氯嘧磺隆与尿素对土壤微生物生物量碳、氮及无机氮的影响

Effects of chlorimuron-ethyl and urea on soil microbial biomass carbon and nitrogen and soil inorganic nitrogen

通过室内培养试验,研究了不同浓度氯嘧磺隆(20、200、2000μg.kg-1土)单一施用及与尿素(120mg.kg-1土)配合施用情况下,土壤微生物生物量碳、氮和土壤铵态氮、硝态氮随时间的动态变化规律.结果表明:各浓度氯嘧磺隆单独处理在整个培养期(60d)中对微生物生物量碳、氮均有抑制作用,且浓度越高,后期抑制作用越强;各浓度氯嘧磺隆处理在培养前期对硝态氮、铵态氮没有明显影响,中期(15d)能显著提高土壤中铵态氮的含量,后期(30d后)显著提高了土壤中硝态氮的含量.尿素单独施用及与氯嘧磺隆配施均能在短时间内增加微生物生物量碳、氮,但随后配施处理的促进作用减弱;尿素单独和配施均能持久增加土壤中铵态氮、硝态氮含量.

A microcosm experiment was conducted to study the effects of different concentration chlorimuron-ethyl（20,200,and 2000 μg·kg-1 soil） and its combination with urea（120 mg·kg-1 soil） on the dynamic changes of soil microbial biomass carbon and nitrogen and soil nitrate nitrogen and ammonium nitrogen.Applying chlorimuron-ethyl alone decreased the soil microbial biomass carbon and nitrogen throughout the experiment period（60 days）,and the decrement increased with increasing chlorimuron-ethyl concentration.Chlorimuron-ethyl had little effects on the soil ammonium nitrogen and nitrite nitrogen in the early period of the experiment,but increased the soil ammonium nitrogen in the mid-period（15 d） and the soil nitrate nitrogen in the late period（after 30 days） significantly.Both urea addition and its combination with chlorimuron-ethyl increased the soil microbial biomass carbon and nitrogen obviously in a short time,but the effect of combined addition of urea and chlorimuron-ethyl weakened then.Applying urea and its combination with chlorimuron-ethyl resulted in a lasting increase of soil nitrate nitrogen and ammonium nitrogen.