Agriculture provides a long list of benefits to society, and is an essential industry for some key reasons (it’s impact on the economy, employment and other sectors like food and fibre manufacturing being some of the main ones).
But, there can be some downsides to agricultural production as well.
In this guide, we list some of the negative effects agriculture can have on the environment and the sustainable use of resources.
Summary – Environmental & Sustainable Use Of Resource Problems Resulting From Agriculture
Agriculture can result in or contribute to a whole range of environmental issues, including but not limited to water pollution, air pollution, land degradation, soil contamination, deforestation and land use, general waste pollution, and a changing climate.
The causes for these environmental issues vary.
Agriculture can also contribute to the unsustainable use of resources through the use of resources like agricultural land (grazing land and cropland), topsoil, irrigated water, synthetic fertilizers, pesticides, and the raw materials that go into making some of these resources (like for example the mined resources that go into making potash fertilizer)
There’s also more controversial issues like the use of genetically modified seeds and crops used in agriculture that may or may not have an impact on the environment and sustainability
Sustainable agriculture is one solution that has been proposed to help address some of the current issues related to conventional farming
*Note – this is a generalized guide only. Ultimately, environmental and resource sustainability problems are specific to individual farms, geographic locations, agricultural methods and processes used, types of agricultural products being grown or produced, and many more variables and factors.
Agriculture Impacts Many Different Aspects Of The Environment & Society
The environmental impact of agriculture involves a variety of factors from the soil, to water, the air, animal and soil variety, people, plants, and the food itself.
The Different Key Variables In Agriculture That Contribute To Environmental & Sustainability Issues
The main variables and factors that contribute to the range of environmental issues are:
The clearing of land and forests, and conversion into farms and ranches
The use of synthetic fertilizers like nitrogen, phosphorus and potash fertilizers
The use of synthetic pesticides and herbicides
The use of non renewable and irrigated water
The farming of livestock, and their associated waste and emissions
Intensive or unsustainable farming practices which don’t consider long term soil health, topsoil, and other long term considerations
General farming waste
A Changing Climate & Greenhouse Gases
There’s several ways that agriculture contributes to a changing climate:
– First, there’s the clearing of land of trees and vegetation to convert them into farms, ranches and agricultural land.
Trees and vegetation are a carbon sink
– Second, the clearing of land and the change of land use changes the composition of the Earth’s surface, and can chance the way it absorbs and reflects/releases heat
– Third, there are greenhouse gases that are emitted from the use of fertilizers – like for example, nitrous oxide being released from nitrogen based synthetic fertilizers.
– There is also the manufacturing stage of fertilizers to consider and the associated emissions
– Fourth, there are greenhouse gases that are emitted from the use of pesticides – at the manufacturing stage, and at the usage stage.
Although, emissions from pesticides are likely largely being ignored right now in some agricultural GHG emissions data
– Fifth, there are greenhouse gases that are emitted from livestock – from …
1. Producing animal feed,
2. Fermentation (digestion) and burping and farting,
And, 3. Manure storage and processing. About 44 percent of livestock emissions are in the form of methane (CH4). The remaining part is almost equally shared between Nitrous Oxide (N2O, 29 percent) and Carbon Dioxide (CO2, 27 percent) (fao.org)
– Sixth, agriculture uses fossil fuels for machinery and transport, and there is also agricultural waste that might be disposed of – both of which can emit greenhouse gases
The climate and weather have a give and take relationship with a changing climate:
Agricultural activity on one hand can contribute to climate change
But, a changing climate and weather patterns – a change in temperature, changing rainfall patterns, and so on – can change growing seasons, can change yields and production, can change crop suitability in a region, and more
Deforestation & Land Use
When land is cleared to make agriculture, or logging, palm oil plantations, and other uses – forests and vegetation can be cleared in some regions
Linked to a changing climate – specifically a change in land use, and the removal of tree and vegetation carbon sinks
Other effects of deforestation for agriculture might include:
When trees are removed from forests, the soils tend to dry out because there is no longer shade, and there are not enough trees to assist in the water cycle by returning water vapor back to the environment.
