Wild jicama
Calopogonium caeruleum
Family: Fabaceae
What it is like
Calopogonium caeruleum is an evergreen Climber growing to 5 m (16ft) by 0.3 m (1ft in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10. The flowers are pollinated by Insects. It can fix Nitrogen. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers moist soil.
Height (m): 5
Where it is found
Widely planted and naturalised throughout the humid tropics.
Eastern tropical S. America, north through C. America to Mexico and the West Indies.
Conservation Status:
Countries/locations it is found in
Antilles, Argentina, Asia, Brazil, Central America, Cuba, Indochina, Mexico, Paraguay, SE Asia, South America, Vietnam.
How it is used
Food
Rating: 0
Medicine
Rating: 0
Other
Rating: 4
Agroforestry Uses: Plants can be grown as a green manure crop. The plant gives good soil cover; builds up soil fertility through its leaf fall and nitrogen production; and can be used to smother weeds such as Imperata cylindrica. It is grown in plantations where it can be fully productive in full sun and up to 40% shade, it grows well in mature coconut plantations where there is 30 - 40% shade, and will still do fairly well in heavy shade. Will grow productively in mature coconut plantations (60-70% PAR ). One of the most productive herbaceous legumes, generally producing yields of 3-7 t/ha/year DM. Produced DM yields of 1-1.5 t/ha/year under mature oil palm (10% light transmission), out yielding a wide range of common herbaceous legumes. As a green manure crop/mulch, leaf fall from uncut C. caeruleum can be as high as 7 t/ha/year DM. In Nigeria, it had the second highest green manure effect on maize yield among 12 legumes tested, providing an N equivalent of about 90 kg/ha.Companion species. Legumes: Planted as a cover crop in southeast Asian plantation agriculture, often in a species mixture with one or more of the species C. mucunoides, Centrosema molle, Pueraria phaseoloides and Desmodium ovalifolium . Other Uses: The plant is used by laundresses in El Salvador to take dirt out of clothes whilst rubbing them.
Fodder: Food given to the animals (including plants cut and carried to them) rather than forage for themselves.
Green manure: Fast-growing plants that can be used to increase the fertility of the soil.
Mulch: Used for covering the ground to conserve the nutrients in the soil.
Soap: Plants used directly as a soap substitute.
Soil conditioner: Plants grown to improve the structure of the soil. See also Green manures.
Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.
Agroforestry Services: Understory legume: Legume vegetation, especially the trees and shrubs growing between the forest canopy and the forest floor.
Fodder: Pasture: Enclosed tracts of farmland mainly of grasses, with an interspersion of legumes and other forbs (non-grass herbaceous plants).
Management: Fodder: Non-destructive management systems maintaining the soil organic carbon.
Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.
Agroforestry Services: Nitrogen: Plants that contribute to nitrogen fixation include the legume family – Fabaceae.
Agroforestry Services: Understory legume: Legume vegetation, especially the trees and shrubs growing between the forest canopy and the forest floor.
Fodder: Pasture: Enclosed tracts of farmland mainly of grasses, with an interspersion of legumes and other forbs (non-grass herbaceous plants).
Management: Fodder: Non-destructive management systems maintaining the soil organic carbon.
Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.
Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
The plant is adapted to the humid tropics but it is fairly drought-tolerant. It grows better in cooler conditions than centro (Centrosema pubescens) and in the elevated tropics can grow up to an altitude of about 800 metres. Succeeds in most soils if they are well drained. Plants are very tolerant of shading. Plants can succeed in acid soils with a pH as low as 4.0. It grows best in areas with a mean annual rainfall of 1,000 - 3,000mm, but will persist in environments with as little as 700mm. It prefers environments with 25c maximum and 18c minimum day temperatures, with outer limits of 32c maximum and 10c minimum. It has been widely planted throughout the humid tropics, and has escaped from cultivation and become naturalised in many areas. It has considerable weed potential, often smothering desirable grasses and other understorey species. It has invaded seasonally wet tropical environments. When growing in the humid tropics it flowers indeterminately through the first wet season, producing seed into the dry season. It is capable of producing moderate amounts of seed even in its first year. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.
Propagating it: Seed - Usually established from seed, sowing into a cultivated seedbed at the beginning of the wet season. Establishment can be slow and may be improved by addition of P fertiliser and lime, and by controlling weeds. Current recommendations for cover crop under oil palm in southeast Asia are to seed C. caeruleum and Pueraria phaseoloides at 1-1.5 and 5-7.5 kg/ha seed, respectively. Can be established by stem cuttings but low success rates (5% of cuttings) are common. Using older stem material and treating stems with root-promoting hormones can improve success rates. Slower to establish than C. mucunoides and Pueraria phaseoloides and may take 20 months to achieve a complete cover. As a green manure crop, can be established by broadcasting into upland rice following the final weeding. Mid-season plantings may reduce rice yields.
Best place to grow:
Habit: Climber
Hardiness: 10-12
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Full shade, semi-shade, no shade
Moisture: Moist
Things to keep in mind
Considerable weed potential. Weed of tropical plantation crops, often smothering desirable grasses and other understorey species. Has invaded seasonally wet tropical environments.
Its other names
Local names
Cudzu criollo, Jicama de monte, Jiquima dulce, Lamdau lam
Synonyms
Stenolobium caeruleum Benth.