Sustainable Soil Management
Glossary
U
UPTAKE ANTOGONISM. When the excess of one nutrient interferes with the uptake of another nutrient. Usually, the nutrients in question have a similar uptake mechanism by the plant.
UREA AMMONIUM NITRATE SOLUTION. A non-pressure nitrogen fertilizer solution containing urea and ammonium nitrate in approximately equal proportions dissolved in water. The nitrogen content of the fertilizer solution ranges from 28 percent to 32 percent.
UREA. A nitrogen fertilizer that is a white crystalline solid, is very soluble in water, and has an analysis of 46-0-0.
UTISOLS. An order in Soil Taxonomy. Soils that are low in bases and have subsurface horizons of illuvial clay accumulations. They are usually moist, but during the warm season of the year some are dry part of the time.
