What is soil moisture


05 Jul 2018
Soil moisture and its availability to support plant growth is a primary factor in crop yield. Too little moisture can result in yield loss and plant death. Too much causes root disease and wasted water.
Just as important, water is a delivery mechanism for any nutrients that are not tightly bound to the soil. Whether these nutrients are delivered to the field through the irrigation system or through other means, movement of water within the soil governs how they are delivered to the plant roots.
Good water management is important within itself, but good water management also means good nutrient management.
Precise control of water content in the root zone environment, affects nutrient content,  and leads to healthier crops and higher yields.

Key Concepts for Soil Moisture Monitoring

  • Soil holds water in a soil mixture by action of surface tension attracting water molecules to soil particles
  • Soil type is a primary factor that controls the amount and availability of water stored in soil.
  • Tension is a measure of the amount of water held in a soil expressed as the amount of suction required (for plants) to remove water from the soil
  • Volumetric Water Content (VWC) is a measure of the amount of water held in a soil expressed as a percentage of the total mixture
  • Field Capacity(FC) is a soil water content that results in a state of balance between gravity force and surface tension force. At Field Capacity soil has a balance of air and water that results in good growing conditions.

For more information about soil moisture, see The Ultimate Guide to Soil Moisture,