From the planting season, soybeans are mainly divided into spring sowing and summer sowing. Spring-sown soybeans are generally sown in April-May and harvested in September-65438+1October. Spring-sown soybeans are planted in northeast China and Inner Mongolia all year round. Summer sowing is mostly in June and September-65438+1October after wheat harvest. Summer sowing soybeans are mostly planted in Huang-Huai-Hai area. From the perspective of planting methods, the main soybean producing areas such as Northeast China and Inner Mongolia are generally single species in the field; Other areas are mostly intercropped with crops such as corn and peanuts. According to the color and grain shape of seed coat, soybeans can be divided into five categories: yellow soybeans, green soybeans, black soybeans, other colored soybeans and feed beans. Soybean seed coat is yellow, umbilical color is yellowish brown, light brown, dark brown, black or other colors, and the grain shape is generally round, oval or oblate.
Special classification of soybean
According to the color and grain shape of seed coat, soybeans are divided into five categories:
1. Soybean: The seed coat is yellow. According to the grain shape, it can be divided into two categories: northeast soybean and common soybean.
Green soybean: The seed coat is blue.
3. Black: The seed coat is black.
4. Other colors of soybeans: soybeans with brown, brown and red seed coats.
5. Feed bean (edible bean) soybean is an important agricultural product with both grain and oil, which can be eaten and pressed. As a kind of food, soybean is a high-quality and high-content plant protein resource, and its composition ratio of fat, protein, carbohydrate and crude fiber is very close to that of meat food. The protein content of soybean is 35%-45%, which is 6-7 times higher than that of cereal crops. The composition of amino acids is balanced and reasonable, especially rich in 8 kinds of amino acids necessary for human body. Bean products, such as tofu, thousand sheets, bean paste, tofu, soy sauce, fermented soybean, etc., are delicious and nutritious, and are traditional non-staple foods in East Asian countries. The United Nations Food and Agriculture Organization (FAO) strongly advocates the development of soybean food to solve the current situation of insufficient resources in protein, a developing country.
As an oil crop, soybean is the most important supplier of vegetable oil and protein cake in the world. Every 1 ton of soybean can produce about 0.2 tons of soybean oil and 0.8 tons of soybean pods. Soybean oil is a major edible vegetable oil with good oil quality and high nutritional value. As a by-product of soybean oil extraction, soybean meal is mainly used to supplement protein, feed poultry, pigs and cattle, and a small amount is used in brewing and pharmaceutical industries.