Agriculture has been an integral part of the heritage of world cultures and communities through providing sustenance, economic prosperity and a cultural identity deeply rooted in the countryside. Against this backdrop, N cycling is a topic of fundamental importance, particularly in the context of livestock farming.
Nitrogen, an essential element for all living organisms, plays a pivotal role in sustaining healthy ecosystems, both natural and agricultural. Livestock farming relies heavily on N inputs, primarily as fertilisers and animal feeds, to promote high productivity of feed crops and livestock. Nitrogen is also a unique element in nutrition being associated with protein but not carbohydrates or lipids. However, suboptimal management of N can lead to pollution and environmental degradation, negatively impacting ecosystems and human health, and contributing to climate change. We are becoming more aware of these negative impacts but need to look at them in the context of how N moves through the food system and also account for the value it adds.
To address the challenges, a multifaceted approach is required, involving various stakeholders: government, policymakers and regulators; scientists, research institutions and innovators; fertiliser producers, animal feed manufacturers, farmers and, ultimately, consumers. Collaboration is needed to ensure our food systems make best use of resources but do not waste them. To raise awareness, support research and development of innovative solutions, and to implement best practice, we must have a holistic understanding of the food system. The N cycle underpinning the food system is a key concept to understand.
This report outlines the important role N has in promoting crop growth and animal performance, together with the importance it has in transforming lower-quality feed components into high-quality protein. Livestock hold a unique position in this process through their ability to transform lower-quality feeds into very high-quality food products. Ruminants are uniquely capable of being able to harness the power of their rumen microbiome to ‘add’ protein to the equation while also breaking down complex carbohydrates (fibre) that cannot be digested by most other animal species. The N cycle is fundamental to this special process.
So how can we improve the efficiency with which we use nitrogen, and avoid excessive losses from the food system?
• Innovative feed options can be used to maximise the efficiency with which animals use protein which will reduce N content in animal waste and so play a significant role in increasing NUE within livestock systems
• Adoption of technological solutions to hold or capture more N will be key strategies to improve efficiency in food production while minimising and capturing losses from the N cycle
• Smart farming systems using sensor networks can
help farmers manage N inputs through monitoring soil health, meeting crop N requirements and managing livestock manure appropriately. Data is key to delivering in this area
• Artificial intelligence can use rich datasets to aid in predicting N demand and potential for losses
across landscapes, allowing optimisation of fertiliser and manure applications, to maximise NUE
• Embracing circular economy principles through integration of livestock farming with crop production can help close nutrient loops for N and other key nutrients, reducing need for synthetic inputs, simultaneously increasing nutrient use efficiency and reducing carbon footprint
Several areas require innovations to enhance our ability to better manage N resources. These include:
• Cheap and accurate methods for measuring N in the soil pool, by far the largest pool of N on most farms. This is critically important in modelling the N cycle since, as the largest pool, it acts as a buffer for plant production from a series of N inputs, including the capture of N from animal dung and urine
• Robust and easy-to-use information systems for managing N resources that account for changes over relevant timescales and differential distribution of N in landscapes, to reduce need for additional inputs as safety margins for achieving performance goals:
– For soils to help manage spatial application of organic and inorganic fertilisers
– For body protein changes in lactating and growing animals at level of management groups or at individual animal level where nutritional control can be applied at that level
• Simple, intuitive systems that allow us to equate different N pools or flows on a common scale of impact i.e. equating nutritional value of protein quality, to N value as a fertiliser, to pollution impacts of N2O (atmosphere) and NO3 – (water ways). This will help optimise N use models.
Livestock are a key element of our food system for good reasons. They upcycle nutritional quality of feed to produce highly nutritious food and they play an important role in returning nutrients to soils through manures. This dual role is a key pillar for ‘regenerative agriculture’. This report shows where N can enter or leave the food system. Our aim should be to minimise unnecessary loss, through an understanding of the natural cycle and the use of innovative technologies to capture nutrients at risk of loss, together with monitoring N pools and flows between them on farm, to actively manage N resources. It is not a question of whether we need livestock. Rather it is how should we make best use of livestock.
So, while livestock farming is increasingly subject to scrutiny in terms of its environmental impact, we must also shift perspective and recognise the potential of livestock farming as a catalyst or opportunity for promoting better environmental stewardship and sustainable agricultural practices. This will strengthen the resilience of the agricultural sector in the face of climate change and uncertainty,
while continuing to play a vital role in providing society with essential nutrients in a highly-nutritious form. CIEL commends this report to the agri-food sector, government and wider public interested in farming and food, both here in the UK and abroad, to help inform debate about sustainable food systems.