Questions & Answers: Cover Crop No Till?
We planted a cover crop winter mix in the fall, in our backyard terraced garden. It has done great, I have been prepping to cut it down, give it time to decompose. I have been really into the no till philosophies, read up about the possibility of just leaving it cut down, no till, as a mulch. But I just read something else that says the nitrogen benefits are lost if it is not tilled in. I am confused, any advice? I am all about the low maintenance gardening, companion planting, without too much intervention (not that we are opposed to the work).
Tags: companion planting, cover crops, mulch, nitrogen, no-till, winter mix
March 18th, 2009 at 10:08 am
I was actually wondering about this very same situation in my garden and asked a few people’s opinions. Apparently a lot of the minerals in the soil are taken up into the plant, as well as up to 2/3 the nitrogen in most cover crops. Therefore it is most nutritious for the soil if you work the greenery back into the soil where it can decompose more quickly and make all that nitrogen and minerals available to the next succession of plantings. Mulching is still acceptable, you just would not get as much nutrients, nor as quickly.
But my partner had another idea, what if we mowed down our cover crop and put it in our compost bin? Then once it is fully composted, maybe we would have those minerals and nitrogen in our compost? I’m not sure, because it takes nitrogen to break a lot of things down in a compost bin, and we may not have the perfect composting green to brown ratio in our bin…
I think I’m still going to push for tilling in our Soil Builder cover crop. It seems to be the method that would work the best for our situation. I’d love to know what you decide, and any other opinions on the matter.
March 18th, 2009 at 10:42 am
There are contradicting opinions about when to turn in cover crop. It’s true that it has the most nitrogen when it’s green and young, but it quickly releases into the soil and doesn’t provide a long-term source of nitrogen. A radical farmer named Bob Cannard believes that turning it in before it is brown and carbonaceous is cover crop “infanticide” and that waiting until it’s more mature is the best way to provide nitrogen for your crops. In your case, I would say that if your soil is already plentiful in nitrogen it would be great to try to the no-till method. If not than it might be a good idea to build up the nitrogen first for a few years.
March 18th, 2009 at 1:31 pm
I double dig my beds. Shovels and digging forks are our friends!
March 18th, 2009 at 1:33 pm
site on double digging
http://www.iirr.org/saem/page134-137.htm
March 18th, 2009 at 3:32 pm
It is important to turn in the cover as soon as possible, in order to get the maximum benefit from the nitrogen and organic matter it provides. Approximately 2/3 of the Nitrogen in most cover crops is in the part that is above ground. It will break down quicker if you mow or chop the cover crop before incorporating into the soil. The top several inches of the soil has the most aerobic bacteria, which will speed up the decomposition if it isn’t incorporated too deep. The nitrogen availability will be delayed in a no till situation, as the cover crop will break down much quicker if incorporated If you still prefer to chop it up and leave it on the surface, it would be best to make sure it stays fairly moist. Loss of nitrogen increases with the intensity of drying conditions (higher temps and lower humidity). Over several seasons of no till cover cropping, the surface layer of your soil will definitely show improvement.
March 24th, 2009 at 9:20 pm
Thank you for all of the wonderful advice, tips, & resources. I appreciate it greatly. I think we have decided to go ahead and till it in this time, and go from there with the no till. I know there is great benefit to soil testing, etc., maybe I will get more ’scientific’ about it through the years, but I am more of the intuitive, bit of planning, let nature do what will, and lets try and roll with what comes type. I was really inspired by an article about Ruth Stout some years back (not to mention just what a neat gal she was), as it seemed to call to something in me, in my bits of learning, and what feels right/works for me…. Anyhow, since then, discovered many others on the same lines, and trying to flow with what may work, while still seeking the tried and true advice of others as well. Wow and aren’t we lucky to have so many resources & options to choose & tailor to what works for us. Just wanted to say thanks again, I am sure I will have more questions along the way, and glad to find a place to get some wonderful, varied answers.
March 29th, 2009 at 10:29 pm
Greetings,
I was wondering if anyone has experience or have a good reference on methods of sowing cover crops in a no-till system. I did a couple experiments this past season with my winter cover with 4 test areas. Thought i’d share some observations:
1. tilled 2 inches(wanted to make a dent in the population of perennial clover I’m trying to phase out) and broadcast my winter cover crop mix of rye grass, crimson clover, fava, australian field pea, burdock, queen annes lace, and hairy vetch.
2. cut summer cover crop and broadcast winter cover crop directly into cuttings.
3. cut summer cover crop and spread a mix of compost and soil in a light dusting over mulch then broadcast winter cover crop directly into cuttings
4. cut summer cover crop and spread one inch of Soil builders inc. Mighty Microbe Mulch over cuttings, then broadcast cover crop and racked in seed.
Observations:
First off my fava’s got about 5 inches tall round december, but now I can’t find ANY. I’m thinking the snows crushed them? Anyone else experience that?
Also, this is a fairly wanky expierement since the soil composition on these sites have not been tested, probably highly differ, and all are highly disturbed. But here it goes:
1. Really good growth of sown covercrop, minimal growth by seeds I didn’t sow
2. Minimal growth of sown covercrop and unsown plants growing strong
3. Great growth of sown covercrop, except minimal crimson clover but un-planted red clover came in strong.
4. Planted 11/20 2.5 weeks after other patches. All varieties came up, but had minimal growth so far, we’ll see what spring brings. Minimal unsowed plants coming in.
Next steps:
I’m planning to mow winter cover crop and plant a sudan/sorghum grass and hoping that I can interplant some sunflower, corn, crimson clover, etc. I don’t exactly have experience with sudan grass. Does anyone know if the sudan grass will allow my interplantings to take? Since it’s so geat a weed suppression, will it allow other plants to grow?
some thoughts. thanks for starting the discussion!
cheers,
warren neth