| RAU | radioactive uptake |
|---|---|
| RI | radiation intensity; radioactive isotope; radioimmunology; recession index; recombinant inbred [stra... |
| RIHSA | radioactive iodinated human serum albumin |
| RISA | radioactive iodinated serum albumin; radioimmunosorbent assay |
| RIU | radioactive iodine uptake |
| elements, radioactive | Chemical elements which spontaneously transmute into another element with corpuscular or electromagnetic radiation. The natural radioactive elements are all those with an atomic number above 83, and some other elements, such as potassium (atomic number 19) and rubidium (atomic number 7), which are very weakly radioactive. (12 Dec 1998) |
|---|---|
| buried soil | Soil covered by an alluvial, loessal, or other deposit (including manmade). (09 Oct 1997) |
| very poorly drained soil | <ecology> A condition is which water is removed from the soil so slowly that free water remains at or on the surface during most of the growing season. (18 Nov 1997) |
| mineral soil | <ecology> Any soil consisting primarily of mineral (sand, silt and clay) material, rather than organic matter. (12 Jan 1998) |
| poorly drained soil | <ecology> A condition in which water is removed form the soil so slowly that the soil is saturated periodically during the growing season or remains wet for long periods greater than 7 days. (09 Oct 1997) |
| saturated soil | A condition in which all easily drained voids (pores) between soil particles are temporarily or permanently filled with water, significant saturation during the growing season is considered to be usually one week or more. (09 Oct 1997) |
| hydric soil | A soil that is saturated, flooded or ponded long enough during the growing season to develop anaerobic conditions in the upper part. (09 Oct 1997) |
| soil | Unconsolidated material on the earth's surface that supports or is capable of supporting plants out-of-doors. (09 Oct 1997) |
| soil horizon | A distinct layer of soil, more or less parallel with the soil surface, having similar properties such as colour, texture and permeability, the soil profile is subdivided into the following major horizons: A-horizon, characterised by an accumulation of organic material. B-horizon, characterised by relative accumulation of clay iron, organic matter or aluminum. C-horizon, the undisturbed and unaltered parent material. (Some soils have an E-horizon, characterised by leaching of organic and other material.) (09 Oct 1997) |
| soil hue | A characteristic of colour related to one of the main spectral colours (red, yellow, green, blue or purple), or various combinations of these principle colours, one of the three variables of colour, each colour chart in the Munsell Soil Colour Charts (Kollmorgen Corporation 1975) represents a specific hue. (09 Oct 1997) |
| soil matrix | The portion of a given soil having the dominant colour, in most cases, the matrix will be the portion of the soil having more than 50 percent of the same colour. (09 Oct 1997) |
| soil microbiology | The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms. (12 Dec 1998) |
| soil permeability | The ease with which gases, liquids or plant roots penetrate or pass through a layer of soil. (09 Oct 1997) |
| soil phase | A subdivision of a soil series having features (for example, slope, surface texture, thickness and stoniness) that affect the use and management of the soil, but which do not vary sufficiently to differentiate it as a separate series. (09 Oct 1997) |
| soil pore | An area within soil occupied by either air or water, resulting from the arrangement of individual soil particles. (09 Oct 1997) |