LEGUMINOUS AGROFORESTRY TREES

In addition to the more conventional crops, many trees are used around the small farm for a wide variety of purposes. Leguminous trees are exceptionally valuable for the nitrogen they add when their leaves fall off, or their roots die back. A single species of tree often serves multiple purposes. The potential uses of trees on the small farm are many, including the production of food, feed, industrial raw materials, lumber, and fuel, living fences, alley cropping, shade, source of nutrients for the soil, and erosion control. Altitude ranges are given as a guide. We have an Agroforestry Principles Technical Note if you are interested in this area. A caution on weediness: we heartily agree with the caution printed on the AgroForester order form, "By their nature many nitrogen fixing species are well adapted to harsh conditions, grow vigorously, and can seed prolifically. They are pioneers of degraded, disturbed, and ruined land, and will proliferate freely in such conditions.

Acacia angustissima-Prairie Acacia: Large shrub; provides fuel wood, organic matter; used in tanning; nitrogen fixing; tolerates acid soils, needs>1000 mm annual rainfall; can survive periodic waterlogging; some potential as a fodder crop. Matures to 3 feet in height and spreads from roots.
H, LL.

Acacia auriculoformis- Earleaf Acacia: Widely adaptable to harsh sites (pH 3-9); tolerates soil that is compacted, unstable, waterlogged or dry; quickly suppresses weeds; used as fuel wood or charcoal, crop shade, wind break.
Elevation: less then 100m. LL, MS.

A. mangium: Very fast growing on acidic, degraded soils; >1000 mm annual rainfall; needs full sunlight; good timber and fuel wood, high quality charcoal; quickly suppresses weeds; not flood-, drought- or wind-tolerant; leaves can be used as fodder; also can be used as fire breaks.
Elevation: lower elevations. LL, MS.

Refer to PULSES section for other varieties available and climatic conditions required.

Used for, forage, furniture, fuel, nectar, erosion control, & shingles. A stately deciduous tree, reaching heights of 20-60 m. Flowers appear on tree when leafless, up to 20 dense heads hanging down from branch ends, each 12cm long, dripping nectar from the reddish-green to orange flowers. It is very frost sensitive (15-26 degrees C)! Soil pH: 5.5-6.5.

This tree is indigenous to Malawi and now grows in West, East and Central Africa. In South Africa it is considered a rare species. The mahogany bean tree is used primarily for its durable, reddish-brown wood in the making of furniture, floors, doors, stairs and windows as well as for firewood. The wood is durable and fairly resistant to termites. It fixes nitrogen, the pods and leaves can be used for cattle fodder; vegetable, and medicine. Soil pH: 5.0-7.0. Can reach heights of 25-35m.

Used for reforesting dry, alkaline soils; also tolerates acid and salty soil, and light frost; provides organic matter, fuel wood, crop shade, and wind break; wood is suitable for building, furniture, fuel, charcoal, shade, and erosion control; grows on <500 mm and >1000 mm annual rainfall. Soil pH: 6.0-7.0. Can reach heights of 12-30m.

Used for fodder. Has a 30% protein content in the foliage. Wide-spreading branches make this species a good shade tree. Light colored wood is used for furniture and its pulpwood makes suitable paper. A very rapid growing tree, which makes it susceptible to wind damage. Tolerates a range of soil moisture levels, including water logging. Soil pH 5.5-6.5.

Vigorous, bushy tree; leaves used as fodder; excellent for coppicing and fuelwood production; used to enrich soil and provide stability on steep slopes; moderate drought resistance; good for humid tropics; prolific flowering for honey production; some weed potential. Does not tolerate water logging. Soil pH: 5.0-6.0. Can reach heights of 1.5-12m.

A small deciduous tree that reaches 12 to 15 meters in height. Is thorny and tolerates acidic soil up to 4 pH. Tolerates rainfall from 1500-4000mm per year. Can be used for living fence, fuel, and carving. Scarify seed coat or soak in warm water (40 Celcius) for 12 hours before planting.

Used as live fence posts, fodder, windbreaks, ornamental, living fences and hedges, shade in coffee and cacao, mulching, support for vine crops and alley cropping; needs >1000 mm annual rainfall, relatively easy to grow. Soil pH: 4.3-7.5. Can reach heights of 35m.

