Adsorption, Phytotoxicity, and Leaching of Bromacil in Some Israeli Soils1
- Y. Angemar2,
- M. Rebhun3 and
- M. Horowitz2
Four Isreali soils (Hula, Newe Ya'ar, Sa'ad, and Sharon) were studied in an attempt to identify factors affecting the behavior of bromacil (5-Bromo-3-sec-butyl-6-methyluracil) in a soil environment. Adsorption studies were performed by batch slurry experiments. Freundlich adsorption constants for two varieties of Hula soil and for Newe Ya'ar and Sa'ad soils were: 19.80, 5.05, 1.12, and 0.6, respectively. Experiments with oxidized Hula and oxidized Newe Ya'ar soils gave adsorption constants of 1.70 and 0.60.
Bromacil phytotoxicity was studied by bioassay with black mustard (Brassica nigra L.). Phytotoxicity was expressed by ED50 values (the dose that reduces test plants' fresh weight by 50%), which were 0.4, 0.08, 0.06, and < 0.01 mg/kg soil for Hula, Newe Ya'ar, Sa'ad, and Sharon soils, respectively.
Soil thick layer chromatography was used to determine bromacil leachability in the various soils. Ease of leachability in the four soils was in the decreasing order: Sharon > Sa'ad > Newe Ya'ar > Hula. The experiments showed that the soil organic matter content governed bromacil adsorption, phytotoxicity, and leachability in the various soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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