Extent of zinc deficiency in cane growing soils of North Queensland.

Abstract

Collation and interpretation of soil analysis data has shown a strong relationship between soil type and extractable zinc. Extractable zinc in soils followed the order: metamorphic, beach ridge and granite soils < organic and alluvial soils < basaltic soils. More than 15% (18 000 ha) of north Queensland sugarcane soils from Mossman to Ingham were estimated to be at risk from zinc deficiency and associated constrained productivity. This study has identified and mapped low zinc soils and remedial action can now be taken. While alternative zinc forms applied with planting fertiliser have a role, preliminary data from this project does not support a change in the recommended application technique of zinc sulfate heptahydrate, broadcast and incorporated before planting.