乙草胺对土壤微生物数量和酶活性的影响

采用室内瓶培养试验,研究了乙草胺施用对土壤微生物数量及酶活性的影响。结果表明:乙草胺施用初期对土壤细菌和放线菌数量有明显刺激作用,但施用30d时高施用量处理(30mg·kg-1)呈明显抑制作用,之后各处理放线菌恢复到对照水平,而对细菌的抑制作用一直持续到60d;乙草胺对土壤真菌数量呈"抑制-恢复-刺激"的作用趋势。乙草胺施用初期对土壤脱氢酶产生一定刺激作用,45d后高施用量处理呈明显抑制作用,一直持续到60d;土壤过氧化氢酶对乙草胺不敏感,而转化酶和脲酶对乙草胺施入初期较敏感;低施用量处理对转化酶有抑制作用,高施用量处理对转化酶有刺激作用,各处理对脲酶都有抑制作用。

Effect of acetochlor application on soil microorganism number and enzymes activities

An indoor inoculation experiment was conducted to determine acetochlor effect on soil microbe and enzyme activity. The results indicate that numbers of bacteria and actinomycete increase two weeks after applying acetochlor, then inhibited by 30 mg·kg^-1 acetochlor at the 30th day. After that, actinomycete number recovers while bacteria number is still inhibited till the 60th days. Fungi number decreases at 14 days after applying acteochlor, but then recovers at the 30th day and is stimulated at the 60th day. Soil dehydrogenase activity is stimulated two weeks after applying acetochlor, then is inhibited by 30 mg·kg^-1 acetochlor from 45 to 60 days after application. Catalase activity is not sensitive to acetochlor, but invertase and urease are sensitive at the early period of application. Invertase activity is inhibited by 0.3 mg·kg^-1 acetochlor, but stimulated by 3 mg·kg^-1 and 30 mg·kg^-1 acetochlor. Urease activity is inhibited by acetochlor in different application amount.