Introductory Agroforestry

MUTIPURPOSE TREE SPECIES

The multipurpose tree species (MPTs) is a plant species that is purposefully grown so as to provide two or more than two products and also service function like shelter, shade, land sustainability of the land-use system. Many woody perennial species may be ‘multipurpose’ in one kind of system but ‘single purpose’ in another.

VARIOUS BENEFITS FROM MPTS

FOOD

1. Human food from trees (fruits, nuts, leaves, cereal substitutes, etc).
2. Livestock feed from trees (one step down the trophic chain).
3. Fertilizer trees for improving the nutritional status of food and feed crops through:

(a) Nitrogen fixation
(b) Access to greater volume of soil nutrients through deep rooting trees
(c) Improved availability of nutrients associated with higher cation exchange capacity and organic matter levels.

4. Soil and water conservation.
5. Environment amelioration.

WATER

1. Improvement of soil moisture-retention in rain-fed cropping systems and pastures through improved soil structure and microclimate effects of trees.
2. Regulation of stream flow for reduction of flood hazard and more even supply of water, through reduction of run-off and improvement of interception and storage in infiltration galleries, through various watershed protection practices involving trees.
3. Protection of irrigation works by hedgerows of trees.
4. Improvement of drainage from waterlogged or saline soils by phreatophytic trees.
5. Increased biomass storage of water for animal consumption in forage and fodder trees (higher water content of tree fodder in dry season).

ENERGY

1. Firewood for direct combustion
2. Pyrolytic conversion products (charcoal, oil, gas).
3. Produces gas from wood or charcoal feedstocks.
4. Ethanol from fermentation of high-carbohydrate fruits.
5. Methanol from destructive distillation or catalytic synthesis processes using woody feedstock.
6. Oils, latex, other combustible saps and resins.
7. Augmentation of wind power using appropriate arrangements of trees to create venturi effects (wind power is proportional to the cube of wind velocity).

SHELTER

1. Building materials for shelter construction
2. Shade trees for humans, livestock and shade-loving crops.
3. Wind-breaks and shelter-belts for protection of settlements, cropland and pasture.
4. Living fences.

RAW MATERIALS FOR PROCESSING

1. Wood for a variety of craft purposes.
2. Fibre for weaving industries.
3. Fruits, nuts etc. for drying or other food-processing industries.
4. Tannins, essential oil, medicinal ingredients etc.

CASH

1. Direct cash benefits from sale of above-listed products.
2. Indirect cash benefits from productivity increases (or input savings)
3. Via associated crops or livestock.

SOCIAL PRODUCTION

1. Production of goods for socially motivated exchange (e.g. cattle for bride price, ceremonial foods etc.)
2. Increased cash for social purposes (ritual expenses, development levels, political contributions etc.)

CHARACTERISTICS OF MPTS
Multipurpose trees species should fulfil the following criteria:

• Wider adaptability to local climatic conditions.
• Thin and sparse crown that allows sunlight enter into the system
• Capacity to withstand various management practices like coppicing, lopping and pollarding etc.
• Quick sprouting habit.
• Productive capacity that includes poles, wood, food, fodder, medicinal and other products.
• Good leaf litter making nutrients available at appropriate times in the crop cycle.
• Few and shallow lateral roots (or prunable).
• Ability to assist in nitrogen fixation.
• Resistance to drought, flooding, soil variability and other climatic hazards.
• Deep thrusting taproot system.
• Easy to manage
• Cheap to establish
• Higher demand and better value for the produce.