Summary
Estimates of belowground net primary production (BNP) obtained by using traditional soil core harvest data are subject to a variety of potentially serious errors. In a controlled growth chamber experiment, we examined the aboveground-belowground, labile to structural tissue, and plant to soil dynamics of carbon to formulate a14C dilution technique for potential successful application in the field and to quantify sources of error in production estimates.
Despite the fact that the majority of net14C movement between above- and belowground plant parts occurred between the initial labeling and day 5, significant quantities of14C were incorporated into cell-wall tissue throughout the growing period. The rate of this increase at late sampling dates was greater for roots than for shoots. Total loss of assimilated14C was 47% in wheat and 28% in blue grama. Exudation and sloughing in wheat and blue grama, respectively, was 15 and 6% of total uptake and 22 and 8% of total plant production.
When root production estimates by14C dilution were corrected for the quantities of labile14C incorporated into structural carbon between two sampling dates, good agreement with actual production was found. The error associated with these estimates was ±2% compared with a range of −119 to −57% for the uncorrected estimates. Our results suggest that this technique has potential field application if sampling is performed the year after labelling.
Sources of errors in harvest versus14C dilution estimates of BNP are discussed.
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References
Barber D A and Martin J K 1976 The release of organic substances by cereal roots into soil. New Phytol. 76, 69–80.
Caldwell M M and Camp L B 1974 Belowground productivity of two cool desert communities. Oecologia (Berl.) 17, 123–130.
Coleman D C 1976 A review of root production processes and their influence on soil biota in Terrestrial ecosystems.In The Role of Terrestrial and Aquatic Organisms in Decomposition Processes, pp 417–434. Eds. J M Anderson and A Macfadyen. Scientific Publications, Oxford.
Dormaar J F, Smoliak S and Johnston A 1981 Seasonal fluctuations of blue grama roots and chemical characteristics. J. Range Manage. 34, 62–63.
Martin J K 1977 Factors influencing the loss of organic carbon from wheat roots. Soil Biol. Biochem. 9, 1–17.
McDougall B M 1970 Movement of14C-photosynthate into the roots of wheat seedlings and exudation of14C from intact roots. New Phytol. 69, 37–46.
Minchin P E H and McNaughton G S 1984 Exudation of recently fixed carbon by nonsterile roots. J. Exp. Bot. 35, 74–82.
Morgan C L and Austin R R 1978 Respiratory loss of recently assimilated carbon in wheat. Ann. Bot. 51, 85–95.
Sims P L and Singh J S 1978 The structure and function of ten western North American grasslands. III. Net primary production, turnover, and efficiencies of energy capture and water use. J. Ecol. 66, 573–597.
Singh J S, Lauenroth W K, Hunt H W and Swift D M 1984 Bias and random errors in estimates of net root production: A simulation approach. Ecology 65, 1760–1764.
Snyder J D and Trofymow J A 1984 A rapid accurate wet oxidation diffusion procedure for determining organic and inorganic carbon in plant and soil samples. Comm. Soil Sci. Plant Anal. 15, 587–597.
Van Soest P J 1967 Development of a comprehensive system of feed analysis and its application to forages. J. Anim. Sci. 26, 119128.
Van Soest P J and Wine R H 1967 Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell-wall constituents. J. Associ. Off. Agric. Chem. 50, 50–55.
Warembourg F R and Paul E A 1977 Seasonal transfers of assimilated14C in grassland: Plant production and turnover, soil and plant respiration. Soil Biol. Biochem. 9, 295–301.
Winer B J 1971 Statistical Principles in Experimental Design, 2nd ed. McGraw-Hill, New York.
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Milchunas, D.G., Lauenroth, W.K., Singh, J.S. et al. Root turnover and production by14C dilution: implications of carbon partitioning in plants. Plant Soil 88, 353–365 (1985). https://doi.org/10.1007/BF02197492
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DOI: https://doi.org/10.1007/BF02197492