| The integrated drip irrigation technology of water and fertilizer can improve the utilization efficiency of water and fertilizer in dryland agriculture,improve the uniformity of water and fertilizer distribution in the root zone of crops,promote crop growth and increase yield.However,there are many fine particles of sediment in the irrigation water,which is easy to cause the blockage of the dripper,which seriously limits the application effect of the drip irrigation project.In actual irrigation,in order to prevent the clogging of the dripper,a large number of sedimentation and filtration facilities are usually configured,which will greatly increase the cost of drip irrigation.In addition,frequent sediment treatment significantly reduces the operational efficiency of drip irrigation projects.If the ability of the dripper to transport sediment can be improved,the investment in sedimentation and filtration facilities can be reduced,and more fine-grained sediment can be discharged into the field,which can not only improve the fertility of the farmland,but also improve the operation efficiency of the drip irrigation project.Therefore,improving the sediment transport capacity of the dripper and reducing the clogging of the dripper is an important direction for the development of drip irrigation technology in the Yellow River Diversion Irrigation Area.In recent years,magnetized water has been gradually developed and used in agriculture.After water is magnetized,its intermolecular hydrogen bonding force is reduced,and the water molecules change from disordered state to ordered state.Magnetized water can change the surface tension,electrical conductivity and spectral characteristics of the water body,and the small water molecules after magnetization can penetrate the dirt to loosen and decompose.Magnetization changes the properties of water,promotes the infiltration of soil water,enhances the water retention capacity of the upper soil,increases the amount of dissolved oxygen in the water,and improves the quality and yield of crops such as rice.The input of magnetized water into the field can effectively wash the salt,and discharge water and sediment into the field,which is beneficial to the soil conservation and crop growth in the field,and becomes an effective way of farmland reclamation.The above studies all show that the magnetization of irrigation water has positive effects on crop growth and soil desalination.Some studies have shown that magnetization treatment can significantly improve the flocculation and sedimentation rate of full tailings and high turbidity clay in water.Therefore,the integrated drip irrigation of magnetized water,water and fertilizer may change the movement law of suspended sediment in the drip irrigation pipe network,thereby affecting the However,there are few studies on the dripping characteristics and clogging of the dripper after the irrigation water is magnetized.In order to explore the effect of magnetization treatment on the characteristics of water and fertilizer integrated drip irrigation dripper in the Yellow River Diversion Irrigation Area,this experiment used an inner-chip dripper with magnetization intensity of 0.2,0.4 and 0.6 T,and the non-magnetization treatment was used as the control group.The muddy water with potassium sulfate fertilizer,urea and compound fertilizer in the proportion of 2%,the sediment content was 1.0 g/L(DN)and 3.0 g/L(GN),respectively,and the capillary lengths were 6 m(LM)and 2 m(DM),conducted a short-period intermittent irrigation test,and collected the sediment output from the dripper,studied the effect of magnetization on the clogging of the dripper,and obtained the following main conclusions:(1)The magnetization pole significantly slowed down the downward trend of dripper flow and irrigation uniformity(P<0.01),and the optimum magnetization intensities for different fertilizers were different.When the magnetization is 0.4 T,the slowing effect on the drop of the dripper flow of the potassium sulfate fertilizer and compound fertilizer mixture is the greatest;when the magnetization is 0.2 T,the slowing effect on the drop of the dripper flow of the urea mixture is the greatest.After the irrigation water was magnetized,the number of blocked drippers in the front section of the capillary increased in the potassium sulfate and compound fertilizer treatments,and decreased in the urea treatment.The magnetization treatment significantly affected the sedimentation and movement of the sensitive particle size of the dripper clogging,and significantly increased the proportion of the sensitive particle size(<0.03 mm)of the sediment deposited in the capillary of the mixed solution of potassium sulfate fertilizer and compound fertilizer,while the opposite was true for urea.(2)The magnetization treatment significantly improved the cumulative sediment transport of the drip irrigation dripper and the average sub-irrigation sediment transport of the dripper.When the fertilizer types were potassium sulfate,urea and compound fertilizer respectively,the average amount of sediment transported by the dripper per irrigation increased by 13.68%～26.28%,8.49%～38.41% and 4.66%～17.38%.When the fertilizer type was potassium sulfate fertilizer or compound fertilizer,the clay and silt particles of the output sediment from the dripper were reduced by 9.60%～14.30% and 5.78%～9.59%,9.59%～13.68%and 2.46%～8.60%,respectively.When the fertilizer type was urea,the clay and silt particles in the output sediment of the magnetized dripper increased by 13.29%～17.60% and8.91%～9.23%.(3)Magnetization treatment reduced the aggregate quantity,volume and compactness of the sediment output from the dripper in the potassium sulfate and compound fertilizer treatments,and increased the aggregate quantity,volume and compactness in the sediment output by the urea treatment dripper.The magnetization treatment improved the p H,conductivity and dissolved oxygen of the muddy water output by the dripper.(4)After potassium sulfate is applied,when the magnetization times are 10 and 15 times,the drop rate of the average relative flow rate and irrigation uniformity of the dripper is the smallest;when urea is applied,the magnetization times are lower(1 time and 5 times)and will not Significantly affects the drop rate of the average relative flow rate of the dripper,but when the number of magnetization reaches high(10 and 15 times),it can significantly reduce the rate of decrease of the average relative flow rate of the dripper and the uniformity of irrigation;when the fertilizer is compound fertilizer,The magnetization treatment can significantly reduce the drop rate of the average relative flow rate of the dripper and the uniformity of irrigation,and the effect increases with the increase of the magnetization times.(5)The magnetization device has low cost and strong practicability.The magnetization of irrigation water can increase the effective irrigation times of drip irrigation and increase the amount of sediment.It is an effective measure to increase sediment discharge and reduce the configuration of filtration system.Provide reference for anti-clogging prevention measures of integrated drip irrigation dripper. |
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