Abstract
Two experiments were carried out from 1981 to 1983 in Vertisol field at ICRISAT Center, Patancheru, India to measure N2-fixation of pigeonpea [Cajanus cajan (L.) Millsp.] using the15N isotope dilution technique. One experiment examined the effect of control of a nodule-eating insect on fixation while another in vestigated the effect of intercroping with cereals on fixation and the residual effect of pigeonpea on a succeeding cereal crop. Although both experiments indicated that at least 88% of the N in pigeonpea was fixed from the atmosphere, one result is considered fortuitous in view of the differential rates of growth of the legume and the control, sorghum [Sorghum bicolor (L.) Moench]. The difference method of calculation in dieated negative fixation and the results emphasized the problem of finding a suitable nonfixing control. In a second experiment, when all plants were confined to a known volume of soil to which15N fertilizer was added in the field, these problems were overcome, and isotope dilution and difference methods gave similar results of N2-fixation of about 90%. In intercropped pigeonpea 96% of the total N was derived from the atmosphere. This estimate might be an artifact. There was no evidence of benefit from N fixed by pigeonpea to intercropped sorghum plants. Plant tissue15N enrichments of cereal crops grown after pigeonpea indicated that the cereal derived some N fixed by the previous pigeonpea. Thus residual benefits to cereals are not only an effect of ‘sparing’ of soil N.
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References
Analysis of Crops, Soils, and Fertilizers 1978 Soils and Plant Nutrition Department, Rothamsted Experimental Station, Harpenden, Herts., England.
Conway E J 1939 Microdiffusion Analysis and Volumetric Error. Crosby-Lockwood, London, 435 p.
Eaglesham A R J, Ayanaba A, Ranga Rao V and Eskew D L 1981 Improving the nitrogen nutrition of maize by intercropping with cowpea. Soil Biol. Biochem. 13, 169–171.
Fried M and Broeshart H 1975 An independent measurement of the amount of nitrogen fixed by a legume crop. Plant and Soil 43, 707–711.
Kumar Rao J V D K, Dart P J, Matsumoto T M and Day J M 1981 Nitrogen fixation by pigeonpea.In Proc. of the International Workshop on Pigeonpeas, Vol. 1, 15–19 Dec. 1980. pp 190–199. ICRISAT, Patancheru, India
Kumar Rao J V D K, Dart P J and Sastry P V S S 1983 Residual effect of pigeonpea (Cajanus cajan) on yield and nitrogen response of maize. Expt. Agric. 19, 131–141.
La Favre J S and Focht D D 1983 Comparison of N2 fixation and yields inCajanus cajan between hydrogenase-positive and hydrogenase-negative rhizobia byin situ acetylene reduction assays and direct15N partitioning. Plant Physiol. 72, 971–977.
Legg J O and Sloger C 1975 A tracer method for determining symbiotic nitrogen fixation in field studies.In Proc. of the Second International Conference on Stable Isotopes. Eds. E R Klein and P D Klein. pp 661–666. Oak Broak, Illinois.
Rennie R J 1982 Quantifying dinitrogen (N2) fixation in soybeans by15N isotope dilution: the question of the nonfixing control plant. Can. J. Bot. 60, 856–861.
Rennie R J, Rennie D A and Fried M 1978 Concepts of15N usage in dinitrogen fixation studies.In Isotopes in Biological Dinitrogen Fixation. pp 107–130. International Atomic Energy Agency, Vienna.
Sheldrake A R and Naryanan A 1979 Growth, development and nutrient uptake in pigeopeasCajanus cajan. J Agr. Sci. (Camb.) 92, 513–526.
Willey R W, Rao M R and Natarajan M 1981 Traditional cropping systems with pigeonpea and their environment.In Proc. of the International Workshop on Pigeonpeas, Vol. 1, 15–19 Dec. 1980. pp. 11–25. ICRISAT, Patancheru, India.
Witty J F 1983 Estimating N2-fixation in the field using15N-labelled fertilizer: some problems and solutions. Soil Biol. Biochem. 15, 631–639.
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Rao, J.V.D.K.K., Thompson, J.A., Sastry, P.V.S.S. et al. Measurement of N2-fixation in field-grown pigeonpea [Cajanus cajan (L.) Millsp.] using15N-labelled fertilizer. Plant Soil 101, 107–113 (1987). https://doi.org/10.1007/BF02371037
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DOI: https://doi.org/10.1007/BF02371037