黑龙江体彩61开奖时间 www.ewlqe.icu The application of drip irrigation technology under mulch has achieved the goal of saving water and increasing production. However, in the process of drip irrigation, the phenomenon of burning of drip irrigation belt, scalded holes in drip irrigation belt and water leakage occurred during operation, which resulted in the failure of drip irrigation system to operate normally. In this paper, the causes of the above phenomena in drip irrigation project are analyzed, and the preventive measures are put forward.
Cause Analysis of Burn on Drip Irrigation Belt
Submulch drip irrigation technology is a new irrigation technology which combines the advantages of film mulching technology and drip irrigation technology. It is also an extension and deepening of plastic film cultivation technology. However, the small droplets attached to the film formed convex lenses under sunlight. After sunlight convergence, when the central point of convergence happened to fall on the drip irrigation belt under the film, local high temperature was formed, which melted the surface burns of the drip irrigation belt and produced holes, resulting in the surface damage of the drip irrigation belt.
After crop seeding dripping, there are more small water droplets attached to the film, and more water droplets accumulated on the film. The small water droplets on and under the film have the function of convex lens. Under sunlight, the focus of convex lens of some small water droplets happens to fall on the drip irrigation belt. After sunny weather or shower, the outdoor temperature is high (above 32 C). From 11:30 a.m. to 15:30 noon, the diameter of water droplets is 5 mm-13 mm. When the distance between film and drip irrigation belt is about 13 mm, the temperature inside the film is higher (above 38 C). The focus of water droplets can gather higher temperature (75 C-160 C) in a short time. It is easy to melt and burn drip irrigation belt in the focus. Small holes are created. Small water droplets on the surface of the film are affected by wind, sunshine, evaporation and other environmental factors. Their existence time is shorter than that under the film. However, when the weather is clear, the temperature is high, the light is strong, and there is no wind or rain, they are easy to accumulate larger water droplets on the film and focus intensely, which can also cause large area burns to the drip irrigation belt.
1. When laying drip irrigation belts, keep the ground level, prevent soil blocks, weeds and other things from holding up the plastic film, causing water vapor to accumulate in the film, forming a lens effect burn drip irrigation belt.
2. When laying, drip irrigation belt can be buried shallowly to avoid focus burns.
3. When laying, lay a layer of soil about 1 mm thick on drip irrigation belt or plastic film to destroy the formation of lens and avoid burns.
4. The shadow of the height of plant beads can not cover the drip irrigation belt. When the weather is clear and the sunshine is intense and the temperature is high, it is necessary to beat the water droplets in time when the water droplets appear in the film, or to shake the water droplets in the film with a fire-fighting fan.
5. Make the drip irrigation belt as close to the plastic film as possible. Generally, the distance between drip irrigation belt and film is about 5 mm, which will not burn the drip irrigation belt.
6. Leave some water in the drip irrigation belt after each operation of the system.
7. Cover with black film.
8. Improving production technology to produce drip irrigation belt with high melting point can effectively prevent burns.