There are similarities and differences in fertilization among different cotton varieties.

Recently, when the author went to the cotton producing areas of Tianmen, Hanchuan, Jingshan, Jianli and other counties and cities of Huarong, Anxiang and Nanxian of Hunan Province, many farmers asked about the technical problems of cotton fertilization. They often regard fertilization as one of the important means to increase production, so they are very concerned about fertilization technology.

The experiences and lessons of cotton fertilization for many years tell us that the common experiences of increasing cotton yield are as follows: sufficient base fertilizer, rapid application of seedling fertilizer, stable application of bud fertilizer, heavy application of flower and boll fertilizer, and general application of peach fertilizer. However, there are differences in the application of fertilizer among different cotton varieties.

Cotton varieties can be divided into conventional varieties and hybrid varieties, and there are early-maturing varieties, medium-maturing varieties and late-maturing varieties in the two types of varieties.

Generally speaking, conventional cotton varieties and conventional cotton hybrid varieties need less potash fertilizer, while transgenic insect-resistant cotton, especially transgenic hybrid insect-resistant cotton, is more sensitive to potash fertilizer. According to the field production practice in recent years, their demand for potash fertilizer is often more than double that of non-insect-resistant cotton, and 60 jin or more potash fertilizer with an effective content of 60% per mu is required.

The growth period of early-maturing varieties is relatively short. Peaches of these varieties are generally fast and concentrated in the early stage, and the demand for fertilizer is large in the early stage. If there is not enough fertilizer in the early stage, it is often prone to premature senescence in the later stage, and the lower leaves are decayed quickly and seriously. The upper fruit branch can not be extended, and the top of the growth point is lack of stamina. If flower and boll fertilizer or peach fertilizer can not be applied in time, this kind of early-maturing varieties It can easily lead to a reduction in cotton production and harvest. For this kind of cotton varieties, sufficient base fertilizer must be applied in the early stage, flower and boll fertilizer should be fully applied in the middle and later stage, especially good peach fertilizer should be applied in general. When there are more than 3 mature peaches per plant, urea should be applied not less than 30 jin per mu. Cotton fields with insufficient potash fertilizer in the early stage should also be supplemented with potash fertilizer.

The vegetative growth of late-maturing cotton varieties is generally exuberant in the early stage. for this kind of varieties, one is to control the total amount of fertilizer per mu, and the other is to control the excessive application of nitrogen fertilizer. If the nitrogen fertilizer is too much or the total amount of nitrogen fertilizer is too large, the cotton enters the budding stage or the flower and boll stage. Vegetative growth tends to inhibit reproductive growth, so that the growth period of late-maturing cotton varieties is delayed, and the cotton is closed too early and shaded seriously. Aggravate bud and boll shedding and rotten peaches. When applying fertilizer to this kind of cotton varieties, the early fertilization must be stable, first, the amount of nitrogen fertilizer should be strictly controlled, and second, the total amount of fertilizer per mu should be controlled. For example, when applying base fertilizer, the compound fertilizer with a content of 45% of nitrogen, phosphorus and potassium per mu should not exceed 80 jin. Third, we should advocate the application of compound fertilizer or all kinds of bio-organic compound fertilizer, and it is best to apply these two kinds of fertilizer in combination. Fourth, we should do a good job in chemical control and shape high-yield plant types. Fifth, it is necessary to cooperate with thorough pruning and power control to enhance the ventilation and light transmission performance between cotton rows. Of course, due to the sufficient stamina of these varieties, more autumn peaches, we can not ignore the application of peach fertilizer, 20 kg of urea per mu of peach fertilizer, supplemented by extra-root topdressing.

The fertilization of mid-maturing cotton varieties is between early-maturing and late-maturing cotton varieties, which can be flexibly controlled according to the local climate, soil and seedling conditions.