TY  - JOUR
N2  - 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.
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 natural15 N-abundance technique
UR  - http://dx.doi.org/10.1007/BF00335857
JF  - Biology and Fertility of Soils
SP  - 25
Y1  - 1990///
ID  - icrisat4451
EP  - 30
SN  - 0178-2762
VL  - 9
PB  - Springer Verlag
IS  - 1
ER  -