Unlocking Mechanisms for Soil Organic Matter Accumulation: Carbon Use Efficiency and Microbial Necromass as the Keys

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(1)

Published: Jan. 1, 2025

Soil microorganisms transform plant-derived C (carbon) into particulate organic (POC) and mineral-associated (MAOC) pools. While microbial carbon use efficiency (CUE) is widely recognized in current biogeochemical models as a key predictor of soil (SOC) storage, large-scale empirical evidence limited. In this study, we proposed experimentally tested two predictors POC MAOC pool formation: necromass (using amino sugars proxy) CUE (by 18O-H2O approach). sampling (0-10 10-20 cm depth) was conducted along climatic transect 900 km on the Loess Plateau, including cropland, grassland, shrubland, forest ecosystems, to ensure homogeneous parent material. We found highest accumulation occurred zones MAT between 5°C 10°C or MAP 300 500 mm. Microbial more positively related than (p < 0.05), suggesting that residues may improve strongly compared pool. Random linear regression analyses showed increased with fungal C, whereas bacterial drove MAOC. coupled 0.05) but decoupled SOC > 0.05). The have faster turnover rate due lack clay protection, which lead rapid thus their decoupling from CUE. sense, driven by necromass, explains dynamics. Our findings highlight insufficiency relying solely predict bulk storage. Instead, propose should be used together explain dynamics, each influencing distinct

Language: Английский

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Organic Fertilization Leads to N Limitation Rather than P Limitation in Both Vegetable Soils

Agronomy, Journal Year: 2025, Volume and Issue: 15(1), P. 190 - 190

Published: Jan. 15, 2025

Organic amendments are widely used to enhance soil fertility and nutrient cycling in greenhouse cultivation, but their effectiveness can vary depending on origin composition. This study investigated the impact of four organic materials (rice husk, coconut coir, biochar, sheep manure) enzyme activities two tomato soils. The distribution nutrients was analyzed under controlled conditions during a pot experiment. addition amendments, regardless source, significantly altered microbial resource allocation, reducing carbon limitation while increasing nitrogen demand. effect pools largely determined by chemical composition amendments. In clayey soils, biochar rice husk additions most effectively promoted related carbon, nitrogen, phosphorus acquisition. Under sandy conditions, manure increased acquisition enzymes, enhanced enzymes. Biochar emerged as particularly effective amendment, enhancing sequestration across different types. specifically, content carboxyl C, aromatic O-alkyl played crucial role influencing limitations. mean C:N:P ratios for CK, T1, T2, T3, T4 treatments were 1:1.375:0.625, 1:1.244:0.662, 1:0.839:0.610, 1:1.161:0.689, 1:1.038:0.549, respectively. 1:1.117:0.698, 1:1.18:0.75, 1:1.096:0.731, 1:1.217:0.689, 1:1.06:0.669, These findings suggest that improve retention activities, effects influenced both texture. research enhances our understanding transformations, aids optimizing application improved management cultivation.

Language: Английский

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Multifaceted Links Between Microbial Carbon Use Efficiency and Soil Organic Carbon Sequestration

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(1)

Published: Jan. 1, 2025

Conceptual framework to unlock the mechanisms for microbial carbon use efficiency and SOC formation.

Language: Английский

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Dilemmas in Linking Microbial Carbon Use Efficiency With Soil Organic Carbon Dynamics

Global Change Biology, Journal Year: 2025, Volume and Issue: 31(2)

Published: Jan. 31, 2025

There are still large uncertainties on the relationships between microbial carbon use efficiency and soil organic across (1) different estimation methods, (2) various temporal, spatial biological scales, (3) multiple climate change scenarios. These call for further efforts to re-examine better represent processes in current modelling frameworks. Microbial (CUE), proportion of substrate that microorganisms assimilate growth out total uptake, is an important parameter affecting (SOC) (Tao et al. 2023). Although CUE decreases as more used respiration, SOC variable. For example, Wang (2021) reported a positive relationship along forest transect eastern China, whereas was negatively related six temperate forests USA (Craig 2022). Since can effectively integrate changes community composition physiology, this has been increasingly incorporated into models microbially mediated dynamics However, poor understanding SOC, well factors driving (e.g., temperature), may result unrealistic predictions (Luo 2024). two competing hypotheses regarding how metabolic pathways drive SOC. First, higher suggests stronger ability sequestration due increased biomass formation associated necromass accumulation (Liang, Schimel, Jastrow 2017; 2021). Second, often accompanied with larger activity, which will stimulate decomposition enhanced energy nutrient requirements (Allison, Wallenstein, Bradford 2010). increasing debates these hypotheses, have contributed advancing its Here, we provide three emerging issues help (Figure 1). be estimated by several including 13/14C labeling, 18O-H2O stoichiometric models, calorespirometry, flux analysis. methods usually based concepts, assumptions, processes, likely leading Tao (2023) revealed at global scale without considering methods. when their results categorized there negative calculated using stoichiometry model studies labeling (He Based assumptions model, invest resources production extracellular enzymes) acquire nutrients relatively C-rich environments, resulting In contrast, consider proxy growth, correlation since greater typically supports residues (Wang Furthermore, significant observed under rather than This because extra addition trigger 18O substrate. Therefore, limitations beneficial examining Third, becoming complicated change. Knorr (2024) warming decreased content, but effect debate differing temperature sensitivities respiration (Ren Moreover, numerical simulations were largely dependent addition, long-term or nitrogen deposition could suppress reducing quality, low-quality substrates requires energy. return, shift communities towards K-strategists, increase Altogether, affect quality unpredicted ways, complicating To understand recommend potential solutions. (i) experimental procedures relevant terminologies, should standardized facilitate wider comparison studies. It essential advantages disadvantages before choosing appropriate method individual New techniques accurate estimations also required. (ii) A specific pools responsive environmental changes, such labeled compositions, reveal biomarkers isotope 2022), researchers offer insights role variations temporal scales. (iii) Enhancing terms depth breadth resolutions high-frequency measurements), scales ecosystems, zones, depths) multi-factor simulation experiments warming, precipitation manipulation), elucidate range biotic abiotic variables. many hypothesized cause accumulation. not CUE, highlighting models. found microbial-enzyme where decrease reduction enzymes, Given complexity involved it might useful measurable components core framework future like growth. interaction variables characterized kinetics, The huge databases derived from recent advancements metagenomics probe-based technologies unique opportunities develop alternative CUE. sensitivity positively correlated abundance functional genes labile decomposition, while recalcitrant determined metagenomic sequencing factors, designed output constrained observational data, another opportunity (Allison 2025). From standpoint, paired observations optimize parameters, ultimately enhancing robustness predictions. summary, particular, developing advanced interdisciplinary research involves extensive collaboration among mathematicians, microbiologists, ecologists, modelers. Jiacong Zhou: conceptualization, funding acquisition, visualization, writing – original draft, review editing. Yiqi Luo: Ji Chen: methodology, project administration, authors declare no conflicts interest. Data sharing applicable article new data created analyzed study.

