Key Laboratory of Eco-restoration of Regional Contaminated Environment, Ministry of Education, Shenyang University, Shenyang 110044, China.
Key Laboratory of Eco-restoration of Regional Contaminated Environment, Ministry of Education, Shenyang University, Shenyang 110044, China.
J Environ Manage. 2024 Aug;366:121839. doi: 10.1016/j.jenvman.2024.121839. Epub 2024 Jul 15.
With low cost and stable chemical properties, biochar has great potential in environmental pollution control and improving soil quality. Reusing tailings slag to reconstruct soil ecosystems and applying amendments such as biochar to enhance soil quality are significant for restoring waste mine lands. Phosphorus (P) as the restrictive nutrition element for plant growth is easily affected by freeze-thaw cycles (FTCs). However, effective information about FTCs on P dynamics in biochar-amended reconstructed soil is scanty. To further understand the effect of FTCs on P in reclaimed mine soils, three reconstructed soils composed of equal brown soil and tailings slag with the respective application of no amendment, 5% biochar and 5% powder both derived from Gleditsia japonica shells (GS), were prepared to evaluate P fraction changes after FTCs. The results indicated that GS biochar increased soil pH, total organic matter (TOM), and moisture content (MC). GS biomass had a similar impact on TOM and MC but decreased soil pH. The two agricultural amendments increased active P and microbial biomass P (MBP) by 46.13%-101.63% and 162.8%-185.7%, which might be largely contributed by soil organic matter and moisture. FTC numbers (0, 3, 6, 10, 15) significantly decreased MBP contents and slightly converted non-labile P into labile fractions while FTC temperature (-20∼5 °C and -10∼5 °C) hardly influenced soil P behavior. In addition, GS conditioners simultaneously enhanced available P content and P fixation potential by soil under FTCs.
生物炭具有成本低、化学性质稳定等特点，在环境污染控制和改善土壤质量方面具有巨大潜力。利用尾矿渣重建土壤生态系统，并应用生物炭等改良剂来提高土壤质量，对于恢复废弃矿山土地具有重要意义。磷（P）是植物生长的限制营养元素，容易受到冻融循环（FTCs）的影响。然而，关于 FTCs 对生物炭改良重建土壤中 P 动态的有效信息却很少。为了进一步了解 FTCs 对复垦矿区土壤中 P 的影响，制备了由等量棕壤和尾矿渣组成的三种重构土壤，分别不添加、添加 5%生物炭和 5%来源于皂荚（Gleditsia japonica）壳的粉末（GS），以评估 FTCs 后 P 组分的变化。结果表明，GS 生物炭增加了土壤 pH 值、总有机碳（TOM）和水分含量（MC）。GS 生物质对 TOM 和 MC 具有相似的影响，但降低了土壤 pH 值。这两种农业改良剂将活性 P 和微生物生物量 P（MBP）分别提高了 46.13%-101.63%和 162.8%-185.7%，这可能主要归因于土壤有机质和水分的增加。冻融循环次数（0、3、6、10、15）显著降低了 MBP 含量，并将非稳定态 P 少量转化为不稳定态，而 FTC 温度（-20∼5°C 和-10∼5°C）几乎不影响土壤 P 行为。此外，GS 调节剂在 FTC 条件下同时提高了土壤有效 P 含量和固定 P 的潜力。
