Overstory #35 - Animals in Agroforestry
Most modern systems of raising animals separate animals from their natural environment. In these systems, many of the cycles of nature which are beneficial to both animals and their environment are broken.
The use of animals can be a controversial topic. In many situations, especially in the tropics, animals such as cattle, goats and sheep are associated with ecological degradation and deforestation. There is no doubt that the inappropriate use of animals and poor management leads to many environmental problems. However, this does not necessarily have to be the case.
If planned and managed properly, appropriate kinds of animals can be key components in sustainable farming systems. Agroforestry systems that incorporate animals with tree crops can enhance important cycles of nature such as nutrient cycling and balancing of insect populations while reducing energy intensive management techniques. The key is to integrate the natural needs, behaviors, and products of animals with the environment provided by the agroforestry system in a way that maximizes the benefits to the animals and to the system as a whole.
As a part of their normal behavior, animals forage for plant foods and/or insects, spread manure, and dig and/or scratch in the earth. Many of the products and behaviors of animals, for example manure, are considered problems or pollutants in modern conventional production of e.g. poultry and livestock. However, these animals can perform many beneficial functions when integrated into an agroforestry system.
Some products and services of animals for agroforestry:
- grazing/weed maintenance (livestock, poultry)
- insect control (poultry)
- cleaning of fallen fruit/nuts, other organic wastes (livestock, poultry)
- spreading nutrients in the form of their manure (livestock, poultry)
- scratching and digging to prepare for planting (pigs, chickens, turkeys, etc.)
Similarly, agroforestry systems can have an excess of weedy undergrowth, fallen fruit or nuts and insect populations. Often these excesses are controlled through human intervention--weed cutting, insect control, etc. Animals, when selected carefully for the right agroforestry system can carry out many of the maintenance functions through their normal behavior.
Some products and services of agroforestry systems for animal husbandry:
- favorable habitat
- access to a diverse diet
- access to medicinal plants and insects
- natural population densities
Bill Mollison's "Chicken and egg" example from the Permaculture Designer's Manual is a classic approach to systems thinking as it pertains to animals. In most commercial production systems, chickens are caged in large facilities. Food, water, and grit is provided to them via a massive, energy-intensive infrastructure of farming and transportation. In this unnatural and crowded environment, chickens are often stressed, and producers therefore also supply them with medication from the pharmaceutical industry. The manure from these factory-like facilities is in many cases considered a pollutant, and in some cases is contaminated. The resulting products of eggs or meat are questionable in quality in the eyes of many consumers. (In fact, consumers gaining a greater understanding of the environmental impacts and health conditions of these kinds of animal factories are limiting their intake of animal products.) The chickens are deprived of their natural activities and a healthful environment, and the humans must work very hard to supply the chickens with food and medicine and dispose of their waste. As Mollison asks: "Who is working for whom?"
In an integrated system, by comparison, chickens are raised in managed habitats where they have regular access to a diverse diet rich in plants and insects, as well as their other needs such as shelter and water. In return, the chickens control understory growth through foraging and scratching, eat large quantities of insects, and return the nutrients back to the system through their manure. In such a managed system, the chicken's behaviors and wastes play their natural role in what is a complex natural system. By using the natural cycles, raising chickens in an agroforestry system can reduce human inputs to both the chickens and the plants.
Examples of animals in agroforestry systems:
- Chickens in garden systems, orchards and forest
- Ducks in aquatic environments, such as rice paddies
- Geese to control grasses in orchards
- Livestock in forest plantations (silvopasture)
Of course an animal in the wrong place at the wrong time can create problems, not solve them. For example, the wild pigs prevalent in Hawaii destroy new plantings, damage trees, and spread weedy exotic species throughout native forest. The same pigs have been used successfully for decades in traditional Hawaiian farm forestry in controlled paddocks to graze and consume farm residues, and to provide meat for sustenance. In another example, chickens (and other poultry) are notorious for damaging new plantings, especially gardens. Once an area is prepared and planted, it is essential to exclude the chickens (or other poultry) until the plants can hold their own against them.
+ Advantages of integrating animals:
- Less reliance on outside inputs
- Reduced human maintenance
- Better plant health through natural fertility cycling
- Animals must be carefully selected for particular systems
- Animals require tending and management of grazing
- Food and water may need to be supplemented at times
- Health care required
- Requires a special set of skills and knowledge
The right animal in the right place at the right time
Clearly, the introduction and management of animals must be carefully thought out, to ensure that the right kinds of animals are introduced to the right place, and at the right time. Some environments, like savannas, are naturally suited for certain types of grazing animals; in other areas smaller animals and birds might be more appropriate. For some very fragile ecosystems, animals may not be appropriate at all.
Also, the type of animal is important for the environment, and farmers should not feel they have to limit themselves to conventional animals. All over the world, farmers are branching out to incorporate animals that are more appropriate to their local environment, culture, and market demands. Examples of alternative animals being used successfully include iguanas, small forest deer, and ostriches.
Commingling the right animals with the right agroforestry system can create highly productive systems that require less human intervention for maintenance and control. In this way, animal production can be sustainable.
Bill Mollison's Permaculture: A Practical Guide for a Sustainable Future, covers many systems which integrate animals.
Alice Pell, 1999. "Animals in Agroforestry in the Tropics," in Agroforestry in Sustainable Agricultural Systems (Eds. Louise Buck, et al) offers a more scientific approach to nutrient cycling.
Board on Science and Technology for International Development. 1991. Microlivestock: Little-known Small Animals with a Promising Economic Future. National Academy Press, Washington, D.C.
About the Authors
Kim M. Wilkinson is the Education Director for Permanent Agriculture Resources and editor of The Overstory. She has B.A. degrees in Anthropology and Ecology from Emory University.
Craig R. Elevitch is an agroforestry specialist with more than ten years of public and private sector experience in tropical agroforest and forest management. He has a M.S. degree in Electrical Engineering (Dynamical Systems) from Cornell University.
Related Editions to The Overstory
- The Overstory #50--Animal Tractor Systems
- The Overstory #37--Trees/Livestock Examples
- The Overstory #36--Silvopasture