| soil pollutants | Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading. (12 Dec 1998) |
|---|---|
| soil pollutants, radioactive | Pollutants, present in soil, which exhibit radioactivity. (12 Dec 1998) |
| soil pore | An area within soil occupied by either air or water, resulting from the arrangement of individual soil particles. (09 Oct 1997) |
| soil profile | A vertical section of the soil through all its horizons and extending into the parent material. (09 Oct 1997) |
| soil series | A group of soils having horizons similar in differentiating characteristics and arrangements in the soil profile, except for texture of the surface layer. (09 Oct 1997) |
| soil structure | The combination or arrangement of primary soil particles into secondary particles, units or peds. (09 Oct 1997) |
| soil suborder | Second highest taxonomic level of the current U.S. Soil classification system. (09 Oct 1997) |
| soil surface | The upper limits of the soil profile, for mineral soils, the upper limits of the highest mineral horizon (A-horizon), for organic soils, the upper limit of undecomposed organic matter. (09 Oct 1997) |
| soil texture | The relative proportions of the various sizes of particles (silt, sand and clay) in a soil. (09 Oct 1997) |
| soil value | The relative lightness or intensity of colour, approximately a function of the square root of the total amount of light, one of the three variables of colour. (09 Oct 1997) |
| somewhat poorly drained soil | <botany> A condition in which water is removed slowly enough that the soil is wet for significant periods during the growing season. (04 Mar 1998) |
| expansive soil | Soils that swell when they absorb water and shrink as they dry. (09 Oct 1997) |