Cultivating Questions
Concerning the Bioextensive Market Garden
by Anne and Eric Nordell of Trout Run, PA
RIDGE PLANTING REFINED
The photos for Ridge Planting Refined were taken over the past three years in several different fields. Nevertheless, they represent the exact procedures we used for ridge planting all of the crops grown in Field 6 in 2003.
The photos also document a number of refinements we have made to the ridge-building, ridge-tilling and strip-tilling process. The details of these new-and-improved practices may make a whole lot more sense after reviewing the original ridge planting system described in Ridge-Till Revisited in the Spring 2002 SFJ.
1. Building ridges the last week of August with Buster and Ben. Note, we now use two sets of disc hillers on the cultivator to make a somewhat wider ridge. These “mini-raised beds” make no-till planting much easier than trying to mark a no-till planting furrow on a peaked ridge.
The double-disc action also does a much better job of uniformly incorporating the oat seed broadcast on the field right before hilling. As for the straight shovels attached to the shanks mounted on the outside of each cultivator gang, they throw a little soil on the oat seed in the pathways.
Of most importance to us is the way this setup completely mixes the mulch-tilled cover crop of spring barley and field peas into the ridgetop, more-or-less guaranteeing good, tilthy planting conditions and lots of earthworm activity the next spring.
2. Rolling the ridgetop with a cultipacker creates better seed-to-soil contact for germinating the oats cover crop. This extra step also levels and firms the tops of these mini-raised beds, creating a wider area for rainfall to soak in, and making it possible to experiment with increasing plant density by no-tilling two rows of onions on the top of the ridge.
3. Oats on the ridges the middle of October, 2003, grew 12-16” tall, the perfect height for no-tilling garlic. Topgrowth samples collected the beginning of November by NEON researcher, Steve Vanek, indicated that the oats had produced over 1 and ½ tons of dry biomass right on top of the already planted garlic!
Planting the oats mixed with Canadian field peas on the ridges two weeks earlier, in the first part of August, can double the amount of soil protective cover. However, this tall, tangly topgrowth can sometimes complicate both the no-tilling and ridge-tilling operations. Instead of aiming for peak biomass production on the ridgetops, we now emphasize increasing the amount of organic matter worked into the ridges by planting a spring cover crop of barley and field peas. This combination puts on a lot of topgrowth in a short period of time, so we can mulch-till this large contribution of biomass well ahead of ridge-building the last half of August.
4. Digging into the cover cropped ridges with a spade the middle of October shows the nice crumb structure already developing as a result of the earthworms, fungi, bacteria and cover crop roots working on the barley and pea residues mixed into the ridgetops. We think that building the ridges biologically may be the single most important step in the ridge planting process, for the simple reason that there will not be any opportunities to manipulate the soil into a seedbed mechanically before spring planting. To the contrary, the whole idea of this reduced tillage system is to preserve the superior soil structure created by the soil life throughout the crop season.
5. We use a coulter and narrow, knifelike tooth to make a slit in the winterkilled oats and undisturbed soil on the ridgetops. This slit serves as a planting furrow for no-tilling onion sets and transplants. After handplanting the aliums, we mulch the valleys with straw to conserve moisture. That’s it, other than removing any weeds that germinate in the untilled soil and threaten to go to seed.
6. For most other crops, we replace the narrow, knifelike tooth on the back of the cultivator with this large ridge-till sweep in order to knock the top off the cover cropped ridges. The ridge-tilling process moves the dead cover crop residues on the ridgetops into the pathways, exposing a narrow strip of clean soil for trash-free planting.
The trick is to run the oversize sweep at just the right depth so that the ridgetilled seedbed ends up slightly higher than the soil and cover crop residues moved into the pathways. Even an inch in elevation makes future cultivations much easier and insures that the planting zone will remain well drained and well aerated.
7. For potatoes, peas, and other large seeded crops, we make a second pass with the cultivator to open a wide, Ushaped planting furrow in the middle of the ridge-tilled seedbed. We use an old potato shovel mounted in the middle of the cultivator gangs for this purpose, then place the cut pieces of seed potato in the planting furrow. In the case of peas, we scatter the seed in the furrow mixed with some oats to provide a living trellis for the pea vines.
8. and 9. We cover the seed in the planting furrow using a set of small disc hillers. Attached to the back of the cultivator is a homemade miniature cultipacker. This minipacker does a nice job of firming the soil over the seed to maintain surface soil moisture for quick, even germination.
Note the grooves the cultipacker wheels make in the center of the strip-tilled soil. For fine-seeded crops, like spinach and carrots, we perform the last two operations – furrowing and then covering with the disc hillers and minipacker – before planting. We simply walk our Planet Jr. seeder down the middle minipacker groove.
We discovered this past year that we could eliminate one step in the Ridge-Till/Strip-Till process for directseeded crops. Furrowing with the potato shovel is not really necessary, and can actually be detrimental by drying out the planting zone too deeply. We think by passing the furrowing step may prove to be an improvement in another way because using the disc hiller-andminipacker combo right after ridge-tilling with the large sweep tends to rebuild the mini-raised bed, but this time with residue-free soil on the ridgetop. This lightly-tilled and refirmed berm is ideal for direct seeding in prolonged wet conditions like we faced last spring.
10. If time and soil conditions permit, we have found it beneficial to cultivate right after planting the ridge-till/strip-till seedbed. This extra step loosens the packed pathways and helps to smooth out the shape of the mini-raised bed, in this way facilitating future cultivations. The photo illustrates the results we are looking for: a nicely crowned, residue-free planting area elevated above all the cover crop residues and rough soil concentrated in the ridge-till pathways.
As you can see, we use just two shanks on each cultivator gang for this type of high residue cultivating. The first time through we attach straight shovels to the shanks to rip through the undisturbed soil in the ridge-till pathways without plugging up in the cover crop mulch. For the second cultivation, we replace the straight shovels with sweeps to do a more thorough job of working the soil. Once the cover crop mulch in the pathways has broken down, then we interseed a living mulch like the single row of hairy vetch planted in the ridge-tilled onions and spinach in Field 6.
Yes, the whole ridge-till process requires quite a few more passes over the field than no-tilling the ridges. On the other hand, the overall time spent on ridge-till related field operations with the team is much less than the hand labor involved in mulching and weeding the no-till ridges.
