[Effect of atrazine on urease activity in soils with different fertility].

Four soils with different fertility were treated with different concentrations of atrazine. The results showed that the urease activity was stimulated in the soils treated with low concentration of atrazine at the first day, while inhibited after treated with high concentration of atrazine during the whole period of the experiment. There was a significant difference in urease activity in soils with different fertility after treated with high concentration atrazine. The urease activity in CK and in NPK was significantly inhibited, the inhibition rate reached 30.35% and 28.89%, respectively, but in NPK + S and NPK + M, the inhibition rate was only 21.35% and 16.86%, respectively. The maximum inhibition rate appeared later in soils with high than with low fertility, showing that soils with high fertility could endure the effect of atrazine.