URANIUM ACCUMULATION IN SOILS FROM LONG-CONTINUED APPLICATIONS OF SUPER-PHOSPHATE

This paper describes the accumulation of uranium in soils from superphosphate applied annually to arable and grassland soils. Rates of application of superphosphate were equivalent to about 33kg P and 15 gU ha−1 year−1 in three experiments at Rothamsted and to about 37 kg P and 16g U ha −1 year −1 in one experiment in New Zealand. Most of the uranium (about 1300 g U ha −1) applied in superphosphate to the clay loam soil at Rothamsted since 1889 was retained, like P, in the plough layer of arable soils or was adsorbed by the organic surface layers of soils under permanent grassland. Uranium applied in superphosphate to grassland in New Zealand since 1954 (about 330 g U ha−1) was also concentrated in the surface layers of the soil. Copyright © 1979, Wiley Blackwell. All rights reserved