Quantifying the effect of soil moisture on the aerobic microbial mineralization of selected pesticides in different soils.
Quantifying the effect of soil moisture on the aerobic microbial mineralization of selected pesticides in different soils.
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DOI：
10.1021/es052205j
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发表时间：
2006-04
影响因子：
11.4
通讯作者：
R. Schroll;H. Becher;U. Dörfler;S. Gayler;S. Grundmann;H. Hartmann;Jürgen Ruoss
中科院分区：
文献类型：
--
作者：
R. Schroll;H. Becher;U. Dörfler;S. Gayler;S. Grundmann;H. Hartmann;Jürgen Ruoss
一个标准化的定量方法来可靠地阐明增加土壤水分对农药矿化的影响。在实验室控制条件下，在相同的土壤密度为1.3 g cm（-3）下，研究了三种可好氧降解且化学性质不同的14 C标记农药（异丙隆、草除灵和草甘膦）的矿化作用。所用农业土壤的特点是：（i）土壤质地（含砂量4-88%）和有机质含量（有机碳0.97-2.70%）变化很大，（ii）土壤-水分保持曲线相当不同，（iii）pH值不同。定量研究了土壤水分对农药矿化的影响，结果表明：（1）在土壤水势≤-20 MPa时，农药矿化最小;（2）土壤水分与农药矿化呈线性相关;（P < 0.0001）土壤含水量的增加（在-20 ~-0.015MPa的土壤水势范围内），增加了农药的相对矿化量;当土壤含水量接近土壤持水量时，农药的矿化作用显著降低。由于所选农药和土壤在很大程度上不同，我们建议，在这项研究中观察到的相关性也可能是有效的，在土壤中的其他本地和人工有机化合物的好氧降解的情况下。
A standardized quantitative approach was developed to reliably elucidate the effect of increasing soil moisture on pesticide mineralization. The mineralization of three aerobically degradable and chemically different 14C-labeled pesticides (isoproturon, benazolin-ethyl, and glyphosate) was studied under controlled conditions in the laboratory at an identical soil density of 1.3 g cm(-3). The agricultural soils used are characterized by (i) large variations in soil texture (sand content 4-88%) and organic matter content (0.97-2.70% org. C), (ii) fairly diverse soil-water retention curves, and (iii) differing pH values. We quantified the effect of soil moisture on mineralization of pesticides and found that (i) at soil water potential < or = -20 MPa minimal pesticide mineralization occurred; (ii) a linear correlation (P < 0.0001) exists between increasing soil moisture (within a soil water potential range of -20 and -0.015 MPa), and increased relative pesticide mineralization; (iii) optimum pesticide mineralization was obtained at a soil water potential of -0.015 MPa, and (iv) when soil moisture approximated water holding capacity, pesticide mineralization was considerably reduced. As both selected pesticides and soils varied to a large degree, we propose that the correlation observed in this study may be also valid in the case of aerobic degradation of other native and artificial organic compounds in soils.