Agriculture Reference
In-Depth Information
from one year to the next. Every change you make in the orchard and in your
management practices affects the soil and the macro- and microorganisms
that dwell there, in turn affecting your fruit trees and bushes.
Unlike fertilization, which often has a quick or short-term effect, nutrient
management requires a long-term approach, particularly in an organic sys-
tem. Preplant applications of colloidal phosphorus, for example, will provide
phosphorus to the fruit crops for decades. The green manure crop that you
till in this season will supply nitrogen and micronutrients to your crops for
years. Our goal is to guide the nutrient status of the soil so that the crop
plants always have adequate, but not excessive, readily available supplies of
all required nutrients. In some cases, quick fixes will still be required, even in
the best organic orchard. That should be the exception, however, not the rule.
At the very beginning, a caution is needed: Having been a professional
fruit specialist for 30 years, I have found nutrient deficiencies in market and
home orchards to be quite rare and problems associated with excessive fer-
tilization quite common. The old adage that “if a little is good, more is better”
does not apply to fruit growing. Quite the contrary is true! The abundant, lush
foliage created by excessive applications of nitrogen is generally accompan-
ied by many problems that are described below. Adequate but not excessive
is the rule.
A second caution: As the size of an organic orchard grows, so does the
difficulty and cost of supplying adequate nitrogen in the form of fertilizers.
Organic fertilizers typically have low concentrations of nitrogen, compared
with industrial fertilizers, and are required in much greater quantities. Com-
posts, manures, alfalfa pellets, alfalfa meal, soybean meal, feather meal, fish
emulsions and meal, and cottonseed meal are all fine organic sources of ni-
trogen. They tend, however, to be expensive to purchase and ship in the large
amounts needed for a big commercial orchard. Along with pest and disease
management, supplying adequate nitrogen is one of the greatest challenges
in operating a large organic orchard. As in the days before industrial fertil-
izers, fruit growers near livestock operations or other sources of inexpensive,
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