
%0 Journal Article
%A Marcellos, H. 
%A Felton, W. L. 
%A Herridge, D. F. 
%T Chickpea in wheat-based cropping systems of northern New South Wales I. N<emph type="8">2</emph> fixation and influence on soil nitrate and water
%J Australian Journal of Agricultural Research
%D 1997/03/13
%V 49
%N 3
%P 391-400
%K rotation, nitrate, water, mineralisation.
%R https://doi.org/10.1071/A97066
%U https://www.publish.csiro.au/paper/A97066 
%X Chickpea has potential as a rotation or break crop in the northern grains region of New South Wales and Queensland. Definition of that potential requires information on chickpea N2 fixation and on effects of chickpea on maintenance of soil N fertility and delivery of mineral N for use by a following cereal crop. Results from 6 experiments in northern NSW in which chickpea and wheat in one season were followed by wheat in subsequent seasons indicated variable N2 fixation by chickpea (mean 73 kg/ha; range 4-116 kg/ha), associated with variable Pfix (percentage of chickpea N derived from N2 fixation) (mean 57%; range 4-79%). There were no consistent differences between chickpea and wheat in effects on soil water, either pre-harvest or after the summer fallow. Chickpea &#8216;spared&#8217; nitrate, relative to wheat (mean 15 kg/ha; range 1-35 kg/ha), and mineralised additional nitrate during the summer fallow (mean 18 kg/ha; range 5-40 kg/ha). Nitrate-N in the top 1&#183;2 m of the soil profile at sowing of the following wheat crop was on average 89 kg/ha after chickpea (range 63-113 kg/ha) and 56 kg/ha after wheat (range 33-94 kg/ha). Nitrogen mineralisation rates during the summer fallow at 2 sites of 0&#183;17 and 0&#183; 21 kg N/ha &#183; day (after chickpea), although greater than the rates after wheat (0&#183; 07 and 0&#183;12 kg N/ha &#183; day), were not sufficient to meet the N requirements of a moderate to high yielding cereal crop. We concluded that chickpea did not fix sufficient N2 or mineralise sufficient N from residues either to maintain soil N fertility or to sustain a productive chickpea&#123;wheat rotation without inputs of additional fertiliser N. 
