Drip irrigation water is directly poured into the soil near the root of the crop through the dripper, forming an ellipsoid or spherical wet body in the root zone of the crop. The sprinkler is an important equipment component in the drip irrigation system. It guarantees the realization of drip irrigation. The quality of the dripper directly affects the quality of irrigation. It is the core component of the drip irrigation system. The dripper is the most important equipment in the drip irrigation system. Its performance and quality The quality directly affects the reliability of the drip irrigation fertilization system and the advantages and disadvantages of drip irrigation and fertilization.
However, irrigation drip tape often gets clogged due to physical, chemical, and biological reasons, affecting the uniformity of irrigation water and the efficiency of fertilization. According to the recommendations given by the International Organization for Standardization, when the actual flow rate of the irrigator is less than 75% of the rated flow rate, the irrigator is considered to be blocked (ISO/TC 23/SC18/EG5 N4 2003). Once the irrigator is blocked, it will cause uneven water distribution in the irrigation area, the system performance will be reduced, and even the entire system will be paralyzed in severe cases, so it will have to spend a lot of manpower and financial resources to eliminate the blockage or rebuild the system.
What are the causes of the clogging of the drip irrigation belt? Drip tape manufacturer shares this article for you.
Irrigation Drip Tape
(1) The blockage caused by irrigation water.
1. Physical blockage. Physical clogging refers to the clogging caused by organic or inorganic suspended matter contained in irrigation water, such as biological debris, sand, silt, and clay particles, as well as the clogging caused by the negative pressure suction of the underground drip irrigation system.
2. Chemical blockage. Chemical blockage generally refers to chemical substances such as soluble salts that were originally dissolved in irrigation water, such as carbonates, phosphates, sulfates, silicates, hydroxides, iron ions, manganese ions, calcium ions, sulfides, etc. Under certain conditions, chemical reactions will occur and insoluble precipitated substances will be formed, which will be deposited in the internal flow channel of the irrigation device and cause the irrigation device to block. When the carbonate content is greater than 5 mmol/L, calcium carbonate precipitation is more likely to occur in the irrigation water, causing chemical clogging of the irrigation device.
Special attention is to be paid to the northern area. When the water source contains both carbonate and calcium and magnesium ions, the pH of the drip irrigation water may increase and cause the precipitation of calcium carbonate and magnesium carbonate, which will cause the dripper to block.
3.Biological blockage. Biological clogging refers to the biomass in the irrigation water source, such as algae, zooplankton, bacterial slime, etc., which enters the drip irrigation system and continuously grows and reproduces.
(2) The blockage caused by fertilization.
There are four main reasons for the clogging of the drip irrigation system:
1. Clog caused by large water-insoluble matter in the fertilizer itself. Some solid fertilizers are coated with a film outside the fertilizer granules during production to prevent moisture absorption. Three types of membranous materials commonly used in commercial fertilizers are the clay, diatomaceous earth, and hydrous silica. In order to avoid clogging of these coating materials after dissolution, it is recommended to prepare a small amount of mixture before application and observe whether the coating material settles to the bottom of the container, whether it will form a foam on the surface or be suspended in the solution. If the coating material quickly sinks to the bottom of the container, the entire batch of solution can be prepared. After the coating material has settled, the transparent liquid can be injected into the irrigation system.
In addition, some low-level mono ammonium phosphate and potassium sulfate on the market currently contain water-insoluble substances; at the same time, many farmers use diammonium phosphate, superphosphate, and other poorly soluble products in drip irrigation, which will directly block Drip irrigation system.
2. Fertilizer reacts with irrigation water, blocking the drip irrigation system.
The cations such as calcium in irrigation water react with anions such as phosphate and sulfate to produce insoluble or sparingly soluble substances, blocking the dripper.
In addition, the water quality in some areas is relatively alkaline, and most areas draw snow from the Tianshan Mountains for drip irrigation. The snow water will absorb the soil salt flowing through the ground during the flow distribution process, resulting in increased salt in the water. At this time, choose calcium nitrate and nitric acid. The drip irrigation of fertilizers such as ammonium calcium and calcium magnesium nitrate will cause the calcium and magnesium ions in the fertilizer to react with the salt segregants in the water to form a precipitate, which will easily block the drip irrigation system for a long time and cause the entire integrated system to be paralyzed.
3. The reaction of improper fertilizer coordination will cause precipitation.
Farmers mix phosphate fertilizer or potassium sulfate with medium and trace element fertilizers (inorganic) when fertilizers are mixed, or fertilizers such as calcium nitrate and phosphate drip irrigation together to cause chemical precipitation.
4.Microbial growth in the drip irrigation belt caused by improper application of biological fertilizers, blocking the drip irrigation belt.
There are problems with the application time and application methods of many organic microbial fertilizers. Especially in the emergence of water, due to the short drip irrigation time, there are often microbial agents and organic residues in the drip irrigation belt. At the same time, the humidity in the drip irrigation belt is large. With the increase of temperature, a large number of microorganisms breed, Formation of biofilm to block drip irrigation belt.
How to solve common blocking problems?
In view of the above-mentioned blockages of the seven middle schools caused by water and fertilizer, it can be summarized as the causes of the three aspects of physics, chemistry and biology, and the countermeasures of the three aspects.
1.Solution for physical blockage caused by irrigation water and fertilizer. Filtration is the core of solving clogging. The main types of filters for drip irrigation systems are centrifugal filter, sand filter, laminated filter and mesh filter. In addition to the centrifugal filter, these four filters can not be used independently, the other three can be independent or combined to form a filtration system. Large particles can be considered centrifugal filters, floating objects can be considered sand filters, mesh filters, and laminated filters can effectively intercept suspended impurities such as sediment particles in irrigation water, or two or more types can be used The filters are mixed.
2.Solutions for clogging of drip irrigation system caused by chemical reaction. The substances that cause chemical clogging in drip irrigation systems are complex and diverse, and due to the sensitivity of chemical precipitation to the water environment, it is more difficult to study the mechanism of chemical clogging. At present, the precautionary measures against chemical clogging are mainly acidification of irrigation water, the addition of biological fungicides, and appropriate operation strategies to alleviate chemical clogging of the irrigation system. Combined with the water quality and ion content of irrigation water, the fertilizer type, and its maximum concentration are comprehensively considered to avoid the reaction of calcium and other cations in the water with anions such as phosphate and sulfate, resulting in insoluble or slightly soluble substances, blocking the dripper.
In addition, the problem caused by the "cooling effect" is that when the solution is very cold, the solubility of the fertilizer becomes very small, which in turn causes the same amount of water to not dissolve the expected fertilizer. The solution to this problem is to leave the solution for several hours to increase the temperature, or to continue stirring until all the fertilizer is dissolved.
2. Solutions for biological blockages. The prevention and control measures of biological clogging are mainly from the perspective of controlling the growth of microorganisms. Measures such as periodic chlorine flushing of the drip irrigation system are commonly used methods to control the biological clogging of the drip irrigation system.
Adding different concentrations of hypochlorous acid, ethanol, or chlorine gas has different effects on the anti-clogging effect of drip irrigation systems. Of course, pay attention to the irrigation of the drip irrigation system.
In summary, the reasons for the current farm drip tape clogging include irrigation water quality problems and improper fertilizer application, but the clogging of the drip irrigation system is caused by physical, chemical, and biological reasons. The solution is also to solve the problem from the aspects of filtering before the pump and filtering before the drip irrigation belt, acidizing the irrigation water, rationally matching the fertilizer, and treating the irrigation system.