Site Details
Site ID: DPAC
Research Leader: Jane Frankenberger
Co-Leader: Laura Bowling and Eileen Kladivko
Institution: Purdue University
Site Location: Randolph County, IN
Latitude & Longitude: 40°15'58"N 85°09'36"W
Site Acreage: 39 acres
Years of Data: 2006-2015
Description
The research was conducted at the Davis Purdue Agricultural Center (DPAC) located near Farmland, IN. The site consist of silt loam and silty clay loam soils (Blount, Condit, Glynwood, and Pewamo). There were 4 research plots, approximately 9 ac. in size, with two replications for conventional drainage and controlled drainage treatments.
Characteristics
- Drainage system installed in 2004
- Soil: Blount, Condit, and Glynwood silt loams, Pewamo silty clay loam
- Rotation: Continuous Corn (2006-2010), Corn-Soybean (from 2011)
Water Management Practices
- Conventional Drainage (depth 3', spacing 50')
- Controlled Drainage (depth 3', spacing 50')
Measurements in Database (2006-2017)
- Crop Yield (10 years)
- Drainage, Water Table, and Soil Moisture
- Tile flow (10 years, 2006-2017; estimated X years)
- Concentration of Nitrate-N (10 years), Soluble reactive phosphorus (3 years; 200x-200x), Total phosphorus (3 years; 200x-200x)
- Water table depth (10 years)
- Soil moisture and temperature (5 years; 200x-200x)
- Soil
- Texture, Infiltration Rate (1 year; 200x)
- Bulk Density, Water Retention: 0, 0.003, 0.05, 0.1, 0.33, 15 bar (3 years; 200x, 200x, 200x)
- Soil Fertility: pH, Cation Exchange Capacity, Soil Organic Carbon, Total N (3 years; 200x, 200x, 200x)
- Soil Nitrate and Ammonium (4 years; 200x, 200x, 200x, 200x)
- Plants
- Final Plant Population; Biomass, Total N, and Total C: Vegetative, Grain, Cob (2 years, 200x and 200x)
- Weather
- Precipitation, Air Temperature, Relative Humidity, Solar Radiation, Wind Speed and Direction (10 years)
Results
Crop Yield
Controlled drainage significantly increased the nine-year mean corn yield by 2.3%, while mean soybean yield was not significantly different. There was only one year when CD significantly decreased corn and soybean yield.
The linear mixed model provided additional insight on the influence of other variables and their interactions. Classifying the years by wetness clarified that CD significantly increased yields in the dry years by 5.9%.
The spatial analysis using gridded data provided greater information on influential characteristics. In this study, the very poorly drained soils had the greatest positive response to controlled drainage, while the elevations at which the response was greatest were those more than 60 cm above the water control structure, challenging a common assumption that controlled drainage will not impact yield in areas more than 60 cm above the water control structure. The grid-based linear mixed model analysis could be expanded to include different variables such as soil moisture or variable fertilizer application rate. It could also be used on other fields to determine spatially and temporally varying yield impacts of controlled drainage.
Water Quality
Nitrate concentration was measured for 11 years and phosphorus (total and dissolved reactive) for 4 years, while drain flow measurements and estimates were available for 10 years (Figure 2). Results showed that controlled drainage is a reliable management practice for reducing nitrate loads from subsurface drains, mainly due to the reduction in flow.
Nitrate Load
Nitrate-N load was reduced by 37% on an annual basis.
Phosphorus Load
Neither total nor soluble reactive phosphorus was significantly reduced under controlled drainage.
Publications
- Delbecq, B.A., J.P. Brown, R.J.G.M. Florax, E.J. Kladivko, A.P. Nistor, and J.M. Lowenberg-DeBoer. 2012. The impact of drainage water management technology on corn yields. Agronomy Journal 104(4):1100-1109.
References
- Saadat, S., Bowling, L., Frankenberger, J. and Kladivko, E., 2018. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage. Journal of hydrology, 556, pp.339-348.
- Saadat, S., Bowling, L., Frankenberger, J. and Kladivko, E., 2018. Nitrate and phosphorus transport through subsurface drains under free and controlled drainage. Water research, 142, pp.196-207.