Detailed Explanation of Key Technical Points for Formula Fertilization of Cotton

Cotton has an indeterminate growth habit, strong regeneration capacity, highly controllable plant architecture, and a high fertilizer demand. Generally speaking, adequate fertilizer is the foundation for high yield and quality in cotton. Sufficient phosphate fertilizer can promote vigorous growth of cotton plants, increase boll weight, and advance maturity. Potassium fertilizer is a catalyst for various enzymes in plants, and can promote photosynthesis and cellulose synthesis. The fertilization technique for cotton is the eight-character formula fertilization method of "adjust nitrogen, increase potassium, supplement phosphorus, spray boron." Specifically, the following 5 technical measures should be well implemented.

1. Attach importance to the application of farmyard manure. Farmyard manure can improve the soil and build up soil fertility. It supplies various nutrient elements to crops, and applying it together with a certain amount of chemical fertilizer is a supplement to and enhancement of farmyard manure. On this basis, applying micro-fertilizers will have a significant synergistic effect. If farmyard manure or chemical fertilizer is not adequately supplied, then the effect of micro-fertilizers will not be significant either.

2. Adjust the nitrogen fertilizer ratio. Farmers have long applied nitrogen fertilizer in a one-sided way, which not only causes the loss and waste of nitrogen nutrients, but also seriously imbalances the ratio of nitrogen, phosphorus, and potassium. According to different soil fertility levels, adjust the nitrogen fertilizer applied per 667 sq m to 10-15 kg (including nitrogen from organic fertilizer).

3. Increase the amount of potassium fertilizer applied. From emergence to squaring, cotton absorbs about 24% of the total potassium for the entire growth period, about 42% from squaring to flowering, and about 34% from flowering to maturity. Therefore, potassium fertilizer should be applied as a base fertilizer or as a topdressing before squaring, so as to benefit early cotton growth and mainly meet the needs of bud, flower, and boll growth and development. In the later stage, potassium fertilizer (Heferti Potassium or Phosphorus-Potassium Power) can also be sprayed on the leaves to supplement potassium. The amount of potassium fertilizer per 667 sq m should be increased to 10-15 kg.

4. Supplement phosphate fertilizer. Phosphorus is not easy to move in the soil, and it dissolves and releases slowly, so it is not easily absorbed by the root system. Therefore, phosphate fertilizer can be applied as a base fertilizer so that it takes effect in the early growth stage. In production, nitrogen fertilizer and phosphate fertilizer are often mixed and used together, and the fertilizer effect greatly exceeds that of applying phosphate fertilizer alone. In the later stage, root-zone topdressing can also be used, spraying on the leaves with high-quality monopotassium phosphate (such as the 99% Phosphorus-Potassium Power imported from Singapore). The amount of phosphate fertilizer should be supplemented to 20-30 kg.

5. Spray boron fertilizer. Sufficient boron can not only promote flower organ development, help pollination, and increase the fruit-setting rate, but can also accelerate the transport of carbohydrates in the plant, increase single boll weight and lint percentage. Therefore, a 1000-fold Heferti Boron solution should be sprayed once each at the squaring stage, early flowering stage, and full flowering stage.