Bian Rongjun, Li Lianqing, Bao Dandan, Zheng Jinwei, Zhang Xuhui, Zheng Jufeng, Liu Xiaoyu, Cheng Kun, Pan Genxing
Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
Environ Sci Pollut Res Int. 2016 May;23(10):10028-36. doi: 10.1007/s11356-016-6214-3. Epub 2016 Feb 11.
A field experiment was conducted in a Cd-contaminated rice paddy field to evaluate the effect of inorganic and organic metal stabilizers on Cd mobility and rice uptake. A dose of inorganic stabilizer of calcium hydroxide (CH), silicon slag (SS), and wheat straw biochar (BC) was amended respectively to topsoil before rice transplanting. Rice production was managed with the same water regime and fertilization practices consistently between treatments including a control without amendment. Samples of topsoil and rice plant were collected at rice harvest to analyze the Cd mobility and uptake by rice. Without affecting rice grain yield, the stabilizers significantly decreased CaCl2-extractable Cd in a range of 44 to 75 % compared to the control, corresponding to soil pH changes under the different treatments. Accordingly, Cd concentrations both in rice tissue and in rice grain were very significantly decreased under these treatments. The decrease in rice Cd uptake was correlated to the decrease in extractable Cd, which was again correlated to soil pH change under the different treatments, indicating a prevalent role of liming effect by the amendments. While applied at a large amount in a single year, organic stabilizer of BC decreased Cd extractability by up to 43 % and Cd rice uptake by up to 61 %, being the most effective on Cd immobilization. However, the long-term effect on soil health and potential tradeoff effects with different stabilizers deserve further field monitoring studies.
在一块受镉污染的稻田中进行了田间试验，以评估无机和有机金属稳定剂对镉迁移性及水稻吸收的影响。在水稻移栽前，分别向表土中添加一定剂量的无机稳定剂氢氧化钙（CH）、硅灰石（SS）和麦秸生物炭（BC）。各处理间包括不添加任何物质的对照处理，均采用相同的水分管理和施肥措施来种植水稻。在水稻收获时采集表土和水稻植株样本，以分析镉的迁移性及水稻对镉的吸收情况。在不影响水稻籽粒产量的情况下，与对照相比，稳定剂显著降低了氯化钙可提取镉的含量，降幅在44%至75%之间，这与不同处理下土壤pH值的变化相对应。相应地，在这些处理下，水稻组织和籽粒中的镉含量均极显著降低。水稻对镉吸收的减少与可提取镉的减少相关，而可提取镉的减少又与不同处理下土壤pH值的变化相关，这表明改良剂的石灰效应起了主要作用。虽然麦秸生物炭这种有机稳定剂在一年内大量施用时，可使镉的提取率降低高达43%，水稻对镉的吸收降低高达61%，是固定镉最有效的物质。然而，其对土壤健康的长期影响以及与不同稳定剂之间潜在的权衡效应，仍值得进一步开展田间监测研究。
