
TY  - JOUR
A1  - Evans, J. 
A1  - Heenan, D. P. 
T1  - Simplified methods for assessing quantities of N<emph type="8">2</emph> fixed by <emph type="2">Lupinus angustifolius</emph> L. and its benefits to soil nitrogen status
JF  - Australian Journal of Agricultural Research
JO  - Aust. J.  Agric. Res.
Y1  - 1997
VL  - 49
IS  - 3
SP  - 419
EP  - 426
KW  - lupin, model, nitrogen balance, N2 fixation, wheat.
UR  - https://doi.org/10.1071/A97016 
N2  - Procedures for assessing the quantity of symbiotically fixed nitrogen (kg N/ha) in standing crops of lupin and for estimating variation of N2 fixation by lupins in different years were determined empirically and described. In standing crops, N2 fixation was estimated from crop height, plant population density, and a bioassay of soil mineral nitrogen (cereal crop N; kg N/ha). In addition it was also estimated from rainfall, sowing date, and cereal N, which consequently enabled prediction of seasonal variation in fixed N using historical rainfall data. Procedures for estimating the potential contribution of N2 fixation to soil N, and the effects of lupin and cereal N budgets on soil N balance based on differences in fixed N and grain N (grain yield&#215;estimated grain N concentration) are also given. The collective procedures are applied to a site in south-eastern Australia and the predicted crop effects on soil N balance compared with actual field data. Perceived limitations of the procedures are discussed. 
ER  -

