Gu Wenqi, Wang Yuning, Sun Yuanyuan, Liu Zifan, Wang Wenjia, Wu Di, Zhang Yuxue, Sun Wen, Wang Xin, Feng Zhibo, Zhang Weiming, Chen Wenfu
Biochar Engineering & Technology Research Center of Liaoning Province, Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, Agronomy College, Shenyang Agricultural University, Shenyang 110866, China.
Biochar Engineering & Technology Research Center of Liaoning Province, Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, Agronomy College, Shenyang Agricultural University, Shenyang 110866, China.
Sci Total Environ. 2024 Nov 15;951:175607. doi: 10.1016/j.scitotenv.2024.175607. Epub 2024 Aug 17.
Soil organic carbon (SOC) and iron/aluminum (Fe/Al) oxides are key cementing agents in driving soil aggregate formation, yet their direct effects and interactions on aggregate under long-term rice straw cyclic utilization (LSCU) in cold regions are still unclear. We compared chemical fertilizer (CF) with LSCU strategy: rice-straw (RS), biochar (RB), and biochar-based fertilizer (BF). We showed that the increase of macroaggregate (2-0.25 mm) is associated with SOC, dissolved organic carbon (DOC), humin carbon (HUC), amorphous and organic complexed Fe/Al oxides (Fe, Fe, Al, Al), and in each size of the aggregate, there exists an interaction between SOC (fractions) and Fe/Al oxides. Furthermore, aggregate stability was determined by Fe, Fe, and Al. LSCU enhances macroaggregate and aggregate stability by increasing SOC and Fe/Al oxides in the bulk soil and aggregates, but there are differences among LSCU. In all treatments, RS had more DOC, fulvic acid carbon (FAC), humic acid carbon (HAC) and Fe; while RB had more SOC, HUC, free Fe/Al oxides (Fe, Al), Fe, Al; and BF had more Al in bulk soil. Over the years, RS increased the DOC, FAC and HAC, whereas RB enhanced the stable SOC fractions (HUC) and promoted high reactive Fe/Al oxides formation (Fe, Fe, Al), and BF increased DOC, Fe, Fe and Al. Moreover, RB increases the direct pathway of SOC and Fe/Al oxides to aggregate, promoting aggregate formation. Our study provides new perspective on the mechanisms and promising practice for improving rice straw utilization efficiently, paddy soil fertility and productivity sustainably in cold regions.
土壤有机碳（SOC）和铁/铝（Fe/Al）氧化物是驱动土壤团聚体形成的关键胶结剂，然而在寒冷地区长期稻草循环利用（LSCU）条件下它们对团聚体的直接影响及相互作用仍不明确。我们将化肥（CF）与LSCU策略进行了比较：稻草（RS）、生物炭（RB）和生物炭基肥料（BF）。我们发现大团聚体（2 - 0.25毫米）的增加与SOC、溶解有机碳（DOC）、胡敏素碳（HUC）、无定形和有机络合的Fe/Al氧化物（Fe、Fe、Al、Al）有关，并且在每个团聚体尺寸中，SOC（组分）和Fe/Al氧化物之间存在相互作用。此外，团聚体稳定性由Fe、Fe和Al决定。LSCU通过增加土壤和团聚体中的SOC和Fe/Al氧化物来提高大团聚体和团聚体稳定性，但LSCU之间存在差异。在所有处理中，RS的DOC、富里酸碳（FAC）、胡敏酸碳（HAC）和Fe含量更多；而RB的SOC、HUC、游离Fe/Al氧化物（Fe、Al）、Fe、Al含量更多；BF在土壤中的Al含量更多。多年来，RS增加了DOC、FAC和HAC，而RB提高了稳定的SOC组分（HUC）并促进了高活性Fe/Al氧化物的形成（Fe、Fe、Al），BF增加了DOC、Fe、Fe和Al。此外，RB增加了SOC和Fe/Al氧化物对团聚体的直接作用途径，促进了团聚体形成。我们的研究为寒冷地区高效改善稻草利用、可持续提高稻田土壤肥力和生产力的机制及有前景的实践提供了新视角。
