Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, February 10, 1994                   TAG: 9402100057
SECTION: CURRENT                    PAGE: NRV-10   EDITION: NEW RIVER VALLEY 
SOURCE: Joe Hunnings
DATELINE:                                 LENGTH: Medium

MINIMUM TILLAGE HAS ADVANTAGES

With minimum-till, soil preparation is done in the fall, so it may be a good idea for local gardens, especially in our area where the spring weather tends to be wet.

Actually, the traditional method of preparing soil in the spring can be bad for the soil, especially in situations where gardeners rototill their soil year after year, perhaps two or three times a year.

That not only can destroy some of the soil's natural structure but can create a hard soil layer just beneath the level that the rototiller reaches.

Two other advantages to the minimum-till method are the constant covering of the garden soil that reduces the potential for soil erosion and the annual addition of organic matter to the garden soil.

The minimum-till program starts in the early fall. At that time, prepare the garden soil for planting fall/winter cover crop seed by tilling under summer crop remains as well as the organic mulch material from that just-ended summer. Pull out any diseased plants first, and cut up big plant parts, such as tomato vines and corn stalks, to make tilling the soil easier and so they will decay faster.

Then, plant an appropriate cover crop. The term "cover crop" means a green crop that comes up quickly and will cover the soil during the off-season. Winter rye is a good cover crop. Mix two pounds of winter rye seed with three-fourths of a pound of hairy vetch seed sown per 1,000 square feet.

Rye germinates very quickly and will be the mulch for the next spring's planting. Hairy vetch is a legume. Therefore, it adds nitrogen back to the soil through a natural process as it grows.

This process may be enhanced if the vetch seed is treated prior to planting with a material (called an inoculant) available from some seed stores. The hairy vetch seed will not germinate in cold soil, so this method must be started in early fall (September) rather than late fall. Many local gardeners already follow this recommended practice.

In the spring, use a scythe or string trimmer to cut the cover crop growth to a few inches above the ground about a week or so before you're ready to plant the garden. Rake the cut cover crop growth off to the side of the area to be planted and save for mulch. Then, use a lawn mower on a high setting to trim the cover crop stems that remain. About a week later, mow that area again, and planting can begin.

To plant, dig a hole for each transplant, large enough to accommodate root spread. Pull weeds and cover crop roots in the surrounding area. Water in the transplants with a water-soluble fertilizer according to package directions. Mulch the entire area between the newly planted vegetables with clippings harvested earlier, although it is a good idea to leave six to eight inches of space around the base of plants to allow the soil to warm up.

During the summer, some additional organic mulch may be needed for proper weed control, especially close to the vegetables. Grass clippings not treated with herbicides or leaves saved from the previous fall are excellent. If any weeds come up, pull them by hand. If at all possible, do not vigorously hoe out weeds because it can mix soil into the mulch layer.

Then, in the fall, repeat this process to continue minimum-till gardening. It may be a good idea to try this with small plots rather than your entire garden. This minimum-till gardening method does not mean the garden does not have to be watered during droughts. However, the increase in organic matter should allow the soil to retain more moisture. Also, as this method is used, vegetable plants may develop deeper roots.

The rye is allelopathic to many vegetable seeds, which means that you might get poor germination unless the rye is completely dead and decayed. For that reason, this method is best adapted only for the parts of the garden where you plan to use transplants.

Joe Hunnings is the Virginia Cooperative Extension Service agent for agriculture in Christiansburg. If you have questions call the Montgomery County extension office at 382-5790.