Do We Put Tiling (Subsurface Drainage) on Hold? or Does Agriculture move towards More Sustainable Agricultural Water Management? Presented at the Ohio Academy of Sciences, April 2012.

1. Do We Put Tiling (Subsurface
Drainage) on Hold?
or
Does Agriculture move towards More
Sustainable Agricultural Water
Management?
Dr. Larry C. Brown
Professor, Extension Agricultural Engineer
Department of Food, Agricultural, and Biological Engineering
The Ohio State University
614-292-3826
brown.59@osu.edu

2. Drainage impacts, research needs, potential
practices for nutrient capture and reduction
• Edge-of-Field data very important (USDA-ARS Soil
Drainage Research Unit)
• Drainage Water Management (controlled drainage),
Estimating Nitrate-load Reductions w/DrainMod
• Nitrate Wood-Chip Bioreactors
• Phosphorus Filters w/Steel Slag Aggregate
• Saturated Buffers (controlled drainage interface
between cropland and buffers)
• Two-Stage Channels
• Water Table Management with Constructed
Wetlands (WRSIS)

3. Water Table
Management
• Conventional
Subsurface
Drainage
• Controlled
Drainage
• Subirrigation

4. Objective of Subsurface Drainage is to
Remove Excess Soil-Water from the
Root Zone, and Sometimes to Provide
Outlet for Surface Inlets

5. Expanded Wetland Yocom Farm
Ag
Constructed Champaign County
Wetland at Ohio
Outlet
Existing Wetland - 2000

8. Ohio is Home to Two Long-
Term Drainage-Crop Yield
Studies
•G.O. Schwab et al., Drainage X
Study at Castalia, Sandusky
X
County
•Toledo Silty Clay – 20 Years
•Brown, Reeder et al.,
Drainage/Tillage Study at
OARDC Northwest Research
Station, Wood Co
•Hoytville Silty Clay
•12-25 yrs (on-going)

9. Study by Professor G.O. Schwab et al.
Managing Soil Water through drainage on poorly drained and
somewhat poorly drained soils helps to decrease year-to-
year variability in crop yield
Contact Dr. Brown for Handout with Data Summary

10. For Many of Ohio’s Poorly Drained, and
Somewhat Poorly Drained Soils:
• Compared to lands with adequate surface
drainage,
–Subsurface drainage improvements
may increase yields by 25-30 bu/ac
for corn and 3-12 bu/ac for soybean
• Compared to lands with adequate subsurface drainage, and where
conditions are appropriate,
– Controlled drainage may increase corn yield by up to 20
bu/ac, soybean yield by to 2 bu/ac
• Compared to lands with adequate subsurface drainage, and where
conditions are appropriate,
– Subirrigation/controlled drainage may increase yields
by 25-60 bu/ac for corn and 9-12 bu/ac for soybean
Ohio State University/USDA-ARS Crop Yield Data

11. What about Subsurface
Drainage and Water
Quality?

12. USGS

13. Source areas of N to Gulf of Mexico and Great Lakes

14. Fausey, 2004

15. Water Quality and Quantity Impacts of
Agricultural Subsurface Drainage
•Fausey, Brown, Belcher and Kanwar (1995)
reviewed/summarized 150+ journal articles
and published reports that discuss application
and impact of agricultural drainage.
•From this literature review, water quantity and
quality impacts related to subsurface drainage
as percentage change of quantity or quality
parameter are summarized below.

16. Water Quality and Quantity Impacts of
Agricultural Subsurface Drainage
It is important to note:
This information should be used in
reference to the studies being conducted
on agricultural land where subsurface
drainage was in place and compared to
similar conditions where subsurface
drainage was not in place. All soils,
slope, surface drainage, climate, cropping
and management conditions, etc., were
generally the same at each site.

