SOIL MAPPING SCALE AND MINIMUM MAPPING AREA FOR CONVENTIONAL SOIL MAPPING OF CENTRAL AND NORTHERN SUGARCANE REGIONS OF QUEENSLAND

MOST EXISTING SOIL data across the northern and central sugarcane regions of Queensland has been collected by conventional soil survey methods. This paper assesses accuracy of these data to provide information that can support research and development to increase sugarcane yields and reduce production costs. Soil data have been collected at greater detail than indicated on the published maps for most conventional soil surveys in the northern and central sugarcane regions of Queensland. Intensity of collection of soil data is not consistent within the area of most conventional soil surveys, as soil sites are concentrated in existing and potential sugarcane areas, with fewer sites located in areas alienated to sugarcane. In most conventional soil surveys, over 10 % of mapping areas are smaller than the minimum indicated by the published map scale, with close to or more than 50 % for the Herbert-Ingham, Proserpine and Mackay areas. Interpreting the intensity of soil mapping directly from the scale of the published map underestimates the accuracy of soil data that are available from conventional soil surveys. Conventional soil mapping provides more than a soil map. It provides data on soil physical and chemical properties that are readily accessible and can assist research in improving yields and decreasing production costs of the Queensland Sugar industry.