On the Occasion of World Soil Day, Dr. Mike McLaughlin discusses his Cutting-Edge Fertilizer Research, the Huge Potential of Subsoil Nutrient Management, and gives an Insight into Global Soil Health
IFA: Can you tell us about some of the research that you are currently working on?
Dr. McLaughlin: We are working on new fertilizer formulations that are more efficient, thus increasing uptake and reducing losses to the environment. .
A current focus is micronutrients, specifically zinc and boron, which are essential for crop growth and flowering. We are exploring ways to use new materials that better synchronize their release with the needs of plants.
For example, boron can leach through the soil very quickly. To counter this, we have developed a material that offers both fast and slow release boron to better match the needs of crops. For zinc, we have developed a simple manufacturing process that increases its solubility in fertilizer and offers better early growth to crops.
Some of the techniques we research are simple ideas that seem obvious, while others are a bit more whacky. We work with chemical engineers and materials scientists and are looking at using some of the newest materials available, such as Graphene which was only discovered in 2004
IFA: Speaking at IFA’s recent Strategic Forum in Zurich in November you said that subsoil management will be the next frontier in crop nutrition. Can you tell us more about this?
Dr. M. McLaughlin: In Africa and parts of Central and South America, the biggest issues are access to fertilizers, the infrastructure for transporting them and getting fertilizer that are cost effective for smallholder farmers. Soil fertility in these regions is low so lifting the fertility of these soils from low to medium can make a huge difference to crop production.
In the developed world, growers are starting to manage the landscape in a precise way – a lot of farmers now have monitors to measure yields and productivity. There is a big opportunity for sensors that can measure soil fertility at the same scale as crop production so that we can start to manage the soil precisely as well.
We have been applying nutrients for than 100 years now. We need to make sure that we don’t apply too much – it’s important that we use the right fertilizer source, at the right rate, at the right time, in the right place so that we don’t over fertilize. .
Another issue is the decline in soil organic matter, which is bad for soil structure and its water holding capacity. While it’s important that we minimize tillage to conserve organic matter in the soil, there is also the potential problem of having nutrients stratified in the soil.
IFA: What more can the fertilizer industry and farmers do to improve soil health?
Dr. McLaughlin: The food for soil biology is carbon and that carbon generally only comes from crops. For example, compost comes from plants as does manure, via the animal that has eaten them.
If you add carbon to the soil this means that it has been taken from somewhere else; unless you grow a big crop. In healthy crops, for every 2 to 3 tonnes of carbon above ground, there will generally be 1 or more tonnes of carbon below ground in the roots and root exudates.
The more healthy crops that are grown, the more carbon is kept in the soil in the form of retained residue. So the best way to inject carbon into the soil is to grow healthy plants, retain residue and minimise tillage.
There isn’t a magic bullet to improve soil health. Soil health is all about the diversity of crops and getting carbon into the soil by growing big crops.
About Dr Mike McLaughlin:
Professor Mike McLaughlin is a Professor at the School of Agriculture, Food and Wine and Director of Fertiliser Technology Research Centre at the University of Adelaide, and a Science Fellow in Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO). Dr. McLaughlin has over 30 years of experience in soil fertility and plant nutrition research, covering more than three continents starting first in Africa, and then in Australia and Southeast Asia. His research has a global impact and coverage. In 2015 Professor McLaughlin won the IFA Norman Borlaug Award .