Bo Zhu

Soil acidification threatens soil health and sustainable agriculture, and conventional mitigation strategies have various limitations, underscoring the need for the creation of more effective and sustainable alternatives. In this study, we evaluated the effects of calcium lignosulfonate (CL) on the physicochemical properties of acidic soils (Rs, K₂j, and J₂s) through pot experiments. Additionally, molecular modeling calculations were employed to investigate the interaction mechanisms between CL and soil exchangeable acidity and active enzyme. The results showed that CL was superior to lime in reducing phytotoxic exchangeable Al³⁺, enhancing soil acidification buffering capacity, and improving soil fertility and plant biomass accumulation. These benefits were attributed to the strong competitive adsorption of exchangeable Al³⁺ by the CL surface active functional groups, enhanced interactions between CL and soil enzymes, and the restructuring of microbial communities. These findings provide valuable insights for developing efficient soil amendments to mitigate the effects of acidification, ultimately enhancing soil health and agricultural productivity.

Biochar has been extensively utilized to amend soil and mitigate greenhouse gas (GHG) emissions from croplands. However, the effectiveness of biochar application in reducing cropland GHG emissions remains uncertain due to variations in soil properties and environmental conditions across regions. In this study, the impact of biochar surface functional groups on soil GHG emissions was investigated using molecular model calculation. Machine learning (ML) technology was applied to predict the responses of soil GHG emissions and crop yields under different biochar feedstocks and application rates, aiming to determine the optimum biochar application strategies based on specific soil properties and environmental conditions on a global scale. The findings suggest that the functional groups play an essential role in determining biochar surface activity and the soil’s capacity for adsorbing GHGs. ML was an effective method in predicting the changes in soil GHG emissions and crop yield following biochar application. Moreover, poor-fertility soils exhibited greater changes in GHG emissions compared to fertile soil. Implementing an optimized global strategy for biochar application may result in a substantial reduction of 684.25 Tg year⁻¹ CO₂ equivalent (equivalent to 7.87% of global cropland GHG emissions) while simultaneously improving crop yields. This study improves our understanding of the interaction between biochar surface properties and soil GHG, confirming the potential of global biochar application strategies in mitigating cropland GHG emissions and addressing global climate degradation. Further research efforts are required to optimize such strategies. Graphical Abstract

Excessive nutrient loss from farmland located on the west bank of Erhai Lake has resulted in significant non-point source pollution within the Lake Erhai basin. However, mitigating this issue proves challenging due to the intricate nature of soil properties and environmental factors. Here, during the rainy season in the Lake Erhai basin, we collected and analyzed soil profile samples, 35 topsoil (0–20 cm) samples, and more than 300 field baseflow samples. Our objective was to explore the influences of soil properties, field baseflow, and agricultural management measures on the spatiotemporal migration of nutrients. The results indicated that the concentration of soil organic matter (SOM) has a significant impact on the spatial patterns of nutrient distribution in sandy soil. Consequently, this leads to a substantial reduction in the potential for nutrient loss in the Lake Erhai basin. The vegetable-field baseflow exhibited the highest concentrations of nitrogen and phosphorus when subjected to high fertilization and flood irrigation. The concentrations of TN and TP in baseflow increase by a factor of 2 and 7.7, respectively, during rainfall compared to periods of no rainfall. Optimizing agricultural measures, such as replacing chemical fertilizers with organic fertilizers and modifying irrigation methods to enhance the organic content of sandy soil and minimize baseflow elution, has a beneficial impact on mitigating agricultural non-point source pollution in the Erhai Lake basin. The research results can enable us to have a more systematic understanding of the problem of non-point source pollution in the Erhai River Basin, and provide a theoretical basis for developing targeted agricultural non-point source pollution mitigation plans. Simultaneously, optimizing agricultural management models to strike a balance between agricultural economic development and ecological protection issues holds significant practical significance for managers.