Cultivation of Soybean

Soybean - Cultivation

Soybeans are an important global crop, with political ramifications. It is grown for its oil and protein. The bulk of the crop is solvent extracted for vegetable oil and the defatted soy meal is used for animal feed. A very small proportion of the crop is consumed directly for food by humans.

Soybeans and were used as food in eastern Asia long before written records, and it is still a major crop in China, Japan and Korea. They were first introduced to Europe in the early 1700s and the United States in 1765, where it was first grown for hay. Benjamin Franklin wrote a letter in 1770 mentioning sending soybeans home from England. Soybeans did not become an important crop outside of Asia until about 1910.

Cultivation is successful in climates with hot summers, with optimum growing conditions in mean temperatures of 20 °C to 30 °C; temperatures of below 20 °C and over 40 °C retard growth significantly. They can grow in a wide range of soils, with optimum growth in moist alluvial soils with a good organic content. Soybeans, like most legumes perform nitrogen fixation by establishing a symbiotic relationship with the bacterium Bradyrhizobium japonicum(syn. Rhizobium japonicum; Jordan 1982). However, for best results an inoculum of the correct strain of bacteria should be mixed with the soybean(or any legume) seed before planting. Modern crop cultivars generally reach a height of 1 m or more, and take between 80-120 days from sowing to harvesting.

Soybeans are native to southeast Asia, but 45 percent of the world's soybean area, and 55 percent of production, is in the United States. The U.S. produced 75 million metric tons of soybeans in 2000, of which more than one-third was exported. Other leading producers are Brazil, Argentina, China, Japan, and India.

Environmental groups, such as Greenpeace and the WWF have reported that soybean cultivation and the threat to increase soybean cultivation in Brazil is destroying huge areas of Amazon rainforest and encouraging deforestation.

The first research on soybeans in the United States was conducted by George Washington Carver at Tuskeegee, Alabama but he decided it was too exotic a crop for the poor black farmers of the South so he turned his attention to peanuts. He also encouraged farmers to use crop rotation. Peanuts, soybeans, sweet potatoes or other plants that would replenish the soil with nitrogen and minerals were planted for two years and then cotton on the third year.