View in EDS

Co-utilization of green manure with straw return enhances the stability of soil organic carbon by regulating iron-mediated stabilization of aggregate-associated organic carbon in paddy soil.

Saved in:

Bibliographic Details
Title:	Co-utilization of green manure with straw return enhances the stability of soil organic carbon by regulating iron-mediated stabilization of aggregate-associated organic carbon in paddy soil.
Authors:	Mehran, Muhammad¹ (AUTHOR), Huang, Li¹ (AUTHOR) daisyh@mail.hzau.edu.cn, Geng, Mingjian¹ (AUTHOR), Gan, Yafen¹ (AUTHOR), Cheng, Jinyun¹ (AUTHOR), Zhu, Qiang¹ (AUTHOR), Ahmad, Iftikhar Ali¹ (AUTHOR), Haider, Sharjeel¹ (AUTHOR), Mustafa, Adnan² (AUTHOR)
Source:	Soil & Tillage Research. Oct2025, Vol. 252, pN.PAG-N.PAG. 1p.
Subjects:	Soil management, Astragalus (Plants), Soil stabilization, Soil structure, Carbon in soils
Abstract:	Despite increasing interest in sustainable soil management, the mechanisms by which long-term green manure and straw return impact Fe-organic associations and soil organic carbon (SOC) stabilization in paddy soils are unclear. This study examines their effects on SOC stability, aggregate fractionation, Fe oxides, aggregate stability, and SOC composition in macro- and micro-aggregates. A well-established 8 year field experiment with four treatments, i.e., Chinese milk vetch without straw incorporation and fertilizer (CK), winter fallow without straw incorporation and with NPK (WF+NSR+NPK), winter fallow with straw incorporation and NPK (WF+SR+NPK), and Chinese milk vetch with straw incorporation and with NPK (MV+SR+NPK), were selected. The results demonstrated that the MV+SR+NPK treatment significantly (p < 0.05) increased SOC storage in macroaggregates by 18.2 % compared to CK, while reducing SOC in microaggregates and non-aggregated fractions by 1.14 % and 21.54 %, respectively. Additionally, this treatment enhanced soil aggregation, as evidenced by a 26.33 % increase in mean weight diameter (MWD) and a 54.62 % increase in geometric mean diameter (GMD), alongside a 21.5 % rise in macroaggregate formation. Further, SOC stability was reinforced by a 16.8 % increase in aromatic-C content and a 19.4 % rise in the aromatic-C/aliphatic-C ratio depicting enhanced chemical stability and resistance to degradation. Amorphous (Feo) and complex Fe oxides (Fep) in macroaggregates were 13.5 % and 17.9 % higher than in CK. In comparison, the WF+SR+NPK treatment improved MWD by 25.94 %, GMD by 31.93 %, and SOC in macroaggregates by 1.69 %, with significant increases in Feo and Fep contents by 39.92 % and 102.08 %, respectively. Furthermore, the aromatic-C/aliphatic-C ratio increased by 33.9 %, indicating enhanced SOC stability. Conversely, the WF+NSR+NPK treatment decreased MWD by 12.97 %, with only a slight increase in SOC and Fed in finer aggregates by 0.80 % and 3.12 %, respectively. These results demonstrate that the co-utilization of green manure and straw return, in combination with NPK fertilization, significantly (p < 0.05) enhances SOC stabilization and aggregate stability by promoting Fe-organic associations, thereby contributing to long-term carbon sequestration in paddy soils. [Display omitted] • Co-application of straw and green manure boosts soil aggregate stability in paddy soils. • Green manure plus straw returns increased SOC complexity. • SRO-Fe mediated selective adsorption of aromatic compounds, improved soil aggregation SOC stability. • Co-precipitation was the dominant mechanism of Fe-mediated SOC stabilization under Green manure plus straw returns. [ABSTRACT FROM AUTHOR]
	Copyright of Soil & Tillage Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database:	Engineering Source

Description
Abstract:	Despite increasing interest in sustainable soil management, the mechanisms by which long-term green manure and straw return impact Fe-organic associations and soil organic carbon (SOC) stabilization in paddy soils are unclear. This study examines their effects on SOC stability, aggregate fractionation, Fe oxides, aggregate stability, and SOC composition in macro- and micro-aggregates. A well-established 8 year field experiment with four treatments, i.e., Chinese milk vetch without straw incorporation and fertilizer (CK), winter fallow without straw incorporation and with NPK (WF+NSR+NPK), winter fallow with straw incorporation and NPK (WF+SR+NPK), and Chinese milk vetch with straw incorporation and with NPK (MV+SR+NPK), were selected. The results demonstrated that the MV+SR+NPK treatment significantly (p < 0.05) increased SOC storage in macroaggregates by 18.2 % compared to CK, while reducing SOC in microaggregates and non-aggregated fractions by 1.14 % and 21.54 %, respectively. Additionally, this treatment enhanced soil aggregation, as evidenced by a 26.33 % increase in mean weight diameter (MWD) and a 54.62 % increase in geometric mean diameter (GMD), alongside a 21.5 % rise in macroaggregate formation. Further, SOC stability was reinforced by a 16.8 % increase in aromatic-C content and a 19.4 % rise in the aromatic-C/aliphatic-C ratio depicting enhanced chemical stability and resistance to degradation. Amorphous (Feo) and complex Fe oxides (Fep) in macroaggregates were 13.5 % and 17.9 % higher than in CK. In comparison, the WF+SR+NPK treatment improved MWD by 25.94 %, GMD by 31.93 %, and SOC in macroaggregates by 1.69 %, with significant increases in Feo and Fep contents by 39.92 % and 102.08 %, respectively. Furthermore, the aromatic-C/aliphatic-C ratio increased by 33.9 %, indicating enhanced SOC stability. Conversely, the WF+NSR+NPK treatment decreased MWD by 12.97 %, with only a slight increase in SOC and Fed in finer aggregates by 0.80 % and 3.12 %, respectively. These results demonstrate that the co-utilization of green manure and straw return, in combination with NPK fertilization, significantly (p < 0.05) enhances SOC stabilization and aggregate stability by promoting Fe-organic associations, thereby contributing to long-term carbon sequestration in paddy soils. [Display omitted] • Co-application of straw and green manure boosts soil aggregate stability in paddy soils. • Green manure plus straw returns increased SOC complexity. • SRO-Fe mediated selective adsorption of aromatic compounds, improved soil aggregation SOC stability. • Co-precipitation was the dominant mechanism of Fe-mediated SOC stabilization under Green manure plus straw returns. [ABSTRACT FROM AUTHOR]
ISSN:	01671987
DOI:	10.1016/j.still.2025.106624