A research poster from the School of Underlying Conditions applies portfolio optimisation to the question of where a soil survey should spend its auger holes.
A minimum-risk allocation moves 47 of a survey's 240 holes downslope without lowering what the season is expected to return
A soil survey has only so many holes in it. How a season’s allowance ought to be divided among the units of a map is the question taken up in The Efficient Frontier of a Field Season: Mean–CVaR allocation of 240 auger holes across the nine map units of one soil survey, a research poster by Dr Brynjar Obiora, Senior Research Fellow in the School of Underlying Conditions, Dr Bram Ntuli, Lecturer and Convenor of Improvement Grand Rounds, and Mr Halvard Nnamani, Doctoral Candidate in the School of Emergent Priorities.
By custom, holes are shared out according to how much ground each unit covers. The poster finds that an allocation built to protect the worst seasons sends 47 of the 240 holes further down the slope, into the swales and drainage lines, and gives up nothing in an ordinary year. Tested on seasons it had not seen, it did better than custom, and about as well as simply giving every unit the same.
I have carried an auger for a good many years without once being asked how I was invested. It is a generous question, and I intend to keep it by me in the field.
— Dr Brynjar Obiora, Senior Research Fellow, School of Underlying Conditions
The work brings an established framework for balancing return against downside exposure into conversation with the School’s own survey records, positioning the map unit as the point at which the two disciplines exchange capability.
The University counts the careful placement of effort among its quieter strengths, and welcomes its appearance on a poster. Dr Ntuli said the collaboration had been “an education in what a paddock will and will not tell you at short notice”.
The full poster is available from the University’s research repository under an open licence, doi:10.5555/slop.g2wqod.