scholarly journals Long-term doubling of litter inputs accelerates soil organic matter degradation and reduces soil carbon stocks

2015 ◽  
Vol 127 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Oliva Pisani ◽  
Lisa H. Lin ◽  
Olivia O. Y. Lun ◽  
Kate Lajtha ◽  
Knute J. Nadelhoffer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Carbon Stocks ◽  
Organic Matter Degradation ◽  
Soil Carbon Stocks

scholarly journals Greater soil carbon stocks and faster turnover rates with increasing agricultural productivity

SOIL ◽  
2017 ◽  
Vol 3 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Jonathan Sanderman ◽  
Courtney Creamer ◽  
W. Troy Baisden ◽  
Mark Farrell ◽  
Stewart Fallon
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Sugar Content ◽  
Bulk Composition ◽  
Agricultural Productivity ◽  
Carbon Stocks ◽  
Decay Rates ◽  
Turnover Rates ◽  
Soil Carbon Stocks

Abstract. Devising agricultural management schemes that enhance food security and soil carbon levels is a high priority for many nations. However, the coupling between agricultural productivity, soil carbon stocks and organic matter turnover rates is still unclear. Archived soil samples from four decades of a long-term crop rotation trial were analyzed for soil organic matter (SOM) cycling-relevant properties: C and N content, bulk composition by nuclear magnetic resonance (NMR) spectroscopy, amino sugar content, short-term C bioavailability assays, and long-term C turnover rates by modeling the incorporation of the bomb spike in atmospheric 14C into the soil. After > 40 years under consistent management, topsoil carbon stocks ranged from 14 to 33 Mg C ha−1 and were linearly related to the mean productivity of each treatment. Measurements of SOM composition demonstrated increasing amounts of plant- and microbially derived SOM along the productivity gradient. Under two modeling scenarios, radiocarbon data indicated overall SOM turnover time decreased from 40 to 13 years with increasing productivity – twice the rate of decline predicted from simple steady-state models or static three-pool decay rates of measured C pool distributions. Similarly, the half-life of synthetic root exudates decreased from 30.4 to 21.5 h with increasing productivity, indicating accelerated microbial activity. These findings suggest that there is a direct feedback between accelerated biological activity, carbon cycling rates and rates of carbon stabilization with important implications for how SOM dynamics are represented in models.

scholarly journals Greater soil carbon stocks and faster turnover rates with increasing agricultural productivity

2016 ◽  
Author(s):  
Jonathan Sanderman ◽  
Courtney Creamer ◽  
W. Troy Baisden ◽  
Mark Farrell ◽  
Stewart Fallon
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Sugar Content ◽  
Bulk Composition ◽  
Agricultural Productivity ◽  
Carbon Stocks ◽  
Decay Rates ◽  
Turnover Rates ◽  
Soil Carbon Stocks

Abstract. Devising agricultural management schemes that enhance food security and soil carbon levels is a high priority for many nations. However, the coupling between agricultural productivity, soil carbon stocks and organic matter turnover rates is still unclear. Archived soil samples from four decades of a long-term crop rotation trial were analysed for soil organic matter (SOM) cycling relevant properties: C and N content, bulk composition by NMR spectroscopy, amino sugar content, short term C bioavailability assays, and long-term C turnover rates by modeling the incorporation of the bomb-spike in atmospheric 14C into the soil. After > 40 years under consistent management, topsoil carbon stocks ranged from 14 to 33 Mg C ha−1 and were linearly related to the mean productivity of each treatment. Measurements of SOM composition demonstrated increasing amounts of plant- and microbially-derived SOM along the productivity gradient. Under two modelling scenarios, radiocarbon data indicated overall SOM turnover time decreased from 40 to 13 years with increasing productivity; twice the rate of decline predicted from simple steady-state models or static three-pool decay rates of measured C pool distributions. Similarly, the half-life of synthetic root exudates decreased from 30.4 to 21.5 hours with increasing productivity indicating accelerated microbial activity. These findings suggest that there is a direct feedback between accelerated biological activity, carbon cycling rates and rates of carbon stabilization with important implications for how SOM dynamics are represented in models.

scholarly journals Long-term impact of chronosequential land use change on soil carbon stocks on a Swedish farm

2007 ◽  
Vol 81 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Thomas Kätterer ◽  
Liselotte Andersson ◽  
Olof Andrén ◽  
Jan Persson
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Soil Carbon ◽  
Carbon Stocks ◽  
Soil Carbon Stocks ◽  
Long Term Impact

Modelling soil carbon stocks in semi-natural and agro-ecosystems – quantifying national scale impacts of the Anthropocene

