Orchard Floor Management - Growing Organic Orchard Fruits - page 443

While intuitively it seems beneficial to increase the diversity and abundance
of flowering plants in an orchard, either alone or as parts of alley and in-row
cover crops, research has seldom shown measurable improvements in pest
management with such an approach. Washington State University research-
ers report they are having better success targeting specific pests and their
predators or parasites. Alfalfa, for example, has proven to be a promising in-
sectary crop in controlling leaf rollers. Unfortunately, we are just at the be-
ginning of this type of research. For now, strive for a biologically diverse un-
derstory and carefully monitor the understory and fruit canopy for pests and
beneficials. Insectary crops provide excellent habitat for rodents, so employ
aggressive rodent management practices (see page 372 ➔ ). Keep careful re-
cords of the understory crops that are present, your management practices
(such as mowing), the types and abundance of pests and beneficials, and the
fruit yields and quality.
Nutrient Management
In chapter 8 ➔ , we discussed crop nutrition and fertilization in detail. Here
we will integrate nutritional goals with orchard floor management practices.
Integrating tree fruit nutrition practices with vegetation management in
the alleys and under the trees is far more complicated than simply adding
fertilizer to the soil or foliage. Some alley crops add nitrogen to the system
during one phase of their growth and take it away during another phase.
Other alley crops provide no nitrogen to the soil and are always competing
with the trees for nutrients, but even then they are of benefit to the fruit
crops by preventing the nutrients from leaching out of the root zone. Alley
and companion crops also add organic matter to the soil, increasing nutrient
reserves for the fruit crops. In-row companion crops may compete for nutri-
ents or add nitrogen, but they also alter when the nitrogen is available for
the trees. Adding compost to the orchard floor provides nutrients and organ-
ic matter but can interfere with mowing, tillage, and other practices.
Although the situation is complicated, the approach is quite simple: