Soybean (Glycine max L.)

Description

Soybean (Glycine max L.) is a legume that grows in tropical, subtropical, and temperate climates. Approximately half of the world's soybeans are produced in the developing world, and the other half in the developed world. Originally domesticated in China around 1700-1100 B.C., soybean is now cultivated throughout East and Southeast Asia where people depend on it for food, animal feed, and medicine. Soybean reached North America in 1765 via London, and Africa through missionaries in the early 19th century. In addition, it is also cultivated in Brazil and to a very limited extent in sub-Saharan Africa and West Asia.

Nutritional Information

Soybean is an important source of high quality, inexpensive protein and oil. At 38% soybean has the highest protein content of all food crops and is second only to groundnut in terms of oil content (18%) among food legumes. Compared to other protein-rich foods such as meat, fish, and eggs, soybean is by far the cheapest. It also has a superior amino acid profile compared to other sources of plant protein. It provides nearly 5% of protein consumption in China and Southeast Asia. Its fat contribution to diet is 20% in Brazil, 6-7% in China, India and Thailand, and 4-5% in Indonesia.

How Soybean is Used

The crop's main use is flour, protein products and animal feed. Although soybean is an important food crop and an inexpensive source of protein and Vitamin B in East Asia, efforts to introduce it as a food crop elsewhere have met with limited success. However, it is gaining importance in many parts of sub-Saharan Africa where it is used to fortify traditional foods.
The oil produced from soybean is highly digestible and contains no cholesterol. Soybean is the largest single source of edible oil and accounts for roughly 50% of the total seed oil production worldwide. A byproduct from the oil production, called soybean cake, is used as a high-protein animal feed in many countries.
Another advantage of soybean is that it 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 not available or are too expensive for farmers to buy.

How Soybean is Grown
In the United States and Western Europe most soybean is grown on large-scale high-input farms as a monocrop. In contrast, in sub-Saharan Africa soybean is mostly grown by small-scale farmers either as a sole crop or mixed with sorghum, maize, or cassava. Very little or no inputs (fertilizer or pesticides) are used, and field operations such as planting, weeding, and harvesting are usually done manually. Depending on variety, soybeans can be harvested between 100 and 150 days after planting. Threshing of harvested beans is also mostly done by hand.

Statistics

In 2005 over 92 million hectares of soybean were planted worldwide. Brazil accounts for over 22 million hectares, and the United States for almost 29 million hectares. Africa accounts for just over 1 million hectares, Asia for 19 million hectares and Europe for almost 2 million hectares.

Soybean production for 2005 stood at:

Brazil 53,053,000.00 metric tons
United States of America 83,368,000.00 metric tons
Africa 1,238,443.00 metric tons
Asia 25,746,286.00 metric tons
Europe 3,050,403.00 metric tons
World 213,976,284.00 metric tons

Center work on Soybean

CGIAR soybean research is based in sub-Saharan Africa and has progressed well in both crop improvement and post-harvest processing and utilization. The main objective of future research is to develop varieties that give a maximum contribution to the productivity and sustainability of the cereal-based cropping systems of the moist savannas of Africa.
Since the 1970s soybean breeders at the CGIAR's International Institute of Tropical Agriculture (IITA) in Ibadan, Nigeria, have been successfully working on developing improved varieties of soybean that fix more nitrogen from the atmosphere without rhizobium inoculation, are high yielding, store well, and are resistant to pod shattering. When these improved varieties are planted in rotation with maize or sorghum the productivity and sustainability of crop production is enhanced considerably. One study showed that when an improved variety of soybean was grown in rotation with maize for only one season, maize yields nearly doubled.
Breeders at IITA are also currently developing dual-purpose varieties that are tolerant to phosphorus-deficient soils and have enhanced capacity to kill seeds of the parasitic weed Striga hermonthica which attacks cereals. These varieties have high grain yield and also produce large amounts of biomass, making them useful as a soil-building rotation crop and as fodder for livestock.
Postharvest researchers have also developed appropriate technologies that reduce labor and time requirements for processing, and improve the product quality and quantity. Various soybean-processing machines, such as a flour mill (dry mill or grinder), an extruder/expeller, a screw press, and a thresher, have been adapted for use in sub-Saharan Africa and have been widely adopted by both small- and medium-scale processors.
IITA food technologists have come up with a wide range of new food products from soybean. About 150 food products with good nutritive value and consumer acceptability have been developed. Many of the new products have been tried out in villages across the region, modified by local people to suit local culinary tastes, and ultimately adopted with increasing popularity. In some communities in Nigeria up to 98% of households have started eating soybean foods. At the same time, more than 90,000 people have been trained on how to produce and use soybean to fortify their diets. Some of these new soybean products have become so popular that they have been upscaled to industrial production, providing income generation opportunities. The benefits of IITA's soybean research are also seen in other African countries, such as Ghana, Nigeria and Côte d'Ivoire. A study from Benue State in Nigeria showed that the nutritional status of children is significantly better in soybean producing/using households than in those households that did not use soybean. The study also provided evidence that soybean production had a positive impact on the farmers' income.

Constraints to Soybean ProductionIn the major producing countries, many insect pests and diseases (viral, fungal, and bacterial) attack soybean. In Africa, however, soybean has had fewer disease and insect problems because the crop was recently introduced to Africa and extent of cultivation is still relatively small. Important diseases of soybean in Africa include frogeye leaf spot, bacterial pustule, bacterial blight, and soybean mosaic virus. Recently, red leaf blotch and rust have also been reported.Nematodes and insects feed on soybean plants and cause damage. These wounds provide entry points for pathogens, and the plant becomes susceptible to pathogenic organisms. The most destructive pests in the tropics are pod feeders (stink bugs), foliage feeders, and beanflies.One of the major constraints to the adoption of soybean in tropical Africa has been farmers' lack of interest because there was no market for the grain, and lack of knowledge of preparation methods for home consumption.

To read more about soybean from the IITA web site, click here.

Sources

Technical Advisory Committee, CGIAR Priorities and Strategies for Resource Allocation during 1998-2000 and Centre Proposals and TAC Recommendations

IITA web site

FATSTAT. PRODSTAT.