Technology of dripping Water and Fertilizer under plastic Film of Cotton

Cotton drip irrigation under plastic film is a new water-saving technology, which can artificially control the amount of irrigation and field microclimate, greatly alleviate the tension of head water, and control the reproductive and vegetative growth of cotton, which is conducive to shaping the ideal plant type and reducing the ineffective consumption of nutrients. Although there are still some problems in practical application, cotton in drip irrigation has the advantages of early boll opening, good quality and high yield. At the same time, drip irrigation shows unique cold resistance under special climatic conditions. in the special climate of low temperature in spring and autumn, it has normal growth and development, high yield and stability, and relatively concentrated in mature period.

First, dripping water under the film

The cotton field under drip irrigation under plastic film should follow the law of cotton growth and development, that is, the seedling stage is less, the bud stage increases, and the flower and boll stage reaches the peak of water demand. Dripping water should grasp the principle of "a small amount of water for many times, frequent irrigation and light irrigation", and must not drip too much water at one time to avoid surface runoff and can not achieve the effect of water saving.

1. Dripping water 10-11 times during the growth period, once every 7-10 days in principle. At the end of mid-June, 667 square meters dripped 35,40 cubic meters. Drop again 10 days later, 667 square meters dripping 25,30 cubic meters. Drop water 4 times in July, with an interval of 7 days, with 667 square meters dripping 25,30 cubic meters each time. Dripping three times in August, once every 10 days, 667 square meters dripping 2030 cubic meters each time, stopping after the last dripping in early September, 667 square meters dripping 15020 cubic meters, 667 square meters dripping 235310 cubic meters during the growth period. The amount of dripping water of 667 square meters and each drip in late-maturing varieties and growing cotton fields was taken as the lower limit, while that of early-maturing varieties and weak cotton fields was taken as the upper limit of 667 square meters and each dripping water.

two。 The first dripping must take two dripping methods, and the first dripping should be divided into two times (the vertical infiltration of crops is generally stronger than horizontal infiltration, according to local experience, if the first drop is impenetrable, it will be very difficult to drip later, so it is necessary to increase the amount of dripping of the first water, start dripping 3-5 days in advance, increase the soil moisture at the bottom, and alleviate the pressure in the later stage). Bundled drip irrigation can be used to connect two adjacent communities together. after the first drip, the soil longitudinal porosity is greatly reduced, and the second drip is dripped again, and the horizontal infiltration is obviously accelerated. Twice dripping is beneficial to horizontal infiltration, and crop dripping is uniform, which can prevent continuous dripping of the same amount of water, resulting in serious deep leakage, resulting in high middle row and low side row of cotton, resulting in uneven growth.

3. Dripping water for more than one time in the sandy land to ensure the uniform growth of cotton field. Strict dripping times and dripping volume of 667 square meters to prevent excessive dripping volume of 667 square meters and reduce dripping times.

4. Taking measures in accordance with local conditions, depending on the sky, the earth and the seedlings, the water is usually cut off in early September.

Second, dripping fertilizer under the film

1. The drip fertilizer for cotton should be selected according to the soil texture of drip irrigation land. Urea is the main nitrogen fertilizer and potassium dihydrogen phosphate is selected as phosphate fertilizer to improve the utilization rate of potash fertilizer.

two。 Chemical fertilizer was applied in the middle period of irrigation, and an irrigation cycle was divided into three stages to control. In the first stage, the soil is moistened with water without chemical fertilizer for about 1 hour; in the second stage, the calculated amount of chemical fertilizer is timely added to the water, so that the aqueous solution is distributed in the soil layer through the system for about 4-5 hours; in the third stage, stop fertilizing and continue dripping for 0.5 hours, play the role of cleaning the irrigation system and prevent the corrosion of the pipeline and blocking the drip. The amount of fertilizer dripping per 667 square meters should be determined according to the amount of fertilizer remaining in the whole layer. If 25 kilograms of urea and 1.8 kilograms of potassium dihydrogen phosphate are left during the growth period of every 667 square meters, the amount should be divided according to the process of cotton growth and development, and the amount should be dripped with water. In mid-late June, the first fertilizer drop was from full bud to early flowering, adding 0.2 kg of potassium dihydrogen phosphate per 667 square meters of urea, 8 kg of urea and 0.5 kg of potassium dihydrogen phosphate per 667 square meters in early July, 6 kg urea and 0.5 kg potassium dihydrogen phosphate per 667 square meters. The fourth fertilizer drop is from the end of July to the beginning of August, 667 square meters of urea plus 0.3 kg potassium dihydrogen phosphate, and the fifth fertilizer drop is in early August, 667 square meters of urea plus 0.3 kg potassium dihydrogen phosphate.

3. One drop of fertilizer per drop of water is strictly prohibited to prevent prosperous growth in the early stage and late ripening in the later stage. The first drip, the drip after topping, the drip in mid-August and the drip in early September cannot bring fertilizer.

4. When dripping fertilizer with water, there can be no leakage, dripping must be uniform, otherwise it is easy to cause uneven growth of cotton and bring difficulties to chemical blending and pruning in the later stage.