Application proportion of Special Fertilizer in Cotton drip Irrigation Field

I. the total amount of fertilizer applied to cotton

High latitude sub-suitable cotton area per unit yield of seed cotton 300-380 kg, the need to put 70-80 kg of natural fertilizer, equivalent to 160-180 kg of standard fertilizer. To achieve "jin fat cotton". If you put 1 kg of standard fertilizer, you can produce 1 kg of lint. 137 regiment soil test results and cotton plant nutrition diagnosis generally lack zinc, 1-2 kg zinc fertilizer is applied in autumn, and the yield is increased by 5% and 10%. For plots rich in potassium according to the test results, the application of potash fertilizer at 5-10 kg, especially those with potassium less than 180-280 mg / kg, can still increase production by 5% and 8%. Boron fertilizer (Suele boron) can be sprayed on the leaves at the full bud and early flowering stage. Two tons of organic fertilizer was applied to 667 square meters in autumn and winter. The per unit yield of cotton and the application of chemical fertilizer are proportional to the effective range. If 100-120 standard fertilizers are put in, the seed cotton will be 250-280 kg.

II. The ratio of base dressing of special fertilizer for cotton

The cotton needs to absorb nutrients in the whole growth and development period, and the absorption is the largest in the flower and boll stage, drip irrigation in the cotton field, the cotton root system is relatively shallow, coupled with the high horsepower locomotive turning in autumn, the autumn fertilization depth is 30 cm, while the cotton root system is mainly 10-20 cm in the early stage. As a result, 30% of 40% of the nitrogen fertilizer, 80% of the 40% of the phosphorus, potash and zinc fertilizer can be applied to the cotton field in the autumn and during the full-layer application of organic fertilizer, 60% of the 70% nitrogen fertilizer, and 10% of the 20% phosphorus and potassium fertilizer can be applied with water during the cotton growth period. Urea, potassium dihydrogen phosphate or special fertilizer for drip irrigation are used for foliar fertilization. For a small number of furrow irrigated cotton fields, 60% Mel 80% nitrogen fertilizer, 10% Mel 20% phosphorus and potassium fertilizer, zinc fertilizer can be applied to cotton fields in autumn and organic fertilizer full layer fertilization, 20% Mel 40% nitrogen fertilizer, 10% phosphorus and potassium fertilizer can be applied to cotton fields combined with watering "one water, one fertilizer".

The proportion of cotton base dressing is unreasonable, the proportion of base fertilizer is large, the cotton seedling and bud stage are easy to grow, the phenomenon of premature senescence occurs in the middle and later stage of fertilizer removal, the lack of phosphorus and potassium fertilizer in the flower and boll stage leads to bud and boll shedding, the leaves turn red and green, and the boll weight decreases, resulting in a decrease in yield. Therefore, it is an effective way to increase cotton yield by supplying potash fertilizer during cotton growth period.

III. The proportion of nitrogen, phosphorus and potassium applied with special fertilizer in autumn

According to the fertilizer requirement law and fertilization method of cotton in drip irrigation cotton field, the ratio of pure nitrogen, phosphorus pentoxide and potassium oxide to special fertilizer in autumn should be 12-18:27-28:5-9. The content of effective total nutrients is greater than or equal to 45%. According to the target cotton yield and soil test results, autumn application of 20-25 kg / 667 square meters. The proportion of pure nitrogen, phosphorus pentoxide and potassium oxide of special fertilizer applied in autumn in a few furrow irrigated cotton fields should be 20-22:17-18:4-9. The content of effective total nutrients is greater than or equal to 43%. Zinc and boron fertilizer each account for 1%, 2%. The total amount of special fertilizer used in autumn is 35-40 kg / 667 square meters. The content of phosphorus and potassium in the formula of special fertilizer applied in autumn (the ratio of nitrogen, phosphorus and potassium is 22:18:4) is on the low side, and it only satisfies a small part of the special fertilizer applied in furrow irrigation cotton field in autumn.

If the proportion of nitrogen, phosphorus and potassium of special fertilizer applied in autumn is unreasonable, it will not only increase the cost of 667 square meters, but also reduce the utilization rate of fertilizer, which can easily lead to the behavior that workers are unwilling to put in and do not use special fertilizer.

IV. The proportion of nitrogen, phosphorus and potassium of special fertilizer for drip irrigation

According to the fertilizer requirement law and fertilization method of cotton in drip irrigation cotton field, the ratio of pure nitrogen, phosphorus pentoxide and potassium oxide of special fertilizer for drip irrigation should be 9-12:2-12:42-44. The content of effective total nutrients is greater than or equal to 58%. According to the growth of cotton and the fertilizer supply capacity of soil, it can be applied with water during the dripping period. In addition to urea, the commonly used drip irrigation fertilizer can be added with potassium dihydrogen phosphate (the ratio of nitrogen, phosphorus and potassium is 6:12:42). This product is very similar to the Israeli drip irrigation fertilizer product "potassium treasure" (the ratio of nitrogen, phosphorus and potassium is 12:2:44), and the application effect is very good.

If the drip irrigation fertilizer is mainly urea, do not pay attention to the rational use of fertilizer and nutrient elements, too much nitrogen fertilizer, high cotton density, excessive vegetative growth, population is too prosperous, field cover, there will be hollow cotton plants, greedy green late maturity, do not form economic yield.