Soil and Water Research - In Press
Commercial organic amendments as drivers of soil nutrient enhancement: insights from a Laboratory-Scale StudyOriginal Paper
Calabrese Angelantonio, Mariavirginia Campanale, Giovanni Berardi, Fabiola Turchese Liuzzi, Laura Mandrelli, Antonio Monteforte, Adriano Sofo
The growing imperative for sustainable soil management and organic waste valorisation has intensified research into composted soil amendments as viable alternatives to synthetic fertilizers. However, while the agronomic benefits of organic compost are well recognized, the influence of its physical form and application moisture on long-term soil chemical dynamics remains surprisingly unexplored. Addressing this critical knowledge gap, the present study offers a systematic evaluation of how bio-compost derived from organic waste affects agricultural soil properties over time. Through a one-year laboratory-scale experiment using nine replicates, we investigated the interactions between increasing compost application rates (tested at soil-to-compost ratios of 1:1, 1:2, and 1:4), physical formulations (powdered versus granular), and moisture conditions (with and without water addition). Chemical analyses reveal a clear advantage of physical physical formulation: powdered bio-compost significantly outperformed its granular counterpart in improving overall soil quality. Specifically, powdered formulations drove a sustained accumulation of organic matter alongside steady increases in total nitrogen and total phosphorus relative to the untreated control. Crucially, this formulation also provided an effective barrier against environmental loss, markedly suppressing nutrient leaching and reducing total nitrogen concentration in the leachate. Furthermore, dry application conditions often prompted stronger overall soil responses. By demonstrating that physical processing and moisture regimes can be optimized to simultaneously enhance long-term fertility and prevent nutrient runoff, these findings provide a solid empirical basis for integrating tailored organic amendments into circular, bio-based agricultural systems.
Methodological approaches in the development of a quantified Czech soil classification systemOriginal Paper
Tereza Zádorová, Anna Margoldová, Aleš Kučera, Miloš Boček, Jiří Jandák, Pavel Šamonil, Dušan Vavříček, Vítězslav Vlček, Anna Žigová, Daniel Žížala, Petr Zapletal, Jan Skála, Tomáš Hrdlička, Aleš Vaněk, Vít Penížek
Approaches to soil classification have evolved in recent years, driven by a growing need for quantitative, accurate data and detailed soil maps, as well as changes in general understanding of soils and their functions. This study presents methods for innovating the existing Czech soil classification system through various analyses of an extensive database of legacy data from different soil surveys, with the aim of clarifying and refining soil diagnostics and increasing the usability of soil classification in diverse applications. The approaches included establishing precise quantitative limits for diagnostic criteria based on statistical analysis of the dataset, compiling and testing the key to soil types, and evaluating the consistency and taxonomic relationships of the resulting soil units using taxonomic distance analyses. The results demonstrated the importance of legacy data as a basis for quantifying diagnostic criteria, as they allow the setting of thresholds that correspond to actual land cover. Exact limits and the organization of soil groups into a classification key led to redistribution of studied profiles between units, often in favorfavour of less developed soil types (kambizem, regozem). However, the newly proposed and actual soil units are taxonomically very close; thus, despite the change in the approach to classification, continuity between the two systems has been maintained.
Effects of Biochar‑Based Composite Amendments on Nitrogen Migration and Enzymatic Activities in High‑Nitrogen SoilsOriginal Paper
Wenyin Zi, Yu Chen, Fangjing Wang, Yunxue Li, Yan Zou, Jing Shi
High nitrogen leaching from farmlands with excessive residual nitrogen in the Erhai Lake Basin, combined with a lack of effective in situ retention measures, threatens aquatic ecological security. Hence, efficient and regionally adaptable soil amendments are urgently needed. A pot experiment was conducted with cabbage grown in high-nitrogen soil from the western shore of Erhai Lake to evaluate biochar-based composite amendments. The composites consisted of biochar (corn straw, rice husk, or bamboo), bentonite, and humic acid at three ratios (1:1:1, 2:1:1, 3:1:1) and were applied at 2.5% and 5.0% (w/w). The optimal treatment was 5.0% corn straw biochar composite at a 3:1:1 ratio (coded CSB6). Compared to the unamended control, CSB6 significantly increased soil total N, NO₃⁻-N, and NH₄⁺-N by 79.19%, 167.44%, and 200.73%, and reduced leachate total N, NO₃⁻-N, and NH₄⁺-N by 48.8%, 44.9%, and 67.95%, respectively. Urease, leucine aminopeptidase, and peroxidase activities were significantly enhanced by 125.63%, 55.70%, and 262.24%. The enhanced N retention and reduced leaching were attributed to synergistic physical adsorption, cation immobilization, and complexation-mediated slow release. This study elucidates the regulatory mechanisms and optimal formulation, providing theoretical and technical support for source control of agricultural non-point N pollution in high-nitrogen farmlands of plateau lake basins.
Effects of Organic Acid Regulation on the Respiration of Reclaimed SoilOriginal Paper
Zhiguo Zhang, Xiaoyu Yin, Yue Wu, Yonghong Zheng, Ge Wang, Ziyang Zhang, Yi Liu
Soil respiration is a critical process in the terrestrial carbon cycle. This study examined the effects of citric acid (CA) addition on CO2 emissions from reclaimed soils at the Pan No. 1 Coal Mine in Huainan, China. A controlled incubation experiment was conducted using an LI-7810 analyser to monitor the CO2 flux. The results revealed that the soil CO2 respiration rate exhibited a concentration-dependent rise-and-fall pattern with increasing CA levels. Within the promoting concentration range, cumulative CO2 emissions followed a logarithmic model (y = aln x + b, R² = 0.951–0.969). CA addition significantly reduced the soil pH (to as low as 6.67 at >20 mmol/L) and increased the contents of alkali-hydrolyzable N, available P and K, and organic matter, with the pH and organic matter being most responsive. The cumulative emissions increased rapidly and then stabilized under varying temperature and moisture conditions, with the highest emissions observed at 25°C and 25% moisture content. Structural equation modelling indicated that temperature and moisture directly drove cumulative CO2 emissions, whereas the CA concentration indirectly influenced emissions by altering the soil organic matter content and pH. These findings reveal the interactive effects of exogenous acids and environmental factors on soil respiration in reclaimed mining areas, providing insights for managing soil carbon dynamics in disturbed ecosystems.