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Effects of Land Use on Soil Inorganic Carbon Stocks in the Russian Chernozem

Clemson University, Department of Forestry and Natural Resources, 261 Lehotsky Hall, Clemson, SC 29634-0359

^* Corresponding author (eleanam{at}clemson.edu)

Received for publication April 28, 2005.

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Little is known about changes in soil inorganic carbon (SIC) stocks with depth and with land use in grassland ecosystems. This study was conducted to determine SIC stocks under different management regimes in the Mollisol, one of the typical soils in grasslands. Four sites were sampled: a native grassland field (not cultivated for at least 300 yr), an adjacent 50-yr continuous fallow field, a yearly cut hay field in the V.V. Alekhin Central-Chernozem Biosphere State Reserve in the Kursk region of Russia, and a continuously cropped field in the Experimental Station of the Kursk Institute of Agronomy and Soil Erosion Control. All sampled soils were classified as fine-silty, mixed, frigid Pachic Hapludolls. Significant differences occurred in SIC stocks between cultivated and grassland soil. The inorganic carbon stocks in the top 2 m were 107 Mg ha^–1 for the native grassland, 91 Mg ha^–1 for the yearly cut hay field, 242 Mg ha^–1 for the continuously cropped field, and 196 Mg ha^–1 for the 50-yr continuous fallow. The SIC was in the form of calcium carbonate and was mostly stored below the 1-m depth. The largest difference between inorganic carbon stocks was observed between the continuously cropped field and native grassland. The increase in inorganic carbon in the continuously cropped field and continuous fallow was attributed to initial cultivation and fertilization. Soil inorganic carbon in Mollisols is not accounted for in the current global carbon estimates.

Abbreviations: SIC, soil inorganic carbon

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
SOILS PLAY an important role in the global carbon budget, and therefore it is important to account for soil carbon stocks in different soils under different land use regimes. Concerns about the effects of global climate change have triggered intensive research over recent decades on the impacts of cultivation on soil organic C stocks in some of the world's most productive soils, such as Mollisols (Tiessen et al., 1982; Mikhailova et al., 2000b; Mikhailova and Post, 2005). The little research that has been done on SIC was primarily in low-fertility Aridisols, which are soils typical of desert ecosystems (Schlesinger, 1982; Amundson and Lund, 1987). The largest amount of SIC is present in the form of soil carbonates (Schlesinger, 2002) and they account for one-third of the total carbon in soil (Ming, 2002). Calcite (CaCO₃) is the most common carbonate in soil, in contrast to dolomite [CaMg(CO₃)₂], aragonite (CaCO₃), and siderite (FeCO₃), which are found in some soils (Ming, 2002). Carbonates may be either inherited from the soil parent material (lithogenic) or newly formed as a result of soil processes (pedogenic) (Ming, 2002). Carbonates play an important role in the global C cycle with the following pedospheric interactions: (i) exchange between atmosphere, ocean, and terrestrial carbon pools as a result of decomposition of Ca-bearing materials and (ii) carbon sequestration in soil through the formation of secondary carbonates (Lal and Kimble, 2000). The estimates of SIC stocks range from 930 Pg (Schlesinger, 1997) to 1738 Pg (Eswaran et al., 1995) of carbonate C in the top 1-m soil depth. There is a lack of knowledge on the SIC pool in different soil orders and its land use dynamics. Attempts to decrease the atmospheric CO₂ concentration require understanding mechanisms of SIC formation in different soils, especially soils of great agricultural importance, such as Chernozems (Mollisols).

Mollisols are the eighth most common soil order in the world and they cover about 7% of the ice-free land (Bell and McDaniel, 2000). Mollisols develop on a variety of parent materials, but are mostly associated with Ca-rich substrates, resulting in significant quantities of CaCO₃ in the soil profile. Mollisols are typical of grassland ecosystems, which are characterized by high organic matter production rich in basic nutrients, especially Ca²⁺.

