Abstract

Soil respiration in agroecosystem, especially in wheat-maize rotation system is a important component in carbon cycle, which is a key index of soil $CO_2$ efflux from soil to atmosphere. To discern the dynamic variation of soil respiration and the relationship between soil respiration and environmental factors, a experiment was conducted in the experimental field of Qingdao agricultural university. In this study $CO_2$ soil efflux was measured by automated soil $CO_2$ flux system (LI-8100A) during the periods from March to June (maize season) and from June to October (wheat season) in 2014, meanwhile the driving environmental factors were measured by eddy covariance system. The $CO_2$ emission rate from wheat soil varied from $1.093 \:μmol \:CO^2 \:m^{-2}s^{-1}$ in March to $6.028 \:μmol \:CO^2 \:m^{-2}s^{-1}$ in June and that for maize soil from $1.80 \:μmol \:CO_2 \:m^{-2}s^{-1}$ in October to $10.36 \:μmol \:CO_2 \:m^{-2}s^{-1}$ in July. The dynamics of GPP was similar to a shape "W" during wheat and maize seasons. Two peaks of GPP lied in April and August. To find the influence of the driving factors to soil respiration, the correlation analysis was processed between soil respiration and seven environment factors. The analysis showed that there was a significant correlation relationship between soil respiration rate and soil temperature at 10 cm depth and soil water content at 10 cm depth. To clearly understand the relationship between soil respiration and soil temperature and soil water content at 10 cm depth, three models $(y = ae^{bx}, \:y = ae^{bx_1} e^{cx_2}$, and $y = ae^{bx_1}x^c_2)$ were used. The results showed that the bivariate compound model was the best model to depict the relationship between soil respiration rate and soil temperature and soil water content at 10 cm depth. About 88% and 78% of temporal variability in soil respiration could be explained by the variations in soil temperature and soil water content during wheat and maize season, respectively, highest in these three regression models.

Keywords:

Correlation analysis, eddy covariance system, model performance, soil respiration,

References

1. Anonymous, 1998. World reference base for soil resources. World Soil Resources, Report No. 84, ISSS-ISRIC-FAO, Food and Agriculture Organization (FAO), Rome, pp: 88.
   
