Prevention measures for potassium deficiency: First, organic fertilizers are added. Organic fertilizers include human waste, beryllium fertilizer, green manure, compost, cake fertilizer and straw returning. Organic manure not only contains various nutrients, but also can change soil physical and chemical properties. Increase soil fertility and water retention capacity, which is the main way to solve the shortage of potassium in cotton fields. The potassium content of cotton straw is high, and returning the field for three consecutive years can make the potassium content of the cotton field reach the abundance of potassium. Secondly, while increasing the input of potash fertilizer, the method of fertilization should be improved. The sub-basal fertilizer in the south, the bud fertilizer and the flower and bell fertilizer should be applied three times. In the north, the combined application of the farmland should be performed once and the organic fertilizer should be used in combination with the deep application of organic fertilizer. The third is to promptly carry out foliar spray of potassium on the cotton fields where potassium deficiency symptoms are found during late period of boll. Use potassium dihydrogen phosphate 150-200 g/mu, water 75 kg, or spray with 1%-1.5% potassium sulfate solution. Once every 7 days, from mid-August to mid-September, it can obviously play a role in keeping flowers, bells, and increasing the weight.
The field performance of potassium deficiency in cotton fields is: the plants are short, the main stem is thin, and the internodes are short. Symptoms appear on the lower leaves. The tips and edges of the diseased leaves yellow at the beginning and yellow-white patches appear on the rear leaves. Then yellow spots appear between the veins and gradually expand into brown spots. Finally, the entire leaves are red-brown and the leaves are easily dehydrated. Shrinking, leaf margin drooping, leaves dead or fall off early, small bells are difficult to spit. In severe potassium depletion, plants withered prematurely and showed red stems and stems.