Soil Indicator Project

Many crop types need to be harvested and replanted from scratch on an annual basis. To maintain nutrient levels in the soil, farmers often have to put down considerable quantities of fertiliser. This is costly, and a fair proportion of it ends up landing on soil that has enough nutrients anyway. Additionally, some of the nutrients in the fertiliser are often washed away, affecting local ecosystems. This process is called eutrophication. This is a major environmental concern, as it can cause algal blooms that drain oxygen out of rivers and lakes, killing fish and other wildlife.

Our lab has developed and characterised a cheap, versatile soil fertility sensor based on an E.coli chassis. It expresses fluorescent signals upon nutrient detection, producing a high-resolution nutrient distribution map of arable land. The ratio of two fluorescent signals allows farmers to quantify soil nutrient content. agrEcoli bacteria, encapsulated within a gel container to improve visibility and prevent escape, have been shown to work on soil in lab conditions. We have explored the marketing of our device, considering public perceptions of synthetic biology. BSim, our prize-winning modelling framework, has been extended to analyse our new biobricks’ behaviour within gel capsules. In addition, a new interface for BSim has improved its accessibility to the wider synthetic biology community, facilitating collaboration. agrEcoli optimises fertiliser use, saving farmers' money and reducing environmental damage.