Agronomic matching techniques of drip Irrigation under plastic Film for Cotton

Drip irrigation technology under plastic film is a combination of drip irrigation technology and plastic film mulching cultivation technology. water is supplied through a controllable pipeline system, and after the fusion of water and fertilizer, drip by drop can be transported uniformly, regularly and quantitatively, infiltrating the root development area of crops. always keep the root soil loose and the best water-bearing state. The evaporation among crops is reduced and the utilization rate of water is improved.

I. Irrigation system

Buried drip irrigation, a total of 175.48 million cubic meters of water. Drip water 9 times. Precision drip irrigation consumes a total of 177.84 million cubic meters. Drip water 8 times. In drip irrigation, according to the law of water demand of cotton at each growth stage, the irrigation system was established. It has practical value for drip irrigation plan, drip irrigation cycle, irrigation area, irrigation quota, duty system and so on. It can guide cotton production and meet the water needs of cotton. According to the principle of irrigation during cotton growth period, it is less in the early stage, abundant in the middle stage and replenished in the later stage. The first drip irrigation was in late June (bud stage), and the irrigation quota at bud stage was 12 cubic meters per mu. Drip irrigation 3-4 times in July, 22 cubic meters per mu, 15 cubic meters every 10 days in August, and 10 cubic meters in the first ten days of September. Irrigate 200-250 cubic meters throughout the growth period.

In order to give full play to the water-saving and yield-increasing effect of drip irrigation under plastic film, irrigation under plastic film needs to be made according to time, place and seedling. Buried drip irrigation under the measurement of Shengtepu water meter, the change of soil water content of 0-10CM on the ground is small, and the surface layer is basically dry, which prevents water loss, keeps the lower part of cotton dry for a long time, and reduces the occurrence of diseases and insect pests and boll mildew. When the surface drip irrigation is measured by Shengtepu water meter, the dispersion of 0-10CM water on the ground becomes unstable. The irrigation volume of buried drip irrigation is 30-60CM, while that of surface drip irrigation is 10-40CM. From the point of view of digging and flushing roots on July 17th, the distribution range of cotton roots under the two methods was different. The development of cotton roots under buried drip irrigation was narrow and deep, and the main roots were distributed in 10-50CM, with few whisker roots and slender roots. On the other hand, the root system of surface drip irrigation is wide and shallow, and the main root system is distributed in 10-30CM. Because the amount of water needed for cotton growth is supplemented to the soil in multiple levels, the root development is different. According to different types of soil, the amount of drip irrigation should not be too large, too much water can easily cause soil plough layer hardening, soil air permeability becomes worse, soil water, fertilizer, gas and heat conditions are not coordinated, resulting in rotten roots of cotton, which is disadvantageous to the growth of cotton roots.

II. Fertilization management

With the change of irrigation mode, there are corresponding changes in fertilization measures. with the synchronization of water and fertilizer, cotton field water keeps nutrient solution, nutrients are less absorbed and fixed by soil, and are evenly distributed in soil. Cotton absorbs water and nutrients at the same time. In terms of dosage, carry out a few times and a large amount. When applying nitrogen fertilizer, 50% of the total nitrogen fertilizer is used as base fertilizer, and the rest can be applied with drip irrigation. Nitrogen fertilizer is applied 2-3 times during the whole growth period, each time is 3-5kg. Cotton special fertilizer 2-3 times, each time the dosage is 3-5kg. When applying nitrogen fertilizer, we should take into account the temperature of the growth period, grasp the law of cotton fertilizer demand in time, fully coordinate the proportion of water and fertilizer, prevent fertilizer leakage, and give full play to the utilization rate of nitrogen fertilizer. In terms of the amount of phosphate fertilizer, put it into the base fertilizer at one time. Foliar fertilizer was sprayed 3-4 times. When dripping cotton, we should supply cotton timely and appropriately according to the nutrients needed in different growth stages of cotton, so as to ensure that the growth of cotton can save a lot of fertilizer and water and fully improve the utilization rate of fertilizer.