微生物及环境因子对土壤中乙草胺持效性的影响

Persistence of Acetochlor as Influenced by Soil Microorganism and Environmental Factors

以稗草为生物测定材料,研究了土壤微生物及环境因子对乙草胺持效性的影响。结果显示:在相同温度、湿度和光照条件下,相同浓度的乙草胺在灭菌土壤中的持效期比在非灭菌土壤中的持效期长;在中性偏碱的华北褐土中的持效期比在中性偏酸的东北黑土和湖南红土中的短;在试验湿度和温度范围内,乙草胺在非灭菌土壤中的持效期随土壤湿度或温度的提高而变短。与黑暗处理相比,光照可延长土壤中乙草胺的持效期。对5种试验因子的影响程度进行综合分析可知,土壤微生物是影响乙草胺持效性的主要因素,有益于土壤中微生物生长的环境因素对土壤中乙草胺的持效期有降低作用。可以预测,通过栽培耕作等措施改变环境因子可以起到对农药的持效期进行人为调控的作用。

Effects of microorganism and environmental factors on persistence of acetochlor in soils were studied by bioassay using Echinochloa crusgalli. The results indicated that persistence of acetochlor was much shorter in non-sterilized soil than that in sterilized soil under the same (conditions) of acetochlor concentrations, soil moisture, temperature and light. The period of (persistence) of acetochlor was shorter in alkaline soil such as cinnamon soil collected from North China than that in acidic soil such as terra nera soil collected from Northeast China and terra rossa soil collected from South China. Within the range of soil moisture and temperature tested, the persistence decreased with increasing of soil moisture or temperature. Longer persistence was (observed) in light than that in dark. It was considered that microorganism was a key factor and could (significantly) shorten the persistence of acetochlor in soil, while environmental factors (benefiting) microbe growth could reduce the persistence of acetochlor. It may be possible to (regulate) persistence of acetochlor by controlling cultural measures and improving environmental condition.