| 摘要: |
| 盐碱土是重要的耕地后备资源，盐碱土的开发利用对于保障国家粮食安全意义重大。我国盐碱土面积大、分布广、类型复杂，而利用生物炭和腐殖酸改良盐碱土具有较大的潜力。文章通过综合分析国内外生物炭与腐殖酸在改良盐碱土-植物方面的应用，发现生物炭不仅能改善盐碱土壤结构和水力特性、增强土壤团聚体稳定性、降低土壤pH和钠吸附比，还能提高肥料养分利用率；腐殖酸能够改变土壤离子组成，促进土壤团聚体形成，同时也可提高土壤酶活性和养分循环利用效率。两者联合施用在改良土壤时存在协同效应，生物炭的多孔性和吸附性可以为腐殖酸提供稳定的环境，防止腐殖酸的流失；腐殖酸在生物炭表面创造局部的酸性环境，表面反应可增加其在土壤中的溶解度，有利于生物炭的养分释放，缓解逆境胁迫对种子萌发及盐分离子对植物组织细胞的毒害，从而达到改良盐碱土的目的。 |
| 关键词: 盐碱土 生物炭 腐殖酸 土壤改良 协同效应 |
| DOI：10.7515/JEE2024017 |
| CSTR：32259.14.JEE2024017 |
| 分类号: |
| 基金项目:国家重点研发计划项目（2023YFD1901503）；新疆维吾尔自治区天山英才项目（20210045） |
| 英文基金项目: |
|
| Research progress of biochar and humic acid on saline alkali soil improvement: a review |
|
MAO Tingting，SHENG Jiandong，CHENG Junhui，WANG Yaofeng
|
|
College of Resources and Environment, Xinjiang Agricultural University, Urumqi 830052 , China
|
| Abstract: |
| Background, aim, and scope Soil salinization is one of the most severe environmental challenges globally, significantly constraining the efficient utilization of agricultural land and contributing to persistently low crop productivity. Saline-alkali soils are extensively distributed across arid and semi-arid regions, as well as coastal zones, on all continents. Excessive salt accumulation adversely alters the physical and chemical properties of soil, degrading soil structure, impairing water and air permeability, and diminishing the soil's capacity to supply water and nutrients. These changes deteriorate the crop growth environment, severely affecting seed germination, plant establishment, and development, ultimately leading to reduced agricultural yields. Consequently, there is an urgent need to develop highly effective, economical, and environmentally sustainable soil conditioners designed to alleviate salinity stress, enhance crop productivity, and restore the ecological functions of saline-alkali lands. This article provides a systematic review of research progress on the application of biochar and humic acid in the amelioration of saline-alkali soils and the regulation of plant growth under salt stress. This review aims to establish a scientific basis for enhancing the productivity of saline-alkali lands. Materials and methods It begins by outlining the global distribution, formation mechanisms, and conventional remediation strategies for saline-alkali soils. Subsequently, it describes the fundamental physicochemical properties of biochar and humic acid, compares their individual and combined effects on soil improvement, and focuses on elucidating their synergistic mechanisms and comprehensive impacts on soil properties and crop performance. Results A systematic evaluation of domestic and international studies on the application of biochar and humic acid in saline-alkali soil remediation reveals that the use of either amendment alone can improve soil structure and hydraulic properties, enhance aggregate stability, and promote desalination and dealkalization processes. Both amendments also increase soil enzyme activity and nutrient cycling efficiency. Notably, the combined application of biochar and humic acid demonstrates significant synergistic effects: the porous structure and high adsorption capacity of biochar provide a stable matrix for humic acid, reducing its leaching loss; in turn, humic acid forms localized acidic microenvironments on biochar surfaces, enhancing its solubility and facilitating nutrient release. This synergistic interaction alleviates salt stress during seed germination and mitigates the toxic effects of salt ions on plant tissues, thereby effectively improving the quality of saline-alkali soils. Discussion Despite the considerable potential of biochar and humic acid for soil improvement, several limitations persist. First, commercially produced biochar often contains elevated levels of alkali metals and soluble salts; long-term or high-rate application may exacerbate soil salinization, raising concerns regarding its predictability and scientific applicability across different types of saline-alkali soils. Second, humic acid exhibits limited stability and is susceptible to microbial degradation; excessive application may lead to the formation of hydrogels that reduce soil hydraulic conductivity and impede salt leaching, potentially worsening salinization. Third, while the combined use of biochar and humic acid offers complementary benefits and enhanced remediation efficacy— accelerating soil recovery and representing a more promising sustainable improvement strategy— the optimal application rates, ratios, and operational protocols remain to be established. Systematic evaluations are therefore required to determine the practical viability of this composite remediation approach for large-scale restoration of saline-alkali lands. Conclusions The combined application of biochar and humic acid effectively improves soil structure, reduces soluble salt content, enhances nutrient availability and microbial abundance, mitigates salt-induced inhibition of seed germination and plant growth, and ultimately increases agricultural productivity in saline-alkali soils. Recommendations and perspectives The ameliorative effects of biochar and humic acid depend not only on their intrinsic properties but also on external factors such as soil texture, climatic conditions, and irrigation water quality. Current research on their mechanisms of action and ecological effects requires strengthened fundamental investigations to explore the applicability of biochar and humic acid across different climatic zones and soil types. Such efforts will enable the precise optimization of their application efficiency within targeted soil improvement strategies. |
| Key words: saline-alkali soil biochar humic acids soil amendments synergistic effect |
