Emergency supplementary fertilization for cotton to promote plant recovery and regrowth

Yang Xiushen, a researcher at the Industrial Crops Research Institute of the Provincial Academy of Agricultural Sciences, said that since July, our province has been repeatedly hit by torrential rains, and the flooding has caused widespread inundation of farmland, inflicting severe damage on cotton. Draining water and reducing waterlogging, and emergency supplementary fertilization to promote recovery are the critical priorities of the current disaster relief and remediation effort. At the same time, weeds must be removed promptly, the soil loosened, and earth hilled up around the roots, and replanting and supplemental planting should be carried out according to the conditions of each field.

Emergency removal of standing water in the fields must seize the time and adopt all necessary and possible means to quickly drain the standing water, reduce the impact of waterlogging on cotton growth and development, and lower the mortality rate of cotton seedlings. For low-lying areas, especially flooded cotton fields on secondary high ground, the water level in the outer three ditches must be urgently lowered; for cotton fields that still have water at present, dams and embankments must be urgently built and drainage pumps used to drain the water, speeding up the drainage rate. For cotton fields with incomplete ditch systems and low standards, trenches must be urgently dug additionally and more drainage outlets opened; for the existing field water systems, ditches must be promptly cleared and trenches leveled to reduce waterlogging and allow air penetration.

Emergency supplementary fertilization to promote recovery. Affected by flooding, cotton suffers declining physiological functions, poor fertilizer uptake capacity, and inhibited growth, so emergency supplementary fertilization is essential to promote recovery. For cotton fields where standing water has already been drained, the method of "fertilizing below and spraying above" must be immediately adopted for emergency supplementary fertilization. "Fertilizing below" means applying the first flower-and-boll fertilizer early and heavily; as long as soil moisture permits and one can stand in the field, it should be applied, with 8-10 kg of quick-acting nitrogen fertilizer per mu, plus 15 kg of phosphate fertilizer, and 10-15 kg of potassium sulfate. All fertilizers should be applied deeply in opened holes to reduce loss and waste and improve fertilizer use efficiency. "Spraying above" means spraying 883 Fengchanling or a 2% urea solution and other biochemical growth promoters and foliar fertilizers on the leaves per mu, generally once every 3-4 days, for 2-3 consecutive sprays, to supplement nutrients and promote the cotton seedlings to transform and resume growth as quickly as possible. After the cotton seedlings have transformed, chemical regulation should be carried out in a timely manner according to the seedlings, spraying 25 ml of Lingfengbao or Shuangbaijin per mu to reduce redundant buds and excessive branches and improve the ventilation and light penetration conditions in the field.

Timely weed removal, soil loosening, and hilling up around the roots. After flooding, the soil becomes compacted with poor permeability, and field weeds grow quickly, making the conflict with cotton over fertilizer, air, and heat very prominent. When soil moisture permits and one can stand in the field, soil loosening must be carried out urgently to break up compaction, cultivate to destroy stubble, and clear weeds. At the same time, lodged cotton plants must be urgently set upright, and the lower leaf branches promptly reformed. Earth must be hilled up around the roots across the board to form high-quality strip ridges in the cotton field and enhance the cotton plants' disaster resistance in the middle and late stages.

Carry out replanting and supplemental planting according to the conditions of each field. For the few cotton fields that have been flooded for too long and now show dead leaves, rotten roots, and dead seedlings with no hope of growth, other crops should be quickly replanted, such as sesame, carrots, autumn lettuce, summer Chinese cabbage, green beans, edamame, and other dryland crops. For cotton fields with scattered dead seedlings, missing plants and broken rows, and insufficient total population, replanting should generally be avoided as much as possible, focusing on preserving the seedlings and vigorously developing three-dimensional intercropping and relay cropping in cotton fields; short-stalked crops such as autumn soybeans, sesame, and mung beans can be interplanted in places with missing plants and broken rows as well as in empty rows, so as to reduce flood losses as much as possible and improve the benefits of the cotton field.