The effect of fertilizer damage on cotton production is worrying.

In recent years, in the process of promoting new cotton varieties and technical services in cotton areas, we often encounter the problem of farmers' mistakes in applying fertilizer. First, when some cotton seedlings are raised and prepared for soil in a nutrition bowl, too much farm fertilizer or chemical fertilizer is applied in the soil, so that some cotton seeds rot or die after sowing, and although some seedlings emerge more evenly, they burn roots and die seedlings; second, after the emergence of cotton seedlings in the seedbed, excessive application of flushing fertilizer will scald and scorch all the cotyledons of cotton seedlings. Third, when the base fertilizer is applied to the cotton seedling before transplanting, some will sprinkle the chemical fertilizer into the furrow, or apply the chemical fertilizer into the pot hole, there is no fine soil interval between the root of the seedling and the fertilizer applied, and the root of the cotton seedling is in direct contact with the chemical fertilizer. the young roots and stems of cotton seedlings turn brown or black after being damaged by fertilizer, and the seedlings are stiff and do not grow in light cases, and the seedlings die seriously. Fourth, excessive application of urea or ammonium bicarbonate and other nitrogen fertilizers at the bud stage, or excessive input of high-efficiency and multi-component compound fertilizers, regardless of the cost of fertilization, blindly pursuing the early construction of cotton high-yield shelves, resulting in excessive growth of cotton, closure too early, serious shade in cotton fields, leading to serious occurrence of pests such as bug bugs and bolls, especially in rainy years, this phenomenon is more common. Fifth, during the flower and boll period, we saw the application of urea before the heavy rain, the urea dissolved very quickly after the rain, the fertilizer concentration in the cotton field immediately increased, it suddenly cleared up after the rain, the evaporation of cotton leaves was large, and the water in the cotton plant rapidly produced reverse osmosis and serious water loss, so that the lower stems and leaves of the cotton plant seemed to be burnt, and the serious death of the whole cotton plant could not be saved.

Increasing fertilizer input is originally an effective measure to increase cotton production by replenishing nutrients in cotton fields, improving soil fertilizer supply capacity, and improving cotton nutritional status. However, blind fertilization without science is a man-made disaster for cotton. The reduction in cotton production and yield is caused by its own reasons. We should seriously sum up the experiences and lessons, scientifically grasp the cotton fertilization technology, and obtain the maximum cotton planting benefit with the least investment.

First of all, it is necessary to apply fertilizer according to the law of cotton fertilizer demand. The fertilizer requirement of cotton is generally less in the early stage, stable in the middle stage and more in the later stage. Therefore, cotton fertilization should apply sufficient base fertilizer, rapid application of seedling fertilizer, stable application of bud fertilizer, ruthless application of flower and boll fertilizer and general application of peach fertilizer.

Secondly, fertilizers should be applied according to the nature, the land and the seed. For example, early-maturing varieties should apply sufficient peach fertilizer to prevent premature senescence, and transgenic hybrid insect-resistant cotton should increase the amount of potash fertilizer, not less than 60 jin per mu. The soil with high fertility should be fertilized less properly, and the soil with poor fertility should be applied more organic fertilizer. When the weather is dry, we should grab soil moisture and fertilize, adjust fertilizer with water, and pay attention to fertilizing after rain when topdressing.

Third, it is necessary to calculate the cost of economic fertilization. First, we should pay attention to the ratio of input and output. Take 600 jin of seed cotton per mu as an example, the input of fertilizer per mu should not exceed 300 yuan; second, we should apply deep fertilizer, not to apply fertilizer on the soil surface, let it volatilize or lose, let alone spread it before rain, fertilization can not hurt the root system; third, topdressing fertilizer should be applied step by step, the first dosage should not be too large, and the prospect of controlled slow release fertilizer is good, which can be expanded gradually on the basis of experiment and demonstration. Fourth, fertilization must be closely combined with chemical regulation, so that the limited fertilizer can be fully and evenly applied, so that cotton presents a robust and high-yielding plant type.