Agriculture Reference
In-Depth Information
veloped at the University of Idaho: 'Humus' rapeseed and 'Ida Gold' mustard.
If you are using open-pollinated seed, rather than named varieties, brown
mustard appears to be a somewhat more effective biofumigant than white
mustard or rapeseed.
Mustard, canola, and rapeseed crops produce seeds quickly and in enorm-
ous quantities. Be sure to till the green manure crops into the soil before they
set mature seeds. Shredding the crop with a flail mower immediately before
rototilling it into the soil maximizes its biofumigant value.
Instead of growing the
Brassica
plants, you can use cold-pressed meal
from crushed seed. The biofumigant properties of the seed vary greatly,
however, depending on the type and variety of the mustard, canola, or rape-
seed used. While progress is being made in seed meal biofumigation, results
often leave much to be desired, and it is best suited for small orchard applic-
ations.
Microorganisms
Mycorrhizae are soil fungi that form beneficial relationships with plants.
The name literally means “fungus root,” and these organisms are extremely
valuable in helping plants take up moisture and nutrients by effectively ex-
tending the plants' root systems. These organisms can also, in some cases,
help protect plants against pathogens and parasitic nematodes by compet-
ing with other microorganisms for space on plant roots and by forming a
physical barrier to nematodes. There are many different mycorrhizal species.
Some are specific to particular plant species or types, while others are gen-
eralists. Some mycorrhizae are adapted to acid soils, others to neutral or al-
kaline soils.
In a healthy soil, native mycorrhizae should already be present and do
not need to be added as a soil amendment. When native mycorrhizae have
been killed or damaged by fumigation, overuse of inorganic fertilizers, or
other causes, it can be beneficial to inoculate an orchard soil at the time
of planting. For example, you might want to place mycorrhizae in bands in
your tree rows immediately before planting if you have grown biofumig-
