Guan'gai paishui xuebao (Mar 2021)
Amending Soil with Biochar Increases Soil Nutrients and Reduce Pb Mobility in Soil Irrigated with Piggery Wastewater
Abstract
【Background】 Piggery wastewater is rich in organic matter and nutrients, and it can be used as a supplementary water source for irrigation. But it also contains various organic and inorganic contaminants, and irrigating with it risks soil and crop contamination. How to make most of the piggery wastewater while in the meantime ameliorating dissemination of its pollutants is thus critical to its safe use and has been studied intensively over the past decade. 【Objective】 The objective of this paper is to study the feasibility and efficacy of using biochar amendment to improve soil nutrients and reducing Pb mobility in soil irrigated with piggery wastewater. 【Method】 The experiment was conducted in rhizobox and used winter wheat as the model plant. It consisted of four treatments with soil amended with biochar at a ratio of 0, 0.5%, 2% and 2.5% respectively; a treatment without fertilization was taken as the control. In each treatment, we measured the change in organic matter, available N, P and K, as well as mobile Pb in the rhizosphere and bulk soils. 【Result】 Biochar amendment improved physical properties of the soil. Compared with the control, amending the soil with 2% and 5% of biochar significantly increased the content of organic matter, available N, P and K, especially in the bulk soil, while in the meantime reducing the mobile Pb by 20.7%~33.3%. It was also found that Pb content in the rhizosphere was higher than that in the bulk soil, indicating that it was root uptake rather than Pb mobility that limited Pd uptake and its translocation in the plant. 【Conclusion】 Biochar amendment of the alkaline soil irrigated with piggery wastewater as studied in this paper can improve physicochemical properties of the soil, and reduced Pb bioavailability thereby ameliorating its root uptake and translocation in winter wheat.
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