Identification and remedy of soybean deficiency

1. When nitrogen deficiency soybean is deficient in nitrogen, the leaves become light green, grow slowly, and the leaves gradually turn yellow. Nitrogen fertilizer should be applied in time, 5 kg ~ 7.5 kg urea can be applied per mu, or foliar fertilizer can be sprayed with 1%-2% urea aqueous solution, spraying once every 7 days or so, a total of 2 ~ 3 times. 2. Phosphorus-deficient plants have dark green leaves in the early stage, and then lack of green in the veins of the lower leaves, the plant shape is small, the leaves are thin, the stems are hard, and the florescence and maturity are delayed. Phosphate fertilizer should be applied in time, 12.5 kg ~ 17.5 kg calcium superphosphate can be applied per mu, or foliar fertilizer can be sprayed with 2%-4% calcium superphosphate aqueous solution, spraying once every 7 days, a total of 2 ~ 3 times. 3. The old leaves with potassium deficiency appeared irregular yellow spots from the edge of the leaves and gradually expanded, and the veins in the middle of the leaves and other parts were still green. The grain is often wrinkled and deformed. 4 kg ~ 6 kg potassium chloride can be applied per mu, or foliar fertilizer can be sprayed with 0.1%-0.2% potassium dihydrogen phosphate aqueous solution, spraying once every 7 days or so, a total of 2 ~ 3 times. 4. in the early stage of iron deficiency, the upper leaves were yellow and a little curly, and the veins remained green. when there was severe iron deficiency, the new leaves, including veins, almost turned white, and brown spots soon appeared near the leaf edge. The old leaves turned yellow and withered and fell off. 0.4%-0.6% ferrous sulfate solution can be used for foliar spraying. 5. When manganese deficiency soybean is deficient, the growth stagnates, there are light green to white spots in the middle of leaf veins, and finally green deficiency occurs, but at this time the leaf veins are still green. Foliar fertilizer can be sprayed with 0.01%-0.02% manganese sulfate. 6. Chlorosis gradually occurred in young leaves with zinc deficiency. Chlorosis begins to occur between leaf veins and gradually spreads to the whole leaf, while no obvious green vein is visible. Foliar fertilizer can be sprayed with 0.1%-0.2% zinc sulfate aqueous solution. 7. The growth of boron deficiency became slow, the young leaves became light green, the leaves were deformed and the internodes were shortened. The apical meristem died and could not blossom. 0.1%-0.2% borax aqueous solution can be used for foliar spraying. 8. Molybdenum deficiency leaves are yellowish in color, poor in growth, showing symptoms of nitrogen deficiency and severe midvein necrosis. The blade is deformed. Foliar fertilizer can be sprayed with 0.05%-0.1% ammonium molybdate aqueous solution. The specific time of foliar fertilizer spraying should be after 4 o'clock in the afternoon on a rainless and windless day, and the functional leaves of the plant should be sprayed evenly.