Abstract: An experiment was carried out to explore dynamics of water suction of corn stalk in alkali treatment and its relationships with conventional physicochemical indexes. The experiment was designed to have six treatments different in alkali concentration in treating corn stalks, i.e. CK (0), 2%, 4%, 6%, 8% and 10%. Results show that all the treatments displayed rising trends in water suction in the first 48 hours, but varied in extent with the concentration of alkali used. Water suction rose from 0.14 kPa to 0.41, 2.30, 2.60, 2.78, 2.94 and 3.21 kPa, respectively, in Treatment CK, 2%, 4%, 6%, 8% and 10%(w) and the time for water suction rising to peak was shortened with alkali concentration, from 40-48 h in CK to 0-3 h in Treatments 8% and 10%. Pearson correlation analysis indicates that the water suction of the corn stalk granules was positively related to concentration of COD, DOC, NH₄⁺-N and NO₃^--N in the alkali solution. And in Treatment 6%, water suction  was extremely significantly related to NH₄⁺-N content. So that, it is quite obvious that both higher alkali concentration and longer time of treatment can increase water suction of corn stalk granules.Further more, the increasing trend of water suction is consistent with changes in COD, DOC, NH₄⁺-N and NO₃^--N concentrations.

Key words: corn stalk, alkali treatment, water suction