In recognition of Mike Hedley: fate of fertiliser in soil and mobilisation of recalcitrant nutrients

This special issue brings together papers that examine topics studied during the career of Professor Mike Hedley, a soil scientist now retired and living on the shores of Lake Taupo in New Zealand.

Mike’s career began when after a BSc Hons in Biochemistry at the University of Leeds, he relocated to New Zealand in 1975 to undertake a PhD on the Biological availability of particulate phase phosphorus (P), supervised by Professors Keith Syers and Neil Macgregor at Massey University in Palmerston North. During this time, the research group focussed on studying the impact of agriculture on water quality and consequently trained several prominent scientists including Professor Andrew Sharpley (formerly of the USDA-ARS and recently retired from the University of Arkansas).

After completing his PhD in 1978, Mike took up a post doc with John W.B. Stewart at the University of Saskatchewan in Canada. During his time in North America, Mike attended the American Society of Soil Science meeting in Denver Colorado where he was inspired to blend the Massey, Saskatchewan, and Colorado P fractionation techniques to improve the characterisation of soil organic P decline in cultivated wheat soils.

In 1980, Mike spent 1.5 years as a post doc at the University of Oxford in the UK, working with Drs Peter Nye and Bob White on how plant roots solubilised soil P and it was here in 1982 that Mike published his seminal P fractionation paper (see next section).

He then returned to Massey University to the then Fertilizer and Lime Research Centre (FLRC) and spent the next few decades researching fertiliser quality, the properties of reactive phosphate rock, resin soils tests, and P, S and K cycling in pasture soils.

In 1998, Mike became director of the FLRC where he supervised hundreds of students and supported world leading research on cadmium, fluoride, biochar, and nitrous oxide emissions. Mike’s role in research on nutrient loss in intensive pasture systems and associated mitigation options such as effluent management, duration-controlled grazing, the use of new pasture species and opportunities for N attenuation in soil and groundwater has had a fundamental impact on New Zealand’s agricultural industry.

Mike retired from the FLRC (now Farmed Landscapes Research Centre) and Massey University in 2018 but continues to advise on national and international issues.