Soil Organic Carbon Dynamics and Driving Factors in Typical Cultivated Land on the Karst Plateau

Due to the impacts of unwise industrial agriculture, extreme precipitation events are increasing in frequency and are accelerating the process of global warming in the karst area. The dynamic change in soil organic carbon (SOC) and its driving factors in cultivated land in the last 35 years were studied by using data from the second national soil survey of China and measurements made in 2015. The results indicated that the SOC per unit area of cultivated land increased by 32.45 × 103 t in the last 35 years in the study area, exhibiting basically the same levels and a slight increasing trend, and the annual average change rate was 0.02 kg C·hm−2·a−1. In terms of spatial distribution, carbon loss areas were mainly concentrated in the middle northern region, western region, and scattered eastern regions of the county. The main factors affecting the change in SOC in the cultivated land in the study area in the last 35 years include nitrogen fertilizer application, stubble, soil thickness, soil total nitrogen, C/N, rock coverage, gravel content, soil organic carbon density (SOCD1980), etc. This study will provide a database for the management of SOC in cultivated land in the future.

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Can Agricultural Management Induced Changes in Soil Organic Carbon Be Detected Using Mid-Infrared Spectroscopy?

Remote Sensing ◽

10.3390/rs13122265 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2265

Author(s):

Jonathan Sanderman ◽

Kathleen Savage ◽

Shree Dangal ◽

Gabriel Duran ◽

Charlotte Rivard ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Carbon ◽

Diffuse Reflectance Spectroscopy ◽

Low Cost ◽

Soil Survey ◽

Mid Infrared ◽

Mir Spectroscopy ◽

Induced Changes ◽

Carbon Change

A major limitation to building credible soil carbon sequestration programs is the cost of measuring soil carbon change. Diffuse reflectance spectroscopy (DRS) is considered a viable low-cost alternative to traditional laboratory analysis of soil organic carbon (SOC). While numerous studies have shown that DRS can produce accurate and precise estimates of SOC across landscapes, whether DRS can detect subtle management induced changes in SOC at a given site has not been resolved. Here, we leverage archived soil samples from seven long-term research trials in the U.S. to test this question using mid infrared (MIR) spectroscopy coupled with the USDA-NRCS Kellogg Soil Survey Laboratory MIR spectral library. Overall, MIR-based estimates of SOC%, with samples scanned on a secondary instrument, were excellent with the root mean square error ranging from 0.10 to 0.33% across the seven sites. In all but two instances, the same statistically significant (p < 0.10) management effect was found using both the lab-based SOC% and MIR estimated SOC% data. Despite some additional uncertainty, primarily in the form of bias, these results suggest that large existing MIR spectral libraries can be operationalized in other laboratories for successful carbon monitoring.

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Supplementary material to "Hot regions of labile and stable soil organic carbon in Germany – Spatial variability and driving factors"

10.5194/soil-2017-30-supplement ◽

2017 ◽

Author(s):

Cora Vos ◽

Angélica Jaconi ◽

Anna Jacobs ◽

Axel Don

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Driving Factors ◽

Supplementary Material

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Spatial Distribution and Reserves Estimation of Soil Organic Carbon Based on GIS in Maiji Area of Tianshui

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.316-317.299 ◽

2013 ◽

Vol 316-317 ◽

pp. 299-306

Author(s):

Ai Hong Gai ◽

Ren Zhi Zhang ◽

Fang Chen ◽

Xiao Long Wang

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Average Density ◽

Soil Survey ◽

Soil Conditions ◽

Carbon Density ◽

Deep Soil ◽

Soil Organic Carbon Density ◽

Secondary Survey ◽

Organic Carbon Storage

The soil organic carbon density and storage of Maiji Area of Tianshui was estmiated, using the data of 6060 soil profile from the second soil survey of China and formulating fertilization for soil conditions in 2008. Integrating the soil map, land use status map and district map of Maiji Area of Tianshui, the index of the characteristic of soil organic distribution in different soil and soil layers were analyzed. Results showed: the soil of Maiji area have low average density, when soil secondary census, depths of 5cm,20cm,1m average density of organic carbon are 0.92kg•m-2,3.31kg•m-2,7.79kg•m-2 respectively, average density of organic carbon at depth of 20cm is 2.43 kg•m-2 in 2008 years, As a standard of Yu Dongsheng’s (2005) estimation of average density of 9.60 kg•m-2 in the depth of 1m all over the China, Maiji area 1m deep soil organic carbon density is lower 1.91kg•m-2 than the average density of whole country; The calculation of the secondary survey, reserves of organic carbon in surface soil (0-5cm) is about 4.83×106t, reserves of organic carbon in fall (0-20cm) is about 12.46×106t, reserves of soil organic carbon in 1m depth is about 45.17×106t, reserves of soil organic carbon in fall (0-20cm) is about 18.55×106t in 2008 years. In a word, the soil organic carbon storage was relatively indigent in Maiji Area of Tianshui.

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