Agriculture Reference
In-Depth Information
uble phosphorus and making it available to the fruit crop. Buckwheat can
become a troublesome weed, so be sure to till it very shallowly into the soil
before the seeds ripen. Mowing is not an effective way to prevent reseed-
ing because some buckwheat plants are short enough to escape the mower
blades, leaving some seed production.
When to plant.
The best time to plant an annual cover crop depends on your
climate and the availability of water. Where spring rainfall is abundant or
water is readily and economically available for sprinkler irrigation, you can
plant early in the growing season. This strategy is good for spring wheat,
spring barley, oats, peas, and buckwheat.
In areas where precipitation during the growing season and irrigation wa-
ter are limited, another strategy is to plant late in the season, after harvest in
bearing orchards. This practice works well when using winter wheat, winter
rye, or winter barley as an alley crop. No further care of the cover crop should
be needed until the following summer. As with spring-planted alley crops,
you may need to mow from one to several times. Leave the stubble in place
until it is time to plant the annual cover crop again. In Washington State
University trials, winter rye proved particularly effective in managing grassy
weeds in orchard alleyways.
How to plant.
In a new orchard, when tree roots are still confined to the tree
rows, there are few problems with plowing in preparation for planting a cov-
er crop. As the tree root systems expand, however, cultivating the alleys can
damage the tree root systems. Remember that many of the tree feeder roots
are located within the top six inches of soil.
Many years ago, some authorities recommended cultivating deeply
around fruit crops to drive the roots deeper into the soil. Apparently they
thought the fruit crops would be more drought-tolerant and have better ac-
cess to soil nutrients if their roots were deeper. Deep cultivation, however,
does not drive the root systems deeper into the soil. It simply cuts off the
vital shallow roots that lie in the most nutrient-rich and biologically active
