I. Introduction and design of experiments

Abstract

The rationale behind a series of trials with different forms of phosphatic fertilisers compared in small plot mowing trials, and the design of the trials and the 8 sites are described. The trials aimed to compare Thermophos, calcined Christmas Island C-Grade rock phosphate (CCIP), a 1: 3 mixture of CCIP with superphosphate, and fitiely ground Nauru and Gafsa rock phosphates with superphosphate as the standard, and to measure the residual effects of heavier than normal applications of these fertilisers. The responsiveness of the sites to phosphate and sulphate was assessed in subsidiary trials with monocalcium phosphate (Ibex) and gypsum. Results for trials at individual sites will be presented in subsequent papers.

Keywords:

• fertiliser efficiency
• phosphorus (nutrient)
• soil fertility
• pastures
• nutrients (plant)