Aaron Stafford

Doctor of Philosophy
Study Completed: 2017
College of Sciences


Thesis Title
Distribution of cadmium in long-term dairy soils, its accumulation in selected plant species, and the implications for management and mitigation

Read article at Massey Research Online: MRO icon

Cadmium is a toxic element that can be taken up by plants and is undesirable in the human diet. The Tiered Fertiliser Management System has been adopted in New Zealand to manage cadmium accumulation in agricultural soils, as ongoing accumulation poses a threat to agricultural trade and land use flexibility. In this research, Mr Stafford investigated soil cadmium variability in long-term dairy farms, its accumulation in livestock forage species, and the influence of different soil variables on soil cadmium availability. He found that soil cadmium variability was influenced by phosphorus fertilisation history, soil type and tillage history, with little influence of slope or dairy shed effluent application. Chicory and plantain were identified as cadmium accumulating species, incurring greater risk of cadmium accumulation in livestock grazing these forages. Cadmium accumulation in chicory was sensitive to soil pH, hence long-term soil acidification poses a risk to increased cadmium accumulation in this species.

Professor Chris Anderson
Professor Michael Hedley
Dr Paramsothy (Jeya) Jeyakumar