Soya bean

1. Nutritional characteristics

The growth process of soybean includes germination stage, seedling stage, flower bud differentiation stage, flowering stage, podding stage and maturity stage.

2, need fertilizer characteristics

In the whole growth period of soybeans, the amount and proportion of nitrogen, phosphorus and potassium required vary according to soil, climate, varieties and planting methods. The yield of 200 ~ 250 kg per mu requires nitrogen (N) 3 ~ 5 kg (Northeast spring soybean) or 6 ~ 9 kg (Huanghuai summer soybean), phosphorus (P2O5) 4 ~ 6 kg, potassium (K2O) 4 ~ 6 kg.

The nitrogen absorbed by soybean is 1/3 ~ 1/2 from the nitrogen fixation of soybean rhizobium, the peak is concentrated in the flowering to the grain filling stage, and the rest comes from soil and fertilizer. Nitrogen absorption of soybean reached the maximum from flowering stage to bulging stage, accounting for 55% of the total amount. Phosphorus absorption from flowering to podding reached the maximum, accounting for 60% of total phosphorus. The absorption of potassium accounted for 32.2% of the lifetime absorption from seedling to flowering, which was higher than that of nitrogen and phosphorus, and 61.9% of the lifetime absorption from flowering to granulation. The podding period is the period when soybean absorbs the most nitrogen, phosphorus and potassium nutrients, and the absorption intensity is large, which is easy to lead to defertilization.

Soybeans have a high demand for calcium. Molybdenum is an important component of nitrogenase in soybean root nodules. Molybdenum helps to form root nodules and improve nitrogen fixation. However, zinc and boron can improve the setting rate of soybean, and boron is very important in soybean life activities. When lacking boron, soybean roots do not develop well, root nodules do not grow well and the ability of nitrogen fixation is lost. (Taken from the network, if there is infringement, please contact to delete.)

3. Fertilization technology

Base fertilizer: It is recommended to apply medium nitrogen type special formula fertilizer (15-6-9), and the application amount is 30 ~ 50 kg per mu.

Topdressing: For areas with high yield requirements, it is recommended to combine soil cultivation at the beginning of flowering, and apply 5 ~ 10 kg urea or 10 ~ 15 kg special formula fertilizer of medium nitrogen type should be applied.

Spreading should be combined with ploughing into the soil, and ditch application should pay attention to the separation of fertilizer and seeds, and keep at least 8-10 cm distance to prevent burning seeds and seedlings.