Dr. Larry C. Brown Professor, Extension Agricultural Engineer Department of Food, Agricultural, and Biological Engineering The Ohio State University Agricultural Water Management brown.59@osu.edu http://www.ag.ohio-state.edu/~agwatmgt/

Crop Yields

Water Quality - Hydrologic Effects Management Techniques Subsurface Drainage Introduction History, Status Installation Design Crop Yields, Benefits Water Quality - Hydrologic Effects Management Techniques

Ohio Soils and Subsurface Drainage USDA-ARS-SDRU/OSU WTM Research Locations Ohio Soils and Subsurface Drainage x x x x x x x x x W x W x x x USGS x x ODNR-DSWC Map

Drainage Improvement Economics for Corn & Soybean Toledo Clay – North Central Ohio Benefits to Cost Ratio Corn Soybean Surface Drainage 3.5 2.1 Subsurface Drain 2.5 1.2 Combination 1.9 1.2 (Based on G.O. Schwab Yield Data from Castalia, Ohio)

Yield Advantage Hoytville Silty Clay – Northwest Ohio Combination Drainage (S+SSD) Compared to Surface Drainage (No SSD) (bu/ac) Continuous Corn 25 to 27 Rotation Corn 29 Rotation Soybean 7 to 10 (17) (Based on Brown, Reeder & Eckert Yield Data from OARDC, Wood County)

Drainage Improvement Economics for Corn & Soybean Hoytville Silty Clay – Northwest Ohio Benefits to Cost Ratio Continuous Corn 1.7 to 2.0 Rotation Corn 1.7 to 2.2 Rotation Soybean 3.1 to 2.3 Notes: Combination Drainage (S+SSD) Compared to Surface Drainage (No SSD) (Based on Brown, Reeder & Eckert Yield Data from OARDC, Wood County)

Two Long-Term Drainage-Crop Yield Studies Toledo Silty Clay (Schwab et al.) Hoytville Silty Clay (Brown et al.) Yield Advantage Hoytville Silty Clay - Combination Drainage (S+SSD) Compared to Surface Drainage (No SSD) Continuous Corn 25 to 27 Rotation Corn 29 Rotation Soybean 7 to 10 (17) (Based on Yield Data from Brown, Reeder & Eckert OARDC, Wood County)

Test Case Simulation Subsurface Drainage Improvement Hoytville Silty Clay Soil Drain Spacings of 15, 30, 45 60, and 100 feet Range of capital costs from $1133/ac to $150/ac Down payment, 40% and 20% MTR 34% and 40% Cost of debt, 8% and 10% Price of corn, means of $2.00 and $2.41 Before- and after-tax analyses

Economics of Drainage Improvements Simple Field-Scale Analyses More Complex Analyses within Farming Enterprise Simulation Modeling

Modeling a Water Balance Midway Between Two Subsurface Drains Predicting Relative Crop Yields Using the DRAINMOD Water Management Model

Kokomo Silty Clay Loam – Apparent Water Table, Glacial Till Crosby Silty Clay Loam – Perched Water Table, Glacial Till Kokomo Silty Clay Loam – Apparent Water Table, Glacial Till 47 Years

Simulation Results Optimal spacing 50’ before-tax analysis NPVbt = $928 Optimal spacing 40’ after-tax analysis NPVat = $818

Water Table Management Conventional Drainage Controlled Drainage Subirrigation

Crop Yields with CWAES @ PREC Brown, Fausey, Bierman, Workman, Subler Corn Soybean Partial-season subirrigation in 1995 and 1998 Full-season subirrigation in 1996 and 1997 7.7 in precipitation during subirrigation period in 1996 13.1 in precipitation during subirrigation period in 1997

Yield Advantage (1996-2001) with Subirrigation/Subsurface Drainage Shininger Farm – Fulton County, Ohio Corn 192 bu/ac SI/SSD 140 bu/ac SSD Six-Year Average Yield advantage 52 bu/ac Soybean 63.6 bu/ac SI/SSD 53.7 bu/ac SSD Six-Year Average Yield Advantage 9.9 bu/ac

Compared to lands with adequate surface drainage, For soils that are proven to respond to drainage improvements, think about more intensity drainage and management for potential to produce greater yields: Compared to lands with adequate surface drainage, adding subsurface drainage improvements may increase yields by 25-30 bu/ac for corn and 3-12 bu/ac for soybean adding subirrigation may increase yields by 25-60 bu/ac for corn and 10-12 bu/ac for soybean Ohio State University/USDA-ARS Crop Yield Data

Dr. Larry C. Brown Professor, Extension Agricultural Engineer Department of Food, Agricultural, and Biological Engineering The Ohio State University Agricultural Water Management brown.59@osu.edu http://www.ag.ohio-state.edu/~agwatmgt/

Shininger Farm Ear Comparison (left SI; right SSD) Photo by Greg La Barge, 2001