Silvopasture

• The silvopastoral system must be well planned in order to lead to the realization of positive benefits. The specific site-context needs to be taken into account, including elements such as: slope of the land, soil characteristics, climatic conditions, and appropriate plant species.
• Species suitability: it is important to use native tree species as they will be more adapted to the local environmental conditions. Furthermore, adequate care must be taken to identify suitable grass and legume species, as not all grasses and legumes tolerate shade and competition well.
• Grazing must be well managed as if it is not controlled, livestock could graze on planted or naturally regenerating trees (younger than 2-3 years).
• Return on investment: it takes about two years to realize the benefits of silvopastoral systems, depending on the region and species combinations being implemented, as well as the scale over which these interventions are practiced.

Materials required:
The type of materials required depends on the situation.

If trees need to be planted:

• good quality seedlings
• fences to protect the seedlings from grazers
• shovel and material to dig (tractor or small dozer if mechanized version)

If trees are already present:

• a rope or something to indicate which trees have been selected for the silvopasture (to prevent them from being accidentally cut)
• fences and other material to protect small trees from grazers
• materials to clean the unwanted vegetation (ex: thorny shrubs, plants poisonous for cattle).

Steps of Implementation:

Silvopasture can be established in an already forested area or over an area where trees and foliage may be lacking but which is suitable for tree growth, as long as there is a soil depth of at least 1.5 meters. Most farmers, however, prefer to use native trees which can be established using natural regeneration (please refer to the ANR intervention) instead of planting trees themselves because of the associated higher tree survival rates and lower costs.

The usual  configuration of trees within a Silvopastoral system consists of  trees which are scattered across  the pasture area, or rows of trees which are fit amongst rows of grasses - this is similar to alley cropping, but with grazing livestock instead of crops.

The density of the forest area should be between 100 and 600 trees per hectare, depending on the environmental conditions. Trees should not be planted too densely, as they must allow sunlight to reach the grass and stimulate its growth. A good practice is to imitate the configuration of trees in surrounding areas and to choose a wide variety of native tree species. High species diversity will allow for better resistance to pests, and a varied succession of crops which provide multiple services, such as trees for medicinal use, food (in the case of fruit trees), timber, and firewood.

During the first years, saplings should be protected from grazers and weeds by installing fences or only allowing livestock in areas where trees are tall enough to survive grazing. Weeding is also very important as weeds can suffocate the trees and compete for nutrients. If necessary, tree growth can be stimulated by watering and adding extra manure.

Different types of livestock can be introduced in a silvopastoral system, from poultry to cattle, but to ensure the success of this technique overgrazing should be avoided. This can be prevented with controlled grazing such as rotational grazing and by always making sure the trees and the grass are able to resprout. To facilitate the confinement of livestock to a specific area, exclosures can be installed, or live fences (simple or multi-strata) can be created using trees and bushes.

OTHER VARIATIONS:

• Agro-silvo-pastures: these are pastures combining trees or shrubs, crops, and cattle. More complex system which should be well planned but that can bring a variety of benefits. Also called crop-livestock-forest system (iCLF).
• Agro-silviculture: combinations of food crops and woody perennials
  Silvo-fishery: combinations of woody perennials and fish resources

Fodder banks
If the main goal of the intervention is to increase fodder for animals, it is also possible to plant “fodder banks”. These consist of trees which are densely planted (10,000 to 40,000 plants/ha) that have the ability to withstand grazing or thinning, have a high nutrient content, and are appetizing for livestock. In fodder banks, livestock should only be allowed in the perimeter of the fodder banks for a few hours per day. The area can also only be used for the cut-and-carry technique (see a definition of it in the Grazing management intervention).

This intervention contributes to:

Estimation of costs & benefits of intervention
In this example, the silvopasture has been created from the conversion of an existing pastureland. The area consists of 4000 acres, with 200-400 trees per acre.

Note: this example is given in acres and not hectares

* Costs of cattle and fencing material excluded

Source: case based in Louisiana, USA, in 2014.

USA:
Silvopasture has also been demonstrated to be successful for the restoration of determined tree species and wildlife habitats, as this example from Florida (USA) illustrates.

India:
Silvopasture can also be used in semiarid lands, for a good example, click  here.

Panama:
Often, Silvopasture can be a sustainable alternative option to traditional systems, here is a successful  example of a silvopastoral system in Panama.

• A very good guide on establishment and management of silvopasture for pine trees can be found here.
• Here you can find other examples of silvopasture interventions around the world and their differences according to location. Such examples are found in Argentina, Uruguay, USA, New Zealand, Paraguay, Brazil and Chili.