Guangdong Provincial Key Laboratory of Eco-Circular Agriculture, South China Agricultural University, Guangzhou, 510642, China.
College of Natural Resources and Environment, South China Agricultural University, No. 483, Wushan Road, Guangzhou, 510642, People's Republic of China.
Environ Sci Pollut Res Int. 2020 Feb;27(6):6312-6325. doi: 10.1007/s11356-019-07353-7. Epub 2019 Dec 21.
Pot experiment was conducted to evaluate the effect of two types of biochar (2% (w/w)), Pennisetum sinese Roxb biochar (PB) and coffee grounds biochar (CB), combined with iron fertilizer (1.3 g kg Fe) on the growth, quality, Cd/Pb accumulation in watercress, soil physicochemical properties, soil fertility, soil enzyme activities, and fraction distribution of Cd/Pb in soil. The results showed that the two types of biochar combined with iron fertilizer (BC-Fe) amendments could increase the shoot height, root length, plant biomass, soluble sugar and soluble protein of watercress, soil pH value, soil organic matter (SOM), ammonium nitrogen (NH-N), available phosphorus, and available potassium. CB-Fe amendment enhanced soil urease, sucrose, and catalase activities, while PB-Fe amendment only enhanced soil urease activity among the three enzymes. The two BC-Fe amendments decreased exchangeable-Cd/Pb and reducible-Cd/Pb concentrations, while enhanced oxidizable-Cd/Pb and residual-Cd/Pb concentrations. Furthermore, the two BC-Fe amendments decreased significantly Cd and Pb accumulation in watercress root and shoot. The reduction rate for Cd and Pb in shoot by 42.9%, 20.0%, and 68.2%, 58.4% under PB-Fe and by 38.1%, 20%, and 62.5%, 48.8% under CB-Fe, respectively, for the first crop and the second crop. In conclusion, BC-Fe amendment could improve soil physicochemical properties and soil fertility, promote Cd and Pb transfer to the stable form, thus, reduce the bioavailability and mobility of Cd and Pb, and further, decrease Cd and Pb ecotoxicity and its accumulation in watercress and improve watercress quality.
采用盆栽试验研究了两种生物炭（2%（w/w）），即狗尾草生物炭（PB）和咖啡渣生物炭（CB）与铁肥（1.3 g kg Fe）组合对水芹生长、品质、Cd/Pb 积累、土壤理化性质、土壤肥力、土壤酶活性以及土壤 Cd/Pb 形态分布的影响。结果表明，两种生物炭与铁肥（BC-Fe）改良剂均可提高水芹的株高、根长、生物量、可溶性糖和可溶性蛋白，增加土壤 pH 值、土壤有机质（SOM）、铵态氮（NH-N）、有效磷和有效钾。CB-Fe 改良剂提高了土壤脲酶、蔗糖酶和过氧化氢酶活性，而 PB-Fe 改良剂仅提高了三种酶中的土壤脲酶活性。两种 BC-Fe 改良剂降低了交换态-Cd/Pb 和可还原态-Cd/Pb 浓度，同时提高了氧化态-Cd/Pb 和残渣态-Cd/Pb 浓度。此外，两种 BC-Fe 改良剂显著降低了水芹根和茎叶中 Cd 和 Pb 的积累。第一茬和第二茬水芹茎叶中 Cd 和 Pb 的去除率分别为 PB-Fe 组 42.9%、20.0%和 68.2%、58.4%，CB-Fe 组 38.1%、20%和 62.5%、48.8%。综上所述，BC-Fe 改良剂可改善土壤理化性质和肥力，促进 Cd 和 Pb 向稳定形态转化，从而降低 Cd 和 Pb 的生物可利用性和迁移性，进一步降低 Cd 和 Pb 的生态毒性及其在水芹中的积累，提高水芹品质。