17. Impact of Agricultural Subsurface Drainage as Percentage
Change in Value of Water Quantity or Quality Parameter
Water and Sediment
• Reduction in total amount of runoff
that leaves site as overland flow
ranged from 29 to 65%
• Reduction in peak runoff rate of
overland flow ranged from 15 to 30%
• Reduction in total amount of
sediment lost from site by water
erosion ranged from 16 to 65%

18. Impact of Agricultural Subsurface Drainage as Percentage
Change in Value of Water Quantity or Quality Parameter
Soil-Bound Nutrients
• Reduction in amount of phosphorus
lost from site by water erosion
ranged from 0.0 to 45%
• P reduction related to reductions in
total soil loss, total runoff, peak
runoff rate
• Reduction in soil-bound nutrients
ranged from 30 to 50%

19. When the research data are reviewed in
the proper context, there are many
positive water quality benefits with
properly designed and installed
subsurface drainage systems.
However, there is no doubt that
the major water quality issue
with subsurface drainage is
the export of nitrate–nitrogen,
N03 to surface waters, and
possibly other solutes (LC Brown).

20. In the Hydrologic Context:
Presence of subsurface drainage generally:
Increases infiltration
Decreases runoff and sediment loss
Therefore, it tends to also:
Increase losses of more mobile compounds,
like nitrate and phosphate, through
subsurface drainage water
Decrease runoff losses of sorbed
compounds, such as particulate
phosphorus, pesticides, etc.

21. Consider that anytime the drains are
flowing, there is most likely some
nitrate-nitrogen being exported.
Image from Kladivko,
Brown and Baker –
Purdue University

22. Pesticide transport to subsurface drains
in humid regions of North America
(Kladivko, Brown and Baker, 2001)
Reviewed 30+ North American studies of
pesticide transport into subsurface
drains
Provided background information on
subsurface drainage use and geography,
for hydrologic context
Evaluated implications of data in light of
other contributions to surface water
degradation

23. Consider that pesticides have the greatest potential to be
exported through subsurface drains to surface waters is
soon after application in the spring.
And,….. When surface
inlets discharge into
subsurface drainage
systems, or
subsurface drainage
system is not
maintained, or when
blowholes or other
short-circuiting
mechanisms are
present……..

24. Modeling Water Balance Midway Between
Two Subsurface Drains
Predicting Relative Crop Yields and
Nitrogen Fate
DRAINMOD Water Management Model

25. Overall Average Relative Crop Yield
for Kokomo Silty Clay Loam from DRAINMOD Simulations
Overall Average Relative Yield (%)
Drain
Depth
(cm) 3’ 4’ 4.5’
Drain Spacing, cm
(ft) 60 70 80 90 100 110 120 130 140 150
500 (16’) 62 66 72 77 79 80 81 81 81 81
750 (25’) 62 66 69 76 80 81 82 82 82 82
1000 (33’) 60 66 69 75 79 81 82 82 83 83
1500 (50’) 57 60 66 70 76 79 81 82 82 82
2000 (66’) 54 57 59 63 68 71 74 77 78 79
3000 (100’) 46 50 53 56 57 60 62 63 64 65
5000 (166’) 36 37 39 42 44 48 49 51 52 53
100000 (3280’) 20
Continue this assessment with DM-NII on 58 soils series

26. Water Table
Management
• Conventional
Drainage
• Controlled
Drainage
• Subirrigation

27. For Many of Ohio’s Poorly Drained, and
Somewhat Poorly Drained Soils:
• Compared to lands with adequate surface drainage,
– Subsurface drainage improvements may increase yields
by 25-30 bu/ac for corn and 3-12 bu/ac for soybean
• Compared to lands with adequate subsurface drainage,
and where conditions are appropriate,
– Controlled drainage may increase corn yield by up to 20
bu/ac, soybean yield by to 2 bu/ac
• Compared to lands with adequate
subsurface drainage, and where conditions
are appropriate,
– Subirrigation/controlled drainage may
increase yields by 25-60 bu/ac for corn
and 9-12 bu/ac for soybean
Ohio State University/USDA-ARS Crop Yield Data

28. Drainage Water Management

29. Artificially Raise the Outlet Elevation
Managing the Outlet Elevation – not Plugging the Outlet
We do NOT suggest that you Plug the Outlet!
NRCS Practice
Standard 554
Drainage Water Management

30. Nitrate N Concentration mg/L 35 OARDC
Northwest
30 Agricultural
Research Station
25 Free Drainage
20
15 Controlled
Drainage
10
5 Subirrigated
0
1m 2m 3m
Depth Norman R. Fausey,
USDA-ARS Soil
Drainage Research Unit

