The fertility of two soils on the University of Queensland Mt. Cotton Farm were investigated with respect to the mineral nutrition of tropical pasture legumes. Three pot experiments were carried out.
The first was the study, in subtractive trials, of grey-brown podzolic and two depths of yellow podzolic soils, using Phaseolus lathyroides as the test plant. The soils are deficient in phosphorus, potassium, sulphur, nitrogen, and molybdenum. Calcium carbonate is required. The variation in fertility between soils and different depths is discussed.
The second was the study, again in subtractive trials, of the responses of Lotononis bainesii, Glycine javanica, Desmodium intortum, and Phaseolus lathyroides to nutrient application on a grey-brown podzolic soil. Nitrogen was not included in the experiment. The soil is deficient in phosphorus, potassium, sulphur, and calcium carbonate for all species. Glycine and Desmodium responded markedly to calcium carbonate, while Lotononis and Phaseolus did so only slightly. Added molybdenum increased the yield of Glycine, Desmodium and Phaseolus, but did not affect Lotononis.