阿特拉津对我国东北半干旱区黑钙土微生物活性影响研究

按照0.5～800 μg·g^-1 soil 施入量添加阿特拉津到黑钙土中培养54 d进行实验室培养试验，研究了阿特拉津对我国东北半干旱区黑钙土微生物量碳、土壤碳及氮矿化量、脲酶和脱氢酶活性影响。结果表明，阿特拉津添加到土壤中后，显著提高了（P〈0.05）土壤微生物量碳，增加了土壤碳及氮矿化量，提高土壤脱氢酶活性；多数情况下，各培养时间添加阿特拉津各处理间土壤脲酶活性的差异未达到显著水平（P〈0.05）。由此得出结论：土壤脱氢酶活性、土壤微生物量碳和土壤碳矿化量及氮矿化量是对阿特拉津处理土壤较敏感的生物学指标，适合作为半干旱区黑钙土微生物活性对阿特拉津响应的参数；而土壤脲酶活性不适合作为半干旱区黑钙土土壤微生物活性的指标，因为它不能敏感地反映阿特拉津作用下土壤脲酶活性差异。

Effect of Atrazine on Chernozem Soil Microbial Activity in Semiarid Region of Northeast China

The objective of the study was to investigate the effects of addition of atrazine to the soil on soil microbial biomass carbon, C and N mineralization in soil, dehydrogenase activity and urease activiy of chernozem soil in semiarid region of northeast China. Atrazine was added to chernozem soil to obtain a range of concentration in the soil from 0.5 to 800μg·g^-1 soil through a soil culture experiment. The soils were incubated at （20/15±2）℃ day/night air temperature （12-h photoperiod ） for 1/3, 1, 3, 9, 27, and 54 days in the growth chamber. The results showed that addition of atrazine to chernozem soil increased significantly soil microbial biomass carbon （P〈0.05）, increased significantly the C and N mineralization in soil（P〈0.05 ）, and enhanced significantly dehydrogenase activity（P〈0.05 ）. In most cases, the differences of urease activiy in soil between atrazine treatments were not significant （P〉0.05） at the different incubation time. It was suggested that atrazine is able to increase soil microbial activity of chernozem soil in semiarid region of northeast China. It was concluded that urease activiy in soil cannot be considered as an index of soil microbial activity while soil microbial biomass carbon, C and N mineralization in soil, and dehydrogenase activity in soil are more sensitive to the microbial activity variation in response to atrazine addition in chernozem soil of semiarid region of northeast China.