Organic and Inorganic Carbon Storage in the Soils of Sardooeyeh Semi-arid Region in South of Kerman

Document Type : Research Article

Authors

• H.R. Rafiei ¹
• A. Jafari ¹
• A. Heidari ²
• Mohammad Hady Farpoor
• A. Abbasnejad ³

¹ Department of Soil Science, Agriculture Faculty, Shahid Bahonar University of Kerman

² Department of Soil Science Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran

³ Department of geology, Faculty of sciences, Shahid Bahonar University of Kerman

https://doi.org/10.22067/jsw.v35i1.82133

Abstract

Introduction: Soil carbon (C) sequestration is recognized as a potentially significant option to off-set the elevation of global atmospheric carbon dioxide (CO₂) concentrations. Soils are the main sink/source of carbon and also, an important component of the global C cycle. Total soil carbon (C) comprises of the soil organic C (SOC) and the soil inorganic C (SIC) components. The soil inorganic C (SIC) stock mainly consists of carbonates and bicarbonates. Processes governing the dynamics of the soil carbon stock differ among ecoregions and strongly interact with soil properties. Understanding the distribution of organic and inorganic carbon stocks in soil profiles is essential for assessing carbon storage at the regional and global scale. Although global estimates provide a general view of carbon stock levels, accurate local estimates and factors affecting soil carbon dynamics are very important. As a result, there is an essential requirement for accurately estimating the distribution of carbon reserves and their differences with regard to soil properties.
Materials and Methods: The study area is located in the Sardooeyeh region, South of Kerman, under semiarid conditions. A total of 5 soil profiles were excavated. Percentage of coarse fragments (> 2 mm) using a 2 mm sieve, total organic C by the K₂Cr₂O₇-H₂SO₄ oxidation method of Walkley-Black, soil inorganic carbon using the Gravimetric carbonate meter method were determined. Bulk density was measured by drying core samples in an oven overnight and dividing the weight of dry soil by the volume of the core occupied by the soil after correction for coarse fragments.
Results and Discussion: Organic carbon in the surface horizons of all profiles is maximum due to vegetation and decreases with increasing soil depth. As the altitude increased, the amount of organic carbon increased in the surface horizons. Lower temperature and higher humidity at higher altitudes lead to the lower organic matter decomposition and consequently higher organic carbon content of the soil. Although the upper soil layers had the maximum soil organic C content, the maximum soil inorganic C content was observed in the sub-surface layers. The soil organic carbon storage was between 5.52 to 9.48 kg m^-2 and the storage of soil inorganic carbon in profiles was between 14.41 and 91.34 kg m^-2. The total soil carbon storage in the profiles varied between 19.92 to 100.83 kg m^-2 and the average was 42.66 kg m^-2. The average of soil organic carbon storage in 0-25, 25-60, 60-120 cm depths were 2.6, 1.97 and 1.26 kg m^-2, respectively. The amount of soil inorganic carbon storage in 0 -25, 25-60 and 60-120 cm depths were equal to 2.7, 10.40 and 8.26 kg m^-2, respectively. Therefore, it seems that more than 50% of the total soil inorganic carbon storage is stored at a depth of 25-60 cm from the soil surface. The portion of inorganic carbon storage of total soil carbon was 77.5%, and about 89% of it was stored in sub-surface horizons (below 25 cm). The portion of organic carbon storage of total soil carbon was 22.4%. It seems that an increase in the partial pressure of CO₂ in soils leads to some dissolution of the pedogenic carbonate in the top soil. Dissolved pedogenic carbonate transfers to the deep soil and then re-crystallizes under relatively dry conditions and low CO₂.
Conclusion: The results showed that soil organic carbon storage was mostly higher in surface horizons, and soil inorganic carbon storage was higher in sub-surface horizons. On average, the ratio of soil inorganic carbon storage to soil organic carbon storage was 4.27. The high percentage of soil inorganic carbon storage in total soil carbon, shows that inorganic carbon plays a very important role in semi-arid regions. Almost 89% of the soil inorganic carbon content and about 80% of the total soil carbon were accumulated in the sub-surface horizon of soil (below 25 cm), indicating the importance of sub-surface soil for storing carbon in semi-arid regions.

