This document summarizes research on conservation channel design and sediment capture in two-stage ditches. It finds that self-forming channels accumulated more sediment, carbon, nitrogen, and phosphorus over time compared to traditional ditches. Sediment analysis showed higher nutrient levels than surrounding soils. A case study site captured over 500 kg of phosphorus over 9 years that could be harvested and reused as fertilizer, offsetting nutrient costs for farmers. The document concludes sediment trapping in two-stage ditches can improve water quality while providing a locally sourced, cost-effective fertilizer resource.

1. Conservation Channel Design

3. The Conservation Toolbox

4. Self-Forming Two-Stage Ditch Sites
Photo Albums: https://www.flickr.com/photos/101539667@N06/albums

5. Beem Ditch

12. Beem Ditch Evolution - As Built
October-2005

13. Beem Ditch Evolution - Anticipated
Some Date in the Future

14. Beem Ditch Evolution - 5.8-Years
June-2011

15. Beem Ditch Evolution - 7.0-Years
October-2012

16. Beem Ditch Evolution - 10.4-Years
February-2016

17. Site Characteristics
Reach Length Catchment Area Reach Reach:Catchment Slope Age
Site (m) (ha) (ha) Area (%) (%) (yrs)
BEE 152 116.6 0.165 0.14% 0.27% 16.2
COL 147 88.1 0.301 0.34% 0.33% 15.9
CLO 511 671.1 0.869 0.13% 0.06% 16.1
FIS 49 658.1 0.089 0.01% 0.89% 13.2
GRA 422 342.0 0.607 0.18% 0.60% 14.3
HOG 323 95.9 0.319 0.33% 0.46% 15.0
HOL 155 248.7 0.092 0.04% 0.30% 12.5
SCI 152 33.7 0.156 0.46% 1.10% 13.2

18. Accumulated
material
Bulk
density
Accumulation
rate
Site (kg/yr) (g/cm3) (kg·m-2·yr-1)
FIS 23,541 0.77 41.6
GRA 53,036 0.99 16.4
HOL 9,956 0.79 18.5
BEE 15,384 0.81 9.9
SCI 5,693 0.80 5.5
HOG 19,037 0.75 5.7
COL 49,662 0.85 20.2

19. BEE COL CLO FIS GRA HOG HOL SCI
Total
P
(ppm)
200
400
600
800
1000
1200
1400
1600
TP Concentrations

20. Organic Matter
BEE COL CLO FIS GRA HOG HOL SCI
OM
(%)
2
4
6
8
10
12
14
16

21. Total Carbon (%)
BEE COL CLO FIS GRA HOG HOL SCI
Total
C
(%)
3
4
5
6
7
8
9
10

22. Total Nitrogen (%)
BEE COL CLO FIS GRA HOG HOL SCI
Total
N(%)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8

23. Accumulation Rates
Total C Total N Total P
Site (g · m-2
· yr-1
) (g · m-2
· yr-1
) (g · m-2 · yr-1
)
BEE 804 34.9 6.2
COL 1411 65.0 24.7
CLO 186 15.9 3.2
FIS 2453 150.7 24.9
GRA 873 39.1 10.2
HOG 256 18.7 5.1
HOL 1362 64.1 17.6
SCI 360 15.9 3.2
Average 963 50.5 11.9
Mean Accumulation rates

24. Indicator System Type Range
Soil organic matter (g/kg)
This study Self-forming channels 28-142
Rokosch et al. 2009† Forested wetlands 15-35
Mitsch et al. 2012‡ Constructed wetlands 50 - 90
Total Carbon (g/kg)
This study Self-forming channels 35 – 90
Anderson and Mitsch 2006 Constructed wetlands 38±2
Rokosch et al. 2009† Forested wetlands 6 - 18
Hossler et al. 2011 Constructed wetlands 29.3±2
Hossler et al. 2011 Natural wetlands 129±50
Total carbon (g/m2/yr)
This study Self-forming channels 186-2453
Anderson and Mitsch 2006 Riverine wetlands 181 – 193
Total nitrogen (mg/kg)
This study Self-forming channels 2193 – 7090
Anderson and Mitsch 2006 Constructed wetlands 320±20
Rokosch et al., 2009† Forested wetlands 500 – 1200
Hossler et al. 2011 Constructed wetlands 2540±160
Hossler et al. 2011 Natural wetlands 11300±4700
Total nitrogen (g/m2/yr)
This study Self-forming channels 15.9-151
Anderson and Mitsch 2006 Riverine wetland 16.2 – 16.6
Total phosphorus (mg/kg)
This study Self-forming channels 377 - 1494
Anderson and Mitsch 2006 Constructed wetlands 701±35
Rokosch et al. 2009† Forested wetlands 700 - 1200
Total phosphorus (g/m2/yr)
This study Self-forming channels 3.2 – 24.9
Mitsch and Gosselink 1993 Treatment wetlands 0.4 – 3.5
Anderson and Mitsch 2006 Riverine wetlands 3.3 – 3.5
Comparison to
Other
Ecosystems

