Zhou Qinghua, Zhou Jiayue, Xiong Weiliang, Li Shiwei, Deng Ouping, Xiao Yi, Li Xingyu, Li Bing, Wang Changquan, Gao Xuesong, Bai Genchuan, Liu Jiang, Huang Rong
College of Resources, Sichuan Agricultural University, Chengdu, 611130, China.
College of Resources, Sichuan Agricultural University, Chengdu, 611130, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
J Environ Manage. 2025 Oct;393:127148. doi: 10.1016/j.jenvman.2025.127148. Epub 2025 Sep 9.
While organic manure application effectively increases soil organic carbon (SOC) content, it may elevate greenhouse gas emissions. Crop straw, a widely available agricultural residue, enhances SOC through gradual decomposition. The effect of organic manure combined with crop straw on the organic carbon components of paddy soil is still unclear. Here, we conducted a field experiment to investigate the effects of organic manure alone versus combined application with crop straw on soil organic carbon (SOC) fractions, with a focus on dissolved organic matter (DOM) in paddy soil. The treatments included the following: organic manure replaced 100 % nitrogen fertilizer (LOM), 150 % nitrogen fertilizer (HOM), LOM combined with crop straw (LOMS), HOM combined with crop straw (HOMS), and conventional fertilization (NPK). The study quantified SOC fractions, DOM concentrations and optical properties, and iron/manganese (Fe/Mn) fractions etc., revealing that combined organic manure significantly enhanced microbial biomass carbon (MBC) and dissolved organic carbon (DOC) in topsoil (0-20 cm). Notably, compared to organic manure alone, the combined application of manure and crop straw increased DOM molecular weight in topsoil (0-20 cm) while elevating chromophoric and aromatic DOM content in subsoil (20-40 cm). The combined application of organic manure and crop straw facilitated the transformation of iron Fe/Mn fractions, and Fe/Al oxides cooperated to promote the stability of soil DOM. Additionally, the changes in Fe/Mn oxide morphology appear to exert distinct effects on soil DOM stabilization processes. Furthermore, crop straw incorporation significantly increased plant-derived DOM containing aromatic structures. These findings demonstrate that the combined application of organic manure and crop straw not only enhances DOM content and stability throughout the soil profile, but also mitigates potential environmental risks (especially CO emission) associated with organic manure alone.
虽然施用有机肥能有效提高土壤有机碳（SOC）含量，但可能会增加温室气体排放。作物秸秆是一种广泛存在的农业废弃物，通过逐渐分解可提高土壤有机碳含量。有机肥与作物秸秆配施对稻田土壤有机碳组分的影响尚不清楚。在此，我们进行了一项田间试验，研究单独施用有机肥与有机肥和作物秸秆配施对土壤有机碳（SOC）组分的影响，重点关注稻田土壤中的溶解有机质（DOM）。处理包括：有机肥替代100%氮肥（低量有机肥，LOM）、150%氮肥（高量有机肥，HOM）、低量有机肥与作物秸秆配施（LOMS）、高量有机肥与作物秸秆配施（HOMS）以及常规施肥（NPK）。该研究对土壤有机碳组分、溶解有机质浓度和光学性质以及铁/锰（Fe/Mn）组分等进行了量化，结果表明，有机肥配施显著提高了表层土壤（0 - 20厘米）中的微生物量碳（MBC）和溶解有机碳（DOC）。值得注意的是，与单独施用有机肥相比，有机肥与作物秸秆配施增加了表层土壤（0 - 20厘米）中溶解有机质的分子量，同时提高了亚表层土壤（20 - 40厘米）中发色和芳香性溶解有机质的含量。有机肥与作物秸秆配施促进了铁的Fe/Mn组分转化，且Fe/Al氧化物协同促进了土壤溶解有机质的稳定性。此外，Fe/Mn氧化物形态的变化似乎对土壤溶解有机质的稳定过程产生了不同影响。此外，添加作物秸秆显著增加了含有芳香结构的植物源溶解有机质。这些研究结果表明，有机肥与作物秸秆配施不仅提高了整个土壤剖面中溶解有机质的含量和稳定性，还降低了单独施用有机肥带来的潜在环境风险（尤其是CO排放）。
