Studies on some neutral red duplex soils (Dr 2.12) in north-eastern Queensland. 2. Glasshouse assessment of plant nutrient status

Abstract

Glasshouse experiments using the subtractive technique were conducted on 15 neutral red duplex soils from north-eastern Queensland. On two of the soils factorial experiments were conducted to obtain information on nutrient interactions. The legumes Phaseolus lathyroides and Stylosanthes humilis were used as test plants. All soils were deficient in phosphorus, sulphur, and molybdenum, although the magnitude of the various deficiencies often differed between soils. Yields of plants were well correlated with phosphorus extracted from the soils by 0.01 N.H,SO, and by 0.5 M. Na HCO3. Soil tests used were unsatisfactory indices of sulphur deficiency. A possible zinc deficiency was indicated.