Cover Crop Water Usage and Affect on Yield in No-Till Dryland Cropping Systems

Editor's Note: You can view the full report with tables and charts by clicking on the link below. The text only version of the report follows.

PROJECT BACKGROUND
Providence Farms, LLC is the joint farming venture of the Brian Berns and Keith Berns families of Bladen, Nebraska. Brian and Keith, along with their families, farm over 2,000 acres in south central Nebraska. The farm ground is about 1/3 pivot irrigated and 2/3 dryland and has been under continuous no-till production for 10-15 years.

Irrigated rotations consist primarily of corn and soybeans with an occasional cropping of irrigated wheat followed by a cash double crop. Dryland rotations are mainly corn-corn-soybeans-wheat-covercrop. A small cow-calf herd of around 45 cows is also maintained on the farm.

We have been no-tilling for 20 years and have been 100% continuous no-till for 10 years now (with the exception of 100 acres of ridge-till gravity irrigated ground). We are strong believers in no-till and are very active in the promotion of no-till farming.

PROJECT DESCRIPTION AND RESULTS
Goals: Our main goal was to look at how cover crops would work in the Midwest and, particularly, how they would affect a dryland cropping system. The first question and major concern any dryland farmer has about cover crops is: “How much water will a cover crop use?” This project attempted to answer this question regarding the use of cover crops in a dryland no-till cropping system.

A secondary goal was to look at how cover crops might effect the yield of the next crop. We recorded the yield of corn that was planted into different cover crop plots and analyzed this data to determine if cover crops had any affect on yield.

Process:
1. Select cover crops to be tested and order seed – Completed: May 2008
We consulted with a number of cover crop “experts” to determine what species to use and what mixtures to consider. Factors that were considered in the selection of cover crops were: [a] cost of seed (needs to be economically feasible), [b] ease of seeding (needs to be able to be seeded with existing equipment) [c] variety (include broadleaves, grasses, legumes, and mixtures) and [d] life span (choose some crop that winter kill and some that over-winter). Cover crops that were used included broadleaves, grasses, legumes, and mixtures. The following table shows crops that were used in this project:

Legumes
• Soybeans
• Lentils
• Vetch – common
• Red Clover
• Alfalfa

Grasses
• Milo
• Sudan
• Millet
• Winter Barley
• Wheat

Other
• Sunflowers

Mixes
Brassica Mix: Graza fodder radish, T-Raptor (rape x turnip), Hunter (rape x turnip), Barkant turnip, Barabas turnip, Rival turnip, Rangiora forage rape, Winfred forage (rape x kale)

Grass Mix: milo, sorghum sudan, pearl millet, proso millet, German millet

Legume Mix: Soybeans, mung beans, lentils, common vetch, alfalfa, red clover

Mix #1: milo, sorghum sudan, pearl millet, proso millet, German millet, Soybeans, mung beans, lentils, common vetch, alfalfa, red clover, oil seed radish, dwarf essex rape, Ethiopian cabbage, specialty brassica’s, sunflowers

Mix #2: sorghum sudan, pearl millet, German millet, lentils, common vetch, oil seed radish, dwarf essex rape, Ethiopian cabbage, specialty brassica’s,

Brassicas
• Oil Seed Radish
• Turnips
• Dwarf Essex Rape
• Ethiopian Cabbage
• Specialty Brassicas
– Graza fodder radish
– T-Raptor (rape x turnip)
– Hunter (rape x turnip)
– Winfred (rape x kale)
– Barkant turnip
– Barabas turnip
– Rival turnip
– Rangiora forage rape

2. Seed cover crops after wheat harvest – Completed: July 20, 2008
A 20 foot strip of each selected cover crop was seeded into wheat stubble using a 10’ rented no-till drill. A burn-down herbicide was applied prior to seeding. In addition, 50 acres of mix #2 listed above was planted on the same field to be used for grazing trials. This 50 acres was planted with a John Deere 1560 drill.

3. Install soil moisture sensors and data loggers – Completed: August 2008
Sensors and data loggers were be installed at 12”, 24” and 36” depths. UNL Extension and Natural Resource District personnel were utilized to ensure proper installation.

4. Read soil moisture sensors on a regular basis – August 2008 – November 2009
Sensors were read on a weekly basis from August through November. Data loggers were downloaded to a computer at the end of November.

5. Host Cover Crop Field Day - Completed: September 2008
A field day was hosted to show area producers the growth of the different cover crops and discuss preliminary data on cover crop water usage. More details on this field day are found later in this report.

6. Record corn yield in each cover crop plot – Completed: November 2009
Corn yields were recorded from several of the individual cover crop plots as well as 2 of the cover crop mix plots. Results are found later in this report.

