Combining Strip-Tillage and Cover Crops for Resource Conservation and Profit in North Central Vegetable Cropping Systems

Combining Strip-Tillage and Cover Crops for Resource Conservation and Profit in North Central Vegetable Cropping Systems

Summary

Our work in 2012 included both on-farm trials and continuation of a long-term research farm trial investigating the impact of tillage (strip tillage [ST] vs conventional tillage [CT]) cover crops (none, rye or rye-vetch) and weed management intensity (low vs high) in sweet corn and winter squash. For sweet corn, ST produced equivalent yields at lower cost than CT; ST in combination with either rye or rye-vetch cover crops also improved soil moisture retention under hot dry conditions; however ST with spring oats was in some cases detrimental to sweet corn establishment. For winter squash, yields in 2012 were reduced under ST due at least in part to inadequate weed suppression in the absence of cultivation. This result contrasted sharply with 2011, when we saw improved yields of winter squash under ST due to reductions in fruit rot (Phytophthora capsici). Outputs from our work in 2012 included newsletter and journal articles, and presentations at grower meetings and conferences. Outcomes in 2012 included increased understanding among vegetable growers of the potential benefits of reduced tillage and identification of complementary weed and cover crop management practices for reduced tillage production.

Objectives/Performance Targets

The central objectives of our proposed work in 2012 were 1) to evaluate the interactive effects of strip-tillage, cover crops, and weed management intensity within vegetable cropping systems on soil health, pest population dynamics, and crop quality and yield; and 2) to work with growers and extension educators to disseminate useful information and identify and address constraints to adoption of reduced tillage production systems.

Accomplishments/Milestones

Research activities included 1) research farm experiment evaluating the long-term (6 yr) effects of tillage and cover crops on sustainability of vegetable cropping systems; 2) on-farm experiments identifying and evaluating complementary weed and cover crop practices for reduced tillage vegetable production systems.

Long-term trial. Rotational crops in the long-term experiment in 2012 included sweet corn and winter squash. The trial is evaluating the effects of tillage (strip tillage [ST] vs conventional tillage [CT]) cover crops (none, rye or rye-vetch) and weed management intensity (low vs high) in a sweet corn/snap bean/winter squash rotation initiated in 2009. For sweet corn in 2012, ST produced equivalent yields at lower cost than CT. ST in combination with cover crops also improved soil moisture retention under hot dry conditions in August (Figure 1). Insect pests were unaffected by ST in sweet corn. For winter squash, yields in 2012 were reduced under ST due at least in part to inadequate weed suppression in the absence of cultivation. Large crabgrass was particularly poorly controlled, especially in low weed management treatments. Under ST with rye, we also observed slight but significant increases in both squash bugs and striped cucumber beetle (Figure 2). This result contrasted sharply with 2011, when we saw improved yields of winter squash under ST due to reductions in fruit rot (Phytophthora capsici) with no increases in either insect or weed pests. Weed seedbank analysis in 2012 revealed higher densities of large crabgrass seeds in ST compared to CT and in low-weed management compared to high weed management treatments (Figure 3). In the absence of winter cover crops, winter annual and perennial weed species including henbit, purple deadnettle and horsenettle have also gradually become more abundant under ST.

On-farm trials and activities. On-farm trials in 2012 included two trials evaluating the effects of tillage (ST vs CT) and cover crop (spring oats vs none) on sweet corn yields on commercial vegetable farms. In both cases, no differences in yields were detected. Oat cover crop treatments initially reduced sweet corn growth, likely due to reduced soil moisture, but differences between treatments were not noticeable after several weeks of growth. In addition to research trials, we have begun interviewing sweet corn farmers on their production practices and attitudes towards reduced tillage. We are updating the sweet corn cost of production bulletin for Michigan, and will use economic data generated from this process to better assess the impact of tillage and cover crop practices on farm profits.

Impacts and Contributions/Outcomes

Impacts and Contributions/Outcomes

Short-term outcomes (changes in knowledge, skills, awareness, and attitudes)
1) Increased understanding of the potential benefits of ST systems for improving soil health and reducing energy and labor costs: In 2012 we observed improvements in soil moisture retention under strip tillage, and reductions in energy costs.
2) Identification of complementary weed management practices to optimize strip-tillage systems: In 2012, we identified the need for greater attention to weed management practices to address potential problems from build-up of large crabgrass and perennial weeds.
3) Increased understanding of optimal cover crop practices for strip-tillage systems: In 2012, we observed benefits of both rye and rye-vetch cover crop residues for reducing weed problems and improving weed suppression under ST. However, spring oats appear to provide no clear benefit, and may interfere with establishment in ST systems for sweet corn.
4) Increased awareness of the circumstances under which reduced tillage systems are most/least likely to be beneficial due to changes in insect, disease and weed dynamics: In 2012, we saw increases in potential insect pests in winter squash production when ST was used in combination with winter rye. We have previously observed increases in beneficial insects
5) Greater grower understanding and interest in reduced tillage systems for vegetable crops: We have seen strong interest in ST systems, both in sweet corn and winter squash.