The objective of this study was to evaluate the long-term cultivation effects on SIC stocks and distribution in the Russian Chernozem (Mollisol) to a depth of 2 m.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Field Sites
Four fields were sampled in the Kursk region of Russia in the summers of 1997 and 1998: a native grassland, a 50-yr continuous fallow field, a yearly cut hay field, and a continuously cropped field. The climate in the region is temperate, moderately cold, with a mean annual precipitation of 587 mm, and a mean annual air temperature of 5.4°C (V.V. Alekhin Central-Chernozem Biosphere State Reserve, 1947–1997). Sampling fields were carefully selected with similar soil type and landscape position. The soils were formed in loess deposits over Tertiary aged sand or over Cretaceous chalks (Afanasyeva, 1966). All sampled soils were classified as fine-silty, mixed, frigid Pachic Hapludolls (Soil Survey Staff, 1998).

The first three fields (native grassland, 50-yr continuous fallow field, and yearly cut hay field) are located in the Streletskyi section of the V.V. Alekhin Central-Chernozem Biosphere State Reserve (51° N, 36° E), approximately 18 km south of the city of Kursk (Vinogradov, 1984). Elevation of these sites is approximately 264 m above mean sea level (Ryabov, 1979). Dominant plant species in the native grassland and yearly cut hay field include meadow brome grass (Bromus riparius Rehm.), great feather grass (Stipa pennata L.), narrow-leaved meadow grass (Poa angustifolia L.), intermediate wheatgrass [Agropyron intermedium (Host.) Beav.], dropwort (Filipendula vulgaris Moench), and wild strawberry [Fragaria viridis (Duch.) Weston] (Mikhailova et al., 2000a). The fourth field, the continuously cropped field, is located in the Experimental Station of the Kursk Institute of Agronomy and Soil Erosion Control. It has been cropped with soybean [Glycine max (L.) Merr.], red clover (Trifolium pratense L.), barley (Hordeum vulgare L.), corn (Zea mays L.), sugar beet (Beta vulgaris L.), winter wheat (Triticum aestivum L.), and sunflower (Helianthus annuus L.), and received various fertilizer and manure inputs in the past 10 yr (Mikhailova et al., 2000b). The depth to water table is 10 to 12 m (Afanasyeva, 1966). Table 1 provides a brief description of the sampling fields and characteristics of the topsoil. Detailed descriptions of the study area and soil organic C and soil bulk density data are in Mikhailova et al. (2000a, 2000b). The cropped field received various manure and fertilizer treatments documented for 10 yr from 1988 to 1997 (Mikhailova et al., 2000b).

Laboratory Methods
Soil samples from each 10-cm depth increment were air-dried, manually crushed, and passed through a 2-mm sieve. One soil profile was randomly selected from each of the sampled fields and particle-size distribution was determined for each of the 10-cm depth increments by the pipette method after pretreating for removal of carbonates with 1 M NaOAc (adjusted to pH 5). Additional pretreatments included organic matter removal with 30% H₂O₂ and soluble salt removal by ceramic candle filtering and repeated washing with deionized water (Gee and Bauder, 1986). Samples from the same soil profiles were used for chemical analysis. Soil pH was measured from a 1:1 soil to water suspension (McLean, 1982). Exchangeable cations were extracted with 1 M NH₄OAc at pH 7.0 using an E2 vacuum extractor (Zero-Max, Plymouth, MN) as described in Method S2030 of the Cornell University Nutrient Analysis Laboratory (McClenahan and Ferguson, 1989). Cation exchange capacity was determined by summation of cations.

Soil organic and total C were determined by dry combustion-mass spectrometry using a Robo-prep-Tracemass system (Europa Scientific, Cheshire, UK), with inorganic carbon calculated by the difference. Samples that reacted to 10% HCl were treated with 4 M HCl for carbonate removal before analysis. Elemental composition of carbonates was determined by scanning electron microscope (SEM) (Model S-3500N; Hitachi, Tokyo, Japan). The soil particle separates (<2 mm) were glued onto the sampler holders, and then coated with gold for 2 and 4 min in a vacuum coating chamber. Soil inorganic C was converted to CaCO₃ equivalent based on the fact that 12.011 g of C will have 100.087 g of CaCO₃.

