This article was originally posted on December 14, 2010.
Benefits of Mustard
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.
Take a look at the interview I did with Kim and Matt Davidson from Mighty Mustard™:
If you’re unable to see the video, simply refresh your browser or click on the link below to watch it on YouTube.
Advantages of mustard as a cover crop:
- Acts as a natural biofumigant
- Generally winterkills (at 26 degrees F)
- Easy to kill with herbicides and tillage
- Provides alleopathic weed control
- Helps “clean up” problem fields where nematodes are a problem
- Hinders the germination/survival of ryegrass and other cover crops…may be used to clean up a problem cover crop ryegrass field
- New varieties are superior to VNS or wild mustard for nematode or weed control/suppression
- Best to be planted 1-2″ deep
- Must be planted as a monoculture
- Must be killed or tilled in for a minimum of three weeks before planting a subsequent cash crop
- Must have rain or irrigation after tillage/killing to help release glucosinilates
- Needs 5-6 weeks growth for best results
- Must not be used for animal feed
Visit Mighty Mustard for additional information on mustard as a cover crop.