Moisture equivalent is proposed by Lyman Briggs and McLane (1910) as a measure of field capacity

Field capacity

Field capacity is the amount of soil moisture or water content held in soil after excess water has drained away and the rate of downward movement has materially decreased, which usually takes place within 2–3 days after a rain or irrigation in pervious soils of uniform structure and texture...

 for fine-textured soil materials.
Moisture equivalent is defined as the percentage of water which a soil can retain in opposition to a centrifugal force 1000 times that of gravity. It is measured by saturating sample of soil 1 cm thick, and subjecting it to a centrifugal force of 1000 times gravity for 30 min. The gravimetric water content after this treatment is its moisture equivalent.
This concept is no longer used in soil physics

Soil physics

Soil physics is the study of soil physical properties and processes. It is applied to management and prediction under natural and managed ecosystems. Soil physics deals with the dynamics of physical soil components and their phases as solids, liquids, and gases. It draws on the principles of...

, replaced by field capacity

Field capacity

Field capacity is the amount of soil moisture or water content held in soil after excess water has drained away and the rate of downward movement has materially decreased, which usually takes place within 2–3 days after a rain or irrigation in pervious soils of uniform structure and texture...

.

Lyman Briggs and Homer LeRoy Shantz (1912) found that:

Moisture Equivalent = 0.02 sand + 0.22 silt + 1.05 clay

See also

• Available water capacity
  Available water capacity
  Available water capacity or available water content is the range of available water that can be stored in soil and be available for growing crops....
  
  
• Field capacity
  Field capacity
  Field capacity is the amount of soil moisture or water content held in soil after excess water has drained away and the rate of downward movement has materially decreased, which usually takes place within 2–3 days after a rain or irrigation in pervious soils of uniform structure and texture...
  
  
• Nonlimiting water range
  Nonlimiting water range
  The Non-limiting water range represents the range of water content in the soil where limitations to plant growth are minimal...
  
  
• Pedotransfer function
  Pedotransfer function
  Pedotransfer function is a term used in soil science literature, which can be defined as predictive functions of certain soil properties from other more available, easily, routinely, or cheaply measured properties...
  
  
• Permanent wilting point
  Permanent wilting point
  Permanent wilting point or wilting point is defined as the minimal point of soil moisture the plant requires not to wilt. If moisture decreases to this or any lower point a plant wilts and can no longer recover its turgidity when placed in a saturated atmosphere for 12 hours...