长期不同施肥土壤中残留五氯酚在水稻中的富集特征

Accumulation characteristics of pentachlorophenol residues by rice plant in the long-term fertilization paddy soil.

研究长期不施肥(CK),施无机肥尿素(N),施有机肥(OM)和无机有机肥配施(N+OM)4种处理红壤水稻土中五氯酚(PCP)的消解及其在水稻根、茎和稻谷中的富集特征.结果表明,4个处理土壤中残留态氯代酚显著降低水稻茎和稻谷生物量,但对根生物量的影响未达显著水平.N处理表层土壤中可提取PCP残留量为2.42mg/kg,显著高于CK、OM和N+OM处理,表明长期单施N抑制土壤中PCP的消解.在水稻根中检测到PCP及其脱氯降解产物2,3,4,5-四氯酚(2,3,4,5-TeCP)和3,4,5-三氯酚(3,4,5-TCP).在OM和N+OM处理水稻根中PCP含量显著小于CK和N处理,表明长期单施OM或N+OM均显著减小水稻根对PCP的富集量,而长期单施N对水稻根富集PCP并没有显著影响.在4个处理中的水稻茎和稻谷中只检测到PCP,且在茎和稻谷中PCP含量均没有显著差异,水稻茎和稻谷中PCP浓度均值分别为164.9和75.7ng/g.

Dissipation and accumulation characteristics of pentachlorophenol （PCP） by rice plant in red paddy soil were investigated under four long-term fertilization treatments as follows： no fertilizer （the control, CK）, application of urea （N）, application of organic fertilizer （OM）, and N＋OM. Rice shoot and grain biomass significantly decreased in chlorophenols spiked soil, where as no effect of chlorophenols on the rice root biomass was observed. PCP residues in surface soil in treatment N was 2.42mg/kg, that was significantly higher than those in treatments CK, OM and N＋OM, indicating that long-term application of urea inhibited PCP dissipation. PCP and its two dechlorinated metabolites including 2,3,4,5-TeCP and 3,4,5-TCP were detected in rice root, PCP concentrations in rice root in treatments OM and N＋OM were significantly lower than those in treatments CK and N, showing that long-term application of organic fertilizer or inorganic plus organic fertilizer significantly decreased PCP accumulation in rice root, and long-term application of urea did not effect PCP accumulation in rice root. Only PCP was detected in rice shoot and grain in four treatments, and no difference in PCP concentrations in shoot or in grain was observed among four treatments, PCP mean concentrations in rice shoot and root were 164.9ng/g and 75.7ng/g, respectively.