Technical overview:

Corn is a crop that requires more water. Especially in recent years, with the increase of planting density, fertilization amount and the improvement of corn yield level, the water demand of corn has increased significantly, and the problem of water shortage has become increasingly prominent. Water-saving irrigation technologies mainly include engineering water-saving technologies, water-saving irrigation management technologies and inadequate irrigation technologies. After the full-film double ridge and furrow technology in dry farming areas, our province has transformed and innovated the traditional ridge and furrow irrigation and plastic film covering water-saving technologies in the Hexi Irrigation Agricultural Area, and explored and summarized the formation of high-efficiency water-saving irrigation technology for corn. The effect of increasing production and saving water is very obvious.

Technical effects and key points:

(1) Surface water-saving irrigation technology. Surface irrigation has a wide range of applications and simple technology. It has been one of the key research and promotion contents of water-saving irrigation for many years. Improved surface irrigation technology has significant water-saving effects compared with traditional surface irrigation. At present, horizontal ditch irrigation, long-border segmented irrigation, small border irrigation, alternate ditch irrigation, surge irrigation and film irrigation are mainly used in corn production. Among them: ditch irrigation. Irrigation water flows in the irrigation ditches between corn rows. After irrigation, the topsoil is loose, which can avoid hardening and reduce evaporation between trees. Long ridge segmented irrigation or small ridge irrigation. Build temporary ridge ridges to reduce deep leakage in the field and soil nutrient leaching, with significant water saving effects. Generally, border fields are about 50 meters long and border fields are about 2 - 3 meters wide. During irrigation, water should be changed when the water flow reaches 80% to 90% of the ridge length.

(2) Alternate ditch irrigation technology. This technology is a traditional irrigation method that changes the full and uniform wetting of the root layer of crops in the field. Through alternating irrigation in ditches, it increases the function of the root system to conduct water, reduces the wetted area on the soil surface, reduces water evaporation loss, and improves water utilization efficiency. While ensuring corn yield, reduce the irrigation quota by 50 - 100 m3/mu, and reduce the water fee input per mu by 30 - 50%. Ditch and ridge. The plot should be made soft and free of weeds. Before planting, mark with meters, ditch along the line, evenly mix chemical fertilizers and sprinkle them into the middle of the ridge, ditch and ridge. The ditch depth is about 30 - 40cm, the ditch width is 60cm, and the ridge top is 40cm wide. Corn is planted by ridge planting and ditch irrigation. Sow seeds with sufficient moisture. In order to ensure that sufficient moisture water should be irrigated before planting the whole seedlings, generally about 50m3/mu. After the water dries, scrape off the dry soil along the water surface line, make the ridges, and sow seeds in time. Immediately after sowing the corn, cover the ridges with 120cm plastic film, tighten the film at the bottom of the ditch, and release the seedlings in time after emergence. The seedling density is 5,500 plants/mu. The film is removed for weeding as appropriate. Water is irrigated alternately in zones and ditches. Corn is irrigated 5 to 7 times during the entire growth period, with alternate irrigation in ditches. Irrigation is conducted one ditch after another; for the next irrigation, only the ditches that were not irrigated last time are irrigated, and alternate irrigation is implemented. The irrigation amount per ditch is about 30% more than normal, and the irrigated area each time is only equivalent to 50% to 70% of the traditional irrigated area, which can be reduced by about 25% to 35% compared with the original water consumption.

(3) Ridge film furrow irrigation technology Corn ridge film furrow irrigation technology is a technology summarized from the promotion of farmland water-saving technology in irrigation areas in Gansu Province. There are two application modes of this technology, namely semi-film ridge farming and full-film ditch sowing and ditch irrigation. The application of this technology can solve the problems of ineffective evaporation and leakage of water, waste of fertilizers with water, pollution of groundwater, and high number of pests and diseases caused by flood irrigation in irrigation areas. The water saving and increasing production can be obvious. Among them, the semi-film ridge planting and furrow irrigation technology saves an average of about 100m3 per mu, and increases the yield by about 10%. The full-film furrow sowing and furrow irrigation technology irrigates an average of 350m3 per mu, saves 120m3, and has an average water saving rate of 25%. The average yield increase rate per mu is 9%.

Notes:

Corn ridge film furrow irrigation technology increases soil surface area by ridging, changes soil light, heat, water conditions and microbial activity environment, coordinates the microclimate on which crops rely for survival, and overcomes the unfavorable irrigation methods of traditional flat-cropping cultivation by changing the micro-topography, planting methods and irrigation methods in the field. Corn is planted on ridges or ditches, water is poured into the ditches between the two ridges, the ditches are V-shaped or U-shaped, and the ridges or the entire ground are covered with film.