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采用室内恒温通气培养法,以北京大棚蔬菜地土壤为研究对象,以未使用熏蒸剂土壤为对照,研究4种熏蒸剂[氯化苦(Pic)、1,3-二氯丙烯(1,3-D)、二甲基二硫(DMDS)和威百亩(MS)]对土壤可溶性氮素和微生物量碳、氮的影响。结果表明,4种熏蒸剂处理均能增加土壤中可溶性有机氮的含量,熏蒸处理后敞气0 d时,Pic、MS、DMDS和1,3-D处理的土壤可溶性有机氮累积量分别为47.55 mg·kg-1、42.15 mg·kg-1、40.34 mg·kg-1和32.02 mg·kg-1,较对照(29.97 mg·kg-1)分别增加58.67%、40.65%、34.61%和6.87%。敞气后14~84 d,Pic、DMDS和MS处理DON含量仍持续上升,1,3-D和对照变化不大,各处理之间DON含量差异显著。4种熏蒸剂处理后短时间内,土壤中可溶性氨基酸(DAA)与对照相比大幅上升,在熏蒸后7 d达到最大值,其中Pic处理的上升幅度最大,为12.87 mg·kg-1,对照DAA含量最低,为5.74 mg·kg-1。4种熏蒸剂处理之后,土壤中微生物量碳和氮均呈现急剧下降的趋势,其中Pic处理对微生物的杀灭作用最强,敞气后0 d,Pic处理的微生物量碳和微生物量氮含量分别比对照下降69.39%和70.95%,MS和DMDS次之,1,3-D的杀灭作用最弱。
The indoor flue-curing culture method was used to study the soils of vegetables in greenhouse in Beijing. The fumigants were used as control. Four kinds of fumigants [Picrochloride (Pic), 1,3-Dichloropropene (1,3 -D), DMDS and MS on soil soluble nitrogen and microbial biomass carbon and nitrogen. The results showed that the four kinds of fumigants could increase the content of soil soluble organic nitrogen. After 0 days of fumigation, the accumulative contents of soil soluble organic nitrogen of Pic, MS, DMDS and 1,3-D were 47.55 mg · kg-1, 42.15 mg · kg-1, 40.34 mg · kg-1 and 32.02 mg · kg-1, increased by 58.67%, 40.65%, 34.61% and 6.87% respectively compared with the control (29.97 mg · kg- . After 14 to 84 days of open air, the contents of DON in Pic, DMDS and MS treatments continued to increase, with little changes in 1,3-D and control, with significant differences in DON content among treatments. In the short time after the four fumigants were treated, the content of soluble amino acids (DAA) in soil increased significantly compared with the control and reached the maximum at 7 d after fumigation, in which the maximum increase of Pic treatment was 12.87 mg · kg -1 The lowest content of DAA was 5.74 mg · kg -1. After treatment with fumigant of 1.4, the soil microbial biomass C and N showed a drastic downward trend. Among them, Pic treatment had the strongest killing effect on microorganisms. After 0 d , Pic treated microbial biomass carbon and microbial biomass nitrogen decreased by 69.39% and 70.95%, respectively, followed by MS and DMDS, with the weakest effect of 1,3-D.