Schroll Reiner, Becher Hans Heinrich, Dörfler Ulrike, Gayler Sebastian, Grundmann Sabine, Hartmann Hans Peter, Ruoss Jürgen
GSF-National Research Center for Environment and Health Institute of Soil Ecology, Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany.
Environ Sci Technol. 2006 May 15;40(10):3305-12. doi: 10.1021/es052205j.
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.
开发了一种标准化的定量方法，以可靠地阐明土壤湿度增加对农药矿化的影响。在实验室控制条件下，以1.3 g cm(-3)的相同土壤密度，研究了三种需氧可降解且化学性质不同的14C标记农药（异丙隆、苄草隆乙酯和草甘膦）的矿化情况。所使用的农业土壤具有以下特点：(i) 土壤质地（砂含量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多样；(iii) pH值不同。我们量化了土壤湿度对农药矿化的影响，发现：(i) 在土壤水势≤ -20 MPa时，农药矿化极少发生；(ii) 在土壤湿度增加（土壤水势范围为 -20至 -0.015 MPa）与相对农药矿化增加之间存在线性相关性（P < 0.0001）；(iii) 在土壤水势为 -0.015 MPa时获得最佳农药矿化；(iv) 当土壤湿度接近持水量时，农药矿化显著降低。由于所选农药和土壤都有很大程度的变化，我们认为本研究中观察到的相关性在土壤中其他天然和人工有机化合物的需氧降解情况下可能也有效。