Keywords

• Climate change
• Deep soil carbon
• Total soil carbon
• Global warming

20.1001.1.20084757.1400.35.1.3.8

References

1. Ajami M., Heidari A., Khormali F., Gorji M., and Ayoubi S. 2016. Environmental factors controlling soil organic carbon storage in loess soils of a subhumid region, northern Iran. Geoderma 281: 1-10.
2. Alidoust E., Afyuni M., Hajabbasi M.A., and Mosaddeghi M.R. 2018. Soil carbon sequestration potential as affected by soil physical and climatic factors under different land uses in a semiarid region. Catena 171: 62-71.
3. Bishop T.F.A., McBratney A.B., and Laslett G.M. 1999. Modelling soil attribute depth functions with equal-area quadratic smoothing splines. Geoderma 91: 27-45.
4. Bower C.A., and Hatcher J.T. 1966. Simultaneous determination of surface area and cation exchange capacity. Soil Science Society of America Journal 30: 525–527.
5. Bughio M.A., Wang P., Meng F., Qing C., Kuzyakov Y., Wang X., and Junejo S.A. 2016. Neoformation of pedogenic carbonates by irrigation and fertilization and their contribution to carbon sequestration in soil. Geoderma 262: 12-19.
6. Du C., and Gao Y. 2020. Opposite patterns of soil organic and inorganic carbon along a climate gradient in the alpine steppe of northern Tibetan Plateau. Catena 186: 104366.
7. Ekelund F., Rønn R., and Christensen S. 2001. Distribution with depth of protozoa, bacteria and fungi in soil profiles from three Danish forest sites. Soil Biology and Biochemistry 33: 475–481.
8. Eshel G., Fine P., and Singer M.J. 2007. Total soil carbon and water quality: an implication for carbon sequestration. Soil Science Society of America Journal 71: 397-405.
9. Eswaran H., Reich F.P., Kimble J.M., Beinroth F.H., Padamnabhan E., Moncharoen P. 2000. Global carbon stocks. In: Lal R., Kimble J.M., Eswaran H., Stewart B.A. (Eds.), Global Climate Change and Pedogenic Carbonates. CRC/Lewis, Boca Raton, FL.
10. Gebeyehu G., Soromessa T., Bekele T., and Teketay D. 2019. Carbon stocks and factors affecting their storage in dry Afromontane forests of Awi Zone, northwestern Ethiopia. Journal of Ecology and Environment 43: 1-18.
11. Gile L.H., Peterson F.F., and Grossman R.B. 1966. Morphological and genetic sequences of carbonate accumulation in desert soil. Soil Science 101: 347-360.
12. Han X., Gao G., Chang R., Li Z., Ma Y., Wang S., and Fu B. 2018. Changes in soil organic and inorganic carbon stocks in deep profiles following cropland abandonment along a precipitation gradient across the Loess Plateau of China. Agriculture, Ecosystems and Environment 258: 1-13.
13. Hanson P.J., Edwards N.T., Garten C.T., and Andrews J.A. 2000. Separating root and soil microbial contributions to soil respiration: a review of methods and observations. Biogeochemistry 48: 115-146.
14. Horton Jr R. 2002. Methods of Soil Analysis: Part 4, Physical Methods. Madison, Wisconsin, USA: Soil Science Society of America.
15. Kimble J.M., and Follett R.F. 2000. The potential of US grazing lands to sequester carbon and mitigate the greenhouse effect. CRC press.
16. Lee M.R., Hodson M.E., and Langworthy G. 2008. Earthworms produce granules of intricately zoned calcite. Geology 36: 943-946.
17. Li C., Li Q., Zhao L., Ge S., Chen D., Dong Q., and Zhao X. 2016. Land-use effects on organic and inorganic carbon patterns in the topsoil around Qinghai Lake basin, Qinghai-Tibetan Plateau. Catena 147: 345-355.
18. Liu W., Wei J., Cheng J., and Li W. 2014. Profile distribution of soil inorganic carbon along a chronosequence of grassland restoration on a 22-year scale in the Chinese Loess Plateau. Catena 121: 321-329.
19. Lorenz K., and Lal R. 2018. Carbon Sequestration in Agricultural Ecosystems. Springer.
20. Mikhailova E.A., and Post C.J. 2006. Effects of land use on soil inorganic carbon stocks in the Russian Chernozem. Journal of Environmental Quality 35: 1384-1388.
21. Monger H.C., Kraimer R.A., Khresat S., Cole D.R., Wang X., Wang J. 2015. Sequestration of inorganic carbon in soil and groundwater. Geology 43: 375–378.
22. Monger H.C., and Martinez-Rios J.J. 2002. Inorganic carbon sequestration in grazing lands. In: Follett R.F., Kimble J.M., Lal R. (Eds.), The Potential of US Grazing Lands to Sequester Carbon and Mitigate the Greenhouse Gas Effect. Lewis Publishers, Boca Raton, USA, pp. 87–118.
