By Dr. Mohammed Sa’id Berigari, Senior Soil and Environmental Scientist, USA, 06/06/2012.
The soybean (Glycine max) of the family Leguminaceae is a species of legume native to East Asia, but widely cultivated now worldwide for its edible beans mainly because of its high oil and protein contents. The Food and Agricultural Organization (FAO) classified the plant as an oilseed rather than a pulse. Soybean oil and protein contents account for 60% of dry seeds by mass, protein 40%, oil 20%, carbohydrates 35%, and about 5% ash. Soybean cultivars consist of about 8% seed coat, or hull, 90% cotyledons, and 2% hypocotyl or germ.
In the US the bulk of the product is solvent extracted with hexane to remove oil and the remaining protein and carbohydrate is used for raising farm animals (chicken, hog, turkey) on an industrial scale never occurred before in human history. Soybean products are available in a large variety of processed foods. The oil is good quality liquid cooking oil for human consumption.
Soybean cultivars grow well in climates with hot summers, with optimum temperature of 20-30 °C. Temperatures below 20 °C and over 40 °C retard growth significantly. However, there are variations among different varieties and it is important to select varieties that best suit the climate of the region. They can grow in a wide range of soil types but do well in moist alluvial soils containing good soil organic matter. Soybean is a legume and has the potential for symbiotic fixation of molecular nitrogen from the atmosphere. However, it is important to inoculate the seeds with the bacterium Bradyrhizobium japonicum before sowing to ensure proper condition for nitrogen fixation.
The leading soybean producer countries in 2009 are USA, Brazil, Argentina, China, India, Paraguay, Canada, Bolivia, and Ukraine with 91.4, 57.3, 31.0, 15.0, 10.1, 3.9, 3.5, 1.5, and 1.0 million metric tons respectively with a world total of 223.0 million metric tons.
The average worldwide yield of soybean crops was 2.5 tons/hectare for 2010. The three major producers of soybeans had an average of 3 tons/hectare. The most productive soybean farms of the world in 2010 were located in Turkey with a nationwide average- farm yield of 3.7 tons/hectare. The world record for soybean yield for 2010 was 10.8 tons/hectare achieved by Kip Culler in Purdy, Missouri, USA. Kip Culler secret to his record breaking of soybean yield year after year is attributed to attention in detail, proactive management, irrigation, herbicide use, keeping plants healthy and free of stress during the entire growing season.
There is no doubt that soybean cultivation in Kurdistan Region has the potential for a success especially in farms with adequate water supply during the growing summer season like the ones in Turkey where they showed pronounced achievement in soybean yield for 2010.