Blair McKenzie

Managing soil to maintain key functions such as food production, storing and filtering water, and preserving biodiversity has been the focus of my research for many years.  In today’s terms, this means my research clearly aligns with Sustainable Development Goals 2 – zero hunger; 6-sustainable management of water; and 15 – protect, restore and promote sustainable use of terrestrial ecosystems: halt and reverse land degradation and biodiversity loss.   My research comes from understanding the interactions between soil, water and root growth for sustainable agriculture. Here I use agriculture in the broadest sense as I have interests ranging from perennial and intensive horticulture to crofting in the Machair of the Western Isles. I have conducted agricultural research based on managing the soil from the tropics through to temperate climates.

My research has built on understanding the interactions of individual roots or organisms such as earthworms with the soil. From the small scale, I am interested to generalise into developing novel ways to screen crops for their ability to cope with physical stresses that manifest through the soil. These stresses include water deficit and excess, mechanical impedance and aeration.  Understanding the stresses leads to interventions and amendments to ameliorate and improve soil conditions. Related to this is investigating the influence of soil structure and strength on root growth and architecture. Because soil and crop conditions vary in time as well as space (e.g. depth in the soil) there is a need to quantify spatial and temporal variability in soil physical conditions for root growth, using approaches such as the least limiting water range.

Major threats to soil and its ability to provide a suitable environment for crops to prosper are erosion, compaction and loss of organic matter. These threats are often linked. Maintaining soil in a soft, stable condition and preventing the loss of soil are keys to preserving all the functions that soil is expected to deliver.

My research for RESAS (Scottish Government) aligns well with my externally funded work. As part of externally funded research I:

• manage the Scottish component of the AHDB-funded and NIAB-led Grower Platforms project.  This project uses on-farm interventions aimed at improving crop production and soil function.
• am one of the Hutton investigators on EU funded GROW citizen science project.
• work with commercial companies interested in soil management with a current focus on cover crops.
• led the completed AHDB funded projects “Platforms to test and demonstrate sustainable soil management: integration of major UK field experiments for combinable crops and potatoes.

One way I try to make a difference is by communicating my science.  Some of my research has clear farmer-oriented outcomes.  This means that I do extensive knowledge exchange or outreach directed at land managers.  This can involve field demonstrations, talks at different forums, including Hutton events such as Potatoes in Practice and Arable Scotland, and online content.  For example, I recently delivered a webinar Tillage, Soils & Crops in conjunction with AHDB and a regional strategic farmer.  I have also presented at farmer focussed events such as the SRUC/AHDB roadshows across four sites in Scotland. Presentations at British Potato from 2015 and 2017 are also available. As part of the EU-funded GROW project, I was a lead educator in the MOOC – From Soil to Sky.  I do a limited amount of teaching to Geography and Environmental Science students at the University of Dundee and very occasionally teach part of specialist soils courses e.g. at Aarhus University.

Postgraduate students

I have supervised numerous postgraduate students.  Currently, I co-supervise two PhD students.

• George Themistocleous (University of Nottingham): Modelling variety dependant least limiting water range: assessing the limits to root elongation in field soil
• Bianca Batista Barreto as a Doctoral Sandwich student form Federal University of Lavras, Brazil: Applications of portable optical equipment to characterize soil surface conditions

Recently completed PhD students, all from Geography & Environmental Science at the University of Dundee, include:

• Ashley Gorman: Understanding seed-soil adhesion by myxospermous seeds and their biophysical function in agroecosystems
• Lizzie Young: Landscape and sediment sensitivity in the machair landscape of the southern Outer Hebrides
• Tim Lewis: Soil Erosion and Seed Banks: The Links for Sustainable Farming

External duties

• Secretary-General of the International Soil Tillage Research Organization (ISTRO).
• I am on the editorial advisory board for Soil & Tillage Research and am currently the guest editor of a special issue of this journal following the 21^st ISTRO conference in Paris.
• Honorary Senior Research Associate, University of Dundee.