23. Nelson D.W., Sommers L.E. 1982. Total carbon, organic carbon, and organic matter. In: Page, A.L. (Ed.), Methods of Soil Analysis. Agron. Monger, No Vol. 9. ASA and SSSA, Madison, WI., pp. 539–577
24. Olaya-Abril A., Parras-Alcántara L., Lozano-García B., and Obregón-Romero R. 2017. Soil organic carbon distribution in Mediterranean areas under a climate change scenario via multiple linear regression analysis. Science of the Total Environment 592: 134-143.
25. Philander G., and Philander S.G. 2008. Encyclopedia of global warming and climate change: AE (Vol. 1). Sage.
26. Poeplau C., Vos C., and Don A. 2017. Soil organic carbon stocks are systematically overestimated by misuse of the parameters bulk density and rock fragment content. Soil 3: 61-66.
27. Raheb A., Heidar, A., and Mahmoodi S. 2016. Storage of Organic and Inorganic Carbon in Arid-Semihumid Soils: A Case Study of the Rangelands of Northwestern Iran. Soil Science 181: 473-486.
28. Raheb A., Heidari A., and Mahmoodi S. 2017. Organic and inorganic carbon storage in soils along an arid to dry sub-humid climosequence in northwest of Iran. Catena 153:66-74.
29. Rahimi J., Ebrahimpour M., and Khalili A. 2013. Spatial changes of Extended De Martonne climatic zones affected by climate change in Iran, Theoretical and Applied Climatology 112: 409–418.
30. Rasmussen C. 2006. Distribution of soil organic and inorganic carbon pools by biome and soil taxa in Arizona. Soil Science Society of America Journal 70: 256–265.
31. Rawlins B.G., Henrys P., Breward N., Robinson D.A., Keith A.M., and Garcia‐Bajo M. 2011. The importance of inorganic carbon in soil carbon databases and stock estimates: a case study from England. Soil Use and Management 27: 312-320.
32. Rodriguez J.B., Self J., and Arriaga F.J. 2016. A simple, gravimetric method to quantify inorganic carbon in calcareous soils. Soil Science Society of America Journal 80: 1107-1113.
33. Schaetzl, R. J., and Thompson, M. L. 2015. Soils: Genesis and Geomorphology, Cambridge university press.
34. Schlesinger W.H. 2017. Inorganic carbon: global carbon cycle. In Encyclopedia of soil science (pp. 1203-1205). CRC Press.
35. Schoeneberger P.J., Wysocki D.A., Benham E.C., and Soil Survey Staff. 2012. Field book for describing and sampling soils, Version 3.0. Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE.
36. Soil Science Division Staff. 2017. Soil survey manual. C. Ditzler, K. Scheffe, and H.C. Monger (eds.). USDA Handbook 18. Government Printing Office, Washington, D.C.
37. Soil Survey Staff. 2014. Keys to Soil Taxonomy, 12^th ed. USDA-Natural Resources Conservation Service, Washington, DC.
38. Sreenivas K., Dadhwal V.K., Kumar S., Harsha G.S., Mitran T., Sujatha G and Ravisankar T. 2016. Digital mapping of soil organic and inorganic carbon status in India. Geoderma 269: 160-173.
39. Stanbery C.A., Pierce J.L., Benner S.G., and Lohse K. 2017. On the rocks: Quantifying storage of inorganic soil carbon on gravels and determining pedon-scale variability. Catena 157: 436-442.
40. Wang J.P., Wang X.J., Zhang J., and Zhao C.Y. 2015. Soil organic and inorganic carbon and stable carbon isotopes in the Yanqi Basin of northwestern China. European Journal of Soil Science 66: 95-103.
41. Wang, Y., Li, Y., Ye, X., Chu, Y., and Wang, X. 2010. Profile storage of organic/inorganic carbon in soil: From forest to desert. Science of the Total Environment, 408: 1925-1931.
42. Wang Z.P., Han X.G., Chang S.X., Wang B., Yu Q., Hou L.Y., and Li L.H. 2013. Soil organic and inorganic carbon contents under various land uses across a transect of continental steppes in Inner Mongolia. Catena 109: 110-117.
43. Yang Y., Fang J., Ji C., Ma W., Mohammat A., Wang S., and Smith P. 2012. Widespread decreases in topsoil inorganic carbon stocks across China's grasslands during 1980s–2000s. Global Change Biology 18:3672-3680.
44. Zhang F., Wang X., Guo T., Zhang P., and Wang J. 2015. Soil organic and inorganic carbon in the loess profiles of Lanzhou area: implications of deep soils. Catena 126: 68-74.
45. Zhao W., Zhang R., Huang C., Wang B., Cao H., Koopal L.K., and Tan W. 2016. Effect of different vegetation cover on the vertical distribution of soil organic and inorganic carbon in the Zhifanggou Watershed on the loess plateau. Catena 139: 191-198.