Plant nutrition studies on some yellow and red earth soils in northern Cape York Peninsula. 1. Soils and their nutrient status

Abstract

Eleven complete profiles and an additional 112 surface soils of deep sandy yellow and red earths in the far northern part of Cape York Peninsula have been sampled for laboratory studies. Chemical analyses showed that these acid soils are very low in organic carbon, nitrogen, phosphorus, potassium, sulphur, copper, zinc, manganese, cobalt, exchangeable basic cations, and base saturation. They have relatively high contents of exchangeable aluminium. The variability of surface soil chemical properties is relatively low. Glasshouse experiments with Stylosanthes humilis cv. Gordon conducted on soils from the 11 profile sites showed responses to sulphur, potassium, zinc and lime on all soils and to copper on about half the sites. Considering the results of both the laboratory and glasshouse studies, it is suggested that responses to nitrogen, phosphorus, zinc and probably calcium and copper are likely in the field. Responses to sulphur may be transitory because of the presence of appreciable levels of phosphate-extractable sulphur at depth.