It’s that time of year again: Brussel sprouts are swelling, parsnips are ready for picking and the apple tree is probably ready for its prune. It is also when The Department of Animal and Plant Science at the University of Sheffield hold its annual Christmas lecture, and this year it was about soil nutrients… and poo!

Over one thousand schoolchildren from across Sheffield flocked to the University to learn about the cycle of nutrients from food through animals (including humans), into soil, up through plants and back into food. With both explosive and electrifying demonstrations, Professor Duncan Cameron spoke about:

• The diminishing reserves of rock phosphate – one of the three major nutrients (along with nitrogen and potassium) essential for plant growth
• The environmental costs of artificially synthesising nitrogen fertiliser (and that it’s fixed naturally by lightning(!) and, less dramatically, by legumes such as peas and clover)
• How soil organisms play a crucial role in the cycling nutrients
• How recycling poo – including our own – can help maintain healthy, nutrient rich soils in a sustainable way

Once the lecture finished (with a bang), the school children had the opportunity to look at table demonstrations of our department’s research. They could see how worms mix the soil and move substances between soil layers, guess the different types of natural fertilisers – from horse manure, to processed poo, and, at the MYHarvest table, guess the weight of allotment harvests.

Through the morning’s exhilarating, educational adventure the children had fun and learnt a little more about the precious substance that is fundamental to our existence: soil.