2017 SWCS Annual Conference July 30-August 2, 2017 Monona Terrace Convention Center

1. Enhancing Environmental Stewardship of
Corn Silage Systems with Cover Crops
and No-tillage
Hatch Multistate Research Project (NC 1178)
Formerly: “Impacts of Crop Residue Removal on Soils”
Laura C. Adams2, Francisco J. Arriaga1, and Michael Bertram3
1-Assistant Professor; 2-M.S. Candidate; 3-Superintendent
Dept. of Soil Science, and Arlington Agricultural Research Station
University of Wisconsin-Madison
2017 Soil and Water Conservation Society Annual Conference
Madison, WI

2. Background
• Dairy is an important agricultural sector in
Wisconsin ($43.4 billion 2016).
• Milking cows need high quality feed, such as corn
silage and alfalfa.
• After corn silage, manure is commonly applied to
the field. Challenge for phosphorus (P)
management since these soils are prone to greater
erosion and nutrient runoff risks.
• Can reduced tillage and cover crops help?

3. Objective
• Determine the impact of using a cereal rye as a
cover crop and no-tillage on sediment and
phosphorus losses from corn silage production.

4. Plot Size = 45’ x 500’ = 0.52 acre
Experiment Site = 555’ x 1740’ = 22.17 acre
T1 NT Cover Crop
T2 NT Cover Crop – Harvest
T3 NT No Cover Crop
T4 CT Cover Crop
T5 CT Cover Crop – Harvest
T6 CT No Cover Crop

6. Rainfall Simulation
• Oscillating nozzle rainfall simulator
• 3-inches per hour for 60 min. (7.6 cm/hr)
• Simulations conducted in June 2016, October 2016,
and April 2017
• Used deionized water

7. Runoff Sample Analysis
• Total runoff volume
• Sediment
• Phosphorus fractions
Other Info:
• Soil: silt loam
• Annual dairy manure
• Bray-P ~40 ppm

8. Cumulative Runoff

9. Total Runoff
Source Probability > F
Tillage (T) 0.3749
Cover (C) 0.0019
Date (D) 0.2412
T x C 0.5841
T x D 0.0702
C x D 0.0083
T x C x D 0.2595

10. Total Runoff (cont.)

11. Total Runoff at Different Times of Year
Year
Source June October April
Tillage (T) 0.0007 0.4534 0.9460
Cover (C) 0.0013 0.7240 0.0049
T x C 0.0038 0.8169 0.4649

12. Sediment Losses
Source Probability > F
Tillage (T) 0.5074
Cover (C) 0.0007
Date (D) 0.8741
T x C 0.1750
T x D 0.0212
C x D 0.0415
T x C x D 0.2886

13. Sediment Losses (cont.)
Treatments Sediment Load
Tillage Cover June October April
___________________ tons ha-1 ___________________
CT NCC
CC
4.70
3.00
1.87
2.89
5.22
1.44
NT NCC
CC
3.65
0.95
6.23
3.08
4.96
1.54

15. Total Phosphorus Losses
Source Probability > F
Tillage (T) 0.9287
Cover (C) 0.0142
Date (D) 0.0006
T x C 0.7051
T x D 0.1885
C x D 0.0428
T x C x D 0.4747

16. Dissolved Phosphorus Loss
Source Probability > F
Tillage (T) 0.6212
Cover (C) 0.5381
Date (D) 0.0472
T x C 0.2862
T x D 0.8258
C x D 0.6385
T x C x D 0.2308

17. Bioavailable Phosphorus Loss
Source Probability > F
Tillage (T) 0.7783
Cover (C) 0.0058
Date (D) 0.0586
T x C 0.2062
T x D 0.3524
C x D 0.1016
T x C x D 0.4005

18. Total Dry Forage Yield

19. What are we learning?
• For the conditions of our
study;
• Cover crop had a greater impact in
reducing runoff, sediment and
sediment bound phosphorus.
• Dissolved phosphorus fractions
need other approaches for
reducing losses.
• Work continues to link soil health
parameters to water quality.
Funding support: UW CALS Hatch Program, Agronomic Science Foundation, and the Monsanto Corporation.