Application of Potassium Fertilizer in Cotton Planting

The method of applying potassium fertilizer to cotton is generally based on base fertilizer and coarse fertilizer. At present, straw returning to the field should be vigorously promoted. According to the survey, about 800 kilograms of returned fields per 667 square meters can not only return 4 kilograms of potassium oxide to the soil, but also convert the delayed-acting potassium in the soil into effective potassium. Potassium fertilizer is better to be applied at the bottom. If it is applied as a top-dressing fertilizer, it can be applied as top-dressing during the budding period, but it is not advisable to mix it with superphosphate. If the application rate is 75 kg of lint cotton per 667 square meters and 12 kg of pure nitrogen per 667 square meters of cotton fields, the ratio of nitrogen, phosphorus and potassium should be 1:0.75:0.37. The general quantity is: 30 kilograms of urea, 50 kilograms of superphosphate, and 10 kilograms of potassium chloride per 667 square meters.

Generally, the higher the yield index, the higher the proportion of potassium fertilizer. On the contrary, it should be appropriately reduced, but the minimum shall not be lower than 0.3. For example, before and after the flowering period of cotton, 0.2% potassium dihydrogen phosphate or 1% plant ash extract should be sprayed outside the roots, and it is advisable to spray 120 kg of solution every 667 square meters for three consecutive sprays.