| 【摘要】 |
采用室内恒温通气培养法, 以北京大棚蔬菜地土壤为对象, 研究熏蒸剂氯化苦(Pic)、碘甲烷(MeI)、
1,3-二氯丙烯(1,3-D)和二甲基二硫(DMDS)对土壤氮素矿化和硝化的影响。结果表明, 4 种熏蒸剂处理后短期内
均能显著增加土壤中氮累积矿化量, 在处理后第0 d, 1,3-D、MeI、DMDS、Pic 处理的氮累积矿化量分别为
320.62 mg·kg−1、317.25 mg·kg−1、287.87 mg·kg−1、278.73 mg·kg−1, 较对照(189.89 mg·kg−1)分别增加68.85%、
67.07%、51.60%、46.78%。4 种熏蒸剂处理后土壤硝化作用过程受到显著抑制, 在药剂熏蒸处理第0 d, 各熏
蒸处理土壤中铵态氮含量均高于对照组, 其中MeI 处理组铵态氮含量最高, 为194.97 mg·kg−1, 对照组铵态
氮含量最低, 为28.82 mg·kg−1。Pic、1,3-D、DMDS、MeI 处理后第0 d 硝化抑制率分别为40.8%、20.8%、
26.9%、24.1%。Pic、1,3-D、MeI 对硝化作用的抑制至少维持两周, DMDS 的抑制作用至少维持1 周。在后期
培养过程中, 各处理矿化作用和硝化作用都逐渐恢复至对照水平。
Soil fumigation has profound effects on N mineralization and nitrification. A quantification of effects on N mineralization and nitrification can be used to optimize N fertilizer application. With laboratory incubation method at constant temperature under aeration condition, the effects of 4 fumigants, Pic, MeI , 1,3-D , and DMDS on soil N mineralization and nitrification in vegetable greenhouse soil in Beijing area were studied. The results presented that the concentration of mineral N was increased significantly within a short-term period after treated with above four fumigants. The cumulative N mineralization treated with 1,3-D、MeI、DMDS、Pic were 320.62 mg • kg-1, 317.25 mg • kg-1, 287.87 mg • kg-1, 278.73 mg • kg-1 respectively, which increased by 68.85%、67.07%、51.60%、47.78% compared with untreated control (189.89 mg • kg-1). Nitrification was strongly inhibited after fumigation in all treatments. The content of ammonium nitrogen was strongly increased after fumigation compared with untreated control, of which the highest content of ammonium nitrogen was MeI treatment (194.97 mg • kg-1), while the lowest was the untreated control (28.82 mg • kg-1). The inhibition rate of nitrification for treatments of Pic, 1,3-D, DMDS, MeI were 40.8%, 20.8%, 26.9%, 24.1% respectively. Nitrification was inhibited at least 2 weeks after treated with Pic, 1,3-D, MeI and at least 1 week treated with DMDS. Nitrification and mineralization were recovered gradually after a long-term incubation. |
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