Alkaline humic acid fertiliser amendment (HAFA) can significantly enhance the microstructural stability of soils, as well as alleviate Al toxicity. Thus, the potential effects of HAFA on soil have attracted increased attention. A soil incubation experiment was conducted to evaluate the effects of HAFA. A typical acidic latosol was cultured for 51 days with five fertiliser treatments—unfertilised (CK), 0.32 g of inorganic fertiliser (IF), 0.32 g of inorganic fertiliser combined with 1.00 g lime (IF.CaO), 0.32 g of HAFA (HAFA0.32), and 0.42 g of HAFA (HAFA0.42)—to investigate the effects of HAFA on the microstructural stability and Al toxicity of soils. The results indicate that HAFA increased the number of aggregates and their honeycomb structures in latosol, as well as enhanced the adsorption capacity of the aggregates. HAFA not only increased latosol pH by 0.72–0.92, but also reduced the exchangeable acid content by 39.49–43.03% as compared with CK, which was similar to the lime treatment; it also significantly increased the soil organic matter content and the availability of N, P, and K, and improved the cation exchange capacity. However, HAFA decreased the effect of increasing the amount of exchangeable Ca when compared to the lime treatment. Additionally, the total amounts of reactive and exchangeable Al in the HAFA treatments were reduced by 45.84–54.59% and 56.67–67.53%, respectively. Both HAFA and lime applications effectively decreased the concentrations of phytotoxic Al species in latosols when compared to the application of inorganic fertiliser alone, with the HAFA0.42 treatment being more effective than lime application in decreasing the amount of dissolved and exchangeable Al. The HAFA0.42 treatment was also the best amendment for stabilising the microstructure, increasing the nutrient content, and mitigating Al toxicity in the potted acidic latosol.

碱性腐植酸肥料改良剂（HAFA）可以显着增强土壤的微观结构稳定性，并减轻铝的毒性。因此，HAFA对土壤的潜在影响引起了越来越多的关注。进行了土壤孵化实验以评估 HAFA 的影响。一个典型的酸性 latosol 用五个肥料处理培养 51 天——未施肥 (CK)、0.32 g 无机肥料 (IF)、0.32 g 无机肥料结合 1.00 g 石灰 (IF.CaO)、0.32 g HAFA (HAFA0 .32) 和 0.42 g HAFA (HAFA0.42)——研究 HAFA 对土壤微观结构稳定性和铝毒性的影响。结果表明，HAFA增加了latosol中聚集体及其蜂窝结构的数量，并增强了聚集体的吸附能力。与石灰处理相比，HAFA 不仅使 latosol pH 提高了 0.72-0.92，而且使可交换酸含量降低了 39.49-43.03%，这与石灰处理相似；显着提高了土壤有机质含量和氮、磷、钾的有效性，提高了阳离子交换能力。然而，与石灰处理相比，HAFA 降低了增加可交换 Ca 量的效果。此外，HAFA 处理中反应性和可交换性铝的总量分别减少了 45.84-54.59% 和 56.67-67.53%。与单独施用无机肥料和 HAFA0 相比，HAFA 和石灰施用均有效地降低了 latosol 中植物毒性铝物种的浓度。42 处理在减少溶解和可交换铝的量方面比石灰施用更有效。HAFA0.42 处理也是稳定微观结构、增加养分含量和减轻盆栽酸性 Latosol 中铝毒性的最佳修正。