With no trees, landscapes that were once forests can potentially become barren deserts.
The removal of trees also can also [cause] extreme fluctuations in temperature.
Subsistence farming is responsible for 48% of deforestation; commercial agriculture is responsible for 32%; logging is responsible for 14%, and fuel wood removals make up 5%
Land Degradation, & Soil Degradation
There’s many different types of land and soil degradation – but, physical and chemical degradation and contamination can be two broad categories
Intensive and unsustainable farming practices can degrade the land over time
Some examples of these practices might include overgrazing, harvesting that involves regularly disturbing and breaking up the soil, the use of agricultural chemicals that kills off beneficial soil microorganisms, not focussing on practices that preserve soil health, and more
Agriculture can cause a loss in soil quality and soil degradation
This can take many forms such as salting, waterlogging, compaction, pesticide contamination, decline in soil structure quality, loss of fertility, changes in soil acidity, alkalinity, salinity, and erosion (when the fertile topsoil is washed away)
This is a problem because soils hold the majority of the world’s biodiversity, and healthy soils are essential for food production and an adequate water supply.
Soil degradation also impacts biological degradation, which affects the microbial community of the soil and can alter nutrient cycling, pest and disease control, and chemical transformation properties of the soil.
Irrigation can also cause problems with soil:
Soil can become over irrigated and cause problems with yields and soil health
Over irrigation can cause deep drainage issues and salinity problems
Under irrigation can also cause soil salinity control issues
Irrigation with contaminated, high salt or unbalanced water can also cause soil health and crop damage issues
Pollution – Water Pollution, Air Pollution, & Land Pollution
There’s many ways agriculture can cause pollution, such as:
Water pollution mainly occurs from the run off (from the rain which washes through the soil and into water sources like ground water and rivers) of synthetic fertilizers, pesticides and even livestock manure and waste.
Pesticide can also drift in the air and settle in nearby water sources.
Air pollution from synthetic nitrogen fertilizers but also animal waste in agriculture emit ammonia gas, and there can be a secondary reaction in the air with oxides to create air pollution
Land pollution, and soil contamination comes from general agricultural waste, but also soil contamination can come from the heavy use of chemicals like pesticides, herbicides and fertilizers
Pollution and contamination in agriculture can occur from sediments, nutrients, pathogens, pesticides, herbicides, fertilizers, metals, salts, animal manure (bacteria and pathogens) and more
Poorly managed animal feeding operations, overgrazing, plowing, and improper, excessive, or badly timed use of pesticides or fertilizers are some activities that release these chemicals and substances
Tillage, fertilization, and pesticide application also releases ammonia, nitrate, phosphorus, and there are many other pesticides that affect air, water, and soil quality, as well as biodiversity.
Agricultural chemicals can leave residue on food, can leach through ground soil and into freshwater reserves as well as the ocean, can be blown through the air, can transfer from one water source to another – and can basically spread via a wide range of sources and impact a wide range of organisms and environments.
