Rational fertilization methods for Cotton

Re-apply flower and boll fertilizer. The flowering and boll stage is the most exuberant period in cotton life, and the vegetative growth and reproductive growth of cotton are at the peak, and the most nutrition is needed. timely supplement of fertilizer plays a key role in promoting cotton peach, preventing premature senility, producing more three peaches and increasing boll weight. In fertilization, the cotton plant should not grow too long, and the cotton field with high fertility and vigorous plant growth can be fertilized late, which can be postponed to 1 or 2 big peaches in the lower part of the plant at full flowering stage, while in the cotton field with low fertility and weak growth, flower and boll fertilizer should be re-applied early in the early flowering stage. Generally, 10-20 kg of urea is applied per mu in mid-and late July, and timely watering and chemical regulation are needed according to the weather and cotton growth after topdressing.

Make up the top fertilizer. In the later stage of cotton growth, if it is found that there is a phenomenon of de-fatting, such as the top of the main stem of cotton plant is red early, the leaf color fades too early, and the peach cap is not firmly covered, cover fertilizer should be applied in time. Generally in the middle and last ten days of August, the mixture of 1% potassium dihydrogen phosphate and 3% potassium dihydrogen phosphate was used for 2 or 3 times of extra-root topdressing, each time with an interval of 7 days, and 50 kg of fertilizer solution was sprayed per mu of leaves.

Pay attention to applying boron fertilizer. Cotton is sensitive to boron, and the application of boron fertilizer can prevent cotton "bud but not flower" disease and increase the boll rate. When the content of available boron in soil is less than 0.5 mg / kg, boron fertilizer should be increased, and 0.5-0.75 kg borax per mu should be mixed with organic fertilizer and phosphate fertilizer. To spray fertilizer outside the root, generally use 0.2% borax solution 50 kg per mu, or use Jindilai liquid boron fertilizer or 20% Jindi instant boron fertilizer 50 grams to 50 kg water, foliar spraying twice from budding stage to early flowering stage, each time with an interval of about 7 days.