Agriculture Reference
In-Depth Information
place for two or more growing seasons before tilling it into the soil. Inoculate
your legume seeds with a
Rhizobium
preparation to ensure that your crops
fix nitrogen. Check the inoculant label carefully to be sure that it is organic-
ally certified and not produced using genetically modified organisms.
Depending on the materials that went into its making, compost is also
a good source of nitrogen and can be a cornerstone of nutrition programs
in small orchards. Composting has the added benefit of recycling discarded
fruit, prunings, and other waste products from the orchard.
Applying Nitrogen
Apply nitrogen fertilizers directly to the soil. Although some people advocate
“foliar feeding” by spraying fertilizers onto the leaves of crop plants, nitrogen
and other macronutrients are generally not taken up by foliage in amounts
large enough to benefit the plants. Foliar feeding can be used effectively for
some micronutrients.
If the level of organic matter in your soil is below about 4 to 5 percent
and nitrogen concentrations are also low, as shown in a soil test, you may
want to begin incorporating slow-release forms of nitrogen before planting
your trees. Your soil test should recommend suggested amounts of nitrogen
to add. If you are using slow-release forms of nitrogen, such as compost, add
the amendment at least by the summer or fall before planting your trees. For
fertilizers that release nitrogen more rapidly, such as blood meal, apply one-
half of the needed amount 1 to 4 months before planting the orchard. Apply
the other half shortly after planting your trees.
Be careful not to apply too much nitrogen before or after planting. In
young trees, excessive nitrogen can cause too much shoot growth at the ex-
pense of root growth. In established orchards, excessive nitrogen causes poor
fruit set; soft, poorly colored fruit; and excessive amounts of lush, pest- and
disease-prone foliage and shoots that require much labor to manage. Re-
member that organic soil systems move more slowly than those in conven-
tional orchards. If you have incorporated a green manure crop or applied
composts or manures, the amount of nitrogen available to the plants will in-
