Carbon-nutrient stoichiometry to increase soil carbon sequestration
TL;DR: In this paper, the effect of N, P and S availability on the net humification efficiency (NHE) following incubation of soil with wheaten straw was investigated, showing that inorganic nutrient availability is critical to sequester C into the more stable FF-SOM pool irrespective of soil type and C input.
Abstract: The more stable fine fraction pool of soil organic matter (FF-SOM; <0.4 mm) has more nitrogen, phosphorus and sulphur (N, P, S) per unit of carbon (C) than the plant material from which it originates and has near constant ratios of C:N:P:S. Consequently, we hypothesised that the sequestration of C-rich crop residue material into the FF-SOM pool could be improved by adding supplementary nutrients to the residues based on these ratios. Here we report on the effect of N, P and S availability on the net humification efficiency (NHE), the change in the size of the FF-SOM pool (as estimated by fine fraction C (FF-C)), following incubation of soil with wheaten straw. Four diverse soils were subjected to seven consecutive incubation cycles, with wheaten straw (10 t ha equivalent) added at the beginning of each cycle, with and without inorganic N, P, S addition (5 kg N, 2 kg P and 1.3 kg S per tonne of straw). This nutrient addition doubled the mean NHE in all soils (from 7% to 15%) and when applied at twice the rate increased NHE further (up to 29%) for the two soils that received this treatment. The FF-N, -P and -S levels increased in concert with FF-C levels in all soils in close agreement with published stoichiometric ratios (C:N:P:S = 10,000:833:200:143). Microbial biomass-C (MB-C) levels were estimated during one incubation cycle and found to increase in parallel with FF-C from 448 μg MB-C g soil (no nutrient addition) to 727 μg MB-C g soil (plus nutrients) and 947 μg MB-C g soil (plus 2× nutrients). There was a significant relationship between MB-C and the change in FF-C during that incubation cycle, providing evidence of a close relationship between the microbial biomass and FF-SOM formation. The two to four-fold increases in NHE achieved with nutrient addition demonstrated that inorganic nutrient availability is critical to sequester C into the more stable FF-SOM pool irrespective of soil type and C input. This has important implications for strategies to build soil fertility or mitigate climate change via increased soil organic C, as the availability and value of these nutrients must be considered.
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TL;DR: Overall, it is shown that addition of nutrients reduces diversity but favours the keystone taxa, and thereby increases microbial biomass.
Abstract: Organic matter (OM) decomposition and breakdown of crop residues are directly linked to carbon (C) sequestration in agricultural soils as a portion of the decomposed C becomes assimilated into stable microbial biomass. Microbial decomposition of OM may vary with quality of OM, addition of nutrients and functional types of microbes. While the role of fungi and bacteria in OM decomposition has received considerable attention, the succession and co-occurrence patterns of these communities during decomposition remain unexplored. Using 454 pyrosequencing and network analysis of bacterial 16S rRNA and fungal ITS genes in a time-course microcosm experiment, this study shows a positive effect of nutrient addition on overall microbial biomass and abundance of bacteria and fungi. Abundance of different bacterial and fungal groups changed up to 300-folds under straw- and nutrient amended treatments while the rate of decomposition remained similar, indicating a possible functional redundancy. Moreover, addition of nutrients significantly altered the co-occurrence patterns of fungal and bacterial communities, and these patterns were resource-driven and not phylogeny-driven. Richness, evenness and diversity decreased and were negatively associated with decomposition rate. Acidobacteria , Frateuria and Gemmatimonas in bacteria and Chaetomium , Cephalotheca and Fusarium in fungi were found as the keystone taxa. These taxa showed strong positive associations with decomposition, indicating their importance in C turnover. Overall, we show that addition of nutrients reduces diversity but favours the keystone taxa, and thereby increases microbial biomass.
515 citations
TL;DR: The model builds on the Microbial Efficiency-Matrix Stabilization framework by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low- quality litters.
Abstract: Labile, ‘high-quality’, plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physicochemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High-quality litters, characterized by high N concentrations, low C/N ratios, and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than ‘low-quality’ litters characterized by low N concentrations, high C/N ratios, and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high-quality litters are not always stabilized in SOM with greater efficiency than low-quality litters.
