Technology of balanced fertilization for Cotton

I. principles of fertilization for cotton

1. Combined application of organic fertilizer and inorganic fertilizer.

Cotton production should be sustainable, and organic fertilizer has the characteristics of complete nutrients and stable and long-term fertilizer effect, which can not be replaced by inorganic fertilizer. Even under the condition of sufficient supply of inorganic fertilizers, the role of organic fertilizers should not be ignored. only the combined application of organic fertilizers can achieve high and stable yield, especially when the price of chemical fertilizers is high, more attention should be paid to the application of organic fertilizers.

2. Balanced application of a large number of elements and trace elements

A large number of elements refer to nitrogen, phosphorus and potassium, and trace elements refer to boron and zinc. The combined application of the two elements is beneficial to improve the utilization rate of fertilizer.

II. Technology of balanced fertilization for cotton

Balanced fertilization for cotton is based on the fertilizer demand law, soil fertilizer supply performance and fertilizer effect of cotton, and on the basis of applying organic fertilizer, puts forward the appropriate amount and proportion of nitrogen, phosphorus, potassium and trace elements and the corresponding fertilization technology. in order to implement the best balanced nutrient scheme and technology to obtain the best economic benefits of cotton production, while insisting on the combination of land use and land cultivation, organic and inorganic combination. Make the soil available nutrients in the best dynamic balance.

Third, the suitable amount and proportion of fertilizer for cotton in our county

According to the general fertilization level of cotton area along the Yangtze River and the results of many years' experiments and demonstrations of our office, the suitable ratio of nitrogen, phosphorus and potassium in cotton in our county is 1: 0.35: 0.4: 1, the target yield of lint is 100: 120 kg per mu, nitrogen (N) 18 kg / mu, urea 40 kg / mu, phosphorus (P2O5) 6 kg / mu, calcium superphosphate 50 kg or ammonium phosphate 20 kg / mu. Potassium (K20) 15kg, potassium chloride 25kg, cake fertilizer 50kg.

IV. fertilization methods for cotton

1. Base fertilizer. If there are conditions, 20 kilograms of farm manure, 10 kilograms of rotten cooked cake fertilizer, 10 kilograms of urea, 50 kilograms of superphosphate or 20 kilograms of diammonium, 10 kilograms of potassium chloride, or ternary compound fertilizer equivalent to the above-mentioned ternary compound fertilizer (the amount of chemical fertilizer should be reduced appropriately for heavy sandy soil), borax and zinc sulfate are 1kg and 1.5kg each. One-time application of cotton special formula slow and controlled release fertilizer 80kg 100kg. Fertilization time: reserved cotton row or empty stubble field 15-20 days before transplanting or 7-8 days before transplanting, transplanting cotton after oil can be applied within 5-7 days after transplanting, fertilizer should be more than 15 cm from cotton, fertilization depth is more than 15 cm, and a small amount of compound fertilizer can be applied in bowl hole when transplanting.

2. Bud stage. The bud stage generally does not need to apply chemical fertilizer, such as the growth is not good can be a small amount of quick-acting fertilizer, boron-deficient cotton field, in the bud stage with about 50 grams of borax plus water 25 kilograms 30 kg foliar spray.

3. Flower and boll fertilizer. Apply flower and boll fertilizer for the first time early. Generally, 30 kilograms of cake fertilizer, 10 kilograms of urea and 15 kilograms of potassium chloride are applied per mu. The plastic film of transplanting cotton must be removed at the end of June and the beginning of July, the first flower and boll fertilizer should be applied in the middle of small rows in the early flowering stage combined with middle tillage, and the first flower and boll fertilizer should be applied in the first ten days of July from early flowering to flowering. When boron fertilizer was sprayed, 100 grams of borax and 50 kilograms of water were sprayed on the leaves of boron deficient cotton fields at flowering stage. Re-apply the second flower and boll fertilizer. The amount of urea applied in holes or furrows in the middle and late July of transplanting plastic film cotton was about 15 kg, and that of transplanting cotton in open field was about 12 kg in late July. In late July, 100 grams of borax was sprayed on 50 kilograms of water in boron-deficient cotton fields.

4. Cover with fertilizer. Look at the growth trend of topdressing urea 5kg / mu (especially one-time application of cotton formula slow and controlled release fertilizer), generally ending before August 10.

5. Extra-root topdressing. After the middle of August, 0.5% urea was sprayed on the leaves (0.3% potassium dihydrogen phosphate was added to the growing cotton field). It was sprayed every 7-10 days for 3 times in a row.