灌漑システムの水圧を理解する

6月 13, 2025

灌漑システムで, pressure is a very important parameter. It directly affects the water delivery efficiency and uniformity in the irrigation pipeline system. 同時に, pressure also impacts the service life of irrigation equipment.

This article will explain in detail from four aspects: the pressure in different irrigation systems, the factors that affect irrigation pressure, how to choose the right pressure, and some important considerations.

Pressure in Different Irrigation Systems

Different irrigation methods have different requirements for pressure. There are many types of irrigation methods, such as the commonly used drip irrigation systems, スプリンクラー灌漑システム, and micro-spray irrigation systems.

1. ドリップ灌漑システム

Drip irrigation is currently the most water-saving technique among all irrigation technologies because it places pipes and drippers directly near the plants, enabling precise, localized water delivery.

It supplies water in the form of drips, without spraying the water out. したがって, its pressure requirement is also the lowest—generally, a pressure of 0.02 に 0.3 MPa is sufficient.

2. Sprinkler Irrigation System

Sprinkler irrigation is suitable for large-scale, wide-area irrigation. 例えば, large farmland irrigation usually adopts sprinkler systems. Sprinklers require relatively high head and range—in other words, they need to spray water both high and far—so the pressure requirement is relatively high, usually 0.2 に 0.4 MPA.

Many people like to classify sprinkler pressure into levels, such as low, medium, and high pressure. 例えば, some sprinklers like impact sprinklers and rain guns belong to medium- and high-pressure sprinkler systems. Low-pressure sprinklers, 一方で, are more often categorized under micro-spray irrigation systems.

Actually, I personally don’t recommend classifying pressure levels, because pressure levels are quite subjective. Everyone has different standards. What might seem like high-pressure sprinkler performance to one person may seem like only medium pressure to another. したがって, the most objective way to compare pressure is by looking at the sprinkler’s range and height.

3. Micro Spray Irrigation System

Micro spray irrigation is a small-scale form of sprinkler irrigation. Its spray radius is generally within 5 meters, and its working pressure usually falls between that of drip and sprinkler systems, ranging from 0.05 に 0.2 MPA.

The spraying effect of micro spray irrigation also lies between that of drip and sprinkler irrigation. It can spray water over a small area. Although its water-saving performance is not as good as drip irrigation, it is better than sprinkler irrigation. さらに, it is worth mentioning that the water sprayed by micro sprayers has a kind of misting effect. Because of this, products like micro sprinkler heads are used not only in irrigation but also widely in construction projects, since they can help with cooling and dust suppression.

Factors Affecting Irrigation Pressure

There are many factors that affect pressure, so choosing the right pressure needs to be based on different conditions. 下に, let’s talk about some of the main influencing factors.

1. Irrigation Type

Different irrigation methods require different pressures. 例えば, as we mentioned above—drip irrigation, sprinkler irrigation, and micro-spray irrigation—they all affect how we choose the pressure.

2. Irrigation Area and Planting Density

The larger the irrigation area and planting density, the higher the required water pressure and flow rate.

3. Soil Type

Soil texture also affects the pressure in irrigation pipelines. 例えば, sandy soil has very good water permeability, so low-pressure water delivery is sufficient.

一方で, clayey soil retains water better, so it requires relatively higher water pressure.

4. Crop Demand

Different crops have different water demands. 例えば, rice and sugarcane require a large amount of water during their growth process, so high-pressure water delivery is needed to ensure a stable and abundant water supply.

一方で, different growth stages of a crop also require different amounts of water. 例えば, during the fruiting stage of certain crops, water pressure and flow rate need to be increased to meet the crop’s needs at that stage.

5. 水源

The water source has a huge impact on pressure. If the water source is located on flat ground, then we can calculate the pump’s working pressure in a conventional way. If the water source is at a higher altitude, then we need to consider the gravity of water when calculating working pressure. If the water source is in a low-lying area, then the water pump needs to work with higher pressure than usual.

Just determine the pump pressure according to the location of the water source. In actual operation, you can also use pressure-increasing or pressure-reducing equipment to achieve the pressure you want.

6. Irrigation Pipeline

The length and height difference of the irrigation pipeline also affect the pressure. 一般的に言えば, under the same pipe diameter, the longer the pipeline, the greater the frictional resistance of the water flow, and thus the greater the required water pressure.

The height difference of the pipeline also needs to be considered. If there is a significant height difference between various pipes, then the greater the difference, the greater the water pressure required.

How to Choose the Right Pressure

Choosing the correct irrigation pressure can be considered from two aspects: the irrigation method and pressure loss.

As for the irrigation method, we’ve already introduced it above. You first need to identify which type of irrigation system your planting area requires—whether it’s drip irrigation, sprinkler irrigation, or micro-spray irrigation. それから, choose the appropriate pressure based on the irrigation method.

When choosing pressure, we also need to consider pressure loss. You can think about it from three angles: pipe material, pipe length, and pipe size.

初め, different pipe materials have different levels of friction. 一般的に言えば, the smoother the inner wall of the pipe, the smaller the pressure loss. In terms of length, the longer the pipe, the greater the pressure loss. サイズに関して, the larger the pipe diameter, the smaller the pressure loss.

Once the irrigation method and pressure loss are determined, calculating the pressure will give you a more suitable answer.

Things to Note

In the above section, we’ve already talked quite a bit about pressure. 今, let’s look at three important notes.

1. When choosing pressure, be sure to ensure that the pressure matches the irrigation system. Both too high and too low pressure will affect the irrigation system and crops. If the pressure is too high, the pipes and irrigation fittings may burst because they can’t withstand it. If the pressure is too low, it may result in insufficient or uneven water supply, or even no supply at all—thus affecting crop growth.

2. Remember to regularly check the irrigation pipes. Pipes are consumables, so they need to be inspected regularly to see if they need cleaning or if there’s any damage. When conditions allow, you can install more pressure gauges in the pipe system, because if there’s a problem with the pipeline, there will definitely be pressure fluctuations. With pressure gauges, we can monitor the system more effectively.

3. Remember to clean filters and similar equipment regularly. Filters remove impurities from the water, making the water inside the irrigation system cleaner. But over time, the filter itself may accumulate a lot of debris, so it needs to be cleaned regularly to ensure the irrigation system runs stably and efficiently.