Summary
Plants of white clover var. Blanca were grown singly in pots in controlled environments, or in small swards in a glasshouse, to determine how their distribution of dry weight between root and shoot was influenced when they were dependent on N2 fixation in their root nodules or when they lacked nodules but utilized an abundant supply of nitrate nitrogen. In single plants and in swards, changes in root/shoot ratio with increasing age and plant development were not influenced by the source of nitrogen, but nodulated plants always displayed a higher root/shoot ratio. When nodulated plants were supplied with nitrate nitrogen, root/shoot ratio declined to values intermediate between those of nodulated and of nitrate plants. The results are discussed in relation to the persistence of white clover, and the general level of productivity, in grass-clover swards.
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References
Brouwer, R. 1962 Distribution of dry matter in the plant. Neth. J. Agric. Sci.10, No. 5 Special issue, 361–376.
Brouwer, R. 1962 Nutritive influences on the distribution of dry matter in the plant. Neth. J. Agric. Sci.10, 399–408.
Bullen, W. A. and LeComte, J. R. 1966 The nitrogenase system from azotobacter: two-enzyme requirement for N2 reduction, ATP-dependent H2 evolution, and ATP hydrolysis. Proc. Nat. Acad. Sci. USA,56, 979–986.
Clement, C. R., Hopper, M. J. and Jones, L. H. P. 1978 The uptake of nitrate byLolium perenne from flowing nutrient solution. J. Exp. Bot.29, 453–464.
Hardy, R. W. F. and Havelka, U. D. 1975 Nitrogen fixation research: a key to world foods? Science N.Y.188, 633–643.
Luckwill, L. C. 1960 The physiological relationships of root and shoot. Scient. Hortic.14, 22–26.
Mahon, J. D. 1977 Respiration and the energy requirement for nitrogen fixation in nodulated pea roots. Plant. Physiol.60, 817–821.
Mahon, J. D. and Child, J. J. 1979 Growth response of inoculated peas (Pisum sativum) to combined nitrogen. Can. J. Bot.57, 1687–1693.
Pate, J. S. 1977 Functional biology of dinitrogen fixation by legumes.In A Treatise on Dinitrogen Fixation. Eds. R. W. F. Hardy and W. S. Silver, Wiley-Interscience, 1977, 473–517.
Pate, J. S., Layzell, D. B. and Atkins, C. A. 1979 Economy of carbon and nitrogen in a nodulated and non-nodulated (NO3-grown) legume. Plant. Physiol.64, 1083–1088.
Robson, M. J. 1973 The growth and development of simulated swards of perennial ryegrass. I. Leaf growth and dry weight change as related to the ceiling yield of a seedling sward. Ann. Bot.37, 487–500.
Russell, W. J. and Johnson, D. R. 1975 Carbon-14 assimilate translocation in nodulated and non-nodulated soybeans. Crop Sci.15, 159–160.
Ryle, G. J. A. 1970 Effects of two levels of applied nitrogen on the growth of S37 cocksfoot in small simulated swards in a controlled environment. J. Br. Grassld. Soc.25, 20–29.
Ryle, G. J. A., Powell, C. E. and Gordon, A. J. 1978 Effect of source of nitrogen on the growth of Fiskeby soya bean: the carbon economy of whole plants. Ann. Bot.42, 637–648.
Ryle, G. J. A., Powell, C. E. and Gordon, A. J. 1979 The respiratory costs of nitrogen fixation in soyabean, cowpea and white clover. II. Comparisons of the cost of nitrogen fixation and the utilization of combined nitrogen. J. Exp. Bot.30, 145–153.
Ryle, G. J. A., Powell, C. E. and Gordon, A. J. 1981 Assimilate utilization in red and white clover either dependent on N2 fixation in root nodules or utilizing nitrate nitrogen. Ann. Bot.In press.
Silsbury, J. H. 1977 Energy requirement for symbiotic nitrogen fixation. Nature London267, 149–150.
Thornley, J. H. M. 1972 A balanced quantitative model for root: shoot ratios in vegetative plants. Ann. Bot.36, 431–441.
Williams, W. 1970 White clover in British agriculture. Occ. Symp. No.6, Br. Grassld. Soc. 1–10.
Winter, H. C. and Burris, R. H. 1968 Stoichiometry of the adenosine triphosphate requirement for N2 fixation and H2 evolution by a partially purified preparation ofClostridium pasteurianum. J. Biol. Chem.243, 940–944.
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The Grassland Research Institute is financed through the Agricultural Research Council.
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Ryle, G.J.A., Arnott, R.A. & Powell, C.E. Distribution of dry weight between root and shoot in white clover dependent on N2 fixation or utilizing abundant nitrate nitrogen. Plant Soil 60, 29–39 (1981). https://doi.org/10.1007/BF02377110
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DOI: https://doi.org/10.1007/BF02377110