Using Mustard as a Green Manure

Mustard is a fast-growing, hardy annual that makes an excellent green manure crop. It can be sown from March to September and grows well on most soil types, particularly fertile ones. Here are some key benefits of using mustard as a green manure:

Weed Suppression

Mustard grows very vigorously, quickly smothering weeds and creating a dense cover crop. When sown in late summer, it will outcompete weeds and provide a weed-free bed for planting in the fall.

Soil Improvement

Mustard produces large amounts of green matter and fibrous roots that improve soil texture and moisture retention when chopped up and incorporated into the soil. It helps add organic matter to soils that are lacking.

Disease and Pest Suppression

Mustard contains compounds that act as natural biofumigants, suppressing nematodes and pathogenic fungi in the soil. Incorporating mustard into the soil can have a cleansing effect on soils with high pathogen loads.

Nitrogen Fixation

As a member of the Brassica family, mustard is good at picking up nitrogen from the soil. It makes an excellent catch crop, with the nitrogen-rich plant matter becoming available to subsequent crops when the mustard is dug in.

Easy Incorporation

Mustard is not winter hardy and will be killed by frost, making it easy to chop down and incorporate into the soil. It has a short growing period of 6-8 weeks and can reach 60-90cm tall. To use mustard as a green manure, simply prepare a seed bed and broadcast the seeds. After 4-8 weeks of growth, chop down the plants and cultivate the chopped material into the top few inches of soil. The mustard will quickly break down, releasing its nutrients and beneficial compounds.