Drip irrigation under plastic film for cotton cultivation

I. Preparation before sowing

1. Variety selection: according to climate and soil conditions, select varieties with growth period of about 130 days, resistance to wilt and verticillium wilt; compact plant type, short fruit branches I ~ II type, small planting angle; moderate small leaves, short petioles, hard to occur fried dough sticks; strong boll setting and good fiber quality. Such as 9665, JD~3, Fengmian 8, Jiumian 2, etc.

2. Deep application of basal fertilizer: the amount of chemical fertilizer is 8~12 kg of pure nitrogen, 7~10 kg of phosphorus pentoxide and 3.5 kg of potassium oxide. Farm manure and calcium superphosphate are deeply ploughed when ploughing and stubble cleaning. In spring, when soil preparation is combined, ammonium nitrate phosphorus 20 kg, diammonium phosphate 20~23 kg and potassium sulfate 6~10 kg are mixed and deeply applied as base fertilizer.

3. Chemical weeding: before mulching and sowing, use 48% dinochlor 100~150 ml or 50% acetochlor 80 g per mu, add 2~3 kg of water, mix with 50 kg of fine sand, evenly sprinkle into cotton field, shallow rake into soil, suppress mulching and sowing.

II. Sowing

1. Prepare the machines and tools: conduct comprehensive inspection and debugging on the machines and tools before sowing, and install the drip irrigation capillary device to achieve safe use.

2, suitable sowing: when 5 cm ground temperature stability through 10℃, as the beginning of sowing. April 15~20 in normal year is the best sowing time, sowing 6~8 seeds per hole, sowing depth 2~2.5 cm, covering soil thickness 1 cm.

3. Sowing method: adopt one film and two pipes water-saving technology. 145 cm wide film planting 4 rows of cotton, planting specifications of 30+60+30cm, inter-film row spacing of 45 cm, plant spacing of 15 cm, 1.1~1.3 thousand seedlings per mu. The laying, film laying and sowing of drip irrigation tape are carried out simultaneously, the drip irrigation tape is arranged in a narrow row, and the capillary surface of the drip irrigation tape is upward, namely, the flow channel is upward. Take care to pull out an extra section of drip irrigation tape after the locomotive stops to prevent the drip irrigation tape from shrinking and shortening.

III. Dripping and Fertilizing

1, seedling dripping: generally in the seedling after the laying of ground branches and attached pipes, must start dripping in early June, each time 18~20 meters 3/mu, drip irrigation cycle for 7~8 days. The fertilizer is dripped with fertilizer easily soluble in water, generally urea and a small amount of potassium dihydrogen phosphate, 6 parts of fertilizer are dripped twice, 3 kg urea and 100 g potassium dihydrogen phosphate are dripped each time. Fertilizer dripping method: adjust the pressure regulating valve in the middle of the filter to make the pressure difference 0.1mpa, generally start fertilizing 1 hour after dripping, finish 30 minutes before dripping, and the dripping time of each tank is 40 minutes to 1 hour. The standard of dripping water is that the seed hole is exposed to wet soil, which is 30cm wet.

2. Flower and bell water: from the middle of July, increase the amount of fertilizer applied by dripping water, 23~25 m 3/mu per drip, 5~7 days of dripping cycle, and increase the amount of fertilizer applied, 4~5 kg of urea and 200 g of potassium dihydrogen phosphate per drip. Dripping standard to film all wet, wet 60cm. From the ground, the general cotton plant outside the line see wet, the ground does not inject water, a little wet soft can be. Stop urea drip by August 10.

3, late dripping: from August can be appropriately reduced dripping volume and frequency, each dripping 20 meters 3/mu, dripping cycle is about 8 days. The water supply shall be stopped before September 8, and the amount of dripping water can be increased according to the field conditions at the last dripping time to ensure sufficient moisture content during the opening period. During the whole growth period, there are 12~14 times of dripping water, the total amount of dripping water is 250~280 m3/mu, the urea is 25~27 kg, and the potassium dihydrogen phosphate is 2 kg.

Fourth, chemical control drip irrigation cotton growth and development steady, coordinated, chemical control should be early, light, frequent.

1. Seedling stage: the first regulation is carried out at 2~3 leaves, spraying 0.2~0.3 g of DPC per mu. After dropping a drop of water, spraying 0.5~0.6 g of metanil per mu on cotton fields with vigorous growth.

2. Bud stage: spray 1.5~2 g of DPC every 7~10 days.

3. Flower and boll period: 2~ 3g of mepivacaine per mu before topping, 7~10 days after topping, 7~ 8g of mepivacaine per mu for re-control.

V. Pest control

Cotton pests in my county are mainly aphids. Aphids are mainly controlled by biological control, such as spraying insecticide on stems or artificial spots. When the crop area is large, the effect of monocrotophos 100~ 200g/mu or 85% carbofuran powder 80g/mu applied with water drops can reach more than 95% after three days.

VI. Recovery of residual film and drip irrigation tape

After cotton harvest, drip irrigation tape should be withdrawn, and after culm cutting, residual film fragments should be picked up to prevent soil pollution. Other field management is the same as conventional irrigation.

VII. Precautions for drip irrigation

1, frequently check the pipe joint, the joint must be firm, in watering should check the capillary head, there can be no rotten hole, the ground can not be flooded; watering should pay attention to observe the water pressure and irrigation situation, such as water pressure suddenly reduced, should check whether the pipe belt is broken, whether the joint falls off, etc. and timely treatment.

2. Irrigation must be started in early June and stopped in early September. The irrigation area should not be too large, and the area of each rotation irrigation group should not exceed 30 mu. When irrigating, start one irrigation group at a time. After one irrigation group is finished, start the next irrigation group first and then close the previous irrigation group. It is forbidden to close first and then open. When the system is in progress, the pressure gauge reading must be strictly controlled, and the system should be controlled to operate at the design pressure to ensure that the system can operate safely and effectively. Each farmer shall obey unified operation management, and shall not open the valve randomly, let alone make holes in the pipe belt.