Modeling the impact of alternative drainage practices in the northern Corn-belt with DRAINMOD-NII

• Published in: Agricultural water management 2010-03, Vol.97 (3), p.389-398
• Main Authors: Luo, W., Sands, G.R., Youssef, M., Strock, J.S., Song, I., Canelon, D.
• Format: Article
• Language: English
• Subjects: accuracy; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agronomy. Soil science and plant productions; Biological and medical sciences; calibration; Controlled drainage; corn; drainage; drainage systems; Drainage water management; environmental impact; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grain yield; hydrologic factors; hydrologic models; Hypoxia; Nitrate-nitrogen; Nitrate-nitrogen NO3-nitrogen loads Subsurface drainage Tile drainage Controlled drainage Drainage water management Shallow drainage Hypoxia; NO 3-nitrogen loads; prediction; seasonal variation; Shallow drainage; simulation models; snowmelt; soil temperature; Subsurface drainage; surface water; Tile drainage; water management; water pollution; water quality; Zea mays
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2009.10.009

The hydrologic and water quality impacts of subsurface drainage design and management practices are being investigated through field and simulation studies throughout the northern Corn-belt. Six years of data from an ongoing field study in south central Minnesota ( Sands et al., 2008) were used to support a modeling effort with DRAINMOD-NII to investigate: (1) the performance of the model in a region where soils are subject to seasonal freeze–thaw and (2) the long-term hydrologic and water quality characteristics of conventional and alternative subsurface drainage practices. Post-calibration model prediction and efficiency were deemed satisfactory using standard model performance criteria. Prediction errors were primarily associated with early spring snowmelt hydrology and were attributed to the methods used for simulating snow accumulation and melting processes, in addition to potential sublimation effects on ET estimates. Long-term simulations with DRAINMOD-NII indicated that drainage design and/or management practices proposed as alternatives to conventional design may offer opportunities to reduce nitrate (NO 3)-nitrogen losses without significantly decreasing (and in some cases, increasing) crop yields for a Webster silty clay loam soil at Waseca, Minnesota. The simulation study indicated that both shallow drainage and controlled drainage may reduce annual drainage discharge and NO 3-nitrogen losses by 20–30%, while impacting crop yields from −3% (yield decrease) to 2%, depending on lateral drain spacing. The practice of increasing drainage intensity (decreasing drain spacing) beyond recommended values appears to not significantly affect crop yield but may substantially increase drainage discharge and nitrate-nitrogen losses to surface waters.