Drip irrigation As one of the irrigation techniques that delivers particularly good water-saving results, it has attracted considerable attention from farmers. In recent years, drip irrigation has received tremendous emphasis in China and has been promoted on an unprecedented scale, with a rate of development that has far exceeded expectations. Drip fertigation has also gained widespread favor. Drip irrigation, short for drip-water irrigation, employs a comprehensive system of equipment to deliver irrigation water at low pressure after filtration, transporting it through pipelines to drip emitters. This ensures that the water is delivered in the form of small droplets, evenly and slowly seeping onto or into the soil near the crop root zone, thereby supplying moisture to the root zone at the right time and in the right amount to maintain optimal soil moisture conditions conducive to crop growth, while keeping the soil outside the root zones between plants and rows relatively dry.

Advantages: First, fertilizers are applied directly to the root-concentrated zone at the appropriate time and in the appropriate amounts—applying small doses frequently—thus achieving precise timing and localized placement of fertilizer. This facilitates nutrient uptake by crops, reduces losses, and maximizes fertilizer efficiency. Second, supplying nutrients to crops in small, frequent applications can meet their nutritional needs throughout the entire growth period. Third, nutrient supply can be adjusted according to changes in the nutritional requirements of crops at different stages of growth. Fourth, thanks to plastic mulch coverage, fertilizer virtually does not volatilize or get lost; although the fertilizer is concentrated, its concentration remains low, making it both safe and labor-saving, with excellent results. The fertilizer utilization rate in drip irrigation–fertilization systems reaches 80% Above are the drawbacks. : The fertilizer selected must be highly water-soluble.

Drip Irrigation Fertilization Regarding fertilizer requirements, to prevent clogging of the drip emitters, fertilizers with high solubility should be selected, such as urea and potassium dihydrogen phosphate. When applying compound fertilizers, it is best to choose fully water-soluble, specialized formulations. If it is necessary to apply fertilizers that are not completely soluble, they must first be dissolved in a container such as a basin or bucket; after sedimentation has occurred, the supernatant solution should be transferred into the fertilizer tank and introduced into the drip irrigation system, while the remaining residue should be discarded. In general, organic fertilizers and phosphate fertilizers are used as base fertilizers, because some phosphate fertilizers, such as superphosphate, only partially dissolve in the soil, and the resulting insoluble residues can easily clog the nozzles.

Fertilizers with low corrosivity to irrigation systems should be selected. For example, ammonium sulfate and ammonium nitrate cause severe corrosion of galvanized iron but are essentially non-corrosive to stainless steel. ; Phosphoric acid causes mild corrosion of stainless steel; urea does not corrode aluminum sheets, stainless steel, or copper, but it does cause mild corrosion of galvanized iron. Fertilizers used for topdressing must be soluble, with high purity and low levels of impurities, and they should not form precipitates when dissolved in water; otherwise, they are unsuitable for topdressing. For nitrogen and potassium fertilizers, it is generally recommended to use urea, ammonium bicarbonate, potassium sulfate, and potassium chloride that meet government or industry standards. Phosphorus supplementation is typically achieved using soluble fertilizers such as potassium dihydrogen phosphate for topdressing. When applying micronutrient fertilizers as a supplement, they should generally not be applied simultaneously with phosphorus topdressing to avoid the formation of insoluble phosphate precipitates that can clog drip emitters or spray nozzles.

Subsurface Drip Fertigation Technology Method of operation: Selection of fertilizer varieties : When applying fertilizer through drip irrigation, it is essential to select appropriate fertilizer types based on the nutrient requirements of the crop. During the mid-to-late growth stages of cucumber, it is necessary to maintain adequate vegetative growth while ensuring high fruit quality; therefore, bulk-element fertilizers such as urea and potassium dihydrogen phosphate are typically used, along with water-soluble multi-effect silicon fertilizer, borax, manganese sulfate, and zinc sulfate to supply secondary and micronutrients.

Among these, trace elements can also be applied directly in the form of nutrient-rich foliar fertilizers, such as FeliBao. The specific fertilizer to be used should be determined based on the base fertilizer application and the growth status of the plants. Preparing the fertilizer solution: The fertilizer solution can be formulated at a high concentration depending on the fertilization method and 6 Prepare two solutions. The high-concentration solution is made by dissolving urea, potassium dihydrogen phosphate, and other substances in 10% aqueous solutions, with meso- and micronutrients formulated 1%~2% aqueous solution ; A low-concentration solution is prepared by dissolving urea, potassium dihydrogen phosphate, and other substances in 0.5%~1% aqueous solutions, with meso- and micronutrients formulated 0.1%~0.2% Apply the aqueous solution directly.

Fertilization method: When applying fertilizer with a high-concentration solution, it can be done simultaneously with irrigation—simply open the fertilizer injector’s suction valve to allow the fertilizer solution to flow into the irrigation hose along with the water; the flow rate of the fertilizer solution is controlled by the valve. : When applying fertilizer directly with a low-concentration solution, close the irrigation valve, open the inlet valve of the fertilizer injector, secure the filter at the bottom of the fertilizer solution container, and then connect the fertilizer supply to begin fertilization. Precautions: : The prepared fertilizer solution should be free of solid precipitates to prevent clogging of the drip emitters.

The flow rate of the high-concentration fertilizer solution must be properly controlled and should not be too high, to prevent excessive concentration from damaging the crop roots. After fertilization is complete, close the switch on the suction pipe and open the valve to continue flushing with water for several minutes, so as to thoroughly rinse out any residual fertilizer remaining in the pipe. Fertilizer application rates and mixing: the amount of urea applied per mu each time 3~4 Kilograms, the amount of potassium dihydrogen phosphate applied per mu each time 1~2 kilograms; these two types of fertilizer can also be applied in combination. As for secondary and micronutrients, the application rate of each type of fertilizer should generally not exceed 1 kilograms, with no more than per year applied to each field. 0.5 Kilogram.