http://oar.icrisat.org/id/eprint/4451 2011-12-04T11:43:33Z info:eu-repo/semantics/descriptiveMetadata http://oar.icrisat.org/4451/ Nitrogen accumulation in three legumes and two cereals with emphasis on estimation of N2 fixation in the legumes by the natural15 N-abundance technique Yoneyama, T Nambiar, P T C Lee, K K Srinivasa Rao, B Williams, J H Groundnut Sorghum Food Legumes N accumulation and natural "N ahundance 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 "N 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% atmospherc-derived N, but the percentage decreased with N application, Estimates of atmosphere-derived N by the N-difference and 15~-abundanctee chniques 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-' 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 Bradyrhizobium strain increased the percentage of atmospherederived N in soybean plants grown without any fertilizer N. The natural "N 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 "N-abundance method. Springer Verlag 1990 Article PeerReviewed application/pdf en http://oar.icrisat.org/4451/1/876.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 natural15 N-abundance technique. Biology and Fertility of Soils, 9 (1). pp. 25-30. ISSN 0178-2762 http://dx.doi.org/10.1007/BF00335857 info:eu-repo/semantics/objectFile info:eu-repo/semantics/humanStartPage