Davies, G. R.2024-10-222024-10-221972https://hdl.handle.net/10182/17758The spinning disc distributor is basically a simple machine and especially suitable for broadcasting granular fertiliser over a large area. Properly designed and operated it can give a wide bout width and a uniform spread. Even spreading is important with some fertilisers and trace elements and essential with most herbicides and pesticides but it is difficult to assess its importance when applying superphosphate to pasture. Very uneven distribution will reduce crop yield; very accurate distribution will be expensive; somewhere between the two extremes is a sensible, practical compromise. After careful study of the whole subject of superphosphate application it was decided, in 1968, that a testing and experimental programme was justified at Lincoln. The project was visualised in three stages. First, the design and installation of test equipment; second, the testing of existing machines and fertilisers; third, but only if warranted by the findings of the second stage, an attempt to help improve design and operation of machines and of fertiliser properties. This last stage would be tackled by a study of published information from this country and overseas, and by a limited experimental programme.25 pages© New Zealand Agricultural Engineering Institutefertiliser applicationspinning disc distributorReportANZSRC::300411 Fertilisers (incl. application)