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 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 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

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.

How useful are MIR predictions of total, particulate, humus, and resistant organic carbon for examining changes in soil carbon stocks in response to different crop management? A case study

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 719 ◽  
Author(s):  
K. L. Page ◽  
R. C. Dalal ◽  
Y. P. Dang
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Management Practices ◽  
Crop Management ◽  
Carbon Stocks ◽  
Carbon Pools ◽  
Spectroscopic Techniques ◽  
Direct Measurements ◽  
Soil Carbon Stocks

Measures of particulate organic carbon (POC), humus organic carbon (HOC), and resistant organic carbon (ROC) (primarily char) are often used to represent the active, slow, and inert carbon pools used in soil carbon models. However, these fractions are difficult to measure directly, and mid infrared (MIR) spectroscopic techniques are increasingly being investigated to quantify these fractions and total organic carbon (TOC). This study examined the change in MIR-predicted pools of TOC, POC, HOC, and ROC in response to different crop management between two time periods (1981 and 2008) in a long-term wheat cropping trial in Queensland, Australia. The aims were (i) to assess the ability of MIR to detect changes in carbon stocks compared with direct measurements of TOC (LECO-TOC); and (ii) to assess how well the behaviour of POC, HOC, and ROC corresponded with the active, slow, and inert conceptual carbon pools. Significant declines in carbon stocks were observed over time using both LECO-TOC and MIR-predicted stocks of TOC, POC, HOC, and ROC, although MIR-TOC under-estimated loss by 27–30% compared with LECO-TOC. The decline in MIR-POC and MIR-HOC was consistent with the expected behaviour of the active and slow conceptual pools; however, the decline in ROC was not consistent with that of the inert pool. In addition, MIR measurements did not accurately detect differences in the rate of carbon loss under different crop management practices.

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