413 citations
Cites background from "Carbon-nutrient stoichiometry to in..."
...Mineral nutrient additions can alter litter quality after plant uptake (Brown et al., 2014) or can be directly accessed by microbes during decomposition (Kirkby et al., 2013)....
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...Presumably, both of these effects of mineral nutrient additions increase litter transformation to SOM by better matching microbe and substrate stoichiometries (Kirkby et al., 2013)....
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...…can also enhance microbial biomass and microbial use efficiency of plant litter, thereby increasing the transfer of plant litter to total SOM and physicochemically stabilized SOM ( Agren et al., 2001; Schimel & Weintraub, 2003; Moran et al., 2005; Thiet et al., 2006; Kirkby et al., 2013)....
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TL;DR: Restoring peatlands is 3.4 times less nitrogen costly and involves a much smaller land area demand than mineral soil carbon sequestration, calling for a stronger consideration of peatland rehabilitation as a mitigation measure.
Abstract: Soil carbon sequestration and avoidable emissions through peatland restoration are both strategies to tackle climate change. Here we compare their potential and environmental costs regarding nitrogen and land demand. In the event that no further areas are exploited, drained peatlands will cumulatively release 80.8 Gt carbon and 2.3 Gt nitrogen. This corresponds to a contemporary annual greenhouse gas emission of 1.91 (0.31–3.38) Gt CO2-eq. that could be saved with peatland restoration. Soil carbon sequestration on all agricultural land has comparable mitigation potential. However, additional nitrogen is needed to build up a similar carbon pool in organic matter of mineral soils, equivalent to 30–80% of the global fertilizer nitrogen application annually. Restoring peatlands is 3.4 times less nitrogen costly and involves a much smaller land area demand than mineral soil carbon sequestration, calling for a stronger consideration of peatland rehabilitation as a mitigation measure.
382 citations
TL;DR: It is demonstrated that co-composting considerably promoted biochars’ positive effects, largely by nitrate (nutrient) capture and delivery, and hypothesize that surface ageing plus non-conventional ion-water bonding in micro- and nano-pores promoted nitrate capture in biochar particles.
Abstract: Soil amendment with pyrogenic carbon (biochar) is discussed as strategy to improve soil fertility to enable economic plus environmental benefits. In temperate soils, however, the use of pure biochar mostly has moderately-negative to -positive yield effects. Here we demonstrate that co-composting considerably promoted biochars' positive effects, largely by nitrate (nutrient) capture and delivery. In a full-factorial growth study with Chenopodium quinoa, biomass yield increased up to 305% in a sandy-poor soil amended with 2% (w/w) co-composted biochar (BC(comp)). Conversely, addition of 2% (w/w) untreated biochar (BC(pure)) decreased the biomass to 60% of the control. Growth-promoting (BC(comp)) as well as growth-reducing (BC(pure)) effects were more pronounced at lower nutrient-supply levels. Electro-ultra filtration and sequential biochar-particle washing revealed that co-composted biochar was nutrient-enriched, particularly with the anions nitrate and phosphate. The captured nitrate in BC(comp) was (1) only partly detectable with standard methods, (2) largely protected against leaching, (3) partly plant-available, and (4) did not stimulate N2O emissions. We hypothesize that surface ageing plus non-conventional ion-water bonding in micro- and nano-pores promoted nitrate capture in biochar particles. Amending (N-rich) bio-waste with biochar may enhance its agronomic value and reduce nutrient losses from bio-wastes and agricultural soils.
338 citations
TL;DR: This work highlights the links between plant functional traits and soil properties in relation to four major ecosystem processes involved in vital ecosystem services: food production, crop protection, climate change mitigation, and soil and water conservation, aiming towards ecological intensification of sustainable agricultural and soil management.
268 citations
Cites background from "Carbon-nutrient stoichiometry to in..."
...Mineral nutrient additions including N fertilisers can also enhance microbial biomass and litter mineralisation, thereby modifying litter trait effects on SOC by increasing the transfer of plant litter to total SOC and stabilised SOC [53]....
