Pasture studies on the coastal lowlands of subtropical Queensland. I. Introduction and initial plant nutrient studies.

Abstract

A general description of the underdeveloped coastal lowlands of southern Queensland is given. Location, soils, vegetation, climate, present use, and problenls confronting investigators are dealt with. Plant nutrient studies on a low humic gley at Beerwah and a humic gley soil at Glasshouse Mountains are reported. For both soils the plant responses are qualitatively similar but they differ in degree. The limiting nutrients for plant growth are phosphorus, nitrogen, calcium, potassium, copper, zinc, molybdenum, and boron in descending order of importance. For an efficiently nodulated legume, added nitrogen is not required. Soil chemical analyses and plant analyses show that the nutrients to which responses are obtained are in extremely low supply in the soils. The effect of over-liming on these soils is discussed in relation to change of soil pH, and availability of copper and zinc. Deficiency symptoms of calcium, potassium, and copper for certain species are discussed and observations made on their intensification through the addition of other major nutrients to the soil. Maximum plant growth on these soils can only be obtained if all limiting nutrients are supplied. This may explain in part the failure of earlier attempts to establish agriculture on these soils.