FACTORS AFFECTING AVAILABLE MICRONUTRIENT CONCENTRATIONS IN SOILS USING COCA-COLA(R) AS EXTRACTANT

Coca-Cola(R) has been found to be an excellent extractant for micronut rients in soils. Correlations with plant concentrations are comparable or superior to already adopted methods. The determination of availabl e micronutrient concentrations in soils in the Coca-Cola(R) extract pr ovides several advantages: ready to use extraction solution, environme ntally friendly extractant and world-wide distribution. The comparabil ity of results, however, requires a high quality standard of the Coca- Cola(R) product in terms of chemical composition. Extensive research o n samples from all over the world shows that the Coca-Cola(R) product has a very consistent composition in major constituents and thus data for available micronutrients obtained by the method show a goad compar ability. The application of 55 Coca-Cola(R) samples from a total of 18 countries to a sandy podzolic soil yielded coefficients of variation for iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) of 10, 8, 8, and 12%, respectively.