Organo–organic interactions dominantly drive soil organic carbon accrual

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(1)

Published: Jan. 1, 2024

Abstract Organo–mineral interactions have been regarded as the primary mechanism for stabilization of soil organic carbon (SOC) over decadal to millennial timescales, and capacity (C) storage has commonly assessed based on mineralogical attributes, particularly mineral surface availability. However, it remains contentious whether C sequestration is exclusively governed by vacancies, making challenging accurately predict SOC dynamics. Here, through a 400‐day incubation experiment using 13 C‐labeled materials in two contrasting soils (i.e., Mollisol Ultisol), we show that despite unsaturation surfaces both soils, newly incorporated predominantly adheres “dirty” coated with native matter (OM), demonstrating crucial role organo–organic exogenous sequestration. Such lead multilayered accumulation not constrained process distinct from direct organo–mineral contacts. The coverage OM new C, representing degree interactions, noticeably larger Ultisol (~14.2%) than (~5.8%), amounting net retention 0.2–1.3 g kg −1 0.1–1.0 . Additionally, are primarily mediated polysaccharide‐rich microbial necromass. Further evidence indicates iron oxides can selectively preserve polysaccharide compounds, thereby promoting interactions. Overall, our findings provide empirical an overlooked but critically important pathway accumulation, prevailing “C saturation” concept emphasizes overriding vacancies. It estimated that, global Mollisols Ultisols might sequester ~0.1–1.0 ~0.3–1.7 Pg per year, respectively, corresponding neutralization ca. 0.5%–3.0% emissions or 5%–30% fossil fuel combustion globally.

Language: Английский

---

Global turnover of soil mineral-associated and particulate organic carbon

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 22, 2024

Abstract Soil organic carbon (SOC) persistence is predominantly governed by mineral protection, consequently, soil mineral-associated (MAOC) and particulate (POC) turnovers have different impacts on the vulnerability of SOC to climate change. Here, we generate global MAOC POC maps using 8341 observations then infer turnover times a data-model integration approach. Global storages are $${975}_{964}^{987}$$ 975 964 987 Pg C (mean with 5% 95% quantiles) $${330}_{323}^{337}$$ 330 323 337 C, while mean $${129}_{45}^{383}$$ 129 45 383 yr $${23}_{5}^{82}$$ 23 5 82 in top meter, respectively. Climate warming-induced acceleration decomposition greater subsoil than that topsoil. Overall, atlas turnover, together distributions stocks, provide benchmark for Earth system models diagnose SOC-climate change feedback.

Language: Английский

---

Enhanced Mineral Preservation Rather Than Microbial Residue Production Dictates the Accrual of Mineral‐Associated Organic Carbon Along a Weathering Gradient

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(6)

Published: March 18, 2024

Abstract Mineral preservation and microbial residue production are vital for the accumulation of mineral‐associated organic carbon (MAOC) in soils. However, their relative importance interactive effects remain unclear. Here MAOC content composition analyzed tandem with soil mineral attributes along a weathering gradient on volcanic sequence. We find that increases increasing states, accompanied by contribution to MAOC. rather than physiological traits strongly related contents, suggesting weathering‐enhanced capacity overrides governing reactive minerals. Furthermore, have strong effect composition, likely fungal abundance community weathering. These findings highlight may effectively boost persistent SOC synergy conversion long term.

Language: Английский

---

Contrasting properties of soil organic matter fractions isolated by different physical separation methodologies

Geoderma, Journal Year: 2024, Volume and Issue: 445, P. 116870 - 116870

Published: April 8, 2024

Physical soil organic matter (SOM) fractions provide increased insight into the biogeochemical functioning of soils. Several fractionation methodologies have been developed to separate particulate (POM) from mineral-associated (MAOM) either by particle size, density, or some combination these two properties. The proliferation approaches separation has led ambiguity regarding what methodologically defined should be understood conceptually represent, hindering robust data synthesis analyses and model development. Here we attempt identify chemical similarities differences amongst POM MAOM separated different physical approaches, with aim guiding choices for future research. We obtained soils 11 farms across United States variable parent materials, textures, pHs, fractionated them using 4 methods. tested single-step methods: a size (53 µm cutoff) density (1.85 g cm−3 cutoff), multi-step combined after full dispersion, which isolates third pool associated coarse, heavy particles (coarse matter; CHAOM), method delayed dispersion free occluded + CHAOM fraction. analyzed all C N concentrations, their isotopic composition, composition via mid-infrared spectroscopy. found that tended very homogenous in character regardless schemes, while varied widely. In particular, isolated floatation was distinct both spectroscopic signature compared alone. Indeed, our results indicated is composite fraction light CHAOM, does not map well onto conceptual pool. more similar terms indicating one-step separations may most effective means isolating contrasting SOM pools time cost-efficient matter. However, analysis highlights POM, exhibit features, three are worth separating size-density when possible.