Aquatic environments can be some of the hardest hit environments
Pesticide drift (soil contamination, and air spray drift), pesticides based on organochloride, pesticide residue on foods, pesticide toxicity to bees and other non target species, and bioremediation are a list of problems associated with the release of chemicals from agriculture
General Waste, & Waste Pollution
Agricultural waste is one of the main types of waste in the world
Agricultural waste can range – pesticides, fertilizers, waste water, livestock waste such as manure, veterinary medicines, and general farm waste like plastic sheets used for drip irrigation, and other agricultural plastics
Farmers can use plastic sheets for drip irrigation, which allows better control over soil nutrients and moisture
Plastic sheets encourage rain runoff and pesticide runoff (the pesticide though can runoff to freshwater and ocean water sources
But, the use of plastic mulch for vegetables, strawberries, and other row and orchard crops exceeds 110 million pounds annually in the United States – and this plastic is a waste problem in itself, because much of it ends up in landfill
The chemicals inside the plastic mulch sheets, plastic micro fibres that break down, and how long the plastic takes to biodegrade as waste are all issues
(Un) Sustainable Use Of Resources
Synthetic fertilizers are used heavily worldwide in agriculture – particularly in developed nations and regions where larger scale industrial and commercial agriculture takes place
Different synthetic fertilizers include nitrogen, potash and phosphorus fertilizers
Each fertilizer takes energy to make, and involves base/raw materials that need to be sourced to make them
For example, phosphate and potash fertilizers both usually involve the mining of minerals and ores that are used to make them
Nitrogen fertilizers (which are responsible for over half the synthetic fertilizer used worldwide) involve the use of non renewable natural gas in the ammonia production process (which is very energy intensive)
Nitrogen fertilizer represents the single largest investment of energy in the production of many crops, and circulation of reactive nitrogen can have negative effects on atmospheric conditions, in terrestrial ecosystems, in freshwater and marine systems, and on human health. Phosphorus fertilizers are produced by mining finite resources of phosphate rock, and can fuel harmful algal blooms when lost to the aquatic environment (journals.plos.org)
Synthetic Pesticides and Herbicides
Synthetic pesticides and herbicides are used widely in commercial and industrial agriculture, particularly in developed regions
Many modern non naturally derived pesticides and herbicides include materials such as … hydrocarbons derived from [non renewable] petroleum … [and] other elements, the type and number of which depend on the pesticide desired. Chlorine, oxygen, sulfur, phosphorus, nitrogen, and bromine are most common (madehow.com)
Not all fresh water is renewable like rain water is
Irrigated water, used as irrigation for crops and plants in agriculture, might come from very slow to recharge groundwater or surface water sources.
When used unsustainably, fresh water sources can deplete
Globally, on average, about 70% of available freshwater goes towards agriculture, 20% to industry, and 10% to municipal
There’s only a limited amount of agricultural land in the world, so it has to be used efficiently and productively (yields and agricultural production per square area can play a part in agricultural land efficiency)
Agricultural land can include grazing land, and crop land (which is usually more fertile and used for growing crops and animal feed as opposed to raising livestock)
Top soil is a resource
Top soil takes thousands of years to renew naturally, and renews when organic matter breaks down
When top soil is eroded by unsustainable farming practices, this can be an issue
Genetic Engineering & The Use Of GMOs In Agriculture
Genetic engineering in agriculture can be a controversial topic when considering the potential environmental side effects.
Just a few might be:
Whether or not GMOs contribute to the development of super weeds (that are resistant to herbicides)
Cross contamination of GMO seeds with conventional, or natural/organic seeds on the same farm, or other farms
Read more about the potential pros and cons of GMO crops and foods in this guide.
A Few Other Notes On Agriculture
Agriculture differs both by the individual farm, and by geographical region i.e. the resources available, and the level of environmental damage caused in each region and by each farm will differ
There are different types of agricultural practices – intensive agriculture, and more sustainable agriculture – both lead to different outcomes environmentally. The same can be said for conventional agriculture, and organic agriculture
There can be large differences in the way developed and developing world countries carry out agriculture. There can also be differences within countries – state by state, or province by province
Not only does what happens on the farm (the actions of the farmer) impact the external environment, but there’s the external conditions that impact the farm e.g. natural rainfall, amount of freshwater supplies available, temperature, quality of land etc.
Agriculture is a circular/connected activity – livestock and fertilizer for example can produce greenhouse gas emissions which speeds up climate change, but then climate change can impact things like temperature, rainfall, growing seasons etc. that impact farming
Overall, there’s many factors that can impact agriculture, and that can change the impact agriculture has on humans, society, animals, and the external environment. It’s a matter of assessing farms on a case by case or individual basis, and not generalising agriculture overall.
2. Conrad, Z., Niles, M.T., Neher, D.A., Roy, E.D., Tichenor, N.E. and Jahns, L., 2018. Relationship between food waste, diet quality, and environmental sustainability. PloS one, 13(4), p.e0195405. – https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0195405