Inorganic C stocks were calculated by adjusting soil mass for bulk density (Afanasyeva, 1966; Mikhailova et al., 2000b) to correct for changes in bulk density due to cultivation (Ellert and Bettany, 1995). Profile data were combined for each soil treatment by 10-cm depth increments within each land use and averaged for each 10-cm depth increment. The data are presented as the SIC stock (Mg ha^–1) in 10-cm depth increments. Total SIC stock in the 2-m soil profile is calculated by summation of SIC stock in each of the 10-cm depth increments. Statistical differences were determined by the Tukey method of multiple comparisons (Neter et al., 1990) using the Minitab statistical software program (Ryan and Joiner, 1994).

	RESULTS AND DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Elemental composition obtained by SEM shows that inorganic carbon in these soils is in CaCO₃ form. Soil inorganic C concentrations for the four sites are shown in Fig. 1. In contrast to soil organic carbon distribution with depth (Mikhailova et al., 2000b; Mikhailova and Post, 2005), most SIC is concentrated below the 1-m depth and its distribution is highly variable within each of the treatments. In the native grassland (Fig. 1a), depth to carbonates varies between 130 and 150 cm in four profiles and 35 cm in one profile, which shows signs of faunalpedoturbation and carbonates may have been brought closer to the earth surface by moles (Fanning and Fanning, 1989). In the hay treatment (Fig. 1b), depth to carbonates varies between 100 and 130 cm in three profiles, and two profiles do not show any carbonates at the 2-m depth. In the cropping treatment (Fig. 1c), depth to carbonates varies between 30 and 50 cm in all profiles, and there is low variation between SIC distribution within 10-cm depth increments in all treatments, probably because of continuous mixing of the topsoil as a result of the cultivation and planting. In the fallow treatment (Fig. 1c), depth to carbonates varies between 40 and 120 cm in the profiles, and SIC distribution within 10-cm depth increments is somewhat variable. Overall, there seems to be a trend of decreasing depth to carbonates as a result of cultivation, with the shallowest depth to carbonates in the cropping treatment (Fig. 1c). It does not appear that soil erosion has impacted the thickness of soil horizons (Fig. 2). All profiles show increases in SIC with depth, but the quantity and vertical distribution of SIC varies among management regimes.

View larger version (21K): [in this window] [in a new window]   Fig. 1. Soil inorganic carbon (C) concentration distribution with depth. Different symbols indicate replicate soil profiles within a treatment.

View larger version (18K): [in this window] [in a new window]   Fig. 2. Thickness of soil horizons in the soil profiles under different land use.

View larger version (19K): [in this window] [in a new window]   Fig. 3. Changes in soil inorganic carbon (C) stocks in cultivated soils relative to native grassland.

View larger version (17K): [in this window] [in a new window]   Fig. 4. Comparison of soil organic (Mikhailova and Post, 2005) and inorganic carbon (C) stocks under different land use.

• The per descensum model: Dissolution of preexisting carbonates in the upper profile by atmospheric additions, their vertical translocation, and their precipitation in the subsoil (Marion et al., 1985).
  
• The per ascensum model: Carbonate formation resulting from capillary rise of Ca²⁺ and bicarbonate from shallow water tables and subsequent precipitation of carbonates in soil (Sobecki and Wilding, 1983).
  
• The in situ model: Short range carbonate dissolution and re-precipitation of carbonates close to bedrock (Rabenhorst and Wilding, 1986).
  
• The biogenic model: Calcium carbonate formation as a result of biological factors such as plants, microbes, termites, etc. (Cerling, 1984; Monger, 2002).
  
• The freeze model: Precipitation of carbonates due to an increase in ion concentrations from ion exclusion during ice formation (Cerling, 1984).
  

