Category: reposts

Below is a post from November 10, 2008, that was originally on a now defunct blog. I still haven’t gotten around to playing with no-till in the years since then but I’m partially posting this because there seems to be interest. I’ll put a few additional thoughts I have looking back at this at the end of the post.

I just got back from the Washington Tilth Producers annual conference in Bellingham, Washington, where Dr. Paul Hepperly of the Rodale Institute gave a keynote address on no-till and then followed it up with a question and answer session that was very informative.  About five or six years ago I spent two seasons trying to get no-till garlic to work.  Those experiments definitely turned me off from no-till in vegetables but Dr. Hepperly’s talk, even though it was on a grain rotation, actually gave me some hope that it might work in a few specific vegetable crops.

When we ran the garlic trials, three farms went in on a SARE Producer Grant.  47th Ave. Farm, Praying Mantis Farm, and Sauvie Island Organics all tried to establish thick stands of sudan grass, plant garlic into the cover crop, and then use the winter-killed cover as a mulch to suppress weeds.  This did not work for us for a variety of reasons, all reasons that Dr. Hepperly’s system avoids.  Also, as an aside, the Producer Grant turned out to be a lot of work for us to manage which made us less excited about those grants, but more excited about the Research and Education grants when the OSPUD project came around in 2005 (more on that in a future post).

The rotations that Dr. Hepperly was primarily talking about were field corn planted into a cover crop of hairy vetch and soybeans planted into a cover crop of cereal rye.  Not only were the cover crops providing all of the weed control, they were also providing all of the fertility for the cash crops, and, at the same time, reducing economic and environmental costs by limiting tractor passes and other inputs, and holding soil from erosion.  Perhaps the most amazing part is that they were out-yielding conventional tillage systems, consistently!

There are some important limitations to the no till approach that Dr. Hepperly described, and in the question and answer session he clarified that the entire rotation is not always no-till, when they have weed problems, or if other issues come up they need to till sometimes to establish strong cover crops.  I made a list of the points I recognized as important to making the system work:

Weedless cover crop

For cereal rye they seed very heavily, I think he was saying 150-200lbs/acre.  A fellow I was talking to at lunch also mentioned that instead of seeding in one pass at a heavier rate, two passes at right angles to each other at a more typical rate of 80-90lbs/acre give more early coverage in the field.  For vetch, since the seed is expensive, a higher rate isn’t used but winter kill oats are added for early weed suppression.  Buckwheat or other summer annuals are also possible, but the cover crop has to be an annual for the system to work.

Sufficient Biomass

To create an effective mulch there needs to be sufficient biomass, I think he was saying about 5 tons per acre. If there is too much biomass there can be problems as well but mostly it sounded like you just need enough so that there’s good ground cover when it’s killed.

Roll down at full flower

To kill the cover crop it has to be rolled down, preferably with a roller crimper, at full flower.  They’ve done some good design work on the roller crimpers and there are a lot of little details available on the web site.  A roller crimper is  available for sale from Buckeye Tractor whose equipment I’ve used and is well made.  

There are a couple of keys here: full flower, leaving the stalks attached to the ground, and crimping the stalks.  The window is narrow for achieving full kill, it has to be after full flower, but before the cover crop sets viable seed.  If full kill isn’t achieved the cover crop becomes the weed.  Leaving the stalks attached to the ground helps keep them in place when the secondary seeding or planting operation happens.  Crimping the stalks helps with more completely killing the cover crop.

Don’t expose soil when planting

The point of the mulch is to shade weed seeds and prevent them from germinating.  If your planter exposes the soil and leave a strip then there will be in line weeds to deal with.

Direct seeding only works with large seeds

Small seeds don’t push through the mulch so this only works with large seeded crops, or transplants.  Another important point with direct seeding is that the press wheels need to be be heavy enough to provide good soil contact for germination.

The mulching effect has a limited time window 

The mulch starts to break down immediately so the system works best when the crop provides a full canopy by the time the mulch has broken down enough to let weed seeds germinate.  

With all of this new information I’m re-inspired to try no till on a few vegetable crops.  Good candidates, I think, are winter squash, tomatoes, eggplant, peppers, fall brassicas, sweet corn, beans, and melons.  The trick, it seems to me, is to find crops where the planting dates roughly match the flowering dates of a cover crop, and that will provide a good canopy later in the season.

On small scale plantings this systems seems like it would require very little investment in equipment for trials.  Crops can be crimped with a 2×4 and some string, and transplanted or seeded by hand or jab planter.  On a larger scale more might need to be invested in a roller crimper and no till seeder or transplanter, but the roller crimper is not terribly expensive and modifications can be made to existing equipment to make them work in no till situations.

February 2015 – Additional Thoughts

Here in the Northwest I think there are a few drawbacks to thinking about no-till systems that are specific to our climate. No-till systems tend to help keep ground moisture and to keep the ground cooler. In hot and dry climates this is a big plus, but for us here in the Northwest we are almost always hoping to warm things us and dry them out a bit so the heavy mulch of no-till can be counter productive in all of the potential crops I mention above. Slugs and voles are also problematic in my area, particularly when there are damp conditions and there is ground cover. Bare soil in the field helps control both of these pests whereas mulch exacerbates the problem.

