Center of Molecular Ecological Physiology (CMEP), College of Resources and Environment, Southwest University, Chongqing 400715, China.
Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China.
Sci Total Environ. 2022 Jul 15;830:154815. doi: 10.1016/j.scitotenv.2022.154815. Epub 2022 Mar 24.
Karst lime soil, commonly found in rocky desert ecosystems of Southwest China, exhibits high pH, poor water retention, and intense erosion. To prevent further soil erosion and soil losses from these ecosystems, stabilization measures based on improved green infrastructure are needed. The present study aimed at elucidating the performance of sweet tea (Lithocarpus polystachyus) seedlings grown on this soil type upon biochar application. Biochar was classified into different particle sizes, viz. 0.25-0.5 mm (medium), 0.5-1 mm (coarse), 1-2 mm (gravel), and their mixture, and added at the concentrations of 1, 2, or 5% soil mass. The pH, moisture, and porosity of soil increased upon biochar application compared to control; however, soil bulk density significantly decreased. The activity of soil phosphatase was increased by biochar particle size. Biochar particle size and concentration significantly enhanced the soil organic carbon content, but they differently affected total and plant-available nutrients in the soil. Light-saturated photosynthesis was positively affected, while stomatal conductance, leaf transpiration, and the intercellular CO concentrations of sweet tea leaves were negatively affected by biochar particle size and/or concentration compared to control. Leaf chlorophyll and soluble protein contents were increased by biochar application. From these results, we conclude that biochar can improve soil properties and the performance of sweet tea seedlings grown on Karst lime soil. We suggest its application at a concentration of 2% soil mass for keeping a high physiological performance of sweet tea seedlings in this environment. The selection of the ideal particle size is context-specific and depends on the target outcome.
喀斯特石灰土常见于中国西南地区的岩石荒漠生态系统，具有高 pH 值、保水能力差和强烈侵蚀等特点。为了防止这些生态系统进一步遭受土壤侵蚀和土壤流失，需要基于改良的绿色基础设施采取稳定措施。本研究旨在阐明在这种土壤类型上种植甜茶（Lithocarpus polystachyus）幼苗时，生物炭的应用效果。将生物炭分为不同粒径，即 0.25-0.5 毫米（中粒径）、0.5-1 毫米（粗粒径）、1-2 毫米（砾石粒径）及其混合物，并以土壤质量的 1%、2%或 5%的浓度添加。与对照相比，生物炭的应用增加了土壤的 pH 值、水分和孔隙度，但显著降低了土壤容重。土壤磷酸酶的活性随着生物炭粒径的增加而增加。生物炭粒径和浓度显著提高了土壤有机碳含量，但它们对土壤中总养分和植物有效养分的影响不同。与对照相比，生物炭粒径和/或浓度显著提高了甜茶叶片的光饱和光合作用，而降低了气孔导度、叶片蒸腾和胞间 CO2 浓度。生物炭的应用增加了叶片叶绿素和可溶性蛋白的含量。综上所述，生物炭可以改善喀斯特石灰土上甜茶幼苗的生长环境。我们建议将其以 2%土壤质量的浓度应用，以保持甜茶幼苗在这种环境下的高生理性能。理想粒径的选择是具体情况具体分析的，取决于目标结果。
