Silvopastoral Alternatives for Fruit Growers
1. Compare income potential of traditional orchard management to combined orchard/sheep
2. Identify management advantages and constraints (time, investment, logistics) to a joint fruit and sheep production system.
3. Measure interactions of pasture understory and fruit production, tree phenology, soil compaction, and soil nitrogen in the orchard.
4. Determine the level of browsing which trees can sustain without affecting fruit production, if complete control of browsing cannot be reasonably achieved.
5. Develop and test training methods and devices for their potential to reduce browsing damage by sheep.
6. Determine potential toxicity to sheep from use of required pesticides in grazed cherry orchards and from unlimited ingestion of cherry foliage.
7. Formulate sweet cherry orchard/pasture management guidelines and stocking rates for this region, and as a model for other fruits and regions.
8. Disseminate information about orchard grazing opportunities and constraints by publication in grower journals, extension publications and scientific journals, and through field days for interested groups, and by actively involving extension personnel in the research.
Abstract of Results
Traditional orchard understory management (mowing and herbicide use) was compared with a variety of orchard grazing strategies using sheep. Over the five years of the study, we determined that sheep (and probably other grazers) can be successfully grazed in a mature orchard, reducing the need to mow and spray in the orchard and providing an additional source of revenue. Management complexity increases such that reduced chemical inputs may be offset by additional labor inputs.
A model was developed that summarizes silvopastoral options for orchardists. Economic analyses are not complete, but economic constraints do not appear insurmountable.
Depending on the type of orchard and how intensely grazing animals are managed, some browsing of fruit trees occurs. Browsing can be contained below the threshold of economic damage. However, even if economic damage does not occur, browsing may be unacceptable to some producers. We must point out that the potential hazards of residues from chemicals used on tree fruits to food animals have not been identified and must be considered for any orchard grazing practice.
Data collected from the major research site during the project are presently being analyzed using farm budgeting and internal rate of return procedures. We expect the first results of these analyses by January of 1996.
Potential Contributions and Practical Applications
The single most substantive benefit of this project was to create awareness of alternative orchard management practices. A number of other orchardists have adopted this idea and modified it to their own needs. None that we know of have made a 100% conversion to using livestock to manage the orchard understory, but livestock have been added to their management strategies.
All of the grazed orchards experienced a reduced investment of labor, machinery and fossil fuels associated with orchard mowing. Those that had used herbicides were able to reduce labor and chemical inputs to vegetation management. All of these would contribute to reduced ground water and air pollution and perhaps to chemical residues in fruit. These changes were to some degree offset by the resources invested in establishing a seeded forage understory where this was done, and by the electric energy used to power fence systems. Labor inputs often changed, but may not have been reduced overall. Involving family members in alternative enterprises may have significant intangible benefits to family well being (such as shared 4-H involvement). The net effect of changes in income stream has not been derived yet, but diversifying sources of income and distributing labor demands more evenly over the year are evident advantages. An added benefit of significance to some is that sheep consume windfall fruit that attracts yellow jackets and helps reduce this hazard to orchard workers.
This technique is still in the development stage and it is too early to try to generalize changes in practice that have occurred on any major scale as a result of this work.
Orchardists interested in diversifying their operation should consider grazing or housing livestock in the orchard understory.
It is not necessary to own livestock, leasing grazing privileges, barter, or even no charge offering of forage may still be advantageous, without the capital and investment in new knowledge needed to add an additional enterprise.
Recently shed leaves from fruit trees are a nutritious and palatable forage that animals will readily consume, clearing the orchard of debris that may harbor pests and diseases. Fall grazing is a good way to begin gradually experimenting with orchard grazing.
Secure perimeter fencing and a non-orchard holding area are essential. Electric fencing is satisfactory if livestock have been trained to an electric fence.
Even among a given species and breed, behavior among different groups of livestock varies and careful monitoring of livestock behavior in the orchard is needed to forestall any potential problems (one group of sheep learned to unplug the electric fence, individual animals may damage tree bark etc...).
Livestock should be removed during irrigation and for the reentry period of any agricultural chemicals used in the orchard.
We did not keep track of numbers in attendance at presentations, but estimate the total number of different producers and land management advisors who have learned about the project from these presentations to be over 2000. In addition, press coverage and word of mouth resulted in continual inquiries about the project from throughout the U.S. and Canada as well as a number of overseas inquiries. A number of local and visiting producers have visited both farms and the investigators have done some on-farm consultation with interested producers as well.
Areas Needing Additional Study
There are many different orchard crops that might be produced in a silvopastoral setting. In addition, there are many different production systems used for production of each crop. The chemical inputs of each system create unique questions about the safety of food animal production in each setting. Even organic producers use a variety of crop amendments whose impact on livestock are largely unknown. The question of potential impacts of accumulated chemical residues on forages and livestock is a critical one that must be considered for each potential combination of crop, livestock and production system. The trend towards integrated pest management and reduced chemical inputs creates additional opportunities for integrating crop and livestock production.
Another area needing more work before crop and livestock production can be optimally integrated is the degree to which livestock feeding behavior can be practically modified.
How a producer's identity affects choices of production technologies is a more important question than it might first appear. We must be able to effectively track the evolving motivations of non-traditional land owners and operators if we are to optimally realize the private and public benefits of agriculture and natural resource management.
Reported in 1995