7. Publish and share cover crop water use and yield results - Ongoing
Information gathered from this project has been shared with thousand of people as will be detailed later in this report.

PEOPLE
Many people were involved in making this project a success.

Person, Agency, Role
* Jenny Reese, UNL Extension, Helped install moisture sensors. Promotion and registration assistance at field day.
* Darrel Anderson, Little Blue NRD, Helped install moisture sensors. Promotion of field day.
* Dewey Linnamen, UNL Extension, Promotion and registration assistance at field day.
* Paul Jasa, UNL Extension –No-till expert, Speaker at and sponsor of field day.
* Dr. Ray Ward, Ward Laboratories, Speaker at and sponsor of field day.
* Brad Young, Prairie States Seed, Supplier of seed, speaker at field day.
* Nebraska Environmental Trust, No-till on the Plains, Krull Agency, Little Blue NRD, UNL Extension, Prairieland RCD, Pioneer Seed, Norder Ag Supply, NRCS, Sponsorship and promotion of field day

RESULTS
The late summer and early fall of 2008 was a very wet year for us which somewhat skewed a moisture use study, but the charts were generated some useful data. The results of our moisture use study were very interesting. In summary:

1. Cover crop mixes showed far less water use than did heavy use crops such as sunflowers and soybeans.

2. Cover crop mix water use charts looked very similar to the water use chart for wheat stubble alone.

3. Some monoculture cover crops did show much water use but these tended to be crops that had limited growth.

An appendix of moisture use charts is found at the end of this report for further study.

Yield test results were interesting as well. We planted corn into all of the cover crop plots. We hand harvested 1/1000 of an acre (2 rows x 8.5’) in 4 different areas in 3 monoculture plots, 2 mix plots and the wheat stubble. We then weighed the ears that were harvested and calculated yield from these weights (Our thanks to Paul Jasa, UNL Extension, for his assistance in this). Yield results are found in the following table:

Cover Plot 2008, 2009 Corn Yield
Sunflowers, 131.4
Soybeans, 134.3
Oil Seed Radish, 128.9
Wheat Stubble, 131.4
Mix #1, 140.0
Mix #2 (higher seeding rate), 154.3

This yield data was very interesting. In summary:

1. Corn planted into cover crop mixes yielded significantly better than corn planted into plain wheat stubble or a monoculture cover crop.

2. Corn planted into a monoculture cover crop mixes did not yield significantly less than corn planted into plain wheat stubble.

Based on these numbers we believe that cover crop mixes are beneficial to yield of the next crop. With this being said however, we acknowledge that these results are from one trial in one year. We think that this question of yield response to cover crop mixes needs to be studied further.

DISCUSSION
We learned many things from this grant. The following is a list of the most important things:

1. Cover crop mixes showed far less water use than did heavy use crops such as sunflowers and soybeans.

2. Cover crop mix water use charts looked very similar to the water use chart for wheat stubble alone.

3. Some monoculture cover crops did show much water use but these tended to be crops that had limited growth.

4. Corn planted into cover crop mixes yielded significantly better than corn planted into plain wheat stubble or a monoculture cover crop.

5. Corn planted into a monoculture cover crop mixes did not yield significantly less than corn planted into plain wheat stubble.

6. There are many biological benefits of having a growing cover crop but these are difficult to see, measure and quantify.

7. Cover crop mixes are an excellent way to provide high quality late fall and winter supplemental grazing for livestock.

8. Cover crop mixes should include a balance of grasses, legumes, and brassicas.

9. Cover crop mixes with good legume growth can produce a significant amount of nitrogen when planted after wheat stubble.

10. There is a great deal of farmer interest in the growth and use of cover crops.

The results of this project have made us firm believers in cover crops and we will plant every acre of our dryland wheat stubble to a cover crop mix. We will continue to experiment with different mixes, seeding rates, plant species, etc. We also hope to continue to monitor water usage of cover crops and also measure yield in the crop following our cover crops.

OUTREACH
We have spoken nearly 25 times and shared our research project results with over 1500 people from across the Midwest. We have hosted two different on-farm field days where people could see, touch and feel our cover crop plots. In addition, we have been interviewed by numerous magazines and newspapers and have had our cover crop research project featured in several articles with others forthcoming. Publications include: Successful Farmer, Nebraska Farmer, The Furrow, and The Leading Edge, Hastings Tribune, and the Blue Hill Leader.

We also designed and published a website for our project and our research findings. http://www.greencoverseed.com/research/08plots_bladen.htm has numerous photos of our cover crop plots and our data findings. To date over 2600 people have visited this website to view our project results.

• Final report with tables and charts, Berns, FNC07-653