Tarps, mulch and reduced tillage can spell success for small vegetable farms

by Elizabeth A. Tomlin
What does it take to be a successful, organic, reduced tillage farmer? What are the practices? What are the keys?
Cornell Small Farm Program recently teamed up with Michigan State University and the University of Maine to offer results of the latest research on reduced tillage for small-scale organic vegetable production in a series of webinars.
First on the list of presentations was ‘Reduced Tillage on Permanent Beds’, featuring Program Manager Ryan Maher and Brian Caldwell, Research/Extension Support Specialists with Cornell University in Ithaca, NY; Mark Hutton, University of Maine, and Vicki Morrone, Organic Farming Specialist with Michigan State University.
“We’re trying to work with everyone out there and learn,” commented Maher, explaining that demonstrations and on-farm research, along with regional meetings and conferences, have been ongoing. “What are the strategies to reduce tillage?”
Learning about practices which fit each specific operation, from permanent beds, tarps, and mulches, to cover cropping, strip tillage, and cultivation tools.
Both goals and barriers were discussed by presenters of the webinar.
“I want to narrow in on permanent beds,” said Maher.
Maher said researchers are talking to growers at the DACUM Resource site, and a lot of growers are looking for a system which will work for many crops not just one or two. They want to develop one system that will provide them the flexibility to reduce tillage. A permanent bed system provides that opportunity.
Permanent beds also allow the grower to manage traffic on beds. Year after year, foot traffic or wheel traffic is concentrated between the crop rows and pathways, compacting soil.
Dividing fields into beds can help growers think and plan for crops from how much bed seed they require to how much row cover they require.
Maher pointed out transitioning to permanent bed systems can be a challenge, however, they are beneficial and can be better managed to improve soils, control weeds, reduce labor and increase productivity and profitability for a wide variety of crops, through reduced tillage, mulching and tarping practices.
Maher stressed reduced tillage is not the goal, but a tool.
“A tool among other tools that farmers can use around this primary goal of building soil health.”
Maher said he has learned from growers that soils are really the key.
“Reduced tillage can be complemented with rotations, cover crops and amendments, such as compost and organic systems to build soil health programs individual to each farm.”
Besides building soil health, goals include utilizing and improving water quality and drainage, improving labor and fuel efficiency and ensuring long-term productivity and profitability.
“Keep in mind we are just beginning this work,” remarked Maher.
Individual farms have been participating in these studies, documenting results.
“Amazing, the ingenuity we are seeing on farms in order to manage beds!”
One method which is having a serious impact on weeds and permanent bed soil health is “tarping”.
Maher reported on results showing tarping with six ml plastic, heavy duty, black tarps, has made a huge contribution to weed control, where tested, killing cover crop residues and weeds in about half the time. Silage tarps are being used by some growers.
Tarping can be used post- or pre-planting and is especially useful when used after shallow tillage.
“Our approach is optimizing no-till with tarping,” said Maher.
Now researchers are wondering if they can cut out tillage by just using the tarping/mulching method on permanent beds.
Maher reported some folks are using cardboard for composting, providing organic matter.
“By avoiding tillage and investing in practices that add organic matter, the system creates ideal conditions for earthworms and a healthy soil biology.”
Results using NOP-approved compost and tarping produced the best results in New York State.
“Put compost down first then cover with tarp,” directed Morrone.
Compost, of course, must not contain weeds or weed seeds. Maher noted using straw did not produce desired results in New York State and slugs were problematic, perhaps because of the high moisture straw produced.
“We don’t understand why our Central New York organic mulch results are poor,” commented Caldwell. “We would welcome your suggestions via email at bac11@cornell.edu .”
One webinar viewer, John Dewar, suggested there may be herbicide residue in the straw.
Another viewer, Paul Barker, commented residue from Glyphosate and 2,4D may be a concern in straw mulch. “With straw it could also be soil temperature reduction that may affect yields,” commented Barker.
Hutton remarked Maine is working under FSMA and GAP guidelines.
Viewers questioned whether there was a waiting period between tarp removal and planting.
“The impervious tarps can keep the soil from becoming either too wet or too dry until removal by not letting moisture in or out,” Caldwell explained.
“When the tarps are applied in the fall or early spring there is usually adequate moisture,” said Hutton. “We have found in Maine we can remove the tarps and plant immediately.”
Other advice is to wait a day so the intense biological activity at work under the tarp has a chance to decrease.
Both New York and Maine sites are experimenting with and comparing results with deep till, no-till and no-till/ tarp systems.
Another study at the University of New Hampshire showed the same positive results when combining a cover crop of rye and hairy vetch in the fall with black tarping in the spring. This study experimented with black tarp, clear tarp and no tarp. When tarps were removed, cabbage was planted directly into the cover crop mulch. Results showed nearly 100 percent weed elimination with black tarps, six weeks after the transplant. With clear tarp, although there was a rapid kill of cover crops and weeds initially, weed suppression was not long term. Where no tarp was provided, there was substantial regrowth of the cover crop.
For fertilizer, many growers are using chicken manure compost pellets at seven cubic yards per acre, at a three ft. by three ft. plant spacing, or 28 cubic yards at 18” by 18”.
“Reduced tillage takes many forms,” acknowledged Maher. “Experienced growers at diverse scales, are developing strategies for tackling weeds, managing rotations, and integrating cover crops while minimizing soil disturbance.”
For more information contact Maher at rmm325@cornell.edu .

2017-06-02T13:37:25+00:00June 2nd, 2017|Grower East|0 Comments

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