Language: Английский

---

A landscape-scale view of soil organic matter dynamics

Nature Reviews Earth & Environment, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 7, 2025

Language: Английский

---

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

---

Rhizosphere engineering for soil carbon sequestration

Trends in Plant Science, Journal Year: 2023, Volume and Issue: 29(4), P. 447 - 468

Published: Oct. 20, 2023

The rhizosphere is the central hotspot of water and nutrient uptake by plants, rhizodeposition, microbial activities, plant-soil-microbial interactions. plasticity plants offers possibilities to engineer mitigate climate change. We define engineering as targeted manipulation soil, microorganisms, management shift processes for specific aims [e.g., carbon (C) sequestration]. components can be engineered agronomic, physical, chemical, biological, genomic approaches. These approaches increase plant productivity with a special focus on C inputs belowground, necromass production, protect organic compounds aggregation, decrease losses. Finally, we outline multifunctional options engineering: how boost sequestration, soil health, global change effects.

Language: Английский

---

“Reactive Mineral Sink” drives soil organic matter dynamics and stabilization

npj Materials Sustainability, Journal Year: 2023, Volume and Issue: 1(1)

Published: Nov. 27, 2023

Abstract Reactive primary and secondary minerals play a critical role in the transformation stabilization of organic matter (OM) soil, aspect that has been largely overlooked existing literature. In this regard, we propose new model known as “reactive mineral sink” (RMS) to illustrate three mechanisms through which these drive bioprocessing, transformation, transport OM soil. Firstly, from biological perspective, reactive influence enzymatic microbial processing binding proteins or influencing structure communities. Secondly, chemical standpoint, have capacity adsorb and/or coprecipitate with it, leading more diverse distribution This distribution, turn, triggers catalysis redox reactions. Thirdly, on physical level, substantial impact soil architecture, aggregate dynamics, porosity development, hydrological processes. These changes then affect transport, reprocessing OM. The RMS provides conceptual framework underscores fundamental driving dynamics carbon (C) sequestration natural Furthermore, it promotes restoration biogeochemical processes ecological resilience. We advocate for implementation strategies based enhance C soils purposes rejuvenating health mitigating CO 2 emission.

Language: Английский

---

Agricultural limitations to soil carbon sequestration: Plant growth, microbial activity, and carbon stabilization

Agriculture Ecosystems & Environment, Journal Year: 2024, Volume and Issue: 367, P. 108986 - 108986

Published: March 20, 2024

Soil carbon (C) sequestration is an important process for mitigating climate change while improving soil productivity. At the same time, it presents challenges nutrient availability and changing agricultural practices. The aim of this study was to survey limitations found on pioneering farms testing C using a Finnish network farmers farming A combination satellite monitoring, on-site measurements analysis used quantify evaluate physical, chemical, biological quality indicators plant productivity 20 (40 fields). were assessed through conceptual model, classifying them into three stages growth, microbial activity or stabilization. Based results, there are in all stages: growth constrained by crop choices which limit leaf area sunlight capture, processing limited poor structure moisture stress, stabilization waterlogging sulfur deficiency. These problems be widespread, but not present farms. Bringing levels best performing could reduce considerable gap between potential that achieved practice.

Language: Английский

---

Learning vs. understanding: When does artificial intelligence outperform process-based modeling in soil organic carbon prediction?

New Biotechnology, Journal Year: 2024, Volume and Issue: 81, P. 20 - 31

Published: March 8, 2024

In recent years, machine learning (ML) algorithms have gained substantial recognition for ecological modeling across various temporal and spatial scales. However, little evaluation has been conducted the prediction of soil organic carbon (SOC) on small data sets commonly inherent to long-term research. this context, performance ML SOC never tested against traditional process-based approaches. Here, we compare algorithms, calibrated uncalibrated models as well multiple ensembles their in predicting using from five experimental sites (comprising 256 independent points) Austria. Using all available data, ML-based approaches Random forest support vector machines with a polynomial kernel were superior models. performed similar or worse when number training samples was reduced leave-one-site-out cross validation applied. This emphasizes that is strongly dependent data-size related quality information following well-known curse dimensionality phenomenon, while accuracy significantly relies proper calibration combination different Our study thus suggests superiority at scales where larger datasets are available, tools targeting exploration underlying biophysical biochemical mechanisms dynamics soils. Therefore, recommend applying combine advantages both

Language: Английский

---