̽��ֱ�� of Cambridge - agriculture

Fish bellies, fava beans and food security

plc32 — Fri, 05 Apr 2024 15:20:27 +0000

Cambridge Zero and Cambridge Global Food Security gather academics and experts to share solutions for the planet’s looming food production problem.

Carbon emissions from fertilisers could be reduced by as much as 80% by 2050

sc604 — Thu, 09 Feb 2023 15:48:50 +0000

̽��ֱ��researchers, from the ̽��ֱ�� of Cambridge, found that two-thirds of emissions from fertilisers take place after they are spread on fields, with one-third of emissions coming from production processes.

Although nitrogen-based fertilisers are already known to be a major source of greenhouse gas emissions, this is the first time that their overall contribution, from production to deployment, has been fully quantified. Their analysis found that manure and synthetic fertilisers emit the equivalent of 2.6 gigatonnes of carbon per year – more than global aviation and shipping combined.

Carbon emissions from fertilisers urgently need to be reduced; however, this must be balanced against the need for global food security. Earlier research has estimated that 48% of the global population is fed with crops grown with synthetic fertilisers, and the world’s population is expected to grow by 20% by 2050.

̽��ֱ��Cambridge researchers say that a combination of scalable technological and policy solutions are needed to reduce fertiliser emissions while maintaining food security. However, they estimate that if such solutions could be implemented at scale, the emissions from manure and synthetic fertilisers could be reduced by as much as 80%, to one-fifth of current levels, without a loss of productivity. Their results are reported in the journal Nature Food.

“Incredibly, we don’t actually know how many chemicals we produce globally, where they end up, where and how they accumulate, how many emissions they produce, and how much waste they generate,” said co-author Dr André Cabrera Serrenho from Cambridge’s Department of Engineering.

Serrenho and his co-author Yunhu Gao undertook a project to accurately measure the total impacts of fertilisers, one of the two main products of the petrochemical industry. Of all the products made by the petrochemical industry, the vast majority – as much as 74% – are either plastics or fertilisers.

“In order to reduce emissions, it’s important for us to identify and prioritise any interventions we can make to make fertilisers less harmful to the environment,” said Serrenho. “But if we’re going to do that, we first need to have a clear picture of the whole lifecycle of these products. It sounds obvious, but we actually know very little about these things.”

̽��ֱ��researchers mapped the global flows of manure and synthetic fertilisers and their emissions for 2019, along all stages of the lifecycle, by reconciling the production and consumption of nitrogen fertilisers and regional emission factors across nine world regions.

After completing their analysis, the researchers found that unlike many other products, the majority of emissions for fertilisers occur not during production, but during their use.

“It was surprising that this was the major source of emissions,” said Serrenho. “But only after quantifying all emissions, at every point of the lifecycle, can we then start looking at different mitigation methods to reduce emissions without a loss of productivity.”

̽��ֱ��researchers listed and quantified the maximum theoretical impact of different mitigation methods – most of these are already known, but their maximum potential effect had not been quantified.

Emissions from the production of synthetic fertilisers are mostly from ammonia synthesis, partly due to chemical reactions used in the production process. ̽��ֱ��most effective mitigation at the production stage would be for the industry to decarbonise heating and hydrogen production. Additionally, fertilisers could be mixed with chemicals called nitrification inhibitors, which prevent bacteria from forming nitrous oxide. However, these chemicals are likely to make fertilisers more expensive.

“If we’re going to make fertilisers more expensive, then there needs to be some sort of financial incentive to farmers and to fertiliser companies,” said Serrenho. “Farming is an incredibly tough business as it is, and farmers aren’t currently rewarded for producing lower emissions.”

̽��ֱ��single most effective way to reduce fertiliser-associated emissions, however, would be to reduce the amount of fertilisers that we use. “We’re incredibly inefficient in our use of fertilisers,” said Serrenho. “We’re using far more than we need, which is economically inefficient and that’s down to farming practices. If we used fertiliser more efficiently, we would need substantially less fertiliser, which would reduce emissions without affecting crop productivity.”

