Studies on some solodic soils in north-eastern Queensland. 2. Glasshouse assessment of plant nutrient status

Abstract

Glasshouse experiments using the subtractive technique were undertaken to assess the nutrient status of a number of solodic soils in north-eastern Queensland. On two of the soils factorial experiments were conducted to obtain more information on nutrient interactions. The legumes, Phaseolus /athyroides and Stylosanthes humilis, were used as test plants. Omission of phosphorus severely depressed yield on all soils. This deficiency was usually corrected by applications of superphosphate equivalent to 670 lb an acre. Omission of sulphur and molybdenum also depressed yields in all except one soil. Soil potassium values were low on several soils and the omission of potassium from these gave lower yields. In the factorial experiments the lime, sulphur, and molybdenum main effects and interactions were generally significant. Lime appeared to be having the dual effect of enhancing the availability from the soil of both sulphur and molybdenum. There was some evidence of slight zinc deficiency on several soils and further investigation is required on this aspect.