Language: Английский

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Unprotected carbon dominates decadal soil carbon increase

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Feb. 27, 2025

Language: Английский

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Soil Organic Carbon Increases With Decreasing Microbial Carbon Use Efficiency During Vegetation Restoration

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(12)

Published: Dec. 1, 2024

ABSTRACT Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil (SOC) content on a global scale. However, it is unclear whether similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated patterns CUE along 160‐year chronosequence (from farmland to climax forest) estimated stoichiometric modeling; additionally, examined between and SOC combined these results meta‐analysis. The combination indicated that decreased from 0.35 0.28. Surprisingly, increased decreasing because forest soils have low pH values high microbial phosphorus limitations compared early ecosystems, implying forests may not sequester as much expected. shift was most important predictor climate, plant, factors. changes were directly induced pH‐induced community. Alkaline acidification tended decrease CUE. This first large‐scale estimate highlights need strengthen sink management mature sustain their sequestration potential.

Language: Английский

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Improved Microbial Carbon Use Efficiency With Low Tillage Intensity: Evidence and Research Gaps

Journal of Sustainable Agriculture and Environment, Journal Year: 2025, Volume and Issue: 4(1)

Published: Feb. 5, 2025

ABSTRACT High microbial carbon use efficiency (CUE) in agricultural soils can limit the return of atmospheric dioxide (CO 2 ) from organic matter mineralisation and potentially increase soil (SOC) accumulation through formation biomass necromass. Therefore, management practices that CUE are relevant for sustainable agriculture climate change mitigation. We conducted an exploratory literature review evidence synthesis to compare between conventional tillage (CT) low‐intensity systems (reduced tillage, RT no‐tillage, NT). The 50 paired observations 11 studies showed overall 12% under compared CT ( p = 0.02). Separate contrasts NT versus (i.e., RT/CT NT/CT) also higher with 0.06 0.05, respectively. is likely due improved substrate availability growth and/or changes community induced by contrasting systems. However, limited quantitative data linking tillage‐induced these drivers constrains further analysis. extracted available SOC eligible studies, but this did not provide increases were correlated content. Future should extend emerging empirical set clarify abiotic biotic which be refined better mitigation strategies. Further aim understand link dynamics, important representation global models.

Language: Английский

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Probing the pump: soil carbon dynamics, microbial carbon use efficiency and community composition in response to stoichiometrically-balanced compost and biochar

Soil Biology and Biochemistry, Journal Year: 2025, Volume and Issue: unknown, P. 109770 - 109770

Published: March 1, 2025

Language: Английский

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Nonlinear microbial thermal response and its implications for abrupt soil organic carbon responses to warming

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: March 20, 2025

Microbial carbon use efficiency (CUE) is a key microbial trait affecting soil organic (SOC) dynamics. However, we lack unified and predictive understanding of the mechanisms underpinning temperature response CUE, and, thus, its impacts on SOC storage in warming world. Here, leverage three independent datasets (n = 618 for CUE; n 591 660 heterotrophic respiration) at broad spatial scales to investigate thermal implications responses warming. We show nonlinear increase decrease CUE respiration, respectively, mean annual (MAT), with threshold ≈15 °C. These relationships are mainly associated changes fungal-to-bacterial biomass ratio. Our microbial-explicit model predicts significant losses MAT above °C due increased total biomass, implying potential abrupt transition more vulnerable under climate This study leverages empirical respiration 15 °C,

Language: Английский

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Divergence of microbial carbon use efficiency and soil organic carbon along a tidal flooding gradient in a subtropical coastal wetland

Water Research, Journal Year: 2025, Volume and Issue: unknown, P. 123527 - 123527

Published: March 1, 2025

Language: Английский

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