Glossary of Terms in Soil Science

1/3-bar percentage

The percentage of water contained in a soil that has been saturated subjected to and is in equilibrium with an applied pressure of l/3 bar. Pressure is applied in a ceramic plate apparatus. It is usually expressed as a weight percentage and is approximately the same as l/3-atmosphere percentage. Also for medium- to coarse-textured soils it is approximately numerically equal to moisture equivalent.

15-atmosphere percentage

The percentage of water contained in a soil that has been saturated subjected to and is in equilibrium with an applied pressure of 15 atm. Pressure is applied in a pressure membrane or ceramic pressure plate apparatus. It is usually expressed as a weight percentage but may be expressed as a volume percentage. It is approximately the same as 15-bar percentage.

15-bar percentage

The percentage of water contained in a soil that has been saturated subjected to and is in equilibrium with an applied pressure of 15 bars. Pressure is applied in a pressure membrane or ceramic plate apparatus. It is usually expressed as a weight percentage but may be expressed as a volume percentage. It is approximately the same as 15-atmosphere percentage.

60-centimetre percentage.

The percentage of water contained in a soil that has been saturated, subjected to, and is in equilibrium with an applied pressure or tension equivalent to a column of water 60 cm high. Pressure may be applied in a pressure plate apparatus or as a tension on a tension table. It may be expressed on a weight or volume basis and is considered by many to approximate the ""field capacity"" especially in medium- to coarse-textured soils.