1. Dr. Larry C. Brown Professor, Extension Agricultural Engineer Department of Food, Agricultural, and Biological Engineering The Ohio State University Agricultural Water Management

2. Crop Yields

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

4. 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

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

7. 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)

8. Drainage Improvement Economics for Corn & Soybean Hoytville Silty Clay – Northwest Ohio
Benefits to Cost Ratio
Continuous Corn 1.7 to 2.0
Rotation Corn 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)

9. 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)

10. 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

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

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

13. 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

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

15. Water Table Management
Conventional Drainage
Controlled Drainage
Subirrigation

17. 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

18. Yield Advantage ( ) 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

19. 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 bu/ac for corn and 3-12 bu/ac for soybean
adding subirrigation may increase yields by bu/ac for corn and bu/ac for soybean
Ohio State University/USDA-ARS Crop Yield Data

20. Dr. Larry C. Brown Professor, Extension Agricultural Engineer Department of Food, Agricultural, and Biological Engineering The Ohio State University Agricultural Water Management

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