The absorbed nutrient content of cotton cotton increased with the increase of its yield. The absorption ratio of N, P and K was about 1.0:0.3:1.0. The ratio of N, P, and K fertilizers is approximately 1:0.65:1.0. In general, 40% of nitrogen fertilizer is used as a base fertilizer, 40% is used as a flower and bell fertilizer, and 20% is applied when peaches are started. Phosphorus fertilizer is preferably used as a base fertilizer for full-layer application. Potassium fertilizer has good effects on base fertilizer and top-dressing, and cotton has a good response to zinc and boron. Attention should be paid to the application of zinc fertilizer and boron fertilizer. First, the nutritional characteristics of cotton and fertilizer requirements. (1) Emergence to budding. The level of nitrogen in cotton's life is highest during this period. (2) bud to flowering period. At this time, if the supply of nitrogen is too much, it will often cause the cotton plants to grow in length and increase the shedding of the bells, thus avoiding the application of too much nitrogen fertilizer. Potassium fertilizer can increase the amount of potassium in stems and leaves, especially for the increase of potassium content in stems and leaves. (3) Flowering period to the beginning of the period. The content of phosphorus and potassium in the reproductive organs increased rapidly. Insufficient supply of phosphorus and potassium will affect the uptake of nitrogen. Second, cotton fertilizer technology. Manure, compost and nitrogen fertilizers. They are commonly used as farmyard fertilizers in cotton fields. Cotton fields generally use 30-45 tons of base fertilizer per hectare (1 hectare about 15 acres), and high-yielding cotton fields have 45-75 tons per hectare. In the general cotton field, under the condition of applying 112.5-150 kg of total nitrogen per hectare, 37.5 kg of pure nitrogen is used as the base fertilizer, and is applied to the soil together with the farmyard fertilizer before the tillage (the rest is used for topdressing during the flowering period), and good results can be obtained. . The medium-to-high-strength soils have strong fertility and fertilizer supply. The nitrogen fertilizer is applied twice, once as basal fertilizer for about 45%, and the other time for about 55% during flowering. The cotton field with high soil fertility and strong fertilizer retention ability can also use appropriate amount of nitrogen fertilizer as base fertilizer. For cotton fields with poor soil fertility, poor texture, and poor fertility retention capacity, nitrogen fertilizer can be applied in 3 separate applications, ie base fertilizer 30%. The top dressing is 20%, and the top dressing is 50%. Potassium fertilizer has good effects in the application of base fertilizer and topdressing, and monocropping of basal fertilizer has good effects. The application of potash fertilizer depends on the condition of soil fertility. On the basis of nitrogen and phosphorus application, generally 135-150 kg of potassium chloride or potassium sulfate is applied per hectare to medium-grade soils in cotton fields, and potassium chloride or potassium sulfate is applied to the middle-and-lower fertility cotton fields per hectare. About 225 kg. Boron fertilizer can be used as base fertilizer, seed fertilizer and topdressing fertilizer. A cotton field that is severely deficient in boron (having a soil available boron below 0.2 mg/kg) is applied very well with 3.75-7.5 kg per hectare applied to sowing trenches or transplanting trenches and holes for fertilizer application. Mule bud stage: The cotton seedlings and buds have little demand for nutrients. Generally, under the condition of applying basic fertilizer, cotton fields may not be topdressed. However, under the condition of intercropping cotton and wheat, the cotton seedlings are affected by the absorption of wheat during the symbiosis between cotton and wheat, and the growth is weak. Appropriate fertilizer must be applied to promote growth. After wheat is harvested, cultivators should be culled as soon as possible to top up shallow water. Usually, the amount of seedling fertilizer is about 52.5-75 kg of urea or 2250-3750 kg of human excrement per hectare. Phosphate fertilizer is mainly used as base fertilizer to meet the needs of the whole growth period of cotton, so cotton is no longer topdressing phosphate fertilizer.