Soils are complex and there may be a combination of the above described models to explain carbonate precipitation. In view of findings of an SIC increase as a result of cultivation both in the Russian Chernozem and Mollisols of the Northern Great Plains of the United States, we propose an "anthropogenic" model to describe carbonate formation as a result of human activities, such as cultivation, fertilization (can be a significant source of Ca²⁺ for carbonate formation), and others.

	CONCLUSIONS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 
Soil inorganic carbon in Mollisols is not accounted for in the current global carbon estimates, because most of SIC stocks are below the 1-m profile depth commonly used in global carbon estimates. Soil inorganic carbon distribution is highly variable and dynamic in both grassland and cultivated soils. This study found a significant increase in SIC stocks in cultivated soils compared to grassland soils, which is consistent with findings for similar soils in the Northern Great Plains of the United States. An anthropogenic model of carbonate formation is proposed to explain the carbonate precipitation as a result of cultivation, irrigation, fertilization, and other man-made processes. Reported results show that it is important to sample the soil profile to at least 2 m to fully capture the SIC stocks and changes as a result of cultivation.

	ACKNOWLEDGMENTS

 
We wish to acknowledge the many people and organizations in Russia who have contributed to this study. We would like to thank the V.V. Alekhin Central-Chernozem Biosphere State Reserve, especially N.A. Maleshin, N.I. Zolotuhin, and O.S. Boiko, and the Russian Institute of Agronomy and Soil Erosion Control in Kursk and its director, V.M. Volodin. The authors greatly appreciate field assistance by E.K. Daineko, Kathy Bryant, and Aleksei Ivanov. This research was supported by National Science Foundation (NSF Grant #2003958).

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS REFERENCES

 

