September: A Very Good Season
Published on: 30 September 2025
In 2024, The Gates Foundation and the UK Foreign, Commonwealth and Development Office (FCDO) awarded Legume Technology a £2.15m grant to identify biological alternatives to synthetic nitrogen for African smallholder farmers. Dr Mike Thomas has the latest.
So here we are, 18 months into the project: what have we achieved so far?
Well, technically, we’ve had a very good season. Dr Nikki Walters, who’s been working with us since she was conducting her PhD at Nottingham University, has been responsible for establishing the research pipeline that’s taken us through the practical elements of the project.
It’s her lab-based screens that have helped establish the nitrogen-fixing potential of all the strains we’ve selected. As we’ve described in previous updates, we’ve been looking for signs of ammonia secretion in these candidates.
From the 50 isolates thus identified, Nikki put half a dozen through their paces in a spring wheat trial organised at the university’s facilities. This has been a grand opportunity to collect as much data as possible. We want to know everything about these isolates; essentially, anything we can measure we are measuring.
We don’t know of what use this might be in future experiments, but it’s important that we gather it; figures that perhaps appear inconsequential today might well become instrumental later in the project. So alongside ‘obvious’ data like nitrogen accumulation, we’re also measuring the effects on chlorophyll content, and even wavelength analysis on different pigments.
Collecting this amount of data has taken Nikki out to the field every day of the season. But it’s been worth it, because the trials have now clearly identified the candidates that showed better responses. These will funnel into the next stage – where we apply the knowledge learnt from UK wheat to African maize.
We’re organising initial trials – split between Ghana and Zimbabwe – in soils known to be naturally low in nitrogen. Now that we know what variables we’re looking for, we can start to measure the effect of the candidate microbes. For example, we’ve collected data on tiller development in the UK wheat, but because maize doesn’t tiller, instead we’ll look for effects on shoot development.
This should allow us to further narrow the candidates and progress to the final stage: how much nitrogen are they able to acquire for the plant? This is the key question. Yes, there are likely to be other benefits – just as we have seen with Bacillus in our ROOTFiX product – but ultimately we want to show quantification.
We’re working on that methodology now, but it will involve using isotope-labelled nitrogen and a special, sealed growing chamber. We’ll know how much of the isotopic nitrogen the plants accumulate after inoculation with the candidate microbe.
And for the update on that – you’ll have to wait!