Some of the material presented in this thesis is based on papers which are already published or are in the process of publication.
Paper 1 is taken from - McClelland, V. P. (1968). - Superphosphate on wheat : The cumulative effect of repeated applications on yield response. Aust. J. agric. Res. 19, 1-8.
and paper 2 from - McClelland, V. P. (1968). - Superphosphate on wheat z The influence of previous level of application on current effect. Aust. J. exp. Agric. Anim. Husb. 9, 622-4.
Other publications from this thesis will also be in this author's name.