̽��ֱ��researchers also looked at the mix of fertilisers used around the world, which varies by region. ̽��ֱ��researchers say that replacing some of the fertilisers with the highest emissions, such as urea, with ammonium nitrate worldwide could further reduce emissions by between 20% and 30%. However, this would only be beneficial after decarbonising the fertiliser industry.

“There are no perfect solutions,” said Serrenho. “We need to rethink how we produce food, and what sorts of economic incentives work best. Perhaps that means paying farmers to produce fewer emissions, perhaps that means paying more for food. We need to find the right mix of financial, technological and policy solutions to reduce emissions while keeping the world fed.”

Serrenho and Gao estimate that by implementing all the mitigations they analysed, emissions from the fertiliser sector could be reduced by as much as 80% by 2050.

“Our work gives us a good idea of what’s technically possible, what’s big, and where interventions would be meaningful – it’s important that we aim interventions at what matters the most, in order to make fast and meaningful progress in reducing emissions,” said Serrenho.

̽��ֱ��research was part of the C-THRU project, led by Professor Jonathan Cullen, where researchers from four UK and US Universities are working to bring clarity to the emissions from the global petrochemical supply chain.

Reference:
Yunhu Gao and André Cabrera Serrenho. ‘Greenhouse gas emissions from nitrogen fertilisers could be reduce by up to one-fifth of current levels by 2050 with combined interventions.’ Nature Food (2023). DOI: 10.1038/s43016-023-00698-w

Researchers have calculated the carbon footprint for the full life cycle of fertilisers, which are responsible for approximately five percent of total greenhouse gas emissions – the first time this has been accurately quantified – and found that carbon emissions could be reduced to one-fifth of current levels by 2050.

Our work gives us a good idea of what’s technically possible, and where interventions would be meaningful – it’s important that we aim interventions at what matters the most, in order to make fast and meaningful progress in reducing emissions

André Cabrera Serrenho

SteveAllenPhoto via Getty Images

Spraying fertiliser on wheat crop - North Yorkshire - England.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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̽��ֱ��future of farming: from eating insects to urban agriculture

sc604 — Wed, 07 Dec 2022 12:50:38 +0000

̽��ֱ��Entrepreneurship Centre at Cambridge Judge Business School is supporting new ventures to improve sustainability in agriculture to meet the demands of a growing global population.  

Concentrate farming to leave room for species and carbon

fpjl2 — Wed, 06 Oct 2021 08:47:09 +0000

Farming should be as high-yield as possible so it can be limited to relatively small areas, allowing much more land to be left as natural habitats while still meeting future food targets.

European summer droughts since 2015 unprecedented in past two millennia

sc604 — Mon, 15 Mar 2021 14:37:48 +0000

Recent summer droughts in Europe are far more severe than anything in the past 2,100 years, according to a new study.

Ecosystems Overload

fpjl2 — Tue, 10 Dec 2019 09:48:57 +0000

We are laying waste to the biosphere. If we're serious about saving millions of species, then it's our own that must change how it thinks about, lives off and values the planet it inhabits.

̽��ֱ��plant scientist with a practical vision for Africa (and who wasn’t content to sit and drink tea).

cg605 — Thu, 17 Oct 2019 13:37:55 +0000

Carol Nkechi Ibe discovered the hard way what it’s like to be bright and educated, and yet feel like you know almost nothing. ̽��ֱ��life science foundation she started as a result has now helped hundreds of Africans prepare for the scientific career she could easily have given up on.

Robot uses machine learning to harvest lettuce

sc604 — Sun, 07 Jul 2019 23:00:59 +0000

̽��ֱ��‘Vegebot’, developed by a team at the ̽��ֱ�� of Cambridge, was initially trained to recognise and harvest iceberg lettuce in a lab setting. It has now been successfully tested in a variety of field conditions in cooperation with G’s Growers, a local fruit and vegetable co-operative.