31. 30 OARDC
Northwest
Nitrate-N load (Kg/ha/yr)
25 Agricultural
Research Station
20
Corn
15 Soybean
10
5
0
Free Controlled Subirrigation Norman R. Fausey,
Drainage Drainage USDA-ARS Soil Drainage
Research Unit

32. Nitrate and
Phosphate
Concentrations in
Drainage Water with
and without
Controlled Drainage
(Fausey data).

33. A different way to approach design, installation and management
for improved water quality and potentially improved crop yields

34. On appropriate landscapes, we expect up to
a 50% reduction in Annual Nitrate Loads, on
average, by Managing Agricultural Drainage
Systems in Ohio and across the Midwest
“Change in Outflow Volume”
Minimal change in Concentration
We continue to research impacts on crop
yields, economics, soil-water, and nitrate-
nitrogen and soluble phosphorus fate, etc.

35. For Many of Ohio’s Poorly Drained, and
Somewhat Poorly Drained Soils:
• Compared to lands with adequate surface drainage,
– Subsurface drainage improvements may increase yields
by 25-30 bu/ac for corn and 3-12 bu/ac for soybean
• Compared to lands with adequate
subsurface drainage, and where conditions
are appropriate,
–Controlled drainage may increase
corn yield by up to 20 bu/ac, soybean
yield by to 2 bu/ac
• Compared to lands with adequate subsurface drainage, and where
conditions are appropriate,
– Subirrigation/controlled drainage may increase yields
by 25-60 bu/ac for corn and 9-12 bu/ac for soybean
Ohio State University/USDA-ARS Crop Yield Data

36. Hydrology of Controlled Drainage/Subirrigated System
(CWAES – USDA-ARS-SDRU & OSU-FABE/Soil Ecology)
Controlled 60-80 day Subirrigation/ Controlled
•Up to 40% Drainage prep, plant, Controlled Drainage
ermerge Drainage
reduction in (Rainfed only) (Rainfed
only)
subsurface Ponded 80-100 day
30 day
subirrigation Ponded
drainage flows Soil 30 day draw-
draw-
•Up to 80% Surface down
down
reduction in nitrate Water
loads Table
•30% to 50%
improvement in Drain
Depth
crop yields
Jan Mar Jun Oct Nov Dec
Brown, Fausey et
al.

38. Crop Yields with CWAES @ PREC
Corn Brown, Fausey, Workman, Subler, Bierman
180
160
156.2 Soybean
140 112.7 116.6 121.4 114.1 60
120 54.2
90.9
100 50 43.1 44.6
76.9
80
60 40
39.7 31.2
28.5 26.5 28.8
40 30 24.1
20
0 20
1995 1996 1997 1998 10
0
SI/CD SSD
1995 1996 1997 1998
Partial-season subirrigation in 1995 and 1998
Full-season subirrigation in 1996 and 1997 SI/CD SSD
7.7 in precip during subirrigation period in 1996
13.1 in precip during subirrigation period in 1997

39. Brown, Fausey et al.

40. Wetland-Reservoir-Subirrigation-Systems (WRSIS)
Agricultural Drainage Water Harvesting, Treatment, Storage, and
Recycling for Irrigation Water Supply, Crop Yield Increase and Water
Quality Improvement
•Increased wetland acres on
farmland
•Improvement in wetland vegetation
and wildlife habitat
•Significant increase in crop yields
•Significant improvement in water
quality
•Potential to provide only clean
water leaving the farm
•Goal was not restoration, but
integrating constructed wetlands Collaboration w/USDA-NRCS; ODNR-DSWC; producers; others
within farming systems –
“Agricultural Constructed Wetland”
•Technology extended to Ontario,
Brown, Allred, Fausey et al.
Michigan, Illinois, Indiana, China

41. Fulton County WRSIS Site, Shininger Farm – August 1996
 Soil predominantly Nappanee loam
 1 - 8.1 ha (20 ac) subirrigated field. Drain spacing is 4.6 m (15 ft)
 One 8.1 ha (20 acre) field with conventional subsurface drainage.
Drain spacing is 13.7 m (45 ft)
 Wetland: 0.57 ha (1.4 ac) area and 3,790 m3 (1.0 million gal) capacity
 Reservoir: 0.64 ha (1.57 ac) area and 8,706 m3 (2.3 million gal) capacity
 Stream provides additional water supply
Ohio WRSIS
Photo Courtesy of USDA-NRCS-MVRC&D

