http://oar.icrisat.org/id/eprint/9704 2017-05-24T05:29:56Z info:eu-repo/semantics/descriptiveMetadata http://oar.icrisat.org/9704/ Nitrogen accumulation in three legumes and two cereals with emphasis on estimation of N2 fixation in the legumes by the natural 15N-abundance technique Yoneyama, T Nambiar, P T C Lee, K K Srinivasa Rao, B Williams, J H Cereals Legume Crops N accumulation and natural 15N abundance in three legumes (groundnuts, cowpeas, and soybeans) and in two cereals (sorghum and maize) were investigated over two seasons in Alfisols with and without N fertilization. Using the N uptake and natural 15N abundance of non-nodulating plants as the indication of N derived from soil and fertilizer, the per cent N derived from atmospheric N2 was calculated for nodulated plants. In the first experiment, the groundnut genotype contained 85% atmosphere-derived N, but the percentage decreased with N application. Estimates of atmosphere-derived N by the N-difference and 15N-abundance techniques gave identical results. The percentages of atmosphere-derived N estimated by the two methods at different stages of groundnut growth were also similar. In the second experiment, atmosphere-derived N was estimated in plants grown with 0–200 kg ha-1 applied N. The estimated atmosphere-derived N ranged from 42% to 61% for groundnuts from 33% to 77% for cowpeas, and from 24% to 48% for soybeans, depending on the amount of N applied. Inoculation with a Brady rhizobium strain increased the percentage of atmosphere derived N in soybean plants grown without any fertilizer N. The natural 15N abundance of sorghum and maize was very close to that of the non-nodulating groundnut, suggesting that these cereals can be used as reference plants in the estimation of atmosphere-derived N by the natural 15N-abundance method. Springer-Verlag 1990-02 Article PeerReviewed application/pdf en http://oar.icrisat.org/9704/1/bf00335857.pdf Yoneyama, T and Nambiar, P T C and Lee, K K and Srinivasa Rao, B and Williams, J H (1990) Nitrogen accumulation in three legumes and two cereals with emphasis on estimation of N2 fixation in the legumes by the natural 15N-abundance technique. Biology and Fertility of Soils, 09 (01). pp. 25-30. ISSN 0178-2762 http://dx.doi.org/10.1007/BF00335857 10.1007/BF00335857 info:eu-repo/semantics/objectFile info:eu-repo/semantics/humanStartPage