2. Bae, K., D.K. Lee, T.J. Fahey, S.Y. Woo, A.K. Quaye and Y.K. Lee, 2013. Seasonal variation of soil respiration rates in a secondary forest and agroforestry systems. Agroforest. Syst., 87(1): 131-139.
   Direct Link
3. Chen, S.T., Y. Huang, J.W. Zou, Y.S. Shi, Y.Y. Lu et al., 2012. Interannual variability in soil respiration from terrestrial ecosystems in China and its response to climate change. Sci. China Earth Sci., 55(12): 2091-2098.
   Direct Link
4. Dhital, D., H. Muraoka, Y. Yashiro, Y. Shizu and H. Koizumi, 2010. Measurement of net ecosystem production and ecosystem respiration in a Zoysia japonica grassland, central Japan, by the chamber method. Ecol. Res., 25(2): 483-493.
   Direct Link
5. Han, G.X., G.S. Zhou, Z.Z. Xu, Y. Yang, J.L. Liu and K.Q. Shi, 2007. Soil temperature and biotic factors drive the seasonal variation of soil respiration in a maize (Zea mays L.) agricultural ecosystem. Plant Soil, 291(1): 15-26.
   Direct Link
6. Hashimoto, S., N. Tanaka, M. Suzuki, A. Inoue, H. Takizawa, I. Kosaka, K. Tanaka, C. Tantasirin and N. Tangtham, 2004. Soil respiration and soil CO2 concentration in a tropical forest, Thailand. J. Forest Res., 9(1): 75-79.
   Direct Link
7. Inoue, T. and H. Koizumi, 2012. Effects of environmental factors upon variation in soil respiration of a Zoysia japonica grassland, central Japan. Ecol. Res., 27(2): 445-452.
   Direct Link
8. Jin, Z., Y.C. Qi and Y.S. Dong, 2007. Diurnal and seasonal dynamics of soil respiration in desert shrubland of Artemisia Ordosica on Ordos Plateau of Inner Mongolia, China. J. Forest. Res., 18(3): 231-235.
   Direct Link
9. Jing, Y.L., A.Z. Wang, D.X. Guan, J.B. Wu, F.H. Yuan and C.J. Jin, 2014. Carbon dioxide fluxes over a temperate meadow in eastern Inner Mongolia, China. Environ. Earth Sci., 72(11): 4401-4411.
   Direct Link
10. Karelin, D.V., A.V. Pochikalov, D.G. Zamolodchikov and M.L. Gitarskii, 2014. Factors of spatiotemporal variability of CO2 fluxes from soils of southern Taiga spruce forests of Valdai. Contemp. Probl. Ecol., 7(7): 743-751.
    Direct Link
11. Kucharik, C.J., K.R. Brye, J.M. Norman, J.A. Foley, S.T. Gower and L.G. Bundy, 2001. Measurements and modeling of carbon and nitrogen cycling in agroecosystems of southern Wisconsin: Potential for SOC sequestration during the next 50 years. Ecosystems, 4(3): 237-258.
    Direct Link
12. Kuzyakov, Y. and O. Gavrichkova, 2010. REVIEW: Time lag between photosynthesis and carbon dioxide efflux from soil: A review of mechanisms and controls. Glob. Change Biol., 16(12): 3386-3406.
    Direct Link
13. Lal, R., 2002. Soil carbon dynamics in cropland and rangeland. Environ. Pollut., 116(3): 353-362.
    Direct Link
14. Law, B.E., F.M. Kelliher, D.D. Baldocchi, P.M. Anthoni, J. Irvine, D. Moore and S.V. Tuyl, 2001. Spatial and temporal variation in respiration in a young ponderosa pine forest during a summer drought. Agr. Forest Meteorol., 110(1): 27-43.
    Direct Link
15. Li, R.P., G.S. Zhou and Y. Wang, 2010. Responses of soil respiration in non-growing seasons to environmental factors in a maize agroecosystem, Northeast China. Chinese Sci. Bull., 55(24): 2723-2730.
    Direct Link
16. Liu, Y., S.J. Han and L. Lin, 2009. Seasonal changes of soil respiration in Betula platyphylla forest in Changbai Mountain, China. J. Forest. Res., 20(4): 367-371.
    Direct Link
17. Lohila, A., M. Aurela, K. Regina and T. Laurila, 2003. Soil and total ecosystem respiration in agricultural fields: Effect of soil and crop type. Plant Soil, 251(2): 303-317.
    Direct Link
18. Novick, K.A., P.C. Stoy, G.G. Katul, D.S. Ellsworth, M.B. Siqueira, J. Juang and R. Oren, 2004. Carbon dioxide and water vapor exchange in a warm temperate grassland. Oecologia, 138(2): 259-274.
    Direct Link
19. Pilegaard, K., P. Hummelshøj, N.O. Jensen and Z. Chen, 2001. Two years of continuous CO2 eddy-flux measurements over a Danish beech forest. Agr. Forest Meteorol., 107(1): 29-41.
    Direct Link
20. Raich, J.W. and W.H. Schlesinger, 1992. The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate. Tellus B, 44(2): 81-99.
    CrossRef    Direct Link
21. Raich, J.W. and A. Tufekciogul, 2000. Vegetation and soil respiration: Correlations and controls. Biogeochemistry, 48(1): 71-90.
    Direct Link
22. Ren, X.E., Q.X. Wang, C.L. Tong, J.S. Wu, K.L. Wang, Y.L. Zhu, Z.J. Lin, M. Watanabe and G.Y. Tang, 2007. Estimation of soil respiration in a paddy ecosystem in the subtropical region of China. Chinese Sci. Bull., 52(19): 2722-2730.
    Direct Link
23. Reth, S., M. Göckede and E. Falge, 2005. CO2 efflux from agricultural soils in Eastern Germany- comparison of a closed chamber system with eddy covariance measurements. Theor. Appl. Climatol., 80(2): 105-120.
    Direct Link
24. Savage, K.E. and E.A. Davidson, 2003. A comparison of manual and automated systems for soil CO2 flux measurements: Trade-offs between spatial and temporal resolution. J. Exp. Bot., 54(384): 891-899.
    Direct Link
25. Schulze, E.D., 2000. Carbon and Nitrogen Cycling in European Forest Ecosystems. Ecological Studies, Springer-Verlag, Berlin, Heidelberg, Vol. 142.
    Direct Link
26. Subke, J.A., M. Reichstein and J.D. Tenhunen, 2003. Explaining temporal variation in soil CO2 efflux in a mature spruce forest in Southern Germany. Soil Biol. Biochem., 35(11): 1467-1483.
    Direct Link
27. Suyker, A.E., S.B. Verma, G.G. Burba and T.J. Arkebauer, 2005. Gross primary production and ecosystem respiration of irrigated maize and irrigated soybean during a growing season. Agr. Forest. Meteorol., 131(3-4): 180-190.
    Direct Link
28. Tang, J.W., D.D. Baldocchi, Y. Qi and L.K. Xu, 2003. Assessing soil CO2 efflux using continuous measurements of CO2 profiles in soils with small solid-state sensors. Agr. Forest. Meteorol., 118(3-4): 207-220.
    Direct Link
29. Vargas, R., M.S. Carbone, M. Reichstein and D.D. Baldocchi, 2011. Frontiers and challenges in soil respiration research: From measurements to model-data integration. Biogeochemistry, 102(1): 1-13.
    Direct Link
30. Wood, S., K. Sebastian and S.J. Scheerr, 2000. Pilot Analysis of Global Ecosystems: Agroecosystems. IFPRI, WRI, Washington, DC, pp: 2-36.
    
31. Xu, M. and Y. Qi, 2001. Soil-surface CO2 efflux and its spatial and temporal variations in a young ponderosa pine plantation in northern California. Global Change Biol., 7(6): 667-677.
    CrossRef    
32. Yan, J.H., Y.P. Wang, G.Y. Zhou and D.Q. Zhang, 2006. Estimates of soil respiration and net primary production of three forests at different succession stages in South China. Global Change Biol., 12(5): 810-821.
    Direct Link
33. Zhang, B.W., Z.Q. Yang, S.P. Chen, L.M. Yan and T.T. Ren, 2014. Evaluating the influences of measurement time and frequency on soil respiration in a semiarid temperate grassland. China Sci. Bull., 59(22): 2726-2730.
    Direct Link

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