The most worrying problem of fertigation through drip irrigation is over-irrigation. Many users always feel that drip irrigation produces less water and feel uneasy. As a result, irrigation time is prolonged. One consequence of prolonging the irrigation time is wasting water, and another consequence is leaching nutrients that are not absorbed by the soil below the root layer and wasting fertilizer.
Drip fertigation only irrigates the root system and fertilizes the root system. Therefore, it is necessary to understand the depth of the root distribution of the managed crop. The easiest way is to use a small shovel to dig the root layer to check the depth of wetting, so that you can judge whether there is excessive irrigation. Or bury a tensiometer in the ground to monitor the depth of irrigation.
Generally, drip water first, and start fertilization after the pipe is completely filled with water. In principle, the longer the fertilization time, the better. After fertigation through drip irrigation, continue to drip water for half an hour to drain all the remaining fertilizer liquid in the pipeline. Many users do not wash the tube after dripping fertilizer. Finally, algae and microorganisms grow on the dripper, which causes the dripper to be blocked. The accurate dripping time can be monitored with a conductivity meter.
When the soil is not short of water, fertigation through drip irrigation should be carried out as usual. It is usually carried out after the rain stops or when the soil is slightly dry. At this time, fertilization must be accelerated. Generally, it takes about 30 minutes to complete. Do not wash the tube after fertilization, wait until the weather is clear, and then wash the tube. If you can monitor the conductivity of the soil solution with a conductivity meter, you can accurately control the fertilization time to ensure that the fertilizer is not leached.
When the concentration of fertilizer is too high, it will "burn" the leaves or roots. Therefore, the concentration must be controlled by spraying or dripping fertilizer through the irrigation system. The most accurate method is to measure the conductivity of the sprayed fertilizer solution or the fertilizer solution at the exit of the dripper. Usually the range of 1.0~3.0ms/cm is safe. Or it is safe to dilute the water-soluble fertilizer 400 to 1000 times, or add 1 to 3 kg of water-soluble compound fertilizer per cubic meter of water. For drip irrigation, due to the buffering effect of the soil, the concentration can be slightly higher without any harm.
Drip irrigation pipes have a variety of specifications, with wall thicknesses ranging from 0.2 mm to 1.2 mm. Obviously, the thicker it is, the more resistant it is to mechanical damage. All drip irrigation pipes are added with anti-aging materials. In the absence of mechanical damage, the service life of thick-walled and thin-walled drip irrigation pipes is the same. The short life of many thin-wall drip irrigation tapes is mainly due to mechanical damage, leading to water leakage. From the perspective of mechanical damage, the thicker the drip irrigation pipe, the longer the life. Different crops and cultivation methods have different requirements for service life.
Generally, products with high cultivation density (such as strawberries) with a design life of 1-3 years are more economical and reasonable, while products with a low cultivation density of fruit trees with a design life of 8-10 years are more economic and reasonable. Of course, with a long service life, the one-time investment cost will be higher.