25. Deposited
Sediment/Soil
Subsoil
P and N Mineralization – Kurt Site

26. OWC - Upstream

27. OWC - Downstream

28. Subsoil
Topsoil
Deposited
Soil
Bench in
Trapezoidal
Channel
Deposited
Soil
Core
Subsoil Core
Original Trapezoidal Ditch
Constructed
Two-Stage
Ditch
Excavated Floodplain in Subsoil
Subsoil Core Deposited Soil Core
Subsoil
Core
Deposited Soil
Core
In Situ Resin Core Method (Noe)

29. Proportion by Resin Bead Bag Position
Threshold in Check Bags (B+E) <10-20%

30. Mineralization Rates (g/m2/yr)
PO4-P NO3-N NH4-N
Watershed Data Period (g · m-2 · yr-1) (g · m-2 · yr-1) (g · m-2 · yr-1) Notes
OWC All 11/21 – 5/22 0.35 -0.42 11.17 This study; two-stage ditch
OWC All 11/21 – 5/22 0.49 -0.60 10.85 This study; self-forming channel
OWC Below Threshold 11/21 – 5/22 0.79 -0.52 9.47 This study; self-forming channel
OWC Worst Case 11/21 – 5/22 0.64 0.46 11.80 This study; two-stage ditch
OWC Worst Case 11/21 – 5/22 0.79 -0.34 12.37 This study; self-forming channel
Kurt Below Threshold 10/20 – 10/21 0.56 1.06 0.47 This study; two-stage ditch deposition
Kurt Below Threshold 10/20 – 10/21 0.26 0.59 0.67 This study; two-stage ditch subsoil
Urban WS (NC ) 0.27 9.11 McMillan et al., 2017; Urban Stream Restoration
Smith Creek (VA) 0.15 - 4.53 (-24.0) - 25.1 0.77 - 25.5 Gillespie et al., 2018; 3rd/4th Order
Difficult Run (VA) 0.11 2.69 1.78 Noe et al., 2013; streams/swamp
Piedmont (VA) 0.15 1.13 5.8 Wolf et al., 2014; Natural and constructed wetlands
Pocomoke (MD) 0.21 - 5.5 2.3 - 28 Noe et al., 2019; Restored/channelized/natural

31. Agronomic Impacts of Sediment and Nutrient
Capture, Harvest and Reuse
Matt Simmons
Advisor: Dr. Jon Witter

33. FERTILIZER TREATMENTS
Preplant (Valmar 1255)
29-lb/ac N (163-lb/ac 18-46-0)
75-lb/ac P2O5 (163-lb/ac 18-46-0)
57-lbs/ac K2O (95-lb/ac 0-0-60)
At Plant (Vapply Surface Bands)
20-lbs/ac 28% N
Sidedress (Hand Spread; 8/17/20)
150-lbs/ac N @V8-V10 (0-46-0)

34. In Season Sampling Observations
(Year 1 – Corn)
• Stand counts lower in several sediment amended plots
• Timing of amendment and seed corn maggot
• Sediment amended plants ahead 1 growth stage
• Taller plants in sediment amended soils (V5-V7)
• Stalk diameters where significantly higher in sediment
amended plots
• Plant tissue analysis of macronutrients all within
acceptable ranges for growth stage
• Weeds not an issue with typical crop protection
program
• Little disease pressure observed during the growing
season
• Insects (Japanese beetles (Year 2 – Soybeans))

35. Corn Yield
T1 T2 T3 T4 T5 T6 T7 T8
Yield
(bu/ac)
120
140
160
180
200
220
240
260
280
300
a
de
bc
abc
cde
bcd
e
ab

36. CONTACT INFORMATION
Jon Witter
Email: witter.7@osu.edu
Office Phone: (330)287-1377
Dan Mecklenburg
Email: mecklenburg.2@osu.edu

37. Site:Watershed Area vs. P Accumulation
P
Accumulation
(g·m-2·yr)
Site:Watershed Area (%)

38. Site:Watershed Area vs. P Accumulation
P
Accumulation
(g·m-2·yr)
Site:Watershed Area (%)

39. Context – Sediment Capture,
Harvest, and Reuse – OWC Site
• Deposition in 900-ft reach of self-forming channel
• Cost - $13,200 ($14/ft)
• Time since construction – 9.44-yrs
• ~1250-cubic yards (900-ft*25-ft*1.5-ft)
• Bulk density - ~0.5g/cm3
• 542-kg P (1195-lbs P; 127-lbs/yr; 743-lbs/mile/yr)
• 27.5-g P/m2/yr
• ~$8 NPK per yd3
• $6-$12 per yd3 to dredge and spread
• Coverage ~9.3-acres (1-inch spread depth)