The  adsorption  of  imazapyr  in  three  Indonesian  soil  types  was  investigated  with  labelled 
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C-imazapyr  using  Freundlich  adsorption  isotherm.  The  availability  of  adsorbed  imazapyr  to  plants  as 
affected by washing and liming was assayed using root elongation of rice seedlings. 
Red-Yellow  Podsolic  soil  adsorbed  imazapyr  more  than  Andosol  and  sandy  soil  of  Laladon.  The 
adsorption was greater at lower pH. Washing seemed to reduce the concentration of imazapyr as shown by the 
increasing length of rice roots. On the other hand liming facilitated higher concentrations of imazapyr in the solution 
as shown by the reduction of rice root length. 
The practical implication is discussed.