School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan, 750021, China.
School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan, 750021, China; Engineering Technology Research Center of Water-Saving and Water Resource Regulation in Ningxia, Yinchuan, 750021, China.
J Environ Manage. 2024 Aug;366:121653. doi: 10.1016/j.jenvman.2024.121653. Epub 2024 Jul 5.
Biochar has been recognized as a promising practice for ameliorating degraded soils, yet the consensus on its effects remains largely unknown due to the variability among biochar, soil and plant. This study therefore presents a meta-analysis synthesizing 92 publications containing 987 paired data to scrutinize biochar effects on salt-affected soil properties and plant productivity. Additionally, a random meta-forest approach was employed to identify the key factors of biochar on salt-affected soil and plant productivity. Results showed that biochar led to significant reductions in electrical conductivity (EC), bulk density (BD) and pH by 7.4%, 4.7% and 1.2% compared to the unamended soil, respectively. Soil organic carbon (by 55.1%) and total nitrogen (by 31.3%) increased significantly with biochar addition. Moreover, biochar overall enhanced plant productivity by 31.5%, and more pronounced increases in forage/medicinal with higher salt tolerance than others. The results also identified that the soil salinity and biochar application rate were the most important co-regulators for EC and PP changes. The structural equation model further showed that soil salinity (P < 0.001), biochar pH (P < 0.001) and biochar specific surface area (P < 0.01) had a significant negative effect on soil EC, but it was positively impacted by biochar pyrolysis temperature (P < 0.05). Furthermore, plant productivity was positively affected by biochar pH (P < 0.001) and biochar feedstock (P < 0.01), while negatively influenced by biochar pyrolysis temperature (P < 0.01). This study highlights that woody biochar with 7.6 < pH < 9.0 and pyrolyzed at 400-600 °C under 30-70 t ha application rate in moderately saline coarse soils is a recommendable pattern to enhance forage/medicinal productivity while reducing soil salinity. In conclusion, biochar offers promising avenues for ameliorating degradable soils, but it is imperative to explore largescale applications and field performance across different biochar, soil, and plant types.
生物炭已被认为是改善退化土壤的一种很有前途的做法，但由于生物炭、土壤和植物之间的变异性，其效果的共识在很大程度上仍然未知。因此，本研究通过综合 92 篇包含 987 对数据的文献进行荟萃分析，来审视生物炭对盐渍土壤性质和植物生产力的影响。此外，还采用随机元森林方法来确定生物炭对盐渍土壤和植物生产力的关键因素。结果表明，与未施肥土壤相比，生物炭分别使电导率（EC）、容重（BD）和 pH 值显著降低了 7.4%、4.7%和 1.2%。土壤有机碳（增加 55.1%）和总氮（增加 31.3%）随着生物炭的添加而显著增加。此外，生物炭总体上提高了 31.5%的植物生产力，并且对盐度容忍度较高的饲料/药用植物的增产效果更为明显。结果还表明，土壤盐度和生物炭施用量是 EC 和 PP 变化的最重要共同调节因子。结构方程模型进一步表明，土壤盐度（P<0.001）、生物炭 pH 值（P<0.001）和生物炭比表面积（P<0.01）对土壤 EC 有显著的负影响，但受生物炭热解温度（P<0.05）的正影响。此外，植物生产力受生物炭 pH 值（P<0.001）和生物炭原料（P<0.01）的正向影响，受生物炭热解温度（P<0.01）的负向影响。本研究强调，在中度盐渍粗土中，pH 值为 7.6<pH<9.0、热解温度为 400-600°C、施用量为 30-70t·ha 的木质生物炭是一种推荐的模式，可以提高饲料/药用植物的生产力，同时降低土壤盐度。总之，生物炭为改善退化土壤提供了有前途的途径，但必须探索在不同生物炭、土壤和植物类型中进行大规模应用和田间性能。
