The Blumat Tensiometer helps to determine the optimal moment of watering.
The dilemma for many growers is searching for the right moment of watering, and the quantity to be determined is often not simple. Giving too little inhibits, but giving too much is an even bigger problem. Especially on ground, it can be disastrous to give too much water. In general, we irrigate our plants much too richly.
Soil moisture can be determined very accurately by measuring the suction pressure.
Suction tension can be measured via a tensio meter. At the top is a meter that indicates the suction pressure.
In fact, the story is that we can determine soil moisture by means of that suction pressure. The tensio meter is thus seen as an artificial root of a plant in which the negative pressure is always in balance with the suction pressure of the soil.
The tube of a tensio meter is closed at the top by means of a rubber stop. This tube is filled with demi-water and placed in the ground. The water can now enter and exit the pipe through the porcelain. When the soil becomes drier and water is sucked out of the pipe, vacuum is created in the pipe. When this negative pressure is equal to the suction pressure of the soil, no water will be sucked out of the tube.
If the soil is moistened by watering, the tensio meter will have fallen to such an extent that it is equal to the suction power of the soil.
When the soil contains so much water that it is saturated, the water can flow freely in and out of the tube. There is then no suction pressure from the bottom and the pressure in the pipe will therefore be equal to the ambient pressure.
We can use this as a yardstick for the suction pressure a plant has to exert to absorb water from the ground. The soil moisture is measured in hPa.
- Blumat tensiometer Standard
- Blumat tensiometer XL 43cm