Kloss Stefanie, Zehetner Franz, Buecker Jannis, Oburger Eva, Wenzel Walter W, Enders Akio, Lehmann Johannes, Soja Gerhard
Institute of Soil Research, University of Natural Resources and Life Sciences, Peter-Jordan-Str. 82, 1190, Vienna, Austria.
Environ Sci Pollut Res Int. 2015 Mar;22(6):4513-26. doi: 10.1007/s11356-014-3685-y. Epub 2014 Oct 15.
Various biochar (BC) types have been investigated as soil amendment; however, information on their effects on trace element (TE) biogeochemistry in the soil-water-plant system is still scarce. In the present study, we determined aqua-regia (AR) and water-extractable TEs of four BC types (woodchips (WC), wheat straw (WS), vineyard pruning (VP), pyrolyzed at 525 °C, of which VP was also pyrolyzed at 400 °C) and studied their effects on TE concentrations in leachates and mustard (Sinapis alba L.) tissue in a greenhouse pot experiment. We used an acidic, sandy agricultural soil and a BC application rate of 3% (w/w). Our results show that contents and extractability of TEs in the BCs and effectuated changes of TE biogeochemistry in the soil-water-plant system strongly varied among the different BC types. High AR-digestable Cu was found in VP and high B contents in WC. WS had the highest impact on TEs in leachates showing increased concentrations of As, Cd, Mo, and Se, whereas WC application resulted in enhanced leaching of B. All BC types increased Mo and decreased Cu concentrations in the plant tissue; however, they showed diverging effects on Cu in the leachates with decreased concentrations for WC and WS, but increased concentrations for both VPs. Our results demonstrate that BCs may release TEs into the soil-water-plant system. A BC-induced liming effect in acidic soils may lead to decreased plant uptake of cationic TEs, including Pb and Cd, but may enhance the mobility of anionic TEs like Mo and As. We also found that BCs with high salt contents (e.g., straw-based BCs) may lead to increased mobility of both anionic and cationic TEs in the short term.
已对各种生物炭（BC）类型作为土壤改良剂进行了研究；然而，关于它们对土壤-水-植物系统中微量元素（TE）生物地球化学影响的信息仍然匮乏。在本研究中，我们测定了四种生物炭类型（木屑（WC）、小麦秸秆（WS）、葡萄园修剪枝条（VP），在525℃下热解，其中VP也在400℃下热解）的王水（AR）和水提取态微量元素，并在温室盆栽试验中研究了它们对渗滤液和芥菜（白芥）组织中微量元素浓度的影响。我们使用了一种酸性沙质农业土壤，生物炭施用量为3%（w/w）。我们的结果表明，生物炭中微量元素的含量和可提取性以及土壤-水-植物系统中微量元素生物地球化学的实际变化在不同生物炭类型之间差异很大。在VP中发现了高含量的可被王水消化的铜，在WC中发现了高含量的硼。WS对渗滤液中微量元素的影响最大，表现为砷、镉、钼和硒的浓度增加，而施用WC导致硼的淋溶增加。所有生物炭类型都增加了植物组织中钼的含量并降低了铜的浓度；然而，它们对渗滤液中铜的影响不同，WC和WS使铜浓度降低，而两种VP则使铜浓度增加。我们的结果表明，生物炭可能会将微量元素释放到土壤-水-植物系统中。生物炭在酸性土壤中引起的石灰效应可能导致植物对阳离子微量元素（包括铅和镉）的吸收减少，但可能会增强阴离子微量元素（如钼和砷）的迁移性。我们还发现，高盐含量的生物炭（如秸秆基生物炭）可能会在短期内导致阴离子和阳离子微量元素的迁移性增加。
