VERSATILE COOL SEASON ANNUALS and effective cover crops when planted in late summer/early fall or late winter/early spring and able to germinate efficiently over a broad range of seed bed temperatures. Brassicas are highly palatable to grazing animals, have aggressive growth, and suppress weeds. In addition radishes, a popular brassica, can have a “pre-emergent herbicide” effect on some weed species due to allopathy.

Brassicas move nitrogen and other nutrients scavenged from the subsoil to the upper portions of the plant. This “nutrient recycling” benefit starts to accrue early, within a few weeks of planting. Winter killed plants decay rapidly and deposit absorbed nutrients near the soil surface. Increased biological activity and enhanced fertility levels at the soil surface contribute to vigorous growth by cash crop seedlings and may accelerate the decomposition of crop residue.

Tillage, compaction reduction and infiltration improvement are best achieved with early seeded brassicas that are given adequate time to develop large roots. Brassicas are sensitive to residual levels of some herbicides, particularly triazines and ALS inhibitors. Radishes have been proven to reduce nematode populations and as a class are considered among the most effective biological tillage plants. The addition of 1 to 2 pounds of radish seed per acre to cash crop winter wheat plantings is gaining in popularity as producers observe increased wheat yields due to this practice. Decomposing radishes smell like rotten eggs, an aroma that is noticeable in the vicinity of the field where they were grown. Most varieties of radish used for cover crop originated from oil seed radish genetics and have been bred to favor either tillage or forage production.

Turnips excel as forage providers since top growth and tubers are palatable and efficiently utilized by grazing animals.

Brassicas