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References
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01 Jan 1982
14,888 citations
TL;DR: In this paper, the effects of fumigation on organic C extractable by 0.5 m K2SO4 were examined in a contrasting range of soils and it was shown that both ATP and organic C rendered decomposable by CHCl3 came from the soil microbial biomass.
Abstract: The effects of fumigation on organic C extractable by 0.5 M K2SO4 were examined in a contrasting range of soils. EC (the difference between organic C extracted by 0.5 M K2SO4 from fumigated and non-fumigated soil) was about 70% of FC (the flush of CO2-C caused by fumigation during a 10 day incubation), meaned for ten soils. There was a close relationship between microbial biomass C, measured by fumigation-incubation (from the relationship Biomass C = FC/0.45) and EC given by the equation: Biomass C = (2.64 ± 0.060) EC that accounted for 99.2% of the variance in the data. This relationship held over a wide range of soil pH (3.9–8.0).
ATP and microbial biomass N concentrations were measured in four of the soils. The (ATP)(EC) ratios were very similar in the four soils, suggesting that both ATP and the organic C rendered decomposable by CHCl3 came from the soil microbial biomass. The C:N ratio of the biomass in a strongly acid (pH 4.2) soil was greater (9.4) than in the three less-acid soils (mean C:N ratio 5.1).
We propose that the organic C rendered extractable to 0.5 m K2SO4 after a 24 h CHCl3-fumigation (EC) comes from the cells of the microbial biomass and can be used to estimate soil microbial biomass C in both neutral and acid soils.
9,975 citations
"Carbon-nutrient stoichiometry to in..." refers methods in this paper
...2.3.5 Microbial biomass The microbial biomass was estimated as chloroform-labile C on treatments 0-Nu, 1-Nu and 2-Nu seven days after the start of the seventh incubation cycle using the fumigationextraction method (Vance et al., 1987)....
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...5 Microbial biomass The microbial biomass was estimated as chloroform-labile C on treatments 0-Nu, 1-Nu and 2-Nu seven days after the start of the seventh incubation cycle using the fumigationextraction method (Vance et al., 1987)....
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Book•
01 Jan 1982
TL;DR: In this paper, the authors present an analysis of organic matter in soil using NMR Spectroscopy and analytical pyrolysis, showing that organic matter is composed of nitrogen and ammonium.
Abstract: Partial table of contents: Organic Matter in Soils: Pools, Distribution, Transformations, and Function. Extraction, Fractionation, and General Chemical Composition of Soil Organic Matter. Organic Forms of Soil Nitrogen. Native Fixed Ammonium and Chemical Reactions of Organic Matter with Ammonia and Nitrite. Organic Phosphorus and Sulfur Compounds. Soil Carbohydrates. Soil Lipids. Biochemistry of the Formation of Humic Substances. Reactive Functional Groups. Structural Components of Humic and Fulvic Acids as Revealed by Degradation Methods. Characterization of Soil Organic Matter by NMR Spectroscopy and Analytical Pyrolysis. Structural Basis of Humic Substances. Spectroscopic Approaches. Colloidal Properties of Humic Substances. Electrochemical and Ion-Exchange Properties of Humic Substances. Organic Matter Reactions Involving Pesticides in Soil. Index.
5,658 citations
"Carbon-nutrient stoichiometry to in..." refers result in this paper
...While our results support this general hypothesis a limitation of one or more of the essential nutrients (NPS) may place a ceiling on the absolute quantity of SOM that can be synthesised (Stevenson 1994)....
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TL;DR: In this paper, the authors present a set of methods for soil sampling and analysis, such as: N.H.Hendershot, H.M.Hettiarachchi, C.C.De Freitas Arbuscular Mycorrhiza, Y.K.Soon and W.J.
