Effects of Herbicide Bispyribac-sodium on Soil Enzyme Activities and Soil Respiration

Effects of herbicide bispyribac-sodium on soil respiration and the activities of catalase,urease were studied by using simulated experiment in laborotary.The results showed that after application of bispyribac-sodium with concentration of 1.5,15,30,60 and 120 mg/kg dried soil,compared with the control,soil respiration was stimulated at the beginning but reduced slightly at 13d,and after the third week,the soil respiration was strongly depressed by higher concentration.The catalase activity in soil was slightly depressed during the early period and recovered after 21days.The activity of urease was stimulated after application of bispyribac-sodium,and the lower concentration of bispyribac-sodium had more effects and lasted a longer time.Bispyribac-sodium belonged to a low toxicity herbicide.