The Manure and Fertilizer Treatments

The treatments used were based on what was considered forward-thinking best practice in 1896 and represent a range of the materials and application rates in use at that time. Hence the nitrogen fertilisers are ammonium sulphate and sodium nitrate (Chile nitre). There has only been one change in the applied treatments. In 1976, it was considered that the phosphate-containing basic slag was becoming too variable so it was replaced by triple superphosphate supplying the same amount of phosphorus.

The organic manure is straw-based farmyard manure from the cattle operation at Cockle Park. Its composition may have changed with changing animal diets over the century; the manured plots do not all receive manure annually; there is a sequence of annual, biennial and quadrennial application with various or no fertilisers used in the other years.

Fertiliser and manure applied to each of the plots and, for plots 3 to 5, the materials applied rotationally