POSSIBLE TRACE-METAL LOAD FROM FERTILIZERS

The annual load of various trace elements (As, Cd, Co, Cr, Ni, Pb) der iving from the application of mineral fertilizers to arable soils, has been calculated. As a data base, averaged trace element contents of f ertilizers, sampled due to state control of fertilizers within the per iod 1986-94, as well as the amount of mineral fertilizers sold in Aust ria in the cropping season 1992/93, are compiled, The phosphate compon ent supplies significantly higher trace element loads than the nitroge n components. The well-known correlation between nominal phosphorus co ntents and cadmium contents found, is reconfirmed. In comparison with the application of sewage sludge, the input of lead and nickel from mi neral fertilizers into arable soils is significantly lower. Approximat ely 80 % of total chromium from mineral fertilizers emanates from basi c slag and basic slag potash. Regional differences in application rate s and crops lead to differences in trace element loads per farmed area up to 6-fold. Further on, inputs from fertilizers have been compared with input by atmospheric deposition, based on data from 1989/90. On t he whole, as a source of lead and cadmium, long-range transport via th e atmosphere supersedes the input from mineral fertilizers, whereas in case of chromium, it is reverse.