General information about crop : Soybean (Glycine max L.) is one of the world’s most important sources of oil and protein. They are an important food crop; the seeds are eaten whole, split or sprouted. The soybean can be processed to yield protein which is used as a supplement as infant feeding or they can yield oil, which is an edible oil in food. The bulk of the oil is used for salad oil and margarine and shortening. The oil can also be used industrially in the manufacture of paints, linoleum, oilcloth, printing inks, soap, insecticides, disinfectants, etc. Soy meal, the residue after the extraction of the oil is a very rich protein feed stuff for livestock for which there is an increasing demand. The meal and soybean protein are used in the manufacture of synthetic fiber, adhesives, textile, sizing, waterproofing, firefighting foam etc. Soy flour prepared from whole beans produces flour used in bakeries and other food products; such as additives and extenders to cereal flour and meat products, in health foods, etc. Sometimes soybean is called the invisible crop because they are found in a large number of products, but the public is unaware that soybean is in these products. Soybean seeds are extremely fragile and subject to damage by handling, auguring, and transporting. Seed moisture influences the extent of damage; drier seed is more easily damaged than seed with higher moisture content.

Botanical name or taxonomic nomenclature : The soybean (U.S.) or soya bean (UK) (Glycine max) is a species of legume native to Eastern Asia. It is an annual plant that may vary in growth, habit, and height. It may grow prostrate, not growing higher than 20 cm (7.8 inches), or even stiffly erect up to 2 meters (6.5 feet) in height. The pods, stems, and leaves are covered with fine brown or gray pubescence. The leaves are trifoliate (sometimes with 5 leaflets), and the leaflets are 6–15 cm (2–6 inches) long and 2–7 cm (1–3 inches) broad. The leaves fall before the seeds are mature. The small, inconspicuous, self-fertile flowers are borne in the axil of the leaf and are white, pink or purple. The fruit is a hairy pod that grows in clusters of 3–5, with each pod 3–8 cm (1–3 inches) long and usually containing 2–4 (rarely more) seeds 5–11 mm in diameter.

	Scientific classification
Kingdom  Plantae  Phylum  Magnoliophyta  Class  Magnoliopsida  Order  Fabales  Family  Fabaceae  Subfamily  Faboideae  Genus  Glycine  Species  G. max  Binomial name  Glycine max (L.) Merr.

Oil content : The oil and protein content together account for about 60% of dry soybeans by weight; protein at 40% and oil at 20%. The remainder consists of 35% carbohydrate and about 5% ash. Soybean cultivars comprise approximately 8% seed coat or hull, 90% cotyledons and 2% hypocotyls axis or germ. The majority of soy protein is a relatively heat-stable storage protein. It is this heat-stability of the soy protein that enables soy food products requiring high temperature cooking, such as tofu, soymilk and textured vegetable protein (soy flour) to be made. The principal soluble carbohydrates, saccharides, of mature soybeans are the disaccharide sucrose(range 2.5–8.2%), the trisaccharide raffinose (0.1–1.0%) composed of one sucrose molecule connected to one molecule of galactose, and the tetrasaccharide stachyose(1.4 to 4.1%) composed of one sucrose connected to two molecules of galactose.

Cultivation

Type of soil and weather for cultivation : The best planting date of vegetable soybean differs with season and location depending upon temperature and daylength. The optimum temperature range of soybean cultivation is 20-30ΊC with short daylength (14 hours or less). However, planting should be avoided at cooler temperatures during winter. Loam soil with pH of 6.0-6.5 is suitable for its cultivation, but the field should be well drained.

Field preparation : Land tillage makes the soil friable for good germination, increases soil porosity and aeration for healthy plant growth. Tillage kills weeds to control weed-crop competition for soil nutrients, moisture and light. This in turn helps plant productivity. Plow and rot till the field. The soil should not be too dry at the time of seedbed preparation. Inadequate moisture will result in poor seed germination.

Harvest : Harvesting is done when 80% of the pods have reached physiological maturity stage. It may take 65 to 75 days after germination for vegetable soybeans to be ready for harvest depending upon variety, temperature and weather conditions. The pods are still green. In Taiwan, harvesting usually begins at midnight when dew and cool temperature help to preserve the green color and freshness of the vegetable soybeans. When harvested in daytime, the plants are kept under the shade. The pods are stripped from the plants by hand. Harvesting machines can save labor, cost and time.