A Low-Till Pumpkin Patch July 03 2012, 0 Comments
No-till farming isn't new, but it's all the rage. Adherents to the practice say that traditional fertilizing, plowing, and seedbed preparation releases large amounts of carbon which is bad for both soil chemistry and the atmosphere.
Beneficial microbes, worms, and insects in the soil are diminished, the subsoil is compacted, and bare ground is exposed to drying and erosion.
In a no-till field, the ground is not disturbed. Instead, seeds and seedlings are sown directly into the soil through residuals of a previous cover crop. No-till and cover crops go hand in hand. The combination preserves the soil's natural nutritional store, lessens the need for chemical fertilizers, protects the surface from erosion, and aids in moisture-retention.
I've always planted a fall cover crop on my pumpkin field (see "Planting the Cover Crop"), but I would plow it under every spring. I liked the idea of reducing my carbon footprint by eliminating some plowing, but I was more intrigued by the associated no-till practice of growing out the cover crop rather than turning it under. The mature cover crop would then be cut down to form a natural mat over the entire field. See "A Cutter in the Rye". It seemed like the best of both worlds: the soil quality and nutritional benefits of a cover crop, plus a thick layer of mulch that pumpkins would love.
There was one complication. Unlike a true no-till farmer, I wasn't prepared to plant directly through the residual surface material. I wanted to continue growing my pumpkins in rows of hand-prepared hills. To do that, I'd need to clear and till swaths or strips through the cover crop. Mine would be a "low-till" rather than a no-till approach.
For timing considerations, I decided it would be best to do the strips and hill-making before the cover crop was cut down rather than after. A winter rye and hairy vetch cover crop needs to reach the anthesis or pollen stage before it can be effectively killed by rolling or a sickle bar cutter. That's late May or early June, right around planting time. I could cut the rye in almost any weather, but working the ground is a different story. I wanted the flexibility of being able to prepare the strips and hills as soon as conditions permitted, and not having to wait until the rye was grown out and cut.
A stretch of dry weather came around in early May. The first step was mowing. I decided to use my walk-behind rather than the big bush hog implement I owned. I didn't need that wide a swath. The rye was a good 6 feet high already on either side. It felt like a green labyrinth. After mowing, I allowed the chop and the ground dry out for a few days before coming-in with the rototiller. It took a few passes, lowering the tiller tynes a little each time. In the end, the surface chop and rye/vetch root biomass were nicely incorporated and I was ready to make pumpkin hills.
The nutrient and soil quality benefit from a cover crop (green manure) is crucial for me, because my farm doesn't produce enough compost to spread on a whole field. Instead, each hill would become its own miniature compost pile. I scooped 3 foot depressions all down my newly-tilled strips, filled them with almost a wheelbarrow full of manure, and mounded them up with soil. Hand-making hills like this is alot of work. It was still reasonable for my patch, but probably impractical for a field of any size. I had some help from a couple neighborhood kids, and we managed to knock out almost 200 hills in a weekend.
A week or so after the hills were done, the rye reached the proper stage to knock down. A sickle bar cutter or roller is the best choice for this. Mowing would chop and scatter the material too much. Cutting the rye at ground level, and letting it fall (overlap) in the same direction, makes the thickest and most effective no-till surface layer. The 40 year old Jari sickle bar cutter I bought explicitly for this job worked great.
The hard work was done. I mulched the hills and any remaining bare ground in the strips with some old hay. Then, finally, I planted pumpkin seeds! The downed rye quickly browned to match the hay mulch, and the rows of healthy green pumpkin plants were a nice contrast in the field. It definitely caught the eye of the real farmers passing by. Low-till pumpkins. It felt good to be something a trend setter.