Potato supplier Branston says it is making good progress in reducing the carbon footprint of the crop – from growing through to storage and transport.
Climate change, increasingly unpredictable weather events and consumer expectations are focusing the attention of the potato supply chain on the transition to net zero, says Andrew Blair, field technical manager at the UK’s largest potato supplier.
Funded by Innovate UK, Branston is mid-way through a three-year net zero project – working with growers as well as agritech firm B-hive Innovations, the University of Lincoln, and crop storage technologists Crop Systems.
The goal is to establish a production process that will achieve the lowest possible greenhouse gas emissions while still producing a commercially viable crop, says Mr Blair.
In this year’s Net Zero field trials – undertaken with David Armstrong Farms in Lincolnshire and Arbikie Farming in Scotland – our main focus is on optimising crop nutrition. Nitrogen fertiliser is an essential element in growing a crop of potatoes, but has a significant carbon footprint.
“As with most other conventional field crops, a good dose of fertiliser is needed to encourage plant growth and boost production,” says Mr Blair.
“We are looking at the potential to reduce reliance on synthetic fertilisers through of different trials – from novel fertilisers as well as the potential for reducing fertiliser inputs and recycling nutrition in the field.”
In both these trial fields, researchers established a base-line plot with no nitrogen applied. They then set up further plots with varying levels of nitrogen application, from both conventional and novel sources.
“We’re already noticing differences in the colour and vigour of the canopies, and it will be interesting to see what variation we get in yield at harvest,” says Mr Blair.
Scientists are also assessing how much nitrogen can feed through the leaf as the crop is growing. New technology such as R-leaf has the potential to change the way growers, agronomists and scientists think about crop nutrition, says Mr Blair.
Developed by Crop Intellect, this photosynthetic catalyst is sprayed onto the leaf – turning atmospheric gases such as nitrous oxide, nitric oxide and nitrogen dioxide into nitrate that can be used by the plant.
“R-leaf could enable growers to reduce the fertiliser application at planting knowing they can top up through the growing season,” adds Mr Blair.
“We’re evaluating a new system from Piketa, which will give in-field, real-time nutrient analysis via the leaves. This has the potential to save the cost of lab analysis and allow growers to respond immediately by feeding the crop what it needs when it needs it.
“The carbon footprint of producing synthetic nitrogen fertiliser is already well documented. What we’re particularly interested in for the Net Zero project is what happens as the crop grows and the fertiliser breaks down in the soil.
“On this project we’re working closely with Lincoln university looking at soil health and gaseous emissions at field scale throughout the growing season.”
Nitrous oxide – a greenhouse has 265 times more potent than carbon dioxide – is released from the soil as synthetic nitrogen-based fertiliser is broken down. Lincoln university is measuring this greenhouse gas throughout the growing season across all the fertiliser plots.
“They are also collecting and analysing the CO2 and other gases that are released from the soil, across the fertiliser trial and the range of different types of cultivations that are also part of the net zero field trial.”