Although the prototype is nowhere near as fast or efficient as a human worker, it demonstrates how the use of robotics in agriculture might be expanded, even for crops like iceberg lettuce which are particularly challenging to harvest mechanically. ̽��ֱ��results are published in ̽��ֱ��Journal of Field Robotics.

Crops such as potatoes and wheat have been harvested mechanically at scale for decades, but many other crops have to date resisted automation. Iceberg lettuce is one such crop. Although it is the most common type of lettuce grown in the UK, iceberg is easily damaged and grows relatively flat to the ground, presenting a challenge for robotic harvesters.

“Every field is different, every lettuce is different,” said co-author Simon Birrell from Cambridge’s Department of Engineering. “But if we can make a robotic harvester work with iceberg lettuce, we could also make it work with many other crops.”

“At the moment, harvesting is the only part of the lettuce life cycle that is done manually, and it’s very physically demanding,” said co-author Julia Cai, who worked on the computer vision components of the Vegebot while she was an undergraduate student in the lab of Dr Fumiya Iida.

̽��ֱ��Vegebot first identifies the ‘target’ crop within its field of vision, then determines whether a particular lettuce is healthy and ready to be harvested, and finally cuts the lettuce from the rest of the plant without crushing it so that it is ‘supermarket ready’. “For a human, the entire process takes a couple of seconds, but it’s a really challenging problem for a robot,” said co-author Josie Hughes.

̽��ֱ��Vegebot has two main components: a computer vision system and a cutting system. ̽��ֱ��overhead camera on the Vegebot takes an image of the lettuce field and first identifies all the lettuces in the image, and then for each lettuce, classifies whether it should be harvested or not. A lettuce might be rejected because it’s not yet mature, or it might have a disease that could spread to other lettuces in the harvest.

̽��ֱ��researchers developed and trained a machine learning algorithm on example images of lettuces. Once the Vegebot could recognise healthy lettuces in the lab, it was then trained in the field, in a variety of weather conditions, on thousands of real lettuces.

A second camera on the Vegebot is positioned near the cutting blade and helps ensure a smooth cut. ̽��ֱ��researchers were also able to adjust the pressure in the robot’s gripping arm so that it held the lettuce firmly enough not to drop it, but not so firm as to crush it. ̽��ֱ��force of the grip can be adjusted for other crops.

“We wanted to develop approaches that weren’t necessarily specific to iceberg lettuce so that they can be used for other types of above-ground crops,” said Iida, who leads the team behind the research.

In future, robotic harvesters could help address problems with labour shortages in agriculture, and could also help reduce food waste. At the moment, each field is typically harvested once, and any unripe vegetables or fruits are discarded. However, a robotic harvester could be trained to pick only ripe vegetables, and since it could harvest around the clock, it could perform multiple passes on the same field, returning at a later date to harvest the vegetables that were unripe during previous passes.

“We’re also collecting lots of data about lettuce, which could be used to improve efficiency, such as which fields have the highest yields,” said Hughes. “We’ve still got to speed our Vegebot up to the point where it could compete with a human, but we think robots have lots of potential in agri-tech.”

Iida’s group at Cambridge is also part of the world’s first Centre for Doctoral Training (CDT) in agri-food robotics. In collaboration with researchers at the ̽��ֱ�� of Lincoln and the ̽��ֱ�� of East Anglia, the Cambridge researchers will train the next generation of specialists in robotics and autonomous systems for application in the agri-tech sector. ̽��ֱ��Engineering and Physical Sciences Research Council (EPSRC) has awarded £6.6m for the new CDT, which will support at least 50 PhD students.

Reference:
Simon Birrell et al. ‘A Field Tested Robotic Harvesting System for Iceberg Lettuce.’ Journal of Field Robotics (2019). DOI: 10.1002/rob.21888

A vegetable-picking robot that uses machine learning to identify and harvest a commonplace, but challenging, agricultural crop has been developed by engineers.

For a human, the entire process takes a couple of seconds, but it’s a really challenging problem for a robot

Josie Hughes

Robot uses machine learning to harvest lettuce

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