Khadijeh Salari NİK, Mohsen NAEL, Ghasem ASSADİAN, Ali Akbar Safari SİNEGANİ, Soheila Javaheri KHA

Soil organic carbon fractions as influenced by vegetation type and land management: A case study in semiarid rangelands of Hamedan, Iran

Soil is an environmental component permanently changing due to the often cyclic processes of litter supply and vegetation cover. To investigate the influence of vegetation type on soil carbon fractions, six vegetation types, including rainfed wheat (RW), grasses (G), Astragallus–Bromus (A-B), Astragallus–lactuca (A-L), Astragallus–Artemisi (A-A), Astragallus–Euphorbia (A-E) were studied in similar environmental conditions in terms of parent material and slope aspect in Gonbad watershed, Hamadan. Total organic carbon (TOC), active carbon (AC), soil carbohydrates (Ch) and basal respiration (BR) were measured in surface soils (0-15 cm) in fall and spring. TOC, CH, and BR were significantly greater in A-B and A-A than other covers. A-B and A-A showed higher vegetation cover and litter compared to other types. TOC and Ch in RW and G were significantly lower than other types. The highest (711.7 mg/kg) and lowest (262.6 mg/kg) AC were observed in A-B and RW, respectively. RW had lowest values of selected soil quality indicators due to tillage and cultivation. The content of TOC and AC were significantly higher in spring than autumn. Amount of BR and Ch showed no significant difference in the two seasons. Significant positive correlations were observed between soil quality indicators, these correlations were stronger in spring than in autumn. In autumn, the highest correlations were observed between AC and Ch (0.701), as well as AC and BR (0.441). In spring, significant correlations were observed between all soil quality indicators at 1% level. It was concluded that AC and Ch are the most sensitive soil quality indicators that reflect land use and vegetation type differences.

Keywords:

soil quality, vegetation type, active carbon, carbohydrate,

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Anonymous, 2008. Meteorological Information Center of Iran (Hamadan), Statistics and information Meteorological Station of Hamedan. Available at: www.hamedanmet.ir.
Bahrami, A., 2012. Modeling soil organic carbon dynamics using APEX Gonbad paired watersheds. Master's thesis. Bu Ali Sina University. Faculty of Agriculture.
Boehm, M.M., Anderson, D.W., 1997. A landscape–scale study of soil quality in three prairie farming systems. Soil Science Society of America Journal 61(4): 1147-1159.
Boone, R.D., Nadelhoffer, K.J., Canary, J.D., Kaye, J.P., 1998. Roots exert a strong influence on the temperature sensitivity of soil respiration. Nature 396: 570–572.
Dubois, M., Gilles, K. A., Hamilton, J. K., Rebers, P. A., Smith, F., 1956. Colorimetric method of determination of sugars and related substances. Analytical. Chemistry 28: 350–356.
Franzluebbers, A. J., Haney, R. L., Honeycutt, C. W., Arshad, M. A., Schomberg, H. H., Hons, F. M., 2001. Climatic influences on active fractions of soil organic matter. Soil Biology and Biochemistry 33(7–8): 1103–1111.
Franzluebbers, A.J., 2010. Soil organic carbon in managed pastures of the southeastern United States of America. In: Abberton, M., Conant, R., Batello, C. (Eds.), Grassland Carbon Sequestration: Management, Policy and Economics. Integrated Crop Manage, vol. 11. United Nations Food Agric, Org., Rome, Italy, p. 163-175.
Graham, M.H., Haynes, R.J., Meyer, J.H., 2002. Soil organic matter content and quality: Effects of fertilizer applications, burning and trash retention on a long-term sugarcane experiment in South Africa. Soil Biology and Biochemistry 34, 93–102.
Greenland, D J., Oades, J.M., 1975. Saccharides. In: Gieseking, J. E. (Eds), Soil Components. Vol. I. Springer-Verlag. New York. pp. 213-261.
Gregorich, E. G., Drury, C. F., Ellert, B. H., Liang, B. C., 1997. Fertilization effects on physically protected light fraction organic matter. Soil Science Society of America Journal 61: 482–484.
Haynes, R.J., Beare, M.H., 1996. Aggregation and organic matter storage in mesothermal, humid Soils. In ‘‘Structure and Organic Matter Storage in Agricultural Soils. In: Carter, M. R., Stewart, B. A. (Eds), pp. 213–262. CRC Press, Boca Raton, FL.
Isermeyer, H., 1952. Eine einfache Methode sur Bestimmung der Bodenatmung and der carbonate in Boden. Z. Pflanzenernähr Bodenkunde 56: 26-38.
Islam, K.R., Weil, R.R., 2000. Land use effects on Soil quality in a tropical forest ecosystem of Bangladesh. Agriculture, Ecosystems and Environment 79: 9-16.
Jonasson, S., Castro, J., Michelsen, A., 2004. Litter, warming and plant affect respiration and allocation of soil microbial and plant C, N and P in Arctic mesocosms. Soil Biology and Biochemistry 36: 1129–1139.
Parton, W.J., Schimel, D.S., Cole, C.V., Ojima, D.S., 1987. Analysis of factors controlling soil organic matter levels in Great Plain grassland. Soil Science Society of America Journal 51: 1173–1179.
Spohn, M., Giani, L., 2011. Total, hot water extractable, and oxidation-resistant carbon in sandy hydromorphic soils-Analysis of a 220-year chronosequence. Plant and Soil 338: 183-192.
Walkley, A., Black, I. A., 1934. An examination of Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid in soil analysis. Experimental Soil Science 79: 459-465.
Weil, R.R., Islam, K.R., Stine, M.A., Gruver, J.B., Samson-Liebig, S.E., 2003. Estimating active carbon for soil quality assessment: a simplified method for laboratory and field use. American Journal of Alternative Agriculture 18: 3–17.