TY  - JOUR
AV  - restricted
A1  - Yoneyama, T
A1  - Nambiar, P T C
A1  - Lee, K K
A1  - Srinivasa Rao, B
A1  - Williams, J H
TI  - Nitrogen accumulation in three legumes and two cereals with emphasis on estimation of N2 fixation in the legumes by the natural 15N-abundance technique
UR  - http://dx.doi.org/10.1007/BF00335857
JF  - Biology and Fertility of Soils
SN  - 0178-2762
PB  - Springer-Verlag
N1  - ICRISAT Journal Article No. 876
N2  - 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.
KW  - N2 fixation
KW  -  Natural 15N abundance
KW  -  N-difference method
KW  -  Atmosphere-derived N
KW  -  Non-nodulating genotype
KW  -  Cereals
KW  -  Legumes
Y1  - 1990/02//
SP  - 25
ID  - icrisat9704
EP  - 30
VL  - 09
IS  - 01
ER  -