Author
ROSS, JARED - Nature Conservancy | |
HERBERT, MATTHEW - Nature Conservancy | |
SOWA, SCOTT - Nature Conservancy | |
FRANKENBERGER, JANE - Purdue University | |
King, Kevin | |
CHRISTOPHER, SHEILA - University Of Notre Dame | |
TANK, JENNIFER - University Of Notre Dame | |
Arnold, Jeffrey | |
White, Michael | |
YEN, HAW - Texas A&M University |
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/20/2016 Publication Date: 10/24/2016 Publication URL: https://handle.nal.usda.gov/10113/5571192 Citation: Ross, J.A., Herbert, M.E., Sowa, S.P., Frankenberger, J.R., King, K.W., Christopher, S.F., Tank, J.L., Arnold, J.G., White, M.J., Yen, H. 2016. A synthesis and comparative evaluation of drainage water management. Agricultural Water Management. 178:366-376. Interpretive Summary: In the humid poorly drained regions of the world, artificial subsurface (tile) drainage is a necessity rather than an option. While necessary for crop production, tile drainage has also been identified as a major pathway for nutrient transport to surface waters. Drainage water management (DWM) is one best management practice that offers to address nutrient loss from tile drainage. In a comparative analysis, DWM significantly reduced discharge and nutrient (nitrogen and phosphorus) losses by 45% to 55%. Implementation of DWM management in tile drained landscapes will help reduce the environmental footprint of agriculture in tile drained landscapes. Technical Abstract: Viable large-scale crop production in the United States requires artificial drainage in humid and poorly drained agricultural regions. Excess water removal is generally achieved by installing tile drains that export water to open ditches that eventually flow into streams. Drainage water management (DWM) is a best management practice (BMP) that allows farmers to artificially raise the outlet elevation of a field’s drain tile and can reduce nutrient loss during wet periods by storing more water in the field. We intended to assess the effectiveness of DWM to reduce drainage discharge and nutrient loads and additionally identify predictor variables that influence DWM effectiveness. We compared managed (i.e., DWM) and free draining records using paired t-tests, and identified factors associated with DWM effectiveness using a multiple linear regression approach. T-test results indicated that DWM was highly effective in reducing drainage water discharge and nutrient losses via drain tiles as tile discharge volumes were reduced on average 46%, while tile nitrate loads were reduced by 48%. In addition, total phosphorus and dissolved reactive phosphorus loads were reduced by 55% and 57%, respectively. Based on regression results, we found several aspects of farm and tile drain management were associated with DWM effectiveness, while site specific landscape characteristics were less likely to predict effectiveness. While DWM is effective as a BMP to reduce discharges of water and nutrients from drain tiles, we also identified several knowledge gaps. Future research should investigate effects of DWM on water and nutrients lost in other pathways such as surface runoff, preferential flow, groundwater recharge and biological uptake, and also focus more attention on phosphorus as a paucity of research currently exists regarding this topic. |