
%0 Journal Article
%A Rochester, I. J. 
%A Peoples, M. B. 
%A Constable, G. A. 
%A Gault, R. R. 
%T Faba beans and other legumes add nitrogen to irrigated cotton cropping systems
%J Australian Journal of Experimental Agriculture
%D 1998/06/15
%V 38
%N 3
%P 253-260
%K 
%R https://doi.org/10.1071/EA97132
%U https://www.publish.csiro.au/paper/EA97132 
%X Summary. Legumes have become common rotation crops in cotton cropping systems in northern New South Wales. Levels of nitrogen fixation and yield achieved on-farm were measured in commercial faba beans and other winter and summer legume crops sown after cotton over 3 years to assess the relative inputs of fixed nitrogen (N) into this system. Faba bean crops fixed up to 350 kg N/ha, removed up to 160 kg N/ha in harvested grain and contributed up to 270 kg fixed N/ha to soil N after harvest. Grain yields, N2 fixation and dry matter production were reduced in late-sown crops and those water-stressed during pod-filling, but most faba bean crops fixed almost 3 times as much N as was removed in grain. Below-ground legume N, determined with 15N shoot feeding techniques, accounted for 40% of the total crop N at peak biomass, or about 100 kg N/ha for the average faba bean crops. Residual fixed N after harvest was predicted from crop dry matter and grain yield, and this could be used to assess the contribution to soil N from faba beans. Amounts of nitrogen fixed by other legume crops ranged from 20 kg N/ha for adzuki bean and droughted lablab to more than 450 kg N/ha by irrigated soybean. Soybean, peanut and Dolichos lablab contributed more fixed N to the soil than adzuki bean, mung bean or pigeon pea under irrigated conditions. Winter crops including field peas, lentils and lupins and green-manured pasture species fixed up to 240 kg N/ha. 
