| Rhizospheric soil available N,enzyme activities and bacteria related to N transformation under drought stress in two genotypes of maize were investigated with a pot experiment.The results showed that except Baidan9 at seedling,rhizospheric NH+4-N of maize was increased under drought stress,and the increment of Baidan31 was higher than Baidan9.The changes of rhizospheric NO-3-N were not evident under drought stress.Rhizospheric protease activity was enhanced at seedling,but decreased at jointing and tasseling-anthesis under drought stress.Changes of rhizospheric urease activity under drought stress were different along with different genotypes and phases.Drought stress weakened the rhizosphere effect of ammonifying bacteria.Under drought stress,rhizospheric ammonifying bacterium amount of Baidan31 was very significantly different at seedling and jointing,and significantly different at tasseling-anthesis from that of control.Rhizospheric nitrifying bacteria tended to increase under drought stress.Drought stress changed the correlation of NH+4-N and NO-3-N with protease,urease activity,ammonifying bacteria and nitrifying bacteria. |