Abstract: SOIL SAMPLING AND HANDLING, G.T. Patterson and M.R. Carter Soil Sampling Designs, D. Pennock, T. Yates, and J. Braidek Sampling Forest Soils, N. Belanger and K.C.J. Van Rees Measuring Change in Soil Organic Carbon Storage, B.H. Ellert, H.H. Janzen, A.J. VandenBygaart, and E. Bremer Soil Sample Handling and Storage, S.C. Sheppard and J.A. Addison Quality Control in Soil Chemical Analysis, C. Swyngedouw and R. Lessard DIAGNOSTIC METHODS for SOIL and ENVIRONMENTAL MANAGEMENT, J.J. Schoenau and I.P. O'Halloran Nitrate and Exchangeable Ammonium Nitrogen, D.G. Maynard, Y.P. Kalra, and J.A. Crumbaugh Mehlich 3 Extractable Elements, N. Ziadi and T. Sen Tran Sodium Bicarbonate Extractable Phosphorus, J.J. Schoenau and I. P. O'Halloran Boron, Molybdenum and Selenium, G. M. Hettiarachchi and U. C. Gupta Trace Element Assessment, W.H. Hendershot, H. Lalande, D. Reyes, and D. MacDonald Readily Soluble Aluminum and Manganese in Acid Soils, Y.K. Soon, N. Belanger, and W.H. Hendershot Lime Requirement, N. Ziadi and T. Sen Tran Ion Supply Rates Using Ion Exchange Resins, P. Qian, J.J. Schoenau, and N. Ziadi Environmental Soil Phosphorus Indices, A.N. Sharpley, P.J.A. Kleinman and J.L. Weld Electrical Conductivity and Soluble Ions, J.J. Miller and D. Curtin SOIL CHEMICAL ANALYSES, Y.K. Soon and W.H. Hendershot Soil Reaction and Exchangeable Acidity, W.H. Hendershot, H. Laland,e and M. Duquette Collection and Characterization of Soil Solutions, J.D. MacDonald, N. Belanger, S. Sauve, F. Courchesne, and W.H. Hendershot Ion Exchange and Exchangeable Cations, W.H. Hendershot, H. Lalande, and M. Duquette Non-Exchangeable Ammonium, Y.K. Soon and B.C. Liang Carbonates, T.B. Goh and A.R. Mermut Total and Organic Carbon, J.O. Skjemstad and J.A. Baldock Total Nitrogen, P.M. Rutherford, W.B. McGill, C.T. Figueiredo, and J.M. Arocena Chemical Characterization of Soil Sulphur, C.G. Kowalenko and M. Grimmett Total and Organic Phosphorus, I.P. O'Halloran and B.J. Cade-Menum Characterization of Available P by Sequential Extraction, H. Tiessen and J.O. Moir Extractable Al, Fe, Mn, and Si, F. Courchesne and M.C. Turmel Determining Nutrient Availability in Forest Soils, N. Belanger, David Pare, and W.H. Hendershot Chemical Properties of Organic Soils, A. Karam SOIL BIOLOGICAL ANALYSES, E. Topp and C.A. Fox Cultural Methods for Soil and Root Associated Microorganisms, J.J. Germida and J.R. de Freitas Arbuscular Mycorrhiza, Y. Dalpe and C. Hamel Root Nodule Bacteria and Symbiotic Nitrogen Fixation, D. Prevost and H. Antoun Microarthropods, J.P Winter and V.M. Behan-Pelletier Nematodes, T.A. Forge and J. Kimpinski Earthworms, M.J. Clapperton, G.H. Baker and C.A. Fox Enchytraeids, S.M. Adl Protozoa, S.M. Adl, D. Acosta-Mercado, and D.H. Lynn Denitrification Techniques for Soils, C.F. Drury, D.D. Myrold, E.G. Beauchamp, and W.D.Reynolds Nitrification Techniques in Soil Systems, C.F. Drury, S.C. Hart, and X.M. Yang Substrate-Induced Respiration and Selective Inhibition as Measures of Microbial Biomass in Soils, V.L. Bailey, J.L. Smith, and H. Bolton Jr. Assessment of Soil Biological Activity, R.P.Beyaert and C.A. Fox Soil ATP, R.P. Voroney, G. Wen, and R.P. Beyaert Lipid-Based Community Analysis, K.E. Dunfield Bacterial Community Analyses by Denaturing Gradient Gel Electrophoresis (DGGE), E. Topp, Y.