Guidance on Scientific Irrigation Technology for Cotton

(1) Basic information. The northwestern inland cotton areas include Xinjiang and Hexi Corridor cotton areas in Gansu, are rich in light and heat resources and the crops there are ripe once a year. Most of the planting areas are saline-alkali land.

(2) Suggestions on irrigation. This region is short of water resources and is a typical oasis agricultural zone. The core of water management is high-efficiency irrigation, transpiration suppression and moisture conservation, vigorously promoting the integration technology of water and fertilizer of drip irrigation under membrane to promote high cotton yield.

Before sowing, the cotton area of southern Xinjiang should carry out one spring irrigation combined with desalination, and prepare the ground for sowing in time after irrigation. The cotton areas in the northern Xinjiang and Hexi Corridor should conduct winter irrigation, restraint salt content and desalinize the soil by flooding before the freeze-up of the first year. Conduct no irrigation in spring before sowing and adopt dry sowing and wet germination. Drip the water out of the plant timely within 3 to 5 days after sowing. In the seedling stage, there is generally no irrigation, but when the relative soil water content is lower than 50%, irrigate with small amount of water in time. When the relative water content of the soil in the bud stage is less than 60%, it should be irrigated in time. Water-soluble fertilizer should be added combined with irrigation. Irrigate in time when the relative water content of the soil is less than 70% during the flowering and boll stage, and apply fertilizer used in flowering and boll stage in combination with irrigation. The amount of irrigation water should be gradually decreased after the boll-blooming period, and irrigation should be stopped 10-15 days before the chemical defoliation. If the temperature is higher in autumn, the water cut-off time should be postponed appropriately. Cotton should be chemically controlled in time to control its vegetative growth during the seedling, bud, and boll stage.

(3) Irrigation saving measures. This area is a well-canal combined irrigated area, but mainly by canal irrigation. Mainly adopt drip irrigation under film technology, and irrigate with a small amount of water for many times. Drip irrigation pipes (belts) are set parallel to the planting direction of crops in the middle of the narrow row or about 5cm from the side of the crop row. For cotton fields with insufficient moisture content after sowing or dry sowing, 15-20 m3 of water that helps to the emergence of seedling should be drip-irrigated in time per mu after sowing. After that, irrigate 20-30m3/mu each time. Irrigation is 1-2 times in the bud stage, and the irrigation period is 10-12 days. In the blooming and boll stage, irrigation is 8-10 times, and the irrigation period is 7-10 days.