How to Find Plant Available Water Content

Knowing the plant available water content of soil is essential for efficient irrigation and water management. Plant available water content refers to the amount of water in soil that can be absorbed by plants. In order to find plant available water content, several methods can be used.

1. Soil Moisture Sensors

Soil moisture sensors are electronic devices that can be installed in soil to monitor moisture levels. This type of sensor measures the amount of water in soil between two probes. The probes send a signal to a data logger, which records the moisture level at regular intervals. Soil moisture sensors are useful for determining the moisture content of soil and the amount of water that can be absorbed by plants.

2. Tensiometers

Tensiometers are devices that measure soil moisture tension, which is the force with which water is held in soil. A tensiometer consists of a tube, filled with water, that is installed in soil. As soil moisture tension increases, water is pulled out of the tensiometer tube, causing a vacuum. The vacuum can be measured with a gauge, which then indicates the moisture tension in the soil. Using a tensiometer can help determine when to irrigate crops or other plants.

3. Gravimetric Method

The gravimetric method is a simple way of determining the plant available water content of soil. This method involves collecting soil samples from multiple locations within a field. The samples are weighed, dried in an oven, and then weighed again. The weight loss between the wet and dry weight represents the amount of moisture in soil. This can be used to calculate the plant available water content of soil.

4. Neutron Soil Moisture Meter

The neutron soil moisture meter is a device that uses neutron radiation to measure soil moisture content. The device emits a beam of neutrons into soil, which is then absorbed by hydrogen atoms in soil water. The neutrons that are not absorbed by hydrogen are measured by a detector. The amount of hydrogen in soil water is proportional to the amount of moisture in soil. This method can help determine plant available water content in soil.

Conclusion

There are several methods for determining plant available water content in soil. Each method has its own advantages and disadvantages, and the choice of method depends on the specific needs of the user. Regardless of the method used, knowing the plant available water content of soil is essential for efficient irrigation and water management.