The Responses of Soil Enzyme Activities to Exogenous Substances under 2,4-D Stress

This experiment was carried out through pot culture test with three-factor completely randomized design.The dynamic effect of paclobutrazol and urea on soil urease,alkaline phosphatase and protease activities under 2,4-D stress were studied.The results showed that the influences of 2,4-D on soil urease,alkaline phosphatase,and protease activities were different.Compared with the control,low concentration 2,4-D activated the soil urease and alkaline phosphatase activities,but suppressed protease activity during 1～60 days.High concentration 2,4-D inhibited the soil urease and protease activities,but activated alkaline phosphatase activity.Paclobutrazol and urea had activation effect on soil urease,alkaline phosphatase and protease activities,especially on soil urease and protease activities.The average activation rate was up to 44.88% and 63.18% respectively.