Another note that was left out of the original post, the Rodale system wasn’t all no-till all of the time, but for certain years of the rotation there was no tillage. This helps break build up of perennial weeds that establish in no till systems, and also makes crops that aren’t appropriate for no till fit into the rotation system.

Reading a blog post from a friend of a friend’s farm this morning I was inspired to repost these two entries from 2009. The weather hasn’t been as conducive for these crops since that year (read, the weather has been downright terrible for those crops since 2009), but I have still had some success. I don’t really have enough space to play with this technique the way I’d like to, but I really think it has a lot of potential. Unlike the Kerr Center example linked to in the blog referred to above, I have been able to use the standard seeders and cultivating equipment and so there really isn’t much in the way of drawbacks, mostly just benefits.

The Three Sisters July 16, 2009

Pretty much every american grower it seems has heard of the three sisters: corn, beans and squash.  Andy Griffin mentions this planting scheme in his recent excellent post “Corn,” in the ladybug letter.  Earl, the chef at Meriwether’s, convinced me that we should try growing a block this way and we had some space so we are.  We’re doing it a little different that the “milpa” system that Andy talks about, everything for us is in rows.  We seeded the corn first, a type of popcorn actually.  A few weeks later we came back and seeded the beans, five types of pole beans.  Then a week or so later the winter squash was seeded, lots of trial varieties.

We’re also trying to grow these crops with no supplemental irrigation.  The property has limited water but abundant land and soil that holds water well and is deep.  So far everything has germinated beautifully, despite the lack of any rain and a stretch of hot sunny weather for several weeks before the winter squash was even seeded.  We’re raking the soil to keep weeds down and to create a dust mulch to prevent surface evaporation.  I’m hopeful that the crops will do well – meaning they’ll produce a modest harvest with minimal work.  I’m fairly confident but it’s still a long way to harvest in late summer.  I’ll let you know what happens.

Dry Farming August 11, 2009

Two months ago I wrote a post on the “Three Sisters.” Take a look back at those photos and then look at the one above.  Same field, and this field has seen no irrigation this season, we’ve had no significant rain since early May, and the above photo was taken a week after the week long 100+ degree heat wave.  All of the crops were direct seeded in this field but we also have melons in another dry section that were transplanted in June, and are ripening fruit now (pictured below).

The vine growth is not quite as vigorous as I would expect with irrigated vines, but there is good fruit set and so we’ll see how the yield and flavor turns out.  Part of the reason for experimenting with dry farming, meaning growing crops in a rain free summer without supplemental irrigation, was because we didn’t have much irrigation water so we wanted to save that for the crops that really need it, like greens.  I’m certain that we won’t get top yields per space, but I hope that we’ll still get top quality and we have definitely had to do very little cultivation and weeding, and no irrigation work.

 

   Besides the three sisters section and the melons, we’re also dry farming tomatoes, potatoes, dry peas and beans, spelt, flax, several corns and quinoa.  We’ve harvested half the potatoes with very good results, not a record yield, but respectable and good quality spuds.  The tomatoes are just starting and everything else is looking good with no real signs of water stress and very little weed pressure.  The corn pictured above is popcorn and the beans were a late seeding of flagolets, seeded in mid June to available moisture after a month of no rain.

One of the things that I think is allowing us to do this is the impressive water holding capacity and depth of the soil we have.  Even though the site is on a ridge top, 1000’ above Portland, Oregon, there also seems to be a few natural seeps so I suspect there are areas of the field where water naturally flows subsurface late into the spring.  On top of those things we have given the crops slightly more space than we would have if they were irrigated and early on we concentrated on cultivating out even very small weeds and leaving the surface soil loose to reduce weed seed germination and surface evaporation.

2012 Notes

A few follow up notes are appropriate here. My feeling on the three sisters planting is that it works best when it’s a corn that is for drying (popcorn, dent corn, flint, etc, not sweet corn), pole beans for dry beans, and hard squash. None of these crops require entry into the field while the other is fully filled out for harvest. Letting the squash fully cover the ground is one of the benefits, and that makes harvesting the corn and beans impractical before the vines start to die back.

Also, the terrible weather we’ve had the last two years has been cold, wet springs and early summers (and cold through the summer). In 2009 I did notice that the corn and squash we grew together did very slightly better than those that grew separately, the beans seemed to not do quite as well, but the there was absolutely no work done to trellis them so that was a huge labor and materials savings, and there is far more row feet of corn than we’d usually plant in beans so there’s no problem in seeding extra beans to make up for the difference. in 2010 and 2011 none of those crops did well anywhere for us. Also, the beans are essentially in the same space as the corn, so they are bonus income from the same space, not requiring any additional costs over seeding and harvesting – no extra field prep, no extra cultivation, no extra fertilization. They also didn’t interfere with hand harvesting the corn, and the squash was harvested before either of those two crops.

I also experimented a little in my garden and actually seeded the corn and beans at the same time. it seemed like the beans would outstrip the corn, but actually the corn was always just a hair ahead of the beans. I wonder if the beans were forcing it to grow higher by continually shading the lower parts. I’ve also been surprised that I’ve had no trouble with lodging.