Low Tillage Radish Onions
by Joel Miller of Lee, NH
In the summer of 2011, we had a small plot in one of the house gardens that was in need of a cover crop in early August. The previous season we had tried sowing Tillage Radishes in mid September and found this was too late for us in southern New Hampshire because of the reduced growth before the killing frost. Now we decided to try planting them the first week of August to see how that compared. Without putting much further thought to it, we ran the Planet Jr. every 15” or so across the garden. The radishes came up quick, filling the garden canopy completely that fall, and the following spring we found the plot was clean of weeds and rows of open holes were left where the radish roots had been growing. Well, we had a few extra onion plants that spring and decided to plant them in these holes, since we already had very clear lines laid out for us and a clean seedbed. With such little weed pressure and no need to disturb the soil for planting, the soil structure was left almost entirely intact and held moisture very well. We didn’t irrigate or fertilize this crop, beyond a compost application the previous July before sowing the Tillage Radishes. Our intention was to see how the crop would perform in a similar condition to how we would manage it in our fields. What we got were the best looking onions that have ever come out of our gardens. With these good results, we thought that this experiment might be worth trying on a field scale.
The following photo essay describes the August 2012 planting of Tillage Radishes, laid out in preparation for our spring 2013 crop of onions. This layout can work for many other early spring crops as well. We have since used the same design for spinach, carrots, beets, and lettuce. Besides recycling the absorbed nutrients of the cover crop directly into the planted row, the main benefit of this system is the planting pattern it provides without the need for any preparatory tillage in the spring.
A month long summer fallow started us out with a stale and very mellow seedbed. Here we show how our homemade roller levels and firms the soil to prepare for direct seeding the Tillage Radishes with the Planet Jr. This step may not necessarily be wise since it will encourage weed seed germination. It has made following the row marker on the Planet Jr. easier though, which is crucial for the proper spacing of the stand and why we have included it here. In this photo you can see a cover crop of field peas and oats in the adjacent garden.
This shows how we used the Planet Jr. (seed hole #13) with the row marker set to very clearly mark out our rows on 17” centers. This planting was done the morning after a half inch of rain on August 9th. The conditions were perfect and it was a joy to walk barefoot behind the planter.
Two weeks after planting, the radishes are up and looking nice.
October 10th the radishes have filled in the field and are standing beautifully. Brushing aside the thick canopy reveals large roots that tell us they are doing the job expected of them. Besides being a row marking system for us, they are also “bio-drilling” their tap rooted selves down through the compacted subsoil underneath.
Planning ahead to next spring, we were a little worried about the amount of winter killed residue that these giant radishes would leave behind. Thinking of our early cultivation and not wanting to be clogging up the cultivator, we decided to very quickly graze our small dairy herd through the stand for one day. They went right for the greens and sampled a few roots but seemed to prefer the tops.
Right after the last snow melted off in the first week of April. Radish residue is present but thinner than we expected.
As we had hoped, the 17” rows were very clearly marked by the holes left behind from the already well decayed radish roots amongst the plant residues and oak leaves. Using our hand dibbler, we went along opening up the smaller holes for setting the transplants, and substituted new holes where the radishes hadn’t provided one, spacing our onion plantings about 5” apart within the row. We then skipped every other radish marked row, leaving our onion crop to stand on 34” centers designed for managing with our McCormick Deering riding cultivator.
The transplanting team is sitting down on the job on April 10th. We took advantage of being able to plant so early since no fieldwork was involved and the onions could handle the cool soils. This helped us to check one big mark off the planting list before the early season rush really started. Since the spring of 2013 was very cool and wet, the onions all got off to a very slow start and didn’t really pick up until June. The early planting we thought, probably wasn’t any more beneficial for the crop this season, but it did seem worth it to free up our time later in the month for other tasks.
We customized a set of salvaged rolling Lilliston cultivators to mount onto our new Pioneer Homesteader. We put this together the previous winter since we were planning on dealing with lots of residues in the early cultivations. As it turns out, we decided that it would have been better not to graze the plot in the fall because by the time of this photo, our first cultivation pass on the field in early May, the residues are almost completely gone. What little was left behind was no trouble for the Lilliston’s to work through and the only clogging we had was when it spiked a dry cow pie!
By the middle of May we were able to try out our custom tine weeder set up, also on the new Homesteader, to loosen the soil and take out any small weed sprouts. Look closely to see the still very small, but well rooted, onion transplants standing up to the weeder fingers while any small weeds are taken out. At this point the field was completely clean of all radish residues! Those earth worms were really doing their job!
In early June we moved on to the riding cultivator set up with four 12” sweeps. After two years of ground work training, this spring was the first season that our three year old Suffolk Punch colts went to work in the market gardens. It is also the first season that we have looked at our old cultivator with new eyes after reading the “Horsedrawn guidance system” article by Anne and Eric Nordell in the SFJ. By working with some of their ideas on cultivator setup, we were able to train our young and energetic horses to walk a narrow 34” row straight and calmly in a short amount of time. The key to this system that worked out so well for us is the two outside sweeps which track in the same path as the horses, are tipped down slightly so they leave a shallow furrow in the center of the pathway. As described in the guidance system article, this leaves a path that the horse naturally wants to follow during the next cultivation. Being so young and impressionable, they fell for this little trick very quickly and we didn’t have to steer them for the rest of the season while cultivating, letting us focus on watching the plants and working the foot pedals. I believe this also took a lot of the horses’ anxiety away from doing a new task by making their job so easy for them to understand. That set a nice base foundation for all the other new jobs we have been putting them to around the market gardens, making their farm training a real pleasure for teamster and team alike.
On August 15th we had a beautiful harvest of yellow and red storage onions. Here they sit on the 9’x16’ flat bed trailer ready to cure in the sun! Overall we were pleased with this project and have repeated it with a few modifications for our 2014 crop of onions. We hope that this idea can be helpful and adaptable to different reduced tillage systems for others as well.