Outputs

Related Peer-reviewed Publications

1. Haramoto, E. and D.C. Brainard. 2012. Strip tillage and oat cover crops affect soil moisture and N mineralization patterns in cabbage. HortScience 47: 1596-1602.
2. Hayden, Z.D., D.C. Brainard, B. Henshaw, and M. Ngouajio. 2012. Winter annual weed suppression in rye-vetch cover crop mixtures. Weed Technology 26: 818-825.
3. Brainard, D.C., B. Henshaw and S. Snapp. 2012b. Hairy vetch varieties and bi-cultures influence cover crop services in strip-tilled sweet corn. Agronomy Journal 104:629-638.

Presentations at Scientific Conferences

1. Haramoto, E.R., D.C. Brainard, S. Snapp, and K. Kahmark. 2012. Relative location of strips influences sweet corn yields, potentially leachable nitrate, and trace gas flux under strip tillage. ASA, CSSA, SSSA International Annual Meeting, Cincinnati, OH. Nov. (Poster)
2. Bryant, A., D.C. Brainard and Z. Szendrei. 2012. Cover crop mulch and strip tillage influence biological control in cabbage (Brassica oleracea). Entomological Society of America, National Meeting. Knoxville, TN, Nov. (Oral)
3. Brainard, D.C., E. Haramoto and D. Noyes. 2012. Tillage and cover crop effects on weed management in snap beans. Abstract no. 57. Weed Science Society of America Annual Meeting, Waikoloa, HA, Feb. (Poster)
4. Brainard, D.C., E. Haramoto, A. Ranagarjan, J. Luna and E. Peachy. 2012. Weed ecology and management under strip-tillage: Experiences from Northern vegetable cropping systems. Abstract no. 183. Weed Science Society of America Annual Meeting, Waikoloa, HA, Feb. (Oral)

Extension publications

1. Brainard, D.C. 2012. Conserving soil moisture in vegetables: Effects of weed management and cover crop mulches. Vegetable Crop Advisory Team Alert Newsletter, July 18. http://msue.anr.msu.edu/news/conserving_soil_moisture_in_vegetables_effects_of_weed_management_and_cover_crop_mulches

Presentations at Grower Conferences

1. Brainard, D.C. 2012. Saving nitrogen and suppressing weeds with cover crops in vegetables. Indiana Certified Crop Advisory Conference. Indianapolis, Indiana. Dec 18.
2. Brainard, D.C. and C. Lowry. 2012. Balancing weed and soil management objectives with cover crops and tillage. Organic Vegetable Session. Great Lakes Fruit, Vegetable, and Farm Market Expo, Grand Rapids, MI, December 6.
3. Haramoto, E., G. Van Houtte, T. Zilke and D.C. Brainard. 2012. Strip tillage and deep nitrogen placement in sweet corn. Sweet Corn Session. Great Lakes Fruit, Vegetable, and Farm Market Expo, Grand Rapids, MI, December 4.
4. Brainard, D.C. 2012. Tillage and cover crop solutions for sweet corn. Sweet Corn Session. Ontario Fruit and Vegetable Convention, Niagara Falls, ON, Feb. 23.
5. Brainard, D.C. 2012. Innovative ways to fit cover crops into your system. Cover Crops for Annual Crops Session. Ontario Fruit and Vegetable Convention, Niagara Falls, ON, Feb. 22.
6. Brainard, D.C., E. Haramoto and C. Lowry. 2012. Reduced tillage and cover cropping systems for sweet corn: Experiences from Michigan. Sweet Corn Session. Empire State Fruit and Vegetable Expo and Farmers’ Direct Marketing Conference, Syracuse, NY, Jan. 25.

Other presentations

1. Lowry, C.L. and D.C. Brainard. 2012. Strip tillage and segregated cover crop strips for organic sweet corn. Organic Research Field Day. MSU, Kellogg Biological Research Station, Hickory Corners, MI, Sep 18. (Oral)
2. Brainard, D.C., B. Henshaw and C. Lowry. 2012. Integrating reduced tillage and cover crops for organic vegetable production. MSU Organic Reporting Session, Kellogg Center, East Lansing, MI, March 2. (Oral).
3. Brainard, D.C. 2012. Vegetable reduced-tillage research update. Great Lakes Vegetable Working Group Annual Meeting, Henry Center, East Lansing, MI, March 1. (Oral).

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