Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies

Despite the global imperative to enhance carbon sequestration in agricultural landscapes, saline–alkali soils present distinctive soil–microbe constraints that limit our understanding of optimal management strategies. This study addresses critical knowledge gaps regarding the mechanistic relationshi...

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Main Authors: Shenglin Liu, Xiaodong Ding, Zeqiang Sun, Zhaohui Liu, Runxiang Du, Zhichang Jing, Shirong Zhang
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Agronomy
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Online Access:https://www.mdpi.com/2073-4395/15/5/1034
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author Shenglin Liu
Xiaodong Ding
Zeqiang Sun
Zhaohui Liu
Runxiang Du
Zhichang Jing
Shirong Zhang
author_facet Shenglin Liu
Xiaodong Ding
Zeqiang Sun
Zhaohui Liu
Runxiang Du
Zhichang Jing
Shirong Zhang
author_sort Shenglin Liu
collection DOAJ
description Despite the global imperative to enhance carbon sequestration in agricultural landscapes, saline–alkali soils present distinctive soil–microbe constraints that limit our understanding of optimal management strategies. This study addresses critical knowledge gaps regarding the mechanistic relationships between bacterial community structure and carbon stabilization processes in saline–alkali soil. A three-year field experiment was conducted in the Yellow River Delta, China, with two N levels (N1, 270 kg N ha<sup>−1</sup>; N2, 210 kg N ha<sup>−1</sup>) and three C treatments (S0, 0 kg C ha<sup>−1</sup>; S1, 5000 kg C ha<sup>−1</sup>; S2, 10,000 kg C ha<sup>−1</sup>). SOC sequestration by straw incorporation increased by 16.34–22.86% and 8.18–11.91%, with no significant difference between the S1 and S2 treatments, because the specific C mineralization rate (SCMR) of the S2 treatment was 13.80–41.61% higher than the S1 treatment. The reduced nitrogen application (N2) enhanced SOC sequestration efficiency by 3.40–12.97% compared with conventional rates, particularly when combined with half straw incorporation. Furthermore, compared with the N1S1 treatment, the N2S1 treatment induced qualitative transformations in carbon chemistry, increasing aromatic carbon compounds (28.79%) while reducing carboxylic fractions (10.06%), resulting in enhanced structural stability of sequestered carbon. Bacterial community analysis revealed distinctive shifts in bacterial composition under different treatments. Half straw incorporation (S1) increased the abundance of oligotrophic strategists (<i>Verrucomicrobiae</i> and <i>Acidimicrobiia</i>) while decreasing copiotrophic bacteria (<i>Bacteroidia</i>), indicating a transition from r-strategy to k-strategy microbial communities that fundamentally altered carbon cycling. Half straw incorporation and reduced N application were beneficial to stabilize SOC composition, reduce mineralization rates, optimize bacterial survival strategy, and thus achieve SOC sequestration.
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spelling doaj-art-4e69dbc446b44312ae3a8c449bdedc802025-08-20T02:33:43ZengMDPI AGAgronomy2073-43952025-04-01155103410.3390/agronomy15051034Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival StrategiesShenglin Liu0Xiaodong Ding1Zeqiang Sun2Zhaohui Liu3Runxiang Du4Zhichang Jing5Shirong Zhang6State Key Laboratory of Nutrient Use and Management, Key Laboratory of Agro-Environment of Huang-Huai-Hai Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Jinan 250100, ChinaNational Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257347, ChinaState Key Laboratory of Nutrient Use and Management, Key Laboratory of Agro-Environment of Huang-Huai-Hai Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Jinan 250100, ChinaState Key Laboratory of Nutrient Use and Management, Key Laboratory of Agro-Environment of Huang-Huai-Hai Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Jinan 250100, ChinaSchool of Ecology and Biology, Dongying Vocational College, Dongying 257091, ChinaCollege of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, ChinaCollege of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, ChinaDespite the global imperative to enhance carbon sequestration in agricultural landscapes, saline–alkali soils present distinctive soil–microbe constraints that limit our understanding of optimal management strategies. This study addresses critical knowledge gaps regarding the mechanistic relationships between bacterial community structure and carbon stabilization processes in saline–alkali soil. A three-year field experiment was conducted in the Yellow River Delta, China, with two N levels (N1, 270 kg N ha<sup>−1</sup>; N2, 210 kg N ha<sup>−1</sup>) and three C treatments (S0, 0 kg C ha<sup>−1</sup>; S1, 5000 kg C ha<sup>−1</sup>; S2, 10,000 kg C ha<sup>−1</sup>). SOC sequestration by straw incorporation increased by 16.34–22.86% and 8.18–11.91%, with no significant difference between the S1 and S2 treatments, because the specific C mineralization rate (SCMR) of the S2 treatment was 13.80–41.61% higher than the S1 treatment. The reduced nitrogen application (N2) enhanced SOC sequestration efficiency by 3.40–12.97% compared with conventional rates, particularly when combined with half straw incorporation. Furthermore, compared with the N1S1 treatment, the N2S1 treatment induced qualitative transformations in carbon chemistry, increasing aromatic carbon compounds (28.79%) while reducing carboxylic fractions (10.06%), resulting in enhanced structural stability of sequestered carbon. Bacterial community analysis revealed distinctive shifts in bacterial composition under different treatments. Half straw incorporation (S1) increased the abundance of oligotrophic strategists (<i>Verrucomicrobiae</i> and <i>Acidimicrobiia</i>) while decreasing copiotrophic bacteria (<i>Bacteroidia</i>), indicating a transition from r-strategy to k-strategy microbial communities that fundamentally altered carbon cycling. Half straw incorporation and reduced N application were beneficial to stabilize SOC composition, reduce mineralization rates, optimize bacterial survival strategy, and thus achieve SOC sequestration.https://www.mdpi.com/2073-4395/15/5/1034soil organic carboncarbon fraction stabilitybacterial survival strategysaline–alkali soil
spellingShingle Shenglin Liu
Xiaodong Ding
Zeqiang Sun
Zhaohui Liu
Runxiang Du
Zhichang Jing
Shirong Zhang
Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
Agronomy
soil organic carbon
carbon fraction stability
bacterial survival strategy
saline–alkali soil
title Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
title_full Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
title_fullStr Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
title_full_unstemmed Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
title_short Response of the Stabilization of Organic Carbon to Straw Incorporation and Nitrogen Application: Evidence from Carbon Fractions and Bacterial Survival Strategies
title_sort response of the stabilization of organic carbon to straw incorporation and nitrogen application evidence from carbon fractions and bacterial survival strategies
topic soil organic carbon
carbon fraction stability
bacterial survival strategy
saline–alkali soil
url https://www.mdpi.com/2073-4395/15/5/1034
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