By Kate Prescott
Kate was awarded a bursary by her college to attend the British Science Festival 2013. She is about to begin a degree in Natural Sciences at Cambridge, and has recently launched her own blog about STEM opportunities, such as summer schools and taster days for students of all ages – http://www.passionateaboutscience.co.uk/  – to share her love of the subject and give information on upcoming events to support students from all backgrounds in their quest to become scientists! You can follow her on Twitter (@Passion_Science ) or find her on Facebook (Passionate About Science ).
This great talk by Professor David Manning discussed how minerals are a key part of two major global problems – the first on the availability and use of fertilisers, particularly between developed and developing countries, and the second on climate change and how minerals could be used as mass carbon capture and storage.
When growing crops, we are essentially mining minerals from the soil and removing them – therefore we use fertilisers to 'top up' the amount of key minerals (usually nitrogen, potassium and phosphorus) present in the soil, which are required for growing large and healthy crops.
Professor Manning explained that although wealthier, more developed countries tend to do this fairly well, developing countries such as those in Africa often struggle due to a lack of money – and this could be partly to blame on the West since we are constantly trying to knock down the farmers on prices thus forcing them to cut back on their spending on fertiliser. I found this link between the social and economic factors particularly interesting.
This was followed by a discussion of the economics related to the minerals used in fertilisers – particularly phosphorus and potassium (potash). He explained that the major issue with supply in the southern hemisphere was with potash – due to its solubility, it is easily washed out of soil, and since it is a vital component of all food crops it is also mined from the soil in the farming process.
However, a shocking 47 out of 57 African countries import no potash at all, despite consuming 485,000 tonnes a year! This so called 'Potash Gap' means that world production of potash needs to double to meet the current requirements of agriculture.
After these startling statistics, Professor Manning described some of the problems currently being tackled in fertiliser production – including trying to make fertilisers accessible and affordable for all, identifying alternative fertilisers for different soil types and climates, and finding alternative sources of minerals for fertilisers to increase available resources and reduce the price.
The second half of his talk focussed on a new method for combating climate change – by simply adding compost to demolition waste and allowing plants to grow!
This novel idea is based upon research indicating that calcium carbonate becomes deposited on bricks in the soil – removing carbon from the atmosphere through the photosynthetic pathway. I was surprised to hear that a fifth of all carbon in the atmosphere passes through the plant-soil system each year – so there is clearly a huge potential to remove significant quantities of the greenhouse gas through this method.
The calcium carbonate produced is very stable, but further tests are required to investigate its longer term effects on the soil and crops. Although this technology is still being researched, it was incredibly interesting to learn about a completely new potential method for fighting climate change.
Overall, the talk was fascinating and very informative, and it was amazing to hear about such pioneering research from an expert in the area.