Feeding The World Sustainably: Reducing Nitrogen Pollution

Nitrogen fertilizers are essential for producing enough food for the world's growing population. However, their overuse has led to substantial nitrogen release into the environment, causing air and water pollution. An analysis of over 1,500 field observations has identified agricultural practices that can improve nitrogen fertilizer use, increase crop yields, and reduce pollution. Adopting advanced nitrogen management practices can help produce more food with less nitrogen pollution. The benefits of mitigating nitrogen pollution from agriculture far outweigh the costs of implementing these practices.

Efficient fertilization

• Improved nitrogen-management practices: Adopting advanced nitrogen-management practices can help produce more food with less nitrogen pollution. This includes synchronizing the application of nitrogen fertilizers with the crop's demand, as well as optimizing the type, dosage, placement, and timing of fertilization.
• Slow-release and controlled-release fertilizers: Using slow-release or controlled-release fertilizers can improve nitrogen use efficiency and reduce environmental pollution. These fertilizers release nitrogen slowly over time, matching the crop's uptake rate and reducing losses due to leaching, volatilization, and runoff.
• Deep fertilization: Deep placement of nitrogen fertilizers, such as applying them below the root zone, can reduce nitrogen losses to the environment. This technique is particularly effective for reducing ammonia emissions and has been shown to have the potential to cut emissions by half.
• Nitrification and urease inhibitors: Applying nitrification and urease inhibitors with urea can increase the residence time of ammonium in the soil, reducing nitrogen losses through leaching, volatilization, and runoff. This technique also helps sustain crop yields while lowering nitrous oxide and ammonia emissions.
• Biostimulants: Co-applying biostimulants, such as a biostimulant (BS), with urea can enhance nitrogen uptake by crops and reduce nitrogen losses. This leads to comparable grain yields and improved nitrogen use efficiency while reducing environmental pollution.
• Precision agriculture: Implementing precision agriculture techniques, such as soil testing and formulated fertilization technologies, can optimize nitrogen application rates and reduce over-fertilization. This ensures that nitrogen fertilizers are used efficiently and minimizes their environmental impact.
• Machine learning models: Developing machine learning models to estimate crop-specific ammonia emission factors can guide farmers in optimizing fertilizer management practices. These models consider various factors, such as climate, soil type, and management practices, to provide tailored recommendations for reducing emissions.

Efficient livestock management

• Improved feeding practices: Optimise the feed energy requirements of animals by selecting better breeds and improving the deployment of existing feedstock. This will reduce manure excretion and increase livestock productivity.
• Manure recycling: Increase the recycling of animal manure as organic fertiliser. Aim for a recycling share of 90% for animal manure, which is the highest plausible recycling share according to the most efficient animal waste management systems.
• Reduce waste: Minimise food waste at the household level. Implement measures to reduce the waste share to 20%, which is lower than the global per capita average. Recycle nutrients from sewage and household waste back into agriculture.
• Lower consumption of animal products: Encourage a shift towards plant-based diets. Aim for no more than 15% of calories or 29% of proteins to be derived from animal-based products. This will reduce the demand for livestock production and decrease nitrogen pollution.
• Optimise fertiliser use: Improve the efficiency of nitrogen application on cropland. Ensure the right amount of the right fertiliser is applied at the right time and place (4R). This will reduce nitrogen losses through volatilisation, leaching, and denitrification.
• Integrated crop-livestock systems: Promote integrated crop-livestock farming systems, such as recycling manure as fertiliser for crops and using crop residues as feed for livestock. This can improve nitrogen use efficiency and reduce pollution.
• Precision livestock farming: Utilise precision livestock farming technologies, such as sensors and data analytics, to optimise feeding, health monitoring, and manure management. This can help reduce nitrogen inputs and improve nutrient utilisation.
• Breeding and genetics: Select livestock breeds that are more efficient in converting feed into meat, milk, or other products. This will reduce the amount of feed required and decrease nitrogen excretion.
• Sustainable livestock production systems: Encourage sustainable livestock production practices, such as rotational grazing, that improve nitrogen cycling and reduce pollution.
• Manure treatment and storage: Implement proper manure treatment and storage techniques to minimise nitrogen losses and odour emissions. This includes using covered storage facilities and anaerobic digestion to treat manure.

By implementing these strategies, efficient livestock management can play a crucial role in reducing nitrogen pollution while contributing to global food security.