2020 ◽  
Author(s):  
Victoria Janes-Bassett ◽  
Jessica Davies ◽  
Richard Bassett ◽  
Dmitry Yumashev ◽  
Ed Rowe ◽  
...  
Keyword(s):  
Land Use ◽  
Nutrient Cycling ◽  
Soil Carbon ◽  
Carbon Storage ◽  
Management Practices ◽  
Carbon Stocks ◽  
Soil Carbon Storage ◽  
National Scale ◽  
Soil Carbon Stocks

<p>Throughout the Anthropocene, the conversion of land to agriculture and atmospheric deposition of nitrogen have resulted in significant changes to biogeochemical cycling, including soil carbon stocks. Quantifying these changes is complex due to a number of influential factors (including climate, land use management, soil type) and their interactions. As the largest terrestrial store of carbon, soils are a key component in climate regulation. In addition, soil carbon storage contributes to numerous ecosystem services including food provision. It is therefore imperative that we understand changes to soil carbon stocks, and provide effective strategies for their future management.</p><p>Modelling soil systems provides a means to estimate changes to soil carbon stocks. Due to linkages between the carbon cycle and other major nutrient cycles (notably nitrogen and phosphorus which often limit the productivity of ecosystems), models of integrated nutrient cycling are required to understand the response of the carbon cycle to global pressures. Simulating the impacts of land use changes requires capacity to model both semi-natural and intensive agricultural systems.</p><p>In this study, we have developed an integrated carbon-nitrogen-phosphorus model of semi-natural systems to include representation of both arable and grassland systems, and a range of agricultural management practices. The model is applicable to large spatial scales, as it uses readily available input data and does not require site-specific calibration.  After being validated both spatially and temporally using data from long-term experimental sites across Northern-Europe, the model was applied at a national scale throughout the United Kingdom to assess the impacts of land use change and management practices during the last two centuries. Results indicate a decrease in soil carbon in areas of agricultural expansion, yet in areas of semi-natural land use, atmospheric deposition of nitrogen has resulted in increased net primary productivity and subsequently soil carbon. The results demonstrate anthropogenic impacts on long-term nutrient cycling and soil carbon storage, and the importance of integrated nutrient cycling within models.</p>

Does long-term center-pivot irrigation increase soil carbon stocks in semi-arid agro-ecosystems?

Geoderma ◽  
2008 ◽  
Vol 145 (1-2) ◽  
pp. 121-129 ◽  
Author(s):  
K. Denef ◽  
C.E. Stewart ◽  
J. Brenner ◽  
K. Paustian
Keyword(s):  
Soil Carbon ◽  
Carbon Stocks ◽  
Center Pivot ◽  
Soil Carbon Stocks ◽  
Semi Arid

Impact of Sampling Depth on Differences in Soil Carbon Stocks in Long-Term Agroecosystem Experiments

2011 ◽  
Vol 75 (1) ◽  
pp. 226-234 ◽  
Author(s):  
A. J. VandenBygaart ◽  
E. Bremer ◽  
B. G. McConkey ◽  
B. H. Ellert ◽  
H. H. Janzen ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Carbon Stocks ◽  
Sampling Depth ◽  
Soil Carbon Stocks

scholarly journals Relationships between soil quality indicators, redox properties, and bioactivity of humic substances of soils under integrated farming, livestock, and forestry

Revista CERES ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 373-380 ◽  
Author(s):  
Marihus Altoé Baldotto ◽  
Lílian Estrela Borges Baldotto
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Humic Substances ◽  
Soil Quality ◽  
Quality Indicators ◽  
Carbon Stocks ◽  
Redox Properties ◽  
Soil Quality Indicators ◽  
Integrated Farming ◽  
Soil Carbon Stocks

ABSTRACT Once it is stabilized in the soil, organic matter minimizes limitations of Brazilian Oxisols, such as low cation exchange capacity, low nutrient availability, toxicity due to high aluminum content, and phosphate adsorption. Moreover, humified organic matter fractions are bioactive. It is, therefore, important to evaluate the biostimulant ability of compounds present in soil carbon stocks to develop sustainable technologies for tropical agriculture based on renewable natural resources. The objective of this research was to correlate some soil quality indicators, redox properties, and bioactivity of humic acids isolated from integrated farming, livestock, and forestry systems aiming to understand the mechanisms involved in plant stimulation by humified organic matter. Carbon stocks and their stability were determined from oxidation by dichromatometry and iodometry, respectively. Bioactivity was assessed using yield data of corn indicator plants. The results indicated that when native-like forests were reintroduced instead of pastureland, soil carbon stocks and their stability increased along with overall improvements in soil fertility, chemical and physical properties, and soil biodiversity. The bioactivity of humic substances isolated from soils used in integrated crop, livestock, and forestry management was higher than that of soils derived from pastures or eucalyptus alone.

