Air Pollution's Impact On Farming And Agricultural Produce

Air pollution is a pressing environmental issue that negatively impacts many aspects of our society, including agriculture. While agriculture can contribute to air pollution and climate change, it is also affected by the poor air quality caused by other sources. This bidirectional relationship between air pollution and agriculture is complex and has severe consequences for food security and the environment.

Livestock waste and chemical discharge

Ammonia from livestock waste combines with nitrogen oxides and sulphates from vehicles, power plants, and industrial processes to create tiny solid particles or aerosols, no more than 2.5 micrometres across, which can penetrate deep into the lungs, causing heart and pulmonary disease. These fine particles, or PM10, are a form of particulate matter air pollution, accounting for 58% of such pollution in European cities.

Agricultural air pollution doesn't just affect the air quality where crops are grown. Chemical drift with pesticides, herbicides, and fertilisers can occur as these compounds reach nearby lands or neighbourhoods, contributing to poor air quality elsewhere.

To address livestock waste and chemical discharge, several interventions can be implemented:

• Agri-environment-climate commitments (AECCs) and eco-schemes: These support voluntary farming practices such as directly incorporating or injecting nitrogen fertilisers, manure, or slurry directly into the soil to prevent ammonia volatilisation.
• Investment measures: Funding can be used for installations such as manure and slurry storage facilities, stable sealing, air washers, and biogas installations, all of which help reduce ammonia and methane emissions.
• Knowledge transfer and advisory services: These measures support innovation, raise awareness of emission problems, and help farmers develop practical solutions to reduce air pollution.

Nitrogen-rich fertilisers

Synthetic nitrogen, now used extensively in conventional fertilisers, helps farmers produce higher yields to feed a growing world population. However, when plants do not fully utilise all the nitrogen in the fertiliser, excess nitrogen can be lost from farm fields and negatively impact air and downstream water quality. This excess nitrogen can contribute to increased formation of ground-level ozone, higher amounts of climate-changing greenhouse gases, and thinning of the protective ozone layer in the Earth's atmosphere. It has also contributed to acid rain, polluted drinking water, and caused oxygen depletion and "dead zones" in water bodies, such as the Gulf of Mexico, which seriously harm aquatic wildlife.

To reduce nutrient losses, farmers can adopt nutrient management techniques, such as applying the right amount of fertiliser at the right time of year and with the right method. They can also use conservation drainage practices, ensure year-round ground cover, plant field buffers, implement conservation tillage, and keep livestock and their waste away from streams.

Climate change

Air pollution and climate change are deeply interconnected, with air pollution contributing to up to 40% of the current climate crisis. This, in turn, affects agriculture in a multitude of ways. Firstly, rising temperatures caused by climate change can significantly damage crop production. According to the UN Food and Agriculture Organization, for every degree Celsius rise in global warming, crop yields of staples like rice, maize, and wheat will decrease by up to 10%. Extreme weather and heat will also play a role in reducing crop yields.

Secondly, climate change-induced air pollution contributes to smog and acid rain, which affect both the air and the soil, further limiting crop yields and damaging plant roots and leaves. The impact of air pollution on plants can be seen through "yellowing", which refers to reduced growth, injury, or premature crop death. Along with a change in the colour of leaves, plants affected by air pollution can experience a collapse of their leaf tissue, changes in growth, and delayed maturity.

Thirdly, air pollution and climate change disproportionately affect small farmers and subsistence farmers, who are vulnerable to even minor changes in climate and crop growth. This has implications for food security, as these farmers make up a significant portion of the world's food producers.

Finally, air pollution and climate change also impact the economic aspects of agriculture. A Stanford University study estimated that reductions in ozone, particulate matter, nitrogen dioxide, and sulfur dioxide between 1999 and 2019 contributed to about 20% of the increase in U.S. corn and soybean yield gains during that period, amounting to approximately $5 billion per year. A separate study from 2000 found that ground-level ozone pollution's impact on 23 different crops resulted in 6.7 billion Euros worth of damage.

Air pollution's impact on crops

Air pollution has a two-way relationship with agriculture, and the effects of air pollution on crops are wide-ranging. Firstly, air pollution can cause a phenomenon known as "yellowing" in plants, which refers to reduced growth, injury, or premature death of crops. Along with discoloured leaves, plants affected by air pollution can also experience a collapse of their leaf tissue, changes in growth, and delayed maturity.

Secondly, air pollution contributes to smog and acid rain, which have detrimental effects on both the air and the soil in which plants grow. This, in turn, limits crop yields and damages plant roots and leaves. According to the United Nations Environment Programme (UNEP), ground-level ozone pollution created by fuel burning and chemical use will reduce staple crop yields by 26% by 2030.

A Stanford University-led study revealed that a common air pollutant, nitrogen oxides, found in car exhaust and industrial emissions, has a significant impact on crop productivity. The study found that reducing nitrogen oxide pollution by about half in each region would improve yields by about 25% for winter crops and 15% for summer crops in China, nearly 10% for both winter and summer crops in Western Europe, and roughly 8% for summer crops and 6% for winter crops in India.

Additionally, agriculture is a significant source of air pollution, with food production responsible for a quarter of the world's greenhouse gas emissions. In the EU, agriculture accounts for around 93% of total ammonia emissions, which can lead to the eutrophication of water and acidification of soils. Methane, a by-product of enteric fermentation in livestock, contributes to the formation of ground-level ozone, which is damaging to crops.

Therefore, tackling air pollution caused by agriculture is crucial for the global food system. Sustainable agricultural practices, such as agroforestry and regenerative agricultural practices, can help mitigate the impact of air pollution on crops and ensure food security for the future.

Air pollution's impact on farmers' health

Air pollution poses a serious threat to the health of farmers and those living in agricultural areas. It is a well-known environmental crisis that has a nuanced relationship with agriculture. While agriculture is a contributor to air pollution, it is also affected by it.

Agricultural air pollution is mainly in the form of ammonia, which is emitted from livestock waste and heavily fertilized fields. These emissions combine with pollutants from combustion, such as nitrogen oxides and sulfates from vehicles and power plants, to create solid particles or aerosols. These particles are tiny, no more than 2.5 micrometers across, but they can penetrate deep into the lungs, causing heart and pulmonary disease. According to a 2015 study in the journal Nature, these particles cause at least 3.3 million deaths each year globally.

In addition to the health risks posed by air pollution, farmers also face the issue of reduced crop yields and damaged crops. According to the United Nations Environment Programme (UNEP), ground-level ozone pollution created by fuel burning and chemical use will reduce staple crop yields by 26% by 2030. A Stanford University-led study also found that areas with high amounts of nitrogen oxides pollution experience significant declines in crop yields. This pollution can directly damage crop cells and affect them through the formation of ozone, an airborne toxin that reduces crop yields.

The impact of air pollution on agriculture is not limited to crop yields but also includes economic effects. Previous research by Lobell and Burney estimated that reductions in ozone, particulate matter, nitrogen dioxide, and sulfur dioxide between 1999 and 2019 contributed to about a $5 billion increase in U.S. corn and soybean yields during that period. A 2000 study found that ground-level ozone pollution's impact on 23 different crops amounted to 6.7 billion Euros worth of damage.

To mitigate the health and economic risks posed by air pollution, sustainable agricultural practices are necessary. Some of these practices include planting cover crops, using integrated pest management, properly managing soil, and adopting regenerative agricultural methods. By implementing these practices, farmers can improve air quality, protect their health, and ensure the sustainability of their farms.

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