42. Woodchip Bioreactors and Proposed
Bioreactor - Phosphate Filter
Demonstration at WANRL and FSR
Larry C. Brown (OSU), Norman R. Fausey
(USDA-ARS), Kevin King (USDA-ARS), Ehsan
Ghane (OSU), and Aleksandra Drizo
(University of Vermont)

43. 5’ Soil backfill
10’ Wide
Top View
Diversion 5’ section of non-perforated tile
Capacity control
structure structure
Length dependent on treatment area
Up to soil
surface
Side View
From
Richard
Trench bottom 1’ below tile invert Cooke, UIl

44. Managed Drainage
28 acres
100 ft Spacing
W
Free Drainage
31 acres
100 ft Spacing From
Richard
Cooke, UIl

45. 7
Changes in Nitrate-Nitrogen 6
Concentration (mg/l) 5
Dark Blue – inflow conc 4
Pink – outflow conc
3
2
From Richard Cooke, UIl 1
0
10/10/06 01/18/07 04/28/07 08/06/07
Time
Inlet Outlet
7
1.8
6
1.6
5 1.4
1.2
4
1.0
3 0.8
2 0.6
0.4
1
0.2
0 0.0
10/10/06 01/18/07 04/28/07 08/06/07
01/08/07 01/29/07 02/19/07 03/12/07 04/02/07 04/23/07
Time Time
Inlet Outlet Inlet Outlet

47. Waterman Agricultural and Natural
Resources Lab
“Water Management focuses on Zero-
Discharge”
3 WTC Structures installed March 2009 Outlets, one
8”
with 15” WTC
Manure applied from Dairy
Structure
8”
10”
OSU Dairy
Two-Stage
Channel
WANRL Stormwater Wetlands
Developing Conservation Plan for Zero-Discharge of Pollutants

48. Draft sketch of bioreactor components

49. Phosphorus Filter using Steel Slag
Aggregate
• Dr. Aleksandra Drizo, Research Professor,
University of Vermont, and CEO PhosphoReduc
(www.phosphoreduc.com).
• Implementation and testing of PhosphoReduc
system in a treatment train, for the reduction of
phosphorus contained in point (agricultural
effluents) and non-point source pollution
(untreated urban and rural runoff).
• Dr. Kevin King USDA-ARS using P filter in Upper
Big Walnut Creek Watershed CEAP project

51. Subsurface Drainage Outlets Short Circuit Buffer Function
Conservation Buffers w/Controlled
Agricultural Drainage
(Drainage Water Management NRCS 544)
CREP Supplemental Practice for Scioto Watershed
Possibly included in Western Lake Erie CREP
Buffer and Cropland with Subsurface Drainage and Outlet Control Structure
Seeking support to verify impact of this practice

52. Width and Depth of Small Main Channel
30
y = 6.8x0.3303
25
R2 = 0.56
Dimensions (ft)
20
width
15
0.3124
y = 0.91x mean
10
R2 = 0.60 depth
5
Ditch Width and Stability
0
0 5 10 15 20 25 30 35 40
y = 15.8x0.24
Drainage Area (square miles)
R2 = 0.90
30
Ditch Width (ft)
20 stable
y = 12.9x0.2718
unstable
R2 = 0.93
10 Ward,
Mecklenburg,
0 et al.
0 5 10 15 20 25 30 35
Drainage Area (square miles)

53. Research needs, potential practices for
nutrient capture and reduction
• Edge-of-Field data very important (USDA-ARS Soil
Drainage Research Unit)
• Drainage Water Management (controlled drainage),
Estimating Nirtate-load Reductions w/DrainMod
• Nitrate Wood-Chip Bioreactors
• Phosphorus Filters w/Steel Slag Aggregate
• Saturated Buffers (controlled drainage interface
between cropland and buffers)
• Two-Stage Channels
• Water Table Management with Constructed
Wetlands (WRSIS)

54. For information on any of these
topics, contact:
Dr. Larry C. Brown
Professor, Extension Agricultural Engineer
Department of Food, Agricultural, and Biological
Engineering
The Ohio State University
614-292-3826
brown.59@osu.edu
Agricultural Water Management