Soybean, (Glycine max), is a leguminous vegetable of the pea family that grows in tropical, subtropical, and temperate climates. The soybean is economically the most important bean in the world, providing vegetable protein for millions of people and ingredients for hundreds of chemical products.
Importance
It consists of more than 36% protein, 30% carbohydrates, and excellent amounts of dietary fiber, vitamins, and minerals. It also consists of 20% oil, which makes it the most important crop for producing edible oil.
Malnutrition, particularly protein deficiency, is prevalent in many parts of Africa as animal protein is too expensive for most populations. Many leguminous crops provide some protein, but soybean is the only available crop that provides an inexpensive and high quality source of protein comparable to meat, poultry and eggs.
A by-product from the oil production (soybean cake) is used as a high-protein animal feed in many countries. Soybean also improves soil fertility by adding nitrogen from the atmosphere. This is a major benefit in African farming systems, where soils have become exhausted by the need to produce more food for increasing populations, and where fertilizers are hardly available and are expensive for farmers.
Harvesting
Depending on the variety, soybeans can be harvested between 100 and 150 days after planting. Labor requirements in Africa are high since most cultivation and harvesting are done manually.
Diseases
Diseases in Africa include rust, red leaf blotch, frog-eye leaf spot, bacterial pustule, bacterial blight, and soybean mosaic virus. Pests include pod (stink bugs) and foliage feeders, bean flies and nematodes.
Soybean rust, caused by the Phakopsora pachyrhizi fungus, attacks and destroys the leaves of the plant and can cause up to 60% yield loss. It is widespread throughout many parts of the world and is considered the most destructive of soybean foliar diseases.
Other problems include pod shattering that reduces seed longevity, and production and distribution difficulties. Dual-purpose improved varieties of soybean have not reached many soybean growers to increase production. In many countries only a small market exists for soybean so many farmers are not willing to grow it, and not many people know how to process it or prepare meals with it.