING - Us Environmental Protection Agency (EPA); BOOK, RUTH - Natural Resources Conservation Service (NRCS, USDA); Mankin, Kyle; KOROPECKYJ-COX, LYDIA - Us Environmental Protection Agency (EPA); CHRISTIANSON, LAURA - University Of Illinois; MESSER, TIFFANY - University Of Kentucky; CHRISTIANSON, REID - University Of Illinois

Submitted to: Journal of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2022
Publication Date: 3/1/2022
Citation: Yuan, Y., Book, R., Mankin, K.R., Koropeckyj-Cox, L., Christianson, L.E., Messer, T.L., Christianson, R.D. 2022. An overview of the effectiveness of agricultural conservation practices for water quality improvement. Journal of the ASABE. 65(2):419-426. https://doi.org/10.13031/ja.14503.
DOI: https://doi.org/10.13031/ja.14503

Interpretive Summary: This paper introduces a special collection of literature reviews documenting performance and cost effectiveness of selected agricultural conservation practices (ACPs). The overall objectives of the special collection are to: 1) review published studies on ACP effectiveness in reducing nutrient and sediment losses from agricultural fields; 2) compare, integrate, and synthesize results from those studies; 3) obtain insights on performance-based costs of ACPs on reducing nutrient and sediment losses. This introductory paper summarizes and integrates key information from each review paper to develop a comparative understanding of the selected ACPs. Among the selected ACPs, denitrifying bioreactors, wetlands, cover crops, crop rotation and nutrient management were most effective in reducing nitrate-N load with performance effectiveness in mass reduction ranging from 23% to 40%. Regarding cost-effectiveness, the corn-soybean rotation system is the most cost-effective, which can reduce nitrate-N load at a benefit of about five U.S. dollars per kg nitrate-N from continuous corn. Vegetative filter strips were the most effective in reducing sediment, total nitrogen (N) and total phosphorus (P) loads, and they can be effective in reducing nitrate-N and dissolved P loads under certain conditions (e.g. surface flow dominated areas). Furthermore, cover crops were also effective in reducing sediment and total N loads. Studies of ACPs for performance effectiveness on dissolved P are limited and results varied among ACPs included in the collection; thus, more research is needed to find effective ACPs in reducing dissolved P, particularly in subsurface flow. Finally, although the authors of each review paper attempted to include cost-analysis information, more studies are needed to better understand the cost-effectiveness including ecological benefits gained from implementing those ACPs in the future.

Technical Abstract: This paper introduces the first edition of a special collection of literature reviews documenting performance and cost effectiveness of selected agricultural conservation practices (ACPs). The overall objectives of the special collection are to: 1) review published studies on ACP effectiveness in reducing nutrient and sediment losses from agricultural fields; 2) compare, integrate, and synthesize results from those studies to obtain a systematic understanding of mitigation efficacy for each ACP in a consistent format across all ACPs; 3) Assemble cost analyses and obtain general insights on performance-based costs of ACPs on reducing nutrient and sediment losses. The specific objectives of this introductory paper are to summarize key information from each review paper and develop a comparative understanding of performance effectiveness and cost effectiveness of the selected ACPs. Among the selected ACPs, denitrifying bioreactors, wetlands, cover crops, crop rotation and nutrient management were most effective in reducing nitrate-N load with performance effectiveness in mass reduction ranging from 23% to 40%. Regarding to cost-effectiveness, the corn-soybean rotation system is the most cost-effective, which can reduce nitrate-N load at a benefit of about five U.S. dollars per kg nitrate-N from continuous corn. Vegetative filter strips were the most effective in reducing sediment, total nitrogen (N) and total phosphorus (P) loads and they can be effective in reducing nitrate-N and dissolved P loads under certain conditions (e.g. surface flow dominated areas). Furthermore, cover crops were also effective in reducing sediment and total N loads. Studies of ACPs for performance effectiveness on dissolved P are limited and results varied among ACPs included in the collection; thus, more research is needed to find effective ACPs in reducing dissolved P, particularly in subsurface flow. Finally, although the authors of each review paper attempted to include cost-analysis information, more studies are needed to better understand the cost-effectiveness including ecological benefits gained from implementing those ACPs in the future.