College of Life Sciences, Henan Normal University, Xinxiang, Henan, 453007, China; Puyang Field Scientific Observation and Research Station for Yellow River Wetland Ecosystem, Henan, China.
College of Resources and Environment Sciences, Henan Institute of Science and Technology, Xinxiang, 453003, China.
J Environ Manage. 2024 Nov;370:123097. doi: 10.1016/j.jenvman.2024.123097. Epub 2024 Oct 28.
Biochar has been shown to enhance soil quality and agricultural yields. Previous studies about biochar's effect on soil properties mainly concentrated on the top 30 cm layer but less on the subsoils. Given the subsoil's active role in climate change mitigation and its significance for nutrient cycling and crop productivity, understanding biochar's effects at depth is crucial. This study explored the responses of soil organic carbon (SOC), total nitrogen, available potassium, available phosphorus, pH, and electrical conductivity to different doses of biochar addition (0, 10, 20, and 30 Mg/ha) over the 1 m depth of alkaline soil. Additionally, the impact of biochar on soil microbial community was assessed in the top 20 cm. Results demonstrated that biochar addition can increase SOC and improve soil properties in deep soil horizons. Specifically, a 30 Mg/ha biochar addition increased SOC by 1.2-10.1 Mg C/ha in the 10-40 cm layer and by 3 Mg C/ha in the 60-80 cm depth over two years. Additionally, biochar addition at this rate increased total nitrogen by 0.2-0.3 g N/kg in the 10-40 cm depth and elevated available potassium across the 1 m profile, with a maximum increment of 313 mg/kg in the surface 10 cm and a minimum of 97 mg/kg in the 40-60 cm depth. While biochar application did not increase available phosphorus, it resulted in a minor decrease in soil pH (<0.7 units) and a slight increase in electrical conductivity. Moreover, biochar addition did not significantly alter the soil microbial community. Our findings underscore the importance of considering subsoils when evaluating biochar's impact on soil properties. We suggest that subsoils should be considered when estimating the potential of cropland management for increasing soil carbon sequestration and improving soil conditions.
生物炭已被证明可以提高土壤质量和农业产量。先前关于生物炭对土壤特性影响的研究主要集中在表层 30cm 土层，但对亚土层的研究较少。鉴于亚土层在减缓气候变化、养分循环和作物生产力方面的积极作用，了解生物炭在深度上的影响至关重要。本研究探讨了不同生物炭添加剂量（0、10、20 和 30 Mg/ha）对碱性土壤 1m 深度范围内土壤有机碳（SOC）、总氮、有效钾、有效磷、pH 值和电导率的响应。此外，还评估了生物炭对表层 20cm 土壤微生物群落的影响。结果表明，生物炭的添加可以增加 SOC，并改善深层土壤特性。具体来说，在两年内，30 Mg/ha 的生物炭添加使 10-40cm 土层中的 SOC 增加了 1.2-10.1 Mg C/ha，在 60-80cm 深度增加了 3 Mg C/ha。此外，以这个速率添加生物炭可使 10-40cm 土层中的总氮增加 0.2-0.3g N/kg，并使整个 1m 剖面的有效钾升高，表层 10cm 的最高增量为 313mg/kg，40-60cm 深度的最低增量为 97mg/kg。虽然生物炭的应用没有增加有效磷，但会导致土壤 pH 值略有降低（<0.7 个单位）和电导率略有升高。此外，生物炭的添加并没有显著改变土壤微生物群落。我们的研究结果强调了在评估生物炭对土壤特性的影响时考虑亚土层的重要性。我们建议在估计农田管理增加土壤碳固存和改善土壤条件的潜力时，应考虑亚土层。
