Sustainable Soil Management
Glossary
T
TAXONOMY. The science of classification of soils; laws and principles governing the classifying of soil. Also, a specific soil classification system developed by the U.S. Department of Agriculture.
TENSIOMETER. A device for measuring the negative pressure (or tension) of water in soil in situ; a porous, permeable ceramic cup connected through a tube to a manometer or vacuum gauge.
TILLAGE EROSION. The downslope displacement of soil through the action of tillage operations.
TILLAGE PAN. Also known as a plow pan; a subsurface layer of soil that has a higher bulk density than the layer either above or below it. The compaction is caused by tillage operations.
TILTH. Physical condition of the soil in terms of how easily it can be tilled, how good a seedbed can be made, and how easily seedling shoots and roots can penetrate.
TOPDRESS. To surface broadcast nutrients, pesticides, or soil amendments on the soil surface after crop emergence.
TOTAL NITROGEN. The sum of the organic and inorganic forms of nitrogen in a sample.
TOXICITY LEVEL. A quantity of a material in plants, soil, or water that can harm or impair the physiological function of plants or soil.
TRIPLE PHOSPHATE. A product that has a guaranteed analysis between 40 and 50 percent available phosphoric acid. The most common analysis is 0-46-0.
TROPHIC LEVEL. Levels in a food chain that pass nutrients and energy from one group of organisms to another.
