August 1996
| % of field capacity | Adequacy of soil moisture for plant growth | Loamy sand, sandy loam | Silt loam, loam | Silty clay loam |
|---|---|---|---|---|
| 100 plus | Saturated soil- too much moisture and too little air in the soil; can damage plants if this condition persists | Free water appears on soil when squeezed | Same as sandy loam | sandy loam |
| 100 | Excess moisture has drained into subsoil after rainfall or irrigation and optimum amounts are available in root zone for plant growth | When squeezed, no free water appears on the surface,
but it leaves a wet outlineon your hand Forms weak ball; usually breaks when bounced in hand, will not stick | Same as sandy loam
Forms a very pliable ball; sticks readily | Same as
sandy loam Ribbons out (can be formed into a thin strand when rolled between thumb & forefinger), has a slick feeling |
| 75 | Adequate moisture for plant growth / Marginal moisture for plant growth; time to irrigate | Tends to ball under pressure, but breaks easily when bounced in hand | Forms a ball, somewhat plastic, sticks slightly with pressure | Forms a ball, ribbons out between thumb and forefinger, has a slick feeling |
| 50 | Inadequate moisture for plant growth pressure | Appears to dry; will not form a ball with pressure | Somewhat crumbly, but holds together | Somewhat pliable, balls under pressure |
| 25 | Moisture in soil is unavailable for plant growth | Dry, loose, falls through fingers | Powdery, sometimes crusty, but easily broken down into a powdery condition | Hard, cracked, difficult to break down to powdery condition |
NOTE: Soil sample used was at 4 to 6 inches depth. Adapted with permission from: Craig, C.L. 1976. Strawberry Culture in Eastern Canada. Agric. Canada Publication 1585:19.
(Originally published as "A Guide for Estimating Moisture Content of Soil" in The Virginia Gardener Newsletter, Volume 11, Number 3.)