Cultivating Questions

Concerning the Bio-Extensive Market Garden

by Anne & Eric Nordell of Trout Run, PA

Two Ways of Adjusting the Two-Way for Shallow Plowing

For most of twenty years we relied entirely on the old Leroy walking plow for all of the plowing in the bio-extensive market garden. We thought there was nothing finer than stretching our legs in the furrow, watching the earth turning right before our eyes, listening to the changes in soil quality and texture. It was as if we were connected directly to the pulse of the land through this oversized divining fork in our hands.

For the last seven or eight years we have traded in this profound, aesthetic connection with the earth for a sit-down job on the John Deere-Syracuse two-way riding plow. There were several practical reasons for making this change. The foremost was eliminating the dead furrows and back furrows in the middle of our vegetable fields. Plowing back and forth across the slope with the two-way also made it possible to turn all the furrows uphill, counteracting the inevitable downward movement of soil resulting from secondary tillage, cultivation or the elements. But the clincher was the increasing difficulty of finding replacement shares for the Leroy, especially the original cast shares that hold a point for a long time.

A unique feature of the John Deere two-way sulky, designed for working on steep hillsides, is the convenient foot pedals and depth handles, allowing for on-the-go adjustments to furrow width and thickness. We think this flexibility is a real advantage for shallow plowing a tough sod like well established red clover. But we have no idea if the adjustments described below would work for other soil types or makes of plows. We just hope that these site-and-implement specific details might suggest some of the factors that go into fine-tuning old tillage equipment to achieve specialized soil management goals.

#1A The headless horseman and horses, Frank and Ben, shallow plowing sudex stubble and medium red clover the middle of May, 2008, six weeks before planting the first of the fall vegetables.

We use the foot pedals and depth handles on the John Deere-Syracuse twoway riding plow to our advantage for undercutting the tough clover sod no more than 3-4” deep. To start the furrow at the end of the field, we set the plow moderately deep (third or fourth notch) and angle the share into the soil for enhanced suction by keeping the depth handle for the raised bottom in the top notch. As soon as the plow penetrates the land, we raise the bottom in the soil to the shallowest setting, and then level the plow, as shown in the photo, by dropping the raised bottom to the second or third notch. To prevent the plow from popping out of the ground in the harder or stonier parts of the field, we drop the bottom in the soil a notch or two deeper and/or angle the share for more suction by returning the raised bottom to the top notch.

For a really top notch job of shallow plowing a well developed sod, we make sure to use a good, sharp share and to set the clevis at the end of both beams in the middle position. These seemingly minor details help keep the plow planted permanently in the dense root system without skittering out of the ground helplessly or sucking in too deeply.

Compared to shallow plowing overwintering small grains or grasses, like rye and Italian rye grass, the 3-4” thick furrows of clover can be transformed into a seedbed in short order. This is surprising since the root system of this cover crop is so strong by the middle of May that we can hear the roots tearing from the seat of the plow. Nevertheless, only a couple of passes with the disc – or, in our case, the spring tooth harrow and rotary hoe – are necessary before forming the planting beds fit for direct seeding or transplanting. Time and weather permitting, we take advantage of this unique property by getting the plowed clover into planting beds as quickly as possible in order to settle the soil and restore capillary action to the shallow, but dry, plow layer. However, we do not usually begin planting until six weeks after shallow plowing in hopes we will receive at least one significant rain during this time period to rebuild moisture removed by the live cover crop, and to make sure that all of the clover remnants have died before setting out the first of the fall vegetables.

Be forewarned that even if the live sod is thoroughly severed shallowly in the soil, a significant percentage of the clover may re-root and continue to grow without follow-up cultivation. Killing the clover is much easier if the topgrowth is mowed before plowing under the sod. We failed to mow the 12” tall clover in this photo and paid for it with an extra pass with the harrow and rotary hoe to permanently setback the persistent legume.

#2A For shallow tilling the sudex stubble first thing in the spring we use totally different adjustments due to the soft soil and less developed root system of the still dormant clover. As soon as the plow enters the ground, we move the plow depth handle to the second shallowest setting and drop the raised bottom to the fourth notch. A worn share works just fine in these conditions. In fact, the plow beam clevises may need to be moved to the bottom position to prevent plowing too deeply if the two-way is equipped with new shares.

These simple adjustments reduce the furrow depth to just 2- 3”, a much closer approximation of the “skim plowing” technique we discovered years earlier walking the furrow with Leroy and our original middleweight team of Becky and Buster (see “A Few Long Furrows” in the “Weed the Soil” booklet.) Skim plowing keeps the coarse organic matter even closer to the soil surface for good aerobic decomposition, and makes it much easier to bring some of this residue back up on top with the spring tooth harrow to refiberize the seedbed.

We still use Becky, now 29, for skim plowing in April because it is such easy work. The big difference with skim plowing with the two-way is it is harder to gauge the depth of the furrow from the seat of the plow, but easier to cut a wide furrow especially if we use the extra large share shown in the next photo. For a full, 14” wide furrow, we set the foot pedals in the middle position so that the plow wheel in the furrow runs within an inch or two of the land. By comparison, to do a good job of completely undercutting the live, actively growing clover a month later, we find it necessary to narrow the furrow to no more than 12” by adjusting the foot pedals so the plow wheel rolls right down the middle of the furrow floor.

#3A We found out by accident, when picking up the wrong replacement share for the two-way, that a 14” quick attach share actually fits on the 12” John Deere-Syracuse bottoms. The oversized share not only makes it possible to cut a wider furrow when skim plowing the sudex stubble and dormant clover in April, but it also does a much better job of completely undercutting the tougher sod later in May. At least, we have noticed with the standard 12” share that the clover often revives right in line with the hinge of sod where the shallowly plowed furrow breaks over. Reducing the furrow width to 10” eliminates this problem and also stands the furrow on edge, a shallow version of vertical-furrow plowing. The extra wide 14” share, on the other hand, completely severs the whole root system, even under the furrow hinge, when the plow is set to cut a 12” furrow at a 3-4” depth.

#4A Fall carrots and leeks with an interseeding of hairy vetch in 2007 following the skim plowed sudex and clover shown in the second photo. It may be a total coincidence, but we have consistently seen an improvement in size, uniformity and flavor of root crops with this new cover crop combination. We can’t explain the taste difference, but assume that the improved underground crop growth is due to the deep, compactionalleviating root system of the sudex and clover – and preserving that superior soil structure by minimizing the depth of soil disturbance.