scholarly journals Long-term steady state <sup>13</sup>C labelling to investigate soil carbon turnover in grasslands

2007 ◽  
Vol 4 (3) ◽  
pp. 385-394 ◽  
Author(s):  
K. Klumpp ◽  
J. F. Soussana ◽  
R. Falcimagne
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Residence Time ◽  
Particulate Organic Matter ◽  
Mean Residence Time ◽  
Carbon Turnover ◽  
13C Labelling

Abstract. We have set up a facility allowing steady state 13CO2 labeling of short stature vegetation (12 m2) for several years. 13C labelling is obtained by scrubbing the CO2 from outdoors air with a self-regenerating molecular sieve and by replacing it with 13C depleted (−34.7±0.03‰) fossil-fuel derived CO2 The facility, which comprises 16 replicate mesocosms, allows to trace the fate of photosynthetic carbon in plant-soil systems in natural light and at outdoors temperature. This method was applied to the study of soil organic carbon turnover in temperate grasslands. We tested the hypothesis that a low disturbance by grazing and cutting of the grassland increases the mean residence time of carbon in coarse (>0.2 mm) soil organic fractions. Grassland monoliths (0.5×0.5×0.4 m) were sampled from high and low disturbance treatments in a long-term (14 yrs) grazing experiment and were placed during two years in the mesocosms. During daytime, the canopy enclosure in each mesocosm was supplied in an open flow with air at mean CO2 concentration of 425 µmol mol−1 and δ13C of −21.5±0.27‰. Fully labelled mature grass leaves reached a δ13C of −40.8 (±0.93) and −42.2‰ (±0.60) in the low and high disturbance treatments, respectively, indicating a mean 13C labelling intensity of 12.7‰ compared to unlabelled control grass leaves. After two years, the delta 13C value of total soil organic matter above 0.2 mm was reduced in average by 7.8‰ in the labelled monoliths compared to controls. The isotope mass balance technique was used to calculate for the top (0–10 cm) soil the fraction of 13C labelled carbon in the soil organic matter above 0.2 mm (i.e. roots, rhizomes and particulate organic matter). A first order exponential decay model fitted to the unlabelled C in this fraction shows an increase in mean residence time from 22 to 31 months at low compared to high disturbance. A slower decay of roots, rhizomes and particulate organic matter above 0.2 mm is therefore likely to contribute to the observed increased in soil carbon sequestration in grassland monoliths exposed to low disturbance.

Testing for soil carbon saturation behavior in agricultural soils receiving long-term manure amendments

2014 ◽  
Vol 94 (3) ◽  
pp. 281-294 ◽  
Author(s):  
W. Feng ◽  
M. Xu ◽  
M. Fan ◽  
S. S. Malhi ◽  
J. J. Schoenau ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Field Experiments ◽  
Agricultural Soils ◽  
Agricultural Field ◽  
Soil C ◽  
Carbon Saturation ◽  
Manure Amendments

Feng, W., Xu, M., Fan, M., Malhi, S. S., Schoenau, J. J., Six, J. and Plante, A. F. 2014. Testing for soil carbon saturation behavior in agricultural soils receiving long-term manure amendments. Can. J. Soil Sci. 94: 281–294. Agricultural soils are typically depleted in soil organic matter compared with their undisturbed counterparts, thus reducing their fertility. Organic amendments, particularly manures, provide the opportunity to restore soil organic matter stocks, improve soil fertility and potentially sequester atmospheric carbon (C). The application of the soil C saturation theory can help identify soils with large C storage potentials. The goal of this study was to test whether soil C saturation can be observed in various soil types in agricultural ecosystems receiving long-term manure amendments. Seven long-term agricultural field experiments from China and Canada were selected for this study. Manure amendments increased C concentrations in bulk soil, particulate organic matter+sand, and silt+clay fractions in all the experiments. The increase in C concentrations of silt+clay did not fit the asymptotic regression as a function of C inputs better than the linear regression, indicating that silt+clay did not exhibit C saturation behavior. However, 44% of calculated C loading values for silt+clay were greater than the presumed maximal C loading, suggesting that this maximum may be greater than 1 mg C m−2 for many soils. The influences of soil mineral surface properties on C concentrations of silt+clay fractions were site specific. Fine soil particles did not exhibit C saturation behavior likely because current C inputs were insufficient to fill the large C saturation deficits of intensely cultivated soils, suggesting these soils may continue to act as sinks for atmospheric C.

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