Although no-till production has been widely adopted by row crop farmers, reports of poor weed control and delayed spring planting may have deterred many organic vegetable growers from using this soil-conserving practice. We have found that ridge-tillage is an alternative that solves both of these problems by allowing for cultivation and providing a warm, residue-free seed bed.

Ridge-tillage was developed by corn and soybean growers in parts of the Midwest where the land is too cold or wet for a strictly no-till approach. The way we have adopted ridge tillage to vegetable production is by forming the ridges in late summer using disc hillers on our old row crop cultivator – the same setup we use for hilling potatoes. To match our crops and equipment, we build the ridges on 34-inch centers, adjusting the disc hillers to create a raised ridge about 10 inches tall and 24 inches wide. This is also the time to apply soil amendments and organic matter so that these materials are concentrated in the ridges by the disc hillers. Our preference is to shallowly incorporate a spring-planted cover crop and light application of compost before building the ridges because they noticeably improve soil quality and planting conditions for ridge-tilling the next spring.

Last but not least, we like to broadcast oats immediately before hilling up the ridge so that the cover crop seed gets incorporated as part of the ridge forming process.

The advantage of growing oats on ridges is that they produce a lot of soil protecting top growth in the fall and then die back over winter here in north-central Pennsylvania. (In milder climates, where oats don’t reliably winter kill, a warm season annual such as millet or soybeans might be a better choice.)

Winter-killed cover crops such as oats do not need to be mowed or rolled before planting as is the case when no-tilling vegetables into an overwintering cover crop like rye and hairy vetch. The root system of the oats also has plenty of time to decompose over the course of the winter so that the soil in the ridges crumbles into a nice mellow seed bed when ridge-tilled that spring. The main drawback with a winter-killed cover crop is that the mulch of dead residue can keep the ground too wet and cool for early spring planting. The beauty of the raised ridges is that they warm up and dry out quickly even when covered with residues

Old equipment works well
We use our existing equipment for ridge-till planting of vegetables in two steps: First, we knock the top off the ridges with a coulter and sweep mounted on the row crop cultivator. The coulter slices through the winter killed cover crop on top of the ridges just ahead of the sweep, which moves the residues and winter weeds into the pathways. Then we seed or transplant the 10-inch wide strip of undisturbed soil with the same tools we use for planting a tilled seed bed.
We also use the old cultivator to cultivate the ridge-tilled vegetables by outfitting it with disc hillers and large sweeps to handle the cover crop residues now concentrated in the pathways. For low-growing vegetables, we turn the disc hillers so they are facing out, slicing weeds and soil away from the row. In this position, they also serve as rolling shields to protect the young plants from being buried with cover crop clumps churned up in the pathways by the large sweeps. Letting the winter killed cover crop decompose as long as possible on the ridges before ridge-till planting also greatly reduces problems with trash plugging up our low-clearance cultivator.

Based on six years experience, we fell that ridge-tillage provides a number of benefits for vegetable production. For instance, it allows us to start planting a week or two earlier than in our flat-tilled fields in wet years. This conservation practice also eliminates the need for several spring tillage operations when the soil can be marginally fit to work. And it restricts compaction to the pathways right from the start of the growing season.

But perhaps the biggest advantage over normal spring tillage is that ridge-till does not disturb the beautiful soil structure created by the root system of the cover crop grown on the ridges.
In addition, this minimum tillage technique burns up only slightly more organic matter than no-till – and much less than plowing or discing, according to recent research.

Mellow soil permits no-till ridges
We decide last year we could combine the benefits of no-till and ridge -till by no-till planting alliums on the top of the cover-cropped ridges. In fall, we no-tilled garlic into a live cover crop of oats growing on the ridges. In spring, we no-tilled onion sets into this cover crop on the ridges.
There were two very obvious advantages to no-tilling the ridges. First, we could use our lightweight cultivator for no-tilling simply by replacing the ridge-till sweep with a narrow tooth. There is no way this light-duty setup could penetrate the firm soil under a cover crop grown on flat ground without extra weight or hydraulic pressure.

More importantly, the raised ridges remained warm and well-aerated even after mulching the pathways with straw to conserve moisture. Judging from the healthy growth and good yields, the alliums appreciated the growing conditions, despite our wild weather that year. The results have encouraged us to experiment with no-tilling other crops in ridges this year. We think this hybrid conservation practice holds promise for reducing tillage to a minimum in our cool climate.
Recognizing that there are pros and cons to any tillage system, we choose to use a diversity of tillage techniques and cover crop combinations rather than locking ourselves into one conservation practice

Resources

A video on the Nordells’ alternative tillage techniques and cover crop rotations can be ordered from them for $10 each (postage included), 3410 Rt. 184, Trout Run, PA 17771.

For more details on ridge-tillage, see Steel in the Field: A Farmer’s Guide to Weed Management Tools available for $18 plus $3.75 shipping from NRAES, www.nraes.org or 607-255-7654.