Crops are not like people. There is no way to tell us through words or crying that they are thirsty, hungry, full and ready to eat and drink. Therefore, we need to use certain tools or methods to understand them directly or indirectly. In order to arrange irrigation more reasonably. While meeting the water demand of crops, water resources are more effectively used and saved. The soil moisture sensor smart uses the change of water potential inside and outside of the tensiometer. Imitate the ability of plants to absorb water in this situation. It can reflect the soil water content more truly. Understand the thirsty or drunk state of the plant.
Working principle of soil tensiometer
The soil water potential tensiometer is buried in the soil. Due to the difference in water potential inside and outside the ceramic head. Water can enter or exit the tensiometer through the ceramic head. The soil water tension measured by the soil water potential tensiometer is the suction force of the soil to water. The wetter the soil, the lower the suction power for water, and vice versa. When the soil moisture increases so that all voids are filled with water.
The soil water tension will drop to zero. In other words, the soil moisture content has reached saturation at this time. When the soil is dry, the water potential outside the ceramic head is higher than inside. The water is sucked out from the ceramic head. Negative pressure is formed inside the tensiometer. The magnitude of the negative pressure can be read by the vacuum gauge. When the soil is relatively moist due to rainfall or irrigation. The water potential inside the ceramic head is higher than outside. The water flows back into the tensiometer. The negative pressure of the tensiometer drops. The vacuum gauge reading will also decrease. Inside the ceramic head here. It is equivalent to the root system of a plant.