Soybean plants are vertically branched, ranging in height from a few centimeters to more than 2 meters. Self-pollinated, with white or purplish flowers. Seeds are yellow, green, brown, black or bicolor, and each pod contains 1 ~ 4 seeds. Soybean can be planted in all kinds of soil, but it grows vigorously in warm, fertile and well-drained sandy loam. Sow after late frost, mature in September and June, 65438+ 10. Generally speaking, soybeans should be harvested when the water content of seeds falls below 65438 03% after defoliation and storage.
The roots of soybean can be divided into main roots and lateral roots, which can be buried to a depth of 1.5 meters and are bell-shaped roots. Nodules grow from the surface of the soil to the root of about 20 cm, and rhizobia can supply the nitrogen requirement of soybean 1/3 ~ 1/2. The main stem is 60 ~ 100 cm high and has 15 ~ 24 nodes. Pods are planted at nodes, and multi-node soybeans tend to have high yield. The habit of infinite pod setting is suitable for planting in poor fertilizer and water conditions. Limited pod habit is suitable for planting in areas with good fertilizer and water. Limited podding habits are somewhere in between. The leaves of soybean are trifoliate. Hua Hudie. Pods are yellow, black and brown, curved sickle or straight gourd. Soybean is a short-day crop, and its sensitivity to short-day is different among varieties. We need plenty of sunshine and more nutrients such as nitrogen, phosphorus and potassium. Soybean seeds can germinate only when the water absorption reaches 5%, and the soil moisture must be sufficient when sowing, and the field water holding capacity should not be lower than 60%.
Soybean likes soil with good drainage, rich organic matter and pH 6.2 ~ 6.8. It is advisable to sow early at suitable time, mainly by drilling. It needs more fertilizer, and the demand for nitrogen is 4 ~ 5 times that of cereals with the same yield level. Pay attention to timely irrigation and drainage during pod setting. Soybean is a self-pollinated crop, and pure line breeding is still used in some areas. Backcross method has a good effect on improving the disease resistance of varieties. The main method of soybean breeding in China is interspecific hybridization. Reproduce offspring by genealogy.
Annual herb, 30-90 cm tall. Stems stout, erect, or almost twining in the upper part, somewhat angular, densely covered with brown bristles. Leaves usually 3-foliolate; Stipules broadly ovate, acuminate, 3-7 mm long, veined and yellow pilose; Petiole 2-20 cm long, loose and unfamiliar or angular when young, covered with bristles; Leaflets are papery, broadly ovoid, nearly round or elliptic-lanceolate. The terminal leaflets are relatively large, 5-12cm long and 2.5-8cm wide, with an acuminate or nearly round apex, rarely blunt, small tip, wide wedge-shaped or round base, small lateral leaflets, oblique ovoid, and usually rough or hairless on both sides. 5 lateral veins on each side; Stipules are needle-shaped and 1-2 mm long; 2-5 seeds, ovoid, nearly spherical, ovoid to oblong, about 65438±0cm long and 5-8 mm wide, with smooth seed coat and light green, yellow, brown and black colors. The hilum is obvious and oval, which varies with varieties. The flowering period is from June to July, and the fruiting period is from July to September.