The effects of soil manganese status on the bioavailability of soil cobalt for pasture uptake in New Zealand soils
Abstract
The effects of soil properties on the availability of
cobalt (Co) for pasture uptake have been studied
using a wide range of New Zealand soils. There is
a strong positive correlation between total or
EDTA-extractable Co and manganese (Mn) concentration.
However glasshouse studies have shown
that Co availability is inversely related to the Mn
concentration. Across a wide range of soil groups,
EDTA-extractable Co is a poor predictor of cobalt
availability. CaCl₂-extractable Co was found to
decrease with soil pH and was too pH sensitive to
be a good predictor of Co availability. It is concluded
that soil Mn plays a crucial role in soil Co
status and has significant effects on plant Co uptake
because of its involvement in the soil redox system
and the scavenging properties of soil Mn oxides.
Co deficiency is more likely to occur and Co
fertiliser is less effective on soils with high Mn,
especially under dry conditions.... [Show full abstract]