Feasibility study on using combined tomography and spectroscopy techniques to evaluate the physical and chemical characteristics of organo-mineral fertilisers

Ruben Sakrabani^1*Sara Mosca²Alexander Liptak³Genoveva Burca³

• ¹Cranfield University, Cranfield, United Kingdom
• ²Central Laser Facility, Science and Technology Facilities Council, Didcot, Oxfordshire, United Kingdom
• ³Diamond Light Source (United Kingdom), Didcot, Oxfordshire, United Kingdom

Fertilisers play a key role in agriculture, providing key nutrients needed by crops to ensure a secure food supply. However, with increasing prices and rising environmental concerns, there is a growing need to rely on alternative and sustainable fertiliser sources, introducing the opportunity to use organic amendments to formulate organo-mineral fertilisers (OMF). Despite their environmental advantages, the inherent variability in composition of organic amendments within OMF poses a challenge for their standardisation. This study aims to use OMF derived from anaerobic digestate and coupled with carbon capture technologies to analyse for its physical characteristics and chemical composition using neutron computed tomography (NCT), X-ray computed tomography (XCT) and Raman spectroscopy (RS). This is a feasibility study to assess using nondestructive techniques on OMF as previously this has not been explored. This work represents the first attempt to utilise a combination of imaging techniques to investigate on OMF and demonstrates their feasibility for measuring the variability between individual samples. This is a proof-of-concept study which shows that combining NCT and XCT can provide images on how uniformly packed each OMF pellet are. The use of RS is to characterise OMF is more challenging largely due to the high fluorescence background arising from its matrix. This study needs to be further developed to enable image-based analysis using machine learning algorithms to determine characteristics of large batches of OMF. Further development is needed building on this work to quantify OMF pellet characteristics so that it can be confidently used as novel fertilisers in agriculture.