Phosphate is a limited resource vital for global agriculture. Dr Iain Moyles and Dr John Donohue discuss their work funded by Science Foundation Ireland on mathematical modelling of nutrient flow in soil. During the podcast Iain and John describe the phosphate crisis which acknowledges that phosphorus is a limited resource and only a few countries have significant reserves of it including Morocco, China, Algeria and Syria. During their discussions on sulphur, they touch on some surprising outcomes of emissions regulations. Other talking points include the various collaborators in their research programme, the importance of mathematical modelling in science, and advice for scientists interested in collaborating with applied mathematicians or pursuing a career in the field. Recorded by GK Media Ltd.