Summary The affect of applying lime and gypsum on element leashing in
red soil derived from
Quaternary red clay was studied
with soil columns repacked in laboratory. results showed that lime application decreased the
leaching from the short columns (0-10cm layer) of cations exclude Ca2+, but increased the leaching of SO~2-_4 and HCO-3. Supplying gypsum increased the leaching. from topsoil column of all cations, especially of Al3+, but has no effect on the leashing of HCO~-_3. Ca2+ leashed mainly in the form of free ion, and the Percentage of SO2-_4 bound Ca2+ rose when adding gypsum. For the leaching of A13+ from the long colunm (0- 30cm layer), it was mainly in the form of free ion. For the leaching of A13+ from the topsoil column, it was mainly in the form of OH- bound A13+ in lime treared soil; however, the main form was SP2-_4 bound Al in the early stage and free ion in the later stage in gypsum treated soil. Besides that the Percentage of OH- bound A13+ enhanced in the topsoil solution in all lime-addition soils, that of So:- bound A13+ increased in all subsoil solution and in topsoil solution in gypsum treated soils.