Grains and field crops
4th successive crop on new land. Trial has shown that the effectiveness of the different types of rock phosphate were about the fifth to one tenth as effective as the fresh (triple) superphosphate applied in 1984. The effectiveness of the superphosphate, decreased by 60 between year 1 and 2, and by a further 10-15% by 1987. This experiment will continue as pasture for 1988 and 1989, and will be re-cropped in 1990. The experiment is also assessing soil testing for P. but soil test data as yet incomplete.
Number of Pages
Bolland, M D, Baker, M, Phillips, C H, and Proudmore, D. (1987), Residual value of phosphate fertilizers.. Department of Agriculture and Food, Western Australia, Perth. Report.