by Elizabeth A. Tomlin
In a collaborative project funded by the USDA, Michigan State University, Cornell Small Farm Program and the University of Maine teamed up to provide listeners with the latest research results in reduced tillage (RT) tools and tactics, integrating cover crops, managing residue, understanding pest management and attracting beneficial insects and controlling diseases and weeds. The final episodes of a 3-part webinar series provided listeners with the opportunity to interact with specialists in the field.
Presenters of the program included professors and specialists Anu Rangarajan, Director of the Small Farms Program, with Cornell University; Meg McGrath, Cornell University; Organic Farming Specialist Vicki Morrone, Dan Brainard, Zsofia Szendrei and Sam Hitchcock — all with Michigan State University; and Eric Gallandt and Bryan Brown, with the University of Maine.
Promoting and advancing reduced tillage in organic vegetables on small farms and its effect on bio-control was highlighted in the webinars.
It is proven that conventional, intense tillage degrades soil structure and creates compaction restricting plant roots. As a result many small farmers are experimenting with RT.
Strip tillage and cover crop management were focuses of Rangarajan’s presentation. “This is a restricted width tillage system that we’ve been testing in organic,” Rangarajan said. “It’s been commonly used in the mid-west. This is a system that has been used on both large and small farms and across all types of commodities.”
Rangarajan emphasized strategies to incorporate strip tillage into small vegetable farming and how challenges may be overcome.
Strip tillage is a form of RT that is used to reduce the intensity, frequency and depth of tillage and the area of soil disturbed over time, by changing equipment and adjusting techniques. It targets rows to be planted, while leaving surrounding soil undisturbed. The principle, Rangarajan said, is to leave one- to two-thirds of the soil undisturbed, while focusing on the planting zone. Vertical tillage below the planting zone will break up compaction, allowing crop roots to expand, accessing more nutrients, and there will be no tillage between crop rows.
Rangarajan said a core goal of RT is to build soil health, “To really focus in on organic matter retention and soil health and quality.”
Other goals include improving soil’s water-retention use — capturing rainfall which is retained in the soil and available for crop growth.
“Another interesting benefit,” remarked Rangarajan, “is that reducing tillage in some of these strategies, like strip till, can actually make it more efficient to prepare your fields in the spring. So, it can improve farm labor and fuel use efficiency, because many times your field can be prepared and ready for planting, with one pass as opposed to the three or four passes when you’re doing full-width, intensive tillage. So, that’s another advantage — and goal often — for transitioning to these types of systems.”
Another reported advantage is that plant growth and yields often are more stable and resistant to challenging weather events. More rapid draining has been noted with storms and heavy rains.
With drought, crop roots are able to sustain themselves and thrive longer, as they are able to access soil moisture that has been retained. There is also less soil erosion.
Rangarajan said in the end, you want to make sure that you can achieve long term productivity of your farm while using RT methods. A question organic farmers ask is, “Can we do this in organic and maintain yields that we see with intensively tilled systems?”
Although the overall commitment is to enhance soils and ensure soil quality, productivity and profitability must be maintained or boosted by RT methods to keep farms viable.
Reducing tillage is just one strategy that promotes soil health and is the combination of this with other strategies, such as perennial forage rotation and adding compost, mulch and other soil amenities, is encouraged by the team.
“When you cover crop or you reduce tillage, all of those are going to provide an improvement in soil health over time. When you start to stack these practices or layer them, and you combine them, you see greater improvement of soil health,” said Rangarajan. “Our challenge is not just to change the tool we use to do tillage, but to think carefully about how we integrate all of these practices together in a way that’s manageable and provides a solid and sustainable crop yield and crop growth.”
Challenges discussed include biomass interfering with preparation, fertility may be restricted, and it is difficult to cultivate when working in narrow areas. “These are some of the barriers that we know exist.”
Rangarajan said there are times when intensive tillage will be necessary.
Integrating and managing cover crops in strip tillage may be challenging, especially in organic systems. Cover crops can become weeds. Residue build up can impact planting and harvesting methods.
“Adapting strip tillage for organic production requires careful crop planning.”
The time to consider cover crops for next season is now.
Cover crops experimented with for small farms in strip tillage programs are rye, crimson clover, and hairy vetch. These have been experimented with alone and in combination with each other. Results vary depending on soil type and condition — which vary greatly. It is always wise to test your soils before seeding.
Equipment for strip and zone tillage that provide the accuracy required may not be readily available at a cost small farmers can absorb.
“Cultivation of the in-row zone is challenging, especially in reduced tillage systems.”
Farmers have become extremely creative by developing their own devices by adapting and modifying pieces of whatever equipment they have around the farm.
“There’s been a lot of interesting equipment developed because of strip tillage,” Rangarajan remarked.
Brainard, Hitchcock, Gallandt and Brown discussed cultivation for RT systems, including chisel plows, field cultivators and the Yeomans plow, and other “innovative in-row cultivation techniques for managing weeds in reduced tillage crops.”
Core components typically include cutting coulters, deep shanks, hilling coulters, and rolling baskets.
Cutting coulters cut through crop residue, breaking up clods and pushing rocks out of seedbeds. Deep shanks till soil in narrow strips and may also break up subsoil compaction layers, operating up to 20 inches deep.
Hilling coulters are used to “hill” soil over areas tilled by shanks, limiting loss of moisture.
Rolling baskets break up soil clods, creating seedbeds.
Strip tillage is becoming more popular with growers as it easier to implement than changing to no-till. Reduced tillage improves soil health over time, while reducing costs.
For more information contact Ryan Maher, Cornell Small Farms Program, at firstname.lastname@example.org.