Die Bodenkultur - Journal for Land Management, Food and Environment
A. Edelbauer and G. Eder:
Influence of different fertilizing measures in grassland on the selenium content in soil and plants
In a 10-year static performed long-term fertilizing experiment, the effect on the selenium concentration in the different soil layers and in the grassland vegetation was investigated, comparing two treatments receiving increased nutrient supply in the form of sewage sludge or mineral fertilizer, with a control treatment. Selenium enrichment as a result of the fertilizer was most pronounced in the upper soil layers at depths of 0-2.5 and 2.5-5.0 cm. Smaller increases in concentration could also be detected in the depth section from 10 to 20 cm.
A long period of applying no fertilizer also prevents the soil from input of accompanying substances of the fertilizers.
This leads, among other effects, to an analytically detectable decrease of the selenium concentration in the top layer of the turf. However, selenium depletion as a result of omission of fertilization could be detected only in the depth section from 0-2.5 cm.
Based on the analytically determined change in the selenium content of the soil, it may be concluded that selenium quantities transported into the soil are less than 250 g/ha for sewage sludge application and less than 150 g/ha for mineral fertilization, respectively under the experimental conditions described.
With a single exception (1st cut 1990), the vegetation from the non fertilized control contained the highest selenium concentrations.
As demonstrated by the combined amount of selenium taken up over three cuts (Fig. 2), the selenium quantity added with the sewage sludge or mineral fertilizer is relatively poorly available to plants.
Key words: Selenium, grassland, soil, sewage sludge, long-term fertilizing experiment.