Could anaerobic digestion by-products replace manufactured fertilizers?

The government has launched a study into how waste from anaerobic digestion plants could be used to replace manufactured nitrogen fertilizers to help control costs for farmers and boost production.
The government-backed Waste and Resources Action Programme (WRAP) last week announced it has kicked off a research programme designed to boost the understanding of how effective digestate would be as a fertiliser for farmers.
Digestate is a waste produced through anaerobic digestion, a process that breaks down the waste in the absence of oxygen in order to produce biogas that can then be harnesses to produce heat and energy.
The resulting digestate is seen as a valuable source of available plant nutrients, particularly nitrogen, but the rate at which nitrogen is released for uptake by crops is not well understood.
WRAP hopes the project will fill this knowledge gap, enabling farmers to include digestate in their nutrient management plans thereby displacing manufactured fertilisers, which are energy intensive to produce, or phosphates that are mined from non-renewable resources
Study aims to improve understanding of how digestates could be used by the agricultural sector to cut costs and boost yields
By Business Green staff
The government has launched a study into how waste from anaerobic digestion plants could be used to replace manufactured nitrogen fertilizers to help control costs for farmers and boost production.

The government-backed Waste and Resources Action Programme (WRAP) last week announced it has kicked off a research programme designed to improve understanding of how effective digestate would be as a fertilizer for farmers.
Digestate is a waste produced through anaerobic digestion, a process that breaks down the waste in the absence of oxygen in order to produce biogas that can then be harnessed to produce heat and energy.
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The resulting digestate is seen as a valuable source of available plant nutrients, particularly nitrogen, but the rate at which nitrogen is released for uptake by crops is not well understood.
WRAP hopes the project will fill this knowledge gap, enabling farmers to include digestate in their nutrient management plans, thereby displacing manufactured fertilisers, which are energy-intensive to produce, or phosphates, which are mined from non-renewable resources.
By investigating a range of variables in crop, soil and climate types, the project also aims to unearth new applications for digestates. For example, it could be used as a liquid fertiliser and applied to grassland to offer significant cost savings compared to traditional fertilisers.
The four-year project is also funded by the Department for Environment, Food and Rural Affairs, WRAP Cymru, and Zero Waste Scotland.
Agriculture minister Jim Paice said the research will be crucial for boosting innovation in the sector to help farmers reduce costs and become more sustainable.
"Farmers know they have to become more innovative by producing both energy and potentially reducing fertiliser costs, so this research is critical," he said. "Young people especially understand the need for sustainability, so by working with colleges this will be an exciting project."
The news came as the government last week proposed increased feed-in tariff incentives for anaerobic digestion plants in an attempt to accelerate adoption of the technology amongst the farming community.
However, AD experts warned that the proposed incentives are still not attractive enough to encourage investment in the technology