Development of Methods toward Sustainable Apple and Poultry Production

Development of Methods toward Sustainable Apple and Poultry Production

Summary

Objectives:
1) Evaluate the feasibility of integrating livestock and poultry into the orchard system.
2) Evaluate the feasibility of integrating other horticultural crops (vegetables) in the orchard
system.
3) Evaluate the feasibility and merit of pasturing poultry simultaneously with livestock.
4) Develop direct marketing relationships which: a) educate consumers about the social as well
as the environmental implications of sustainable agriculture at the local level and b) encourage
the active involvement of producers and nonproducers in the processes of food production and
distribution at the local level.

Methods:
During the 1993 and 1994 seasons a field experiment was conducted at the Kellogg Biological
Station of Michigan State University to evaluate the feasibility of growing potatoes as a
vegetable intercrop in an apple orchard-domestic fowl agroecosystem, and to determine the
impact of domestic fowl on weeds and insect pests in the system. Potatoes were used as a model
vegetable crop because of their presumed compatibility with domestic birds and because of
current problems with insecticide resistance in Colorado potato beetle, one of the most important
potato pests in Michigan. Three experimental treatments were used in this study: 1) free-range
chickens (Barred Rock), 2) free-range African geese, and 3) control with no birds In addition,
mulching was evaluated as a subtreatment for its effects on potato yield, Colorado potato beetle
populations, and weed biomass.

Results:
The chickens were observed to consume a variety of insects, including important pests such as
Japanese beetle and Colorado potato beetle. In addition, they consumed a variety of weed
seedlings. However, they did not provide any substantial crop protection for apples or potatoes in
replicated experiments. This lack of effect by chickens can probably be attributed to ineffective
weed control, which reduced the ability of the chickens as insect predators. By contrast, the
geese, which are primarily herbivores, provided outstanding weed control in the intercropped
potatoes and in the apple tree rows. This resulted in substantially increased potato yields and
slightly higher apple yields compared to a control. In addition, the geese provided indirect
reductions of certain apple pests, which resulted in slightly higher yields of pest-free fruit. The
potential for intercropping other vegetable crops was assessed in an unreplicated trial which
indicated that tomatoes, broccoli, peppers, and beans may also be compatible with chickens and
geese. Crops which are likely to be incompatible include cucumbers, pumpkins, and melons.

The marketing portion of this research was designed to explore social and economic dimensions
of sustainability and was centered around a small, diversified farm in Dimondale, Michigan. The
primary objective was to promote direct farmer-consumer interaction and to increase consumer
awareness of the overall importance of sustainable food production. This was accomplished via a
farm newsletter, on-farm experience, and voluntary involvement or investment in the farm
enterprise. The results so far are frustrating and enlightening and indicate that the Dimondale
farm will need to develop greater local support for its operation if it is to remain economically
and politically secure in the long-term.

Areas Needing Additional Study:
In the area of applied biological research, one question that could provide important practical
knowledge if addressed is: What effect do trees in an orchard have on the ability of insect pests
to find an intercropped annual? The complete lack of Colorado potato beetle on the intercropped
potatoes in the 1993 experiment indicate that the trees could possibly have had a negative
influence on this pest's ability to find the potato crop. Although studies in the United States and
Europe have begun to provide information on theoretical and practical aspects of intercropping as
a means of reducing pest populations, most studies have focused on intercropping various
combinations of annuals. Few studies have been focused on intercropping annuals and
perennials.

The permanence of the perennial crop may provide habitat for beneficial insects (enemies
hypothesis) or may provide a barrier to the pest's ability to locate the annual crop (resource
concentration hypothesis). To address this question studies would need to be focused on the
process by which herbivores locate hosts. In addition, field studies could be used to evaluate
colonization rates and population dynamics of pests and their natural enemies under
monoculture, annual intercropped systems, and perennial-annual intercropped systems.