In cotton production, reasonable fertilization should be carried out according to the characteristics of the crop's demand for fertilizer and the law of fertilizer requirements. In the past, the ratio of N, P, and K required for non-insecticidal cotton varieties was 3:1:3. However, the transgenic cottons that are currently planted are sensitive to potassium and require large amounts of potassium, which are important for nitrogen, phosphorus and potassium. The demand ratio is 3:1:4.5. According to the basic principle of fertilizing the "minimum nutrient law" and "irreplaceable law", if there is a shortage of potassium fertilizer and trace fertilizer, it is the application of even more nitrogenous fertilizer and phosphate fertilizer. Therefore, the steady application of nitrogen fertilizers, phosphate fertilizers, application of potash fertilizers, supplementation of trace fertilizers, so that cotton “eat†and “eat well†can maximize the high yield and high efficiency.
1. Reasonably apply base fertilizer According to the principle of "nutrition return theory", according to the characteristics of cotton need fertilizer, combined with the current actual, generally 350 ~ 400 kg per mu of cotton fields, applying 10 kg of urea per mu, 20 kg of diammonium phosphate, high quality Potash (above 50% pure potassium) 30 kg. In the middle of the field, generally 20 kg of diammonium phosphate and potassium fertilizer can be applied per acre. In order to benefit the continuous increase of cotton production, farmer fertilizer should be applied as much as possible. If the application of micro-fertilizer (including zinc, boron, manganese, molybdenum, copper and iron trace elements) 800 to 1600 grams per acre, the effect of increasing production is more significant.
2, science topdressing phosphorus, potassium fertilizer is the best one-time application. Nitrogen fertilizers should be applied in stages. Generally, the fertility cotton fields can be topped with 30% nitrogen fertilizer during the budding period, followed by 70% nitrogen fertilizer during the flowering and bolling period, and the super-high yielding cotton field can be topped with 20% nitrogen fertilizer during the bud stage, and can be used during the flowering and bolling period. 60% of nitrogen fertilizer and 20% of nitrogen fertilizer are applied in peach stage. With the same amount of fertilizer applied, nitrogen fertilizer application by stages increased production by more than 10% over one-off topdressing.
3, clever application of foliar fertilizer foliar fertilization is more economical and effective fertilization method, low cost and good effect. The foliar fertilizers containing nitrogen, phosphorus and potassium (especially at the seedling stage and late growth stage) should be used, and they can also be used together with foliar fertilizers containing plant growth agents and trace elements. During the growth of cotton, 0.5% to 2% of diammonium phosphate or 0.2% of potassium dihydrogen phosphate or 0.15% to 0.3% of disease-resistant yield-promoting king solution can be used, combined with the prevention and treatment of pests and foliar spray, the effect is better.