Andy Tweedie

Name: Andy Tweedie

Project title: Soil macronutrient cycles beneathour feet: predicting how soil carbon and nitrogen manipulation regulatesphosphorus cycling for environmental benefits.

Where based: LancasterUniversity student based at James Hutton Institute (Craigiebuckler,Aberdeen)

Project Abstract: 

The use of inorganic phosphorus (P) fertilisers has massively increased global agricultural output but created an unsustainable dependency. Sources of high quality rock phosphate are finite and P fertiliser run-off can cause eutrophication of water courses. Application of inorganic P fertiliser is hugely inefficient with up to 90% becoming bound and unavailable to crops according to soil chemistry and microbial cycling conditions. We propose that a build-up of P stocks in agricultural soils has occurred but that changes in land use practises could render a useful proportion of this available to crops.

The cycling of P is intimately linked to carbon (C) and nitrogen (N) cycling and further study of these interactions in soil is required. This research will investigate the manipulation of the P cycle over agriculturally relevant timescales, by studying the fate of soil P under various C and nitrogen N treatments. Additionally, a spatial study will measure the proportions of P species found in a range of soil types in relation to C and N forms. These data will be used to model the effect of C:N stoichiometry on P cycling in soil, informing further research into the practical utilisation of existing soil P stocks.

I am lucky to have an industry partner in the project in EMS (Enivronmental Monitoring Solutions), providing expertise in in-situ soil and water sensors.

Personal Background:

I have an educational background in plant science (BSc, 2001, University of Nottingham; MSc 2017 Queen Mary University of London / Royal Botanic Gardens, Kew) and a professional background in commercial pet food R&D and marketing I.T. consultancy. The major themes linking these varied domains are an interest in processes/cycles, data handling and defining/solving problems. More detail here: I have a growing interest in discovering how we as individuals can contribute to mitigation of negative human impacts on global and local environments (and make the most of the positive ones!). I like to keep active with Aikido, climbing (indoors mainly), yoga, hiking and cycling. I’m always up for a walk or a climb, if you fancy it.