-C. Tien, and A. Hartmann Indicators of Soil Food Web Properties, T.A. Forge and M. Tenuta SOIL ORGANIC MATTER ANALYSES, E.G. Gregorich and M.H. Beare Carbon Mineralization, D.W. Hopkins Mineralizable Nitrogen, Denis Curtin and C.A. Campbell Physically Uncomplexed Organic Matter, E.G. Gregorich and M.H. Beare Extraction and Characterization of Dissolved Organic Matter, M.H. Chantigny, D.A. Angers, K. Kaiser, and K. Kalbitz Soil Microbial Biomass C, N, P and S, R.P. Voroney, P.C. Brookes, and R.P. Beyaert Carbohydrates, M.H. Chantigny and D.A. Angers Organic Forms of Nitrogen, D.C. Olk Soil Humus Fractions, D.W. Anderson and J.J Schoenau Soil Organic Matter Analysis by Solid-State 13C Nuclear Magnetic Resonance Spectroscopy, M. J. Simpson and C. M. Preston Stable Isotopes in Soil and Environmental Research, B.H. Ellert and L. Rock SOIL PHYSICAL ANALYSES, D.A. Angers and F.J. Larney Particle Size Distribution, D. Kroetsch and C. Wang Soil Shrinkage, C.D. Grant Soil Density and Porosity, X. Hao, B.C. Ball, J.L.B. Culley, M.R. Carter, and G.W. Parkin Soil Consistency: Upper and Lower Plastic Limits, R.A. McBride Compaction and Compressibility, P. Defossez, T. Keller and G. Richard Field Soil Strength, G.C. Topp and D.R. Lapen Air Permeability, C.D. Grant and P.H. Groenevelt Aggregate Stability to Water, D.A. Angers, M.S. Bullock, and G.R. Mehuys Dry Aggregate Size Distribution, F.J. Larney Soil Air, R.E. Farrell and J.A. Elliott Soil-Surface Gas Emissions, P. Rochette and N. Bertrand Bulk Density Measurement in Forest Soils, D.G. Maynard and M.P. Curran Physical Properties of Organic Soils and Growing Media: Particle Size and Degree of Decomposition, L.E. Parent and J. Caron Physical Properties of Organic Soils and Growing Media: Water and Air Storage and Flow Dynamics, J. Caron, D.E. Elrick, J.C. Michel, and R. Naasz SOIL WATER ANALYSES, W.D. Reynolds and G.C. Topp Soil Water Analyses: Principles and Parameters, W.D. Reynolds and G.C. Topp Soil Water Content, G.C. Topp, G.W. Parkin, and Ty P.A Ferre Soil Water Potential, N.J. Livingston and G.C. Topp Soil Water Desorption and Imbibition: Tension and Pressure Techniques, W.D. Reynolds and G.C. Topp Soil Water Desorption and Imbibition: Long Column, W.D. Reynolds and G.C. Topp Soil Water Desorption and Imbibition: Psychrometry, W.D. Reynolds and G.C. Topp Saturated Hydraulic Properties: Laboratory Methods, W.D. Reynolds Saturated Hydraulic Properties: Well Permeameter, W.D. Reynolds Saturated Hydraulic Properties: Ring Infiltrometer, W.D. Reynolds Saturated Hydraulic Properties: Auger-Hole, G.C. Topp Saturated Hydraulic Properties: Piezometer, G.C. Topp Unsaturated Hydraulic Properties: Laboratory Tension Infiltrometer, F.J. Cook Unsaturated Hydraulic Properties: Laboratory Evaporation, O.O. B. Wendroth and N. Wypler Unsaturated Hydraulic Properties: Field Tension Infiltrometer, W.D. Reynolds Unsaturated Hydraulic Properties: Instantaneous Profile, W.D. Reynolds Estimation of Soil Hydraulic Properties, F.J. Cook and H.P. Cresswell Analysis of Soil Variability, B.C. Si, R.G. Kachanoski, and W.D. Reynolds APPENDIX Site Description, G.T. Patterson and J.A. Brierley General Safe Laboratory Operation Procedures, P. St-Georges INDEX
4,631 citations
Journal Article•
3,481 citations
"Carbon-nutrient stoichiometry to in..." refers background in this paper
...…that nutrient stoichiometry has important implications for SOM dynamics as it is central to microbial growth and turnover in soil the same way that Redfield (1958) demonstrated the importance of nutrient stoichiometry for phytoplankton growth, C-turnover and the biogeochemistry of the oceans....
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