Reduce food waste

Reducing food waste is essential to ensuring food security and reducing nitrogen pollution. Here are some measures that can be implemented to address this issue:

Encourage Food Waste Reduction at the Consumer Level:

• Educate the public about the impact of food waste on the environment and promote conscious consumption. Encourage consumers to plan meals, create shopping lists, and utilise leftovers to minimise food waste at home.
• Implement campaigns and initiatives to raise awareness about food waste, such as "Love Food, Hate Waste" or "Ugly Produce" campaigns, which promote the use of imperfect-looking but edible food items.
• Provide clear and accurate food labelling that includes storage instructions and "best before" and "use by" dates to help consumers make informed decisions and reduce waste.

Improve Food Storage, Transportation, and Distribution:

• Optimise storage facilities and transportation systems to maintain the quality and longevity of food products, reducing spoilage and waste.
• Develop and implement innovative packaging solutions that extend the shelf life of products, such as active packaging or modified atmosphere packaging.
• Strengthen collaboration and communication between farmers, retailers, and consumers to ensure efficient distribution and reduce overproduction or surplus.

Enhance Food Donation and Redistribution Programmes:

• Facilitate partnerships between food businesses and food banks or charitable organisations to redistribute surplus food to those in need, ensuring it doesn't go to waste.
• Implement tax incentives or subsidies for food businesses that actively donate safe and edible food instead of discarding it.

Promote Sustainable Food Choices:

• Encourage consumers to choose products with minimal packaging or opt for reusable or recyclable packaging to reduce waste.
• Promote a shift towards more plant-based diets, as plant-based foods generally have lower nitrogen footprints than animal-based products.
• Support local and seasonal food consumption, reducing the environmental impact of transportation and storage.

By implementing these strategies, we can significantly reduce food waste, increase the efficiency of our food system, and contribute to the goal of feeding the world while reducing nitrogen pollution.

Recycle food waste and sewage as fertilizers

Nitrogen fertilizers are essential for producing enough food for the world's growing population. However, their overuse has led to increased nitrogen pollution in the air and water. To address this issue, we can recycle food waste and sewage as fertilizers while reducing nitrogen pollution.

Food waste is composed of organic matter that can be composted to create a nutrient-rich fertilizer. Composting is an effective and eco-friendly way to dispose of food waste, and it can be done at home by collecting and separating kitchen waste, such as vegetable peels and fruit peels, and alternating layers of wet and dry waste in a container with holes for air circulation. This process not only reduces food waste but also produces a highly organic product that can be used to grow vegetables or flowers.

However, it is important to be cautious when recycling food waste as fertilizer due to the risk of plastic contamination. Plastic waste, such as plastic bags and food wrappers, can end up in the compost and eventually make its way into the food chain. This issue is already being faced in parts of Europe, where recycling food waste for fertilizer is popular, and it is now gaining traction in the US.

Sewage sludge from treatment plants, which is sometimes used as fertilizer, has also been found to contain microplastics, further contributing to plastic contamination in the environment.

By properly managing the recycling process and reducing plastic contamination, we can effectively recycle food waste and sewage as fertilizers while reducing nitrogen pollution and promoting sustainable food production.

Lower consumption of nitrogen-intensive animal products

Nitrogen is essential for the production of animal tissue, milk, eggs, and wool. However, the production of these nitrogen-intensive animal products contributes significantly to global nitrogen pollution. Lowering their consumption can help reduce nitrogen pollution while still feeding the world.

Animal production systems convert plant protein into animal protein, but the process is inefficient. Depending on the animal species, ration, and management, only 5% to 45% of the nitrogen in plant protein is converted into animal protein. The remaining 55% to 95% is excreted as urine and feces, contributing to environmental nitrogen pollution.

Cattle, sheep, and pigs are the largest contributors to animal manure nitrogen production, with cattle alone accounting for 60%. The conversion of plant nitrogen into animal nitrogen is generally more efficient in poultry and pork production than in dairy and beef production. However, differences within production systems can be significant due to factors such as animal genetics, feed composition, and management practices.

Improving the efficiency of nitrogen conversion in animal production systems is possible. This can be achieved by enhancing the genetic production potential of the herd, optimizing the composition of animal feed, and implementing effective animal manure management practices. Coupling crop and animal production systems at a regional scale can also increase nitrogen use efficiency.

By focusing on improving nitrogen use efficiency and reducing the environmental impact of animal production, we can lower nitrogen pollution while continuing to produce the animal-source foods needed to feed the world's growing population.

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