What do tensiometers measure in the soil?

Tensiometers measure soil moisture in units of negative pressure, also known as tension. Tension is a measure of the force that plant roots must exert to pull water from soil pores (Figure 2). Large pores (macropores) hold water with less force than small pores (micropores).

How is soil water measured?

Soil water content: It’s just an amount It’s calculated by weighing the wet soil sampled from the field, drying it in an oven, and then weighing the dry soil. Thus gravimetric water content equals the wet soil mass minus the dry soil mass divided by the dry soil mass.

What is tensiometer pressure?

A device known as a tensiometer is used to measure head and pressure in the unsaturated zone (Figure 3.23). The tensiometer consists of a fine-grained porous ceramic cup connected to a sealed pipe that is filled with water.

What is soil water tension?

Soil water tension (SWT) is the force necessary for plant roots to extract water from the soil. Soil water tension reflects the soil moisture status. The higher the tension, the drier the soil.

What is the unit for soil moisture?

Soil water content is a measurement of the amount of water in a known amount of soil; it can be expressed as % water by weight or volume of soil, or inches of water per foot of soil.

What are the advantages of tensiometer?

Tensiometers are relatively inexpensive and reusable. They are simple to operate, although they require some maintenance in the field. Maintenance requires the addition of water and the use of a hand vacuum pump to remove air from the tube.

What are the advantages of a tensiometer?

Tensiometers can be helpful in determining how much moisture has actually penetrated and how quickly. Tensiometers are best used when soil moisture will be maintained at 50 to 75 percent of field capacity such as in high moisture demand crops like corn or vegetables.