TY - JOUR
T1 - Load-discharge relationships reveal the efficacy of manure application practices on phosphorus and total solids losses from agricultural fields
AU - Miller, Melissa D.
AU - Gall, Heather E.
AU - Buda, Anthony R.
AU - Saporito, Lou S.
AU - Veith, Tamie L.
AU - White, Charles M.
AU - Williams, Clinton F.
AU - Brasier, Kathryn J.
AU - Kleinman, Peter J.A.
AU - Watson, John E.
N1 - Funding Information:
This work is supported by the Agriculture and Food Research Initiative (AFRI) Water for Agriculture grant no. 2017-68007-26584/ project accession no. 1013079 from the USDA National Institute of Food and Agriculture. Drs. John E. Watson and Heather E. Gall are supported, in part, by the USDA National Institute of Food and Agriculture Federal Appropriations under Project PEN04574 and Accession number 1004448. The construction of the field plots and management activities was, in part, funded by a grant from the USDA Northeast Sustainable Agricultural Research and Education (NESARE) program . Thank you to Dr. Heather Karsten for providing information about site history and management, and thank you to Dr. Kyle Elkin for his assistance with sample analyses.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Eutrophication and sedimentation are pervasive challenges in many agricultural watersheds. Recent research has promoted shallow-disk manure injection as a means of mitigating phosphorus (P) losses in runoff while maintaining the water quality benefits of no-till, such as reduced particulate P and sediment losses. However, the precision and accuracy of field studies seeking to quantify the effectiveness of shallow-disk injection as a P mitigation strategy are substantially constrained by hydrologic variability across spatial and temporal scales. In this study, overland and subsurface flow from twelve plots in central Pennsylvania (PA) were measured and sampled for all P constituents and total solids (TS) from January 2013 to May 2017. We regressed loads of total P (TP), dissolved P (DP), particulate P (PP), and TS against flow depths to evaluate how P and TS losses changed with increasing flow. The results revealed dilution of all P constituents and near-chemostatic behavior (little change in concentration with change in flow) for TS for both application methods. Shallow-disk injection was found to be more effective than broadcasting in promoting dilution of DP, and to a lesser extent, TP. In contrast, the broadcast plots showed stronger dilution patterns than did the injection plots for PP, and there was no difference between application methods for TS. Variability among plots within each manure application practice was largely dependent on relative contributions of overland and subsurface flow due to increased dilution of P by subsurface flow. Overall, shallow-disk injection appears to be an effective practice to reduce DP and TP losses without negating the erosion-reducing benefits of no-till.
AB - Eutrophication and sedimentation are pervasive challenges in many agricultural watersheds. Recent research has promoted shallow-disk manure injection as a means of mitigating phosphorus (P) losses in runoff while maintaining the water quality benefits of no-till, such as reduced particulate P and sediment losses. However, the precision and accuracy of field studies seeking to quantify the effectiveness of shallow-disk injection as a P mitigation strategy are substantially constrained by hydrologic variability across spatial and temporal scales. In this study, overland and subsurface flow from twelve plots in central Pennsylvania (PA) were measured and sampled for all P constituents and total solids (TS) from January 2013 to May 2017. We regressed loads of total P (TP), dissolved P (DP), particulate P (PP), and TS against flow depths to evaluate how P and TS losses changed with increasing flow. The results revealed dilution of all P constituents and near-chemostatic behavior (little change in concentration with change in flow) for TS for both application methods. Shallow-disk injection was found to be more effective than broadcasting in promoting dilution of DP, and to a lesser extent, TP. In contrast, the broadcast plots showed stronger dilution patterns than did the injection plots for PP, and there was no difference between application methods for TS. Variability among plots within each manure application practice was largely dependent on relative contributions of overland and subsurface flow due to increased dilution of P by subsurface flow. Overall, shallow-disk injection appears to be an effective practice to reduce DP and TP losses without negating the erosion-reducing benefits of no-till.
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U2 - 10.1016/j.agee.2018.11.001
DO - 10.1016/j.agee.2018.11.001
M3 - Article
AN - SCOPUS:85056646910
VL - 272
SP - 19
EP - 28
JO - Agro-Ecosystems
JF - Agro-Ecosystems
SN - 0167-8809
ER -