• Afanasyeva, E.A. 1966. Chernozems of the Middle Russian Upland. (In Russian.) Nauka. Moscow.
• Amundson, R.G., and L.J. Lund. 1987. The stable isotope chemistry of a native and irrigated Typic Natrargid in the San Joaquin Valley of California. Soil Sci. Soc. Am. J. 51:761–767.[Abstract/Free Full Text]
• Bell, J.C., and P.A. McDaniel. 2000. Mollisols. p. E-286 to E-307. In M.E. Sumner (ed.) Handbook of soil science. CRC Press, Boca Raton, FL.
• Cerling, T.E. 1984. The stable isotopic composition of modern soil carbonate and its relationship to climate. Earth Planet. Sci. Lett. 71:229–240.
• Cihacek, L.J., and M.G. Ulmer. 2002. Effects of tillage on inorganic carbon storage in soils of the Northern Great Plains of the U.S. p. 63–69. In R. Lal et al. (ed.) Agriculture practices and policies for carbon sequestration in soil. Lewis Publ., CRC Press, Boca Raton, FL.
• Ellert, B.H., and J.R. Bettany. 1995. Calculation of organic matter and nutrients stored in soils under contrasting management regimes. Can. J. Soil Sci. 75:529–538.
• Eswaran, H., H. Van den Berg, P. Reich, and J. Kimble. 1995. Global soil C resources. p. 27–44. In R. Lal et al. (ed.) Soils and global change. CRC/Lewis Publ., Boca Raton, FL.
• Fanning, D.S., and M.C.B. Fanning. 1989. Soil morphology, genesis and classification. John Wiley & Sons, New York.
• Gee, G.W., and J.W. Bauder. 1986. Particle-size analysis. p. 383–411. In A. Klute (ed.) Methods of soil analysis. Part 1. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Lal, R., and J. Kimble. 2000. Pedogenic carbonates and the global carbon cycle. p. 2–14. In R. Lal et al. (ed.) Global climate change and pedogenic carbonates. CRC Press, Boca Raton, FL.
• Marion, G.M., W.H. Schlesinger, and P.J. Fonteyn. 1985. CALDEP: A regional model for soil CaCO₃ (caliche) deposition in southwestern deserts. Soil Sci. 139:468–481.
• McClenahan, M.C., and G.A. Ferguson. 1989. Methods for soil, plant, and water analysis. Cornell Univ. Nutrient Analysis Lab., Dep. of Agron., Cornell Univ., Ithaca, NY.
• McLean, E.O. 1982. Soil pH and lime requirement. p. 199–224. In A.L. Page et al. (ed.) Methods of soil analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Mikhailova, E.A., R.B. Bryant, D.J.R. Cherney, C.J. Post, and I.I. Vassenev. 2000a. Botanical composition, soil and forage quality under different management regimes in Russian grasslands. Agric. Ecosyst. Environ. 80:213–226.[CrossRef]
• Mikhailova, E.A., R.B. Bryant, I.I. Vassenev, S.J. Schwager, and C.J. Post. 2000b. Cultivation effects on soil carbon and nitrogen contents at depth in the Russian Chernozem. Soil Sci. Soc. Am. J. 64:738–745.[Abstract/Free Full Text]
• Mikhailova, E.A., and C.J. Post. 2005. Organic carbon stocks in the Russian Chernozem. Eur. J. Soil Sci. (in press).
• Ming, D.W. 2002. Carbonates. p. 139–141. In R. Lal (ed.) Encyclopedia of soil science. Marcel Dekker, New York.
• Monger, C.H. 2002. Pedogenic carbonate: Links between biotic and abiotic CaCO₃. p. 897-1 to 897-9. In Proc. 17th WCSS (World Congress of Soil Science), Bangkok, Thailand. 14–21 Aug. 2002.
• Neter, J., W. Wasserman, and M.H. Kutner. 1990. Applied statistical models: Regression, analysis of variance, and experimental designs. 3rd ed. Richard D. Irwin, Chicago.
• Rabenhorst, M.C., and L.P. Wilding. 1986. Pedogenesis on the Edwards Plateau, Texas: I. Nature and continuity of parent material. Soil Sci. Soc. Am. J. 50:678–687.[Abstract/Free Full Text]
• Ryabov, V.A. 1979. Climatological characteristic of the Central-Chernozem Reserve. (In Russian.) p. 5–72. In Transactions of the Central-Chernozem State Biosphere Reserve named after V.V. Alekhin. Vol. 12. Gidrometeoizdat, Leningrad.
• Ryan, B.F., and B.L. Joiner. 1994. Minitab handbook. 3rd ed. Duxbury Press, an imprint of Wadsworth Publ., Belmont, CA.
• Schlesinger, W.H. 1982. Carbon storage in the caliche of arid soils: A case study from Arizona. Soil Sci. Soc. Am. J. 4:247–255.
• Schlesinger, W.H. 1997. Biogeochemistry: An analysis of global change. 2nd ed. Academic Press, San Diego.
• Schlesinger, W.H. 2002. Inorganic carbon and the global carbon cycle. p. 706–708. In R. Lal (ed.) Encyclopedia of soil science. Marcel Dekker, New York.
• Sobecki, T.M., and L.P. Wilding. 1983. Formation of calcic and argillic horizons in selected soils of the Texas Coast Prairie. Soil Sci. Soc. Am. J. 47:707–715.[Abstract/Free Full Text]
• Soil Survey Staff. 1998. Keys to soil taxonomy. 8th ed. USDA-NRCS, Washington, DC.
• Tiessen, H., J.W. Stewart, and J.R. Bettany. 1982. Cultivation effects on the amounts and concentration of carbon, nitrogen, and phosphorus in grassland soils. Agron. J. 74:831–835.[Abstract/Free Full Text]
• Vinogradov, B.V. 1984. Aerospace studies of protected natural areas in the USSR. p. 435–448. In Conservation, science and society. Natural Resources Research, XXI, Vol. 2. UNESCO-UNEP, Paris.
• V.V. Alekhin Central-Chernozem Biosphere State Reserve. 1947–1997. Letopis' prirody (Annual scientific reports). Vol. 1–63. V.V. Alekhin Central-Chernozem Biosphere State Reserve, Kursk, Russia.

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