Prevention and treatment of soybean deficiency

The deficiency of trace elements in soybean is as follows: the true leaves of spring soybean are yellow, which can be yellowed from the bottom up, there are parallel continuous or discontinuous iron patches along the veins of the compound leaves, and chlorosis extends from the tip of the leaves to the base, so that the whole leaves are light yellow, and the veins are also green; the leaves are small and thin, easy to fall off, the stem is slender, the lower leaves of the plant are dark green, thick, uneven and long. When the scale deficiency is serious, the leaf vein is yellow-brown, and the whole leaf is yellow. Yellowing is also difficult to recover, the leaves are thin and easy to fall off.

Calcium deficiency is characterized by yellowing and brown spots, starting from the middle and tip of the leaf, the leaf vein is still green, the leaf margin is drooping and twisted, the leaf is small and long, and the leaf tip is in the shape of a sharp Jun. However, the upper leaf color of aluminum is lighter, the color of the main vein and branch vein is lighter; there are continuous maculae between the veins, the leaf tip is easy to lose green, and the color of the rear macula deepens to light brown; some leaves are uneven and twisted, and some leaf veins appear white in the center.

Prevention and cure method

The main results are as follows: (1) increasing the application of organic fertilizer and applying compost made by enzyme bacteria or rotten organic fertilizer 1000-2000kg per mu can prevent the deficiency of many mineral elements in soybean, and it is also one of the important measures to increase yield.

(2) keep the soil moist at flowering stage of soybean. However, field irrigation should prevent flood irrigation and flood irrigation to avoid the loss of soil nutrients.

(3) in soybean producing areas with insufficient organic fertilizer, supplementation of chemical fertilizers and trace elements can prevent and cure soybean deficiency.

① topdressing urea 3-5kg per mu or spraying 1% urea 50kg per mu at flowering stage can prevent or correct soybean nitrogen deficiency.

The application of 15-25kg superphosphate in ② per mu can prevent phosphorus deficiency and sulfur deficiency in soybean.

Applying 5kg potassium sulfate or 80kg plant ash or kiln ash potassium fertilizer per mu of ③, or spraying 0.5% potassium sulfate solution 50kg after potassium deficiency occurs, can prevent and cure soybean potassium deficiency.

The application of magnesium-rich lime 75kg to ④ can prevent and cure calcium deficiency and magnesium deficiency in soybean.

Spraying 0.5% ferrous sulfate with 50kg 0.3% per mu of ⑤ can prevent and cure the iron deficiency of soybean.

Spraying 50 kg 0.5% manganese sulfate, zinc sulfate and ammonium molybdate per mu of ⑥ can prevent and cure the disease of manganese, zinc and molybdenum deficiency in soybean.

Spraying 50kg 0.1% copper sulfate per mu of ⑦ can prevent and cure copper deficiency in soybean.

Application of 0.3kg boric acid per mu of ⑧ or seed dressing with 0.1% borax can prevent boron deficiency in soybean.