The Factors Influencing the Availability of Cobalt in Soils, Uptake by Herbage and Ruminant Health and Productivity

1. In a series of laboratory experiments involving a total of eighteen soils, the adsorption and desorption characteristics of Co were examined. When the adsorption data from eight soils were applied to various adsorption models, both the Freundlich and Tempkin equations showed good agreement with the observed adsorption pattern. Further, soil pH was identified as the most important factor governing the amount of Co adsorbed and desorbed. For one soil, Co adsorption from a 14.73 ug Co ml -1 solution was complete at pH >8.0, whereas, only negligible amounts of this Co was desorbable. For the same soil at pH