This tree fixes nitrogen in the soil and is often intercropped with sorghum, corn or millet, the yield of which can double. Though it is too lightweight for good firewood, it is thick and strong enough to act as a live fence or windbreak. Charcoal, timber, utensils and canoes are made from the wood. Can be used as a forage and for medicinal purposed. A deep taproot (reaching aquifers up to 80 m below surface), does not compete with the crop planted on the soil surface. Soil pH: 5.0-7.5. Can reach heights to 30m.

Woody, leguminous, deep-rooting shrub; grows up to 2000 m; >1000 mm annual rainfall; tolerates drought, poor drainage, acidic soils, and high aluminum concentration (alluvial soils); used for fodder, fuel wood, medicines, and green manure, and in alley-cropping. Soil pH: 4.5-7.5. Can reach heights up to 3m.

Fast-growing tree; used for living fences, green manure, fodder, honey production, and wind breaks, older wood is especially good for fuel; tolerates dry, acid, alkaline, and salty soils; traditionally grown to shade cocoa trees. Soil pH: 4.5-8.0. Can reach heights of 5-15m

A source of livestock fodder or browse; young foliage also can be eaten by humans in salads, soups or cooked as a vegetable; shade tree, also iplanted as a windbreak or as hedges and living fences; retards soil erosion and rejuvenates soil water-holding capacity; a good choice for paper pulp and fuelwood uses. Also a tropical pasture and feed crop.
Refer to Leguminous Tropical Pasture and Feed Crops section for varieties available and climatic conditions required.

Very hard wood, durable, resistant to rotting. Used for construction & hand tools. Very drought and salt tolerant. Bark is a source of tannin. Flowers important source of nectar for bees. Valuable in dune stabilization and recovery of degraded soils. Can be used as a forage, since pods are highly nutritious for feed concentrate. Also good for fuel. Soil pH: 6.0-8.5. Can reach heights of 8-15m. Can be invasive.

Black locust has been widely planted as a shade tree, in shelterbelts, and in fuel wood plantations. It is fast-growing, tolerant of adverse conditions, and often escapes from cultivation. Can become invasive. Tree can grow up to 15 meters (50 feet). A native to southeastern North America. Could become invasive. Soil pH: 4.5-8.2.

Produces abundant organic matter; used as fuel wood, crop shade, wind break; wood is suitable for building post or furniture; tolerates acid soil. This tree is a legume, but it does not fix nitrogen. Soil pH: 5.0-7.5. Can reach heights up to 20m.

A fast growing leguminous shrub/tree that is useful for fodder, green manure, light shade, and soil enrichment. Refer to the species specific descriptions below.

Quick growing shrub produces firewood in 6 months adapted to difficult soils; stems used for fiber, weed supressant, windbreak, green manure, cover crop, fodder; may be weedy. Soil pH: 4.3-9.0. Can reach up to 2m.

Fast-growing perennial achieving 8-10m in height in 3-4 years. Pods and leaves can be used as a quick source of fodder , medicine, and light shade. It enriches the soil with nitrogen and can also be plowed under as a green manure crop before the stems get too woody. This species can tolerate soil salinity, water logging and will survive in heavy, clay soils. Does not tolerate frost. Soil pH: 4.5-8.5. Can reach heights up of 10-15m.

Quick-growing shrub. Adapted to difficult (saline, alkaline, wet) soils. Stems used for fiber; weed supressant; windbreak; green manure; cover crop; erosion control; fodder; fuelwood.

Fast-growing perennial with moderate drought resistance; from 300-1800 m; good coppicing ability. Use for forage.

Fast-growing perennial with moderate drought resistance; from 300-1800 m; good coppicing ability. Use for forage.

This is a leguminous tree (height: 25m/80ft) that is best adapted to semi-arid conditions. Tamarind pulp taken from the pods is used often in Indian cooking and can be made into a tasty drink. Young trees are suseptible to frost but mature trees can withstand –3 degree Celsius (28 degrees F). Soil pH: 5.5-6.5.

A small bush used as green manure that contains rotenone in leaves and beans. Crushed leaves used for insecticide; beans and leaves are poisonous to fish; used for erosion control and for mulch; Do NOT use as a fodder for animals or as a fish poison in ponds or streams. Soil pH: 4.5-7.0.
See Industrial Crops.