"The Brassica comes in many forms but all touted for their value as a cover crop.
The many forms of the Radish and the Turnip are almost obvious. My question is about the Mustard plant. What is it's redeeming qualities? Does our common wild mustard weed have any redeeming features?
We usually see wild mustard growing in a road right of way, equipment yards, or in wheat.
If all are allowed go to seed would they cross resulting in some kind of wild mustard with a humongous root and side spreading, ground shading leaf style?
Would this produce viable seed resulting in a problem feral Brassica?
Maybe a Vegetable version of a mule?" I must admit I have not played with mustard as a cover crop. My friends in New Zealand have tried it to some success but I am not aware of any in my neighborhood. "Mustards are a good cover crop for a variety of reasons. One of the main benefits is that they have high levels of glucosinolates. According to Cornell University …”The practice of using mustard cover crops to manage soil-borne pathogens is known as biofumigation. Biofumigation is simply the suppression of various soil-borne pests and diseases through naturally occurring compounds.
All brassicas such as cabbage, kale, cauliflower, brussel sprouts, broccoli, mustard, and turnips naturally produce glucosinolates, the compounds that make certain brassicas “hot”. Brassicas sold as cover crops have been identified or specifically developed to contain very high levels of these glucosinolates. The higher the levels of glucosinolates present, the better the biofumigant effect. The process works as so: when plant cells are damaged such as by chopping, glucosinolates are released and come in contact with an enzyme (myrosinase). In the presence of water, the reaction produces the natural gas isothiocyanate (ITC).
ITC is responsible for the suppressive effects of the practice. ITC is similar to the active ingredient in Metham Sodium or the conventional fumigant Vapam (a.i. Methyl ITC). In addition to the soil biofumigation benefits, brassica cover crops are ideal for adding organic matter to the soil and improving many soil health related characteristics due to the large quantity of “green” or fresh biomass produced and incorporated into the system.”
So far I have had no ill effects from any cover crop I've planted getting out of hand. One reader is dead set against annual ryegrass because of the threat of Italian ryegrass but I have not seen that either. Actually, stray vetch, clover, alfalfa, rye, wheat, radish and other once cover crop plants make me smile. I know I planted it.
Anyone have comments they would like to send or post about mustard as a cover?
Thanks,
Ed
I know white mustard was extensively used in organic farming at least 20 years ago. It's not often that you can find a natural way of getting rid of nematodes (red beet, potatoes, strawberries) and some fungi, with cheap seeds and dying naturally over the winter.
ReplyDeleteIt was sometimes planted together with phacelia, because both plants frost at the same temperature (-8°C/18°F).
Cross-pollination is frequent in the whole family of brassicae, rapeseed itself is supposed to come from a natural cross between a cabbage and a forage/oil cabbage that happened about 4,000 years ago, but it's rarely a problem as mustard cover crop needs to be cut before flowering, at least 3 weeks before planting.
And of course, you should not grow rapeseed or canola or any brassicae after mustard, as the larvae of pierid butterflies and other brassicae parasites would then spread to the new culture.
Mustard produces a decent amount of green manure too, and has the same pivot roots as any brassicae, not as large as the cover crop radishes you seem to enjoy, but probably just as long.
I don't think they knew 20 years ago as much as we know now about mustard's fumigation effect. If you have ever tried Japanese wasabi, another brassicae, you wouldn't be surprised mustard kills nematodes and fungi, as wasabi almost kills humans who eat it!
The wild mustard is supposed to make great salad greens and cooked greens if picked early enough. I don't think I'd want to pick a hundred acres of it though!
ReplyDeleteWe are not getting younger, make that 30 years ago, not 20!
ReplyDeleteI wouldn't either, Gorges.
ReplyDeleteThis post stemmed from an email and generated several more:
"Look at mustard in the SARE cover crop PDF for more info...some nematode deterrence if I remember correctly.
I don't recall seeing any mustards in our native units so a non native plant for the most part.
Hedge mustard came in with hay and is in improved pasture areas with poor thatch/ plant cover it will prosper. In good pasture canopy little HM. Hence, hedge mustard is an opportunist and can be spread in mismanaged hay...impact of drought can precipitate HM outbreak the next winter/ spring.
Diversity in cover crop is important...the model for your cover crop program is in the progression of early successional habitat...not the textbook."
"I believe also that it is the glucoseinates which cause hemolytic anemia in ruminants....never lock stock down on straight brassica.... Also a laxative effect so don't stand behind a cow on turnips. Maybe the livestock side for tomorrow's blog Ed...brassica is good cow food with some considerations... Deer eat them as well....some farms."
"I know a lady who raises sheep and uses a lot of forage turnips. She stresses that you must NOT turn hungry livestock loose on them. But to feed them some straw or poor quality hay before turning them out. She has done this for close to 10 years now I would guess with great success. She lives up in Minnesota. Also, have heard of some others grazing green corn too. That might just be a use for that little extra you have when cleaning out the planter…"
"Google....hemolytic anemia ruminants...yes access to hay or grass pasture will work. Good feed....no discredit...just considerations..."
These are just some of the highlights from the email generated from yesterday's blog.
Ed