Effects of Sulfur Dioxide Fumigation in Open-Top Field Chambers on Soil Acidification and Exchangeable Aluminum1
- Edward H. Lee,
- Howard E. Heggestad and
- Jesse H. Bennett2
The effects of sulfur dioxide (SO2) fumigation in open-top field chambers on soil pH and exchangeable Al were evaluated. Soil samples were taken from the surface 0–8 cm in plots where tomato (Lycopersicum esculentum L. ‘Jet Star’) plants were grown. Treatments were: 0, 0.06, 0.12, 0.24, and 0.48 ppm SO2 in non-filtered (NF) air, and 0, 0.12, and 0.48 ppm SO2 in C-filtered (CF) air. The variation in soil pH after 13 weeks of exposure (5 hours/day, 5 days/week) to 0.12 ppm or less SO2 was not statistically significant. However, the highest SO2 dose (0.48 ppm SO2 for 275 hours total exposure) significantly decreased soil pH from 5.84 to 5.05 and from 5.75 to 4.89 in NF and CF chambers, respectively. A high linear correlation was found between SO2 exposure concentration and soil SO4-S levels at the end of the fumigation period (r = 0.95). Exchangeable Al was markedly increased at pH values below 5.5. The highest SO2 exposure dose caused exchangeable Al in the surface soil to be increased more than tenfold from 0.64 to 6.53% of the total cation exchange capacity. Long-term SO2 exposure appears to possess the potential to induce Al phytotoxicity only when the soil pH is reduced to below pH 5.0.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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