
%0 Journal Article
%A Li, G. D. 
%A Helyar, K. R. 
%A Conyers, M. K. 
%A Cregan, P. D. 
%A Cullis, B. R. 
%A Poile, G. J. 
%A Fisher, R. P. 
%A Castleman, L. J. C. 
%T Potassium deficiency and its management in a long-term rotation experiment in the south-western slopes New South Wales
%J Australian Journal of Experimental Agriculture
%D 2001/06/06
%V 41
%N 4
%P 497-505
%K 
%R https://doi.org/10.1071/EA00108
%U https://www.publish.csiro.au/paper/EA00108 
%X Potassium (K) deficiency of wheat and pasture species was found at a site in the south-western slopes of New South Wales. The soil was a subnatric yellow sodosol. Subterranean clover (Trifolium subterraneum) was found to be less competitive for K in the soil compared with its associated grasses. Higher soil K concentrations were required to achieve the same subterranean clover K concentration in the grass&#8211;legume mixtures than in a subterranean clover monoculture. For wheat (Triticum aestivum) production, a soil exchangeable K (Kex ) below 0.25 cmol(&plus;)/kg appeared to be deficient for the limed treatments, but there was no obvious critical value for either limed or unlimed treatments. The critical K exvalues for the grass &ndash;legume mixtures could not be simply specified because the values were affected by competition between species growing in swards of variable botanical composition. An annual rate of 20 kg K/ha for the pasture&#8211;crop rotations (50/50%) and 29 kg K/ha for the permanent pastures was estimated to be sufficient to replenish the K losses from product removal and animal excreta transferred to campsites at this trial site. 
