Agriculture provides many benefits to society, and is one of the key industries in society
Agriculture has a positive impact on the economy, provides employment and income, and provides food and fibre production, just as a few examples of it’s benefits.
But, there can be some downsides to agricultural production as well.
In this guide, we list some of the potential negative effects agriculture can have on the environment, as well as on the sustainable use of resources.
Summary – Potential Negative Effects Of Agriculture On The Environment, & The Sustainable Use Of Resource
Impact On The Environment
Environmental issues agriculture might contribute to might include, but aren’t limited to:
– Water pollution, air pollution, land degradation (such as soil erosion), soil contamination, deforestation and land use issues, general waste pollution, greenhouse gas emissions (and impact on climate change as a consequence), and biodiversity issues
The causes for these environmental issues can vary. Two examples of causes might be:
– the damage done to land by ruminants such as cattle from overgrazing … leading to land degradation and topsoil erosion
– and, agricultural chemicals such as synthetic fertilizers that contain reactive nitrogen … leading to different types of pollution, such as water pollution
Environmental issues can be caused by different types of agriculture, such as livestock, or by the agricultural processes for other agricultural products such as crops and fibres.
idtechex.com indicates that meat production in agriculture specifically contributes to a range of environmental issues
They outline that meat production is ‘one of the most significant contributors to the most serious environmental problems, at every scale from local to global’
Impact On Sustainable Use Of Resources
Agriculture can also contribute to the unsustainable (and/or inefficient) use of resources.
This might happen through the use of resources like:
– agricultural land (grazing land, but also cropland), topsoil, irrigated water, synthetic fertilizers, synthetic pesticides, livestock feed (which humans might be able to eat directly, but also the resources that feed takes to produce), and the raw materials that go into making some of these resources (like for example the mined resources that go into making potash fertilizer)
The use of genetically modified seeds and crops in agriculture may also have an impact on the environment and sustainability.
Although, it’s currently debated as to what the impact of using GMOs might be across different indicators, especially over the long term
More sustainable agricultural practices is one solution that has been proposed to address the environmental and sustainable management of resources issues related to conventional farming. But, there’s also pros and cons to sustainable farming to consider
*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 Society Overall
Agriculture impacts many areas of society overall, such as:
– Soil, water, and air
– Animals, plants, and wild living organisms
– Our food supply itself
… agriculture itself is even impacted upon by factors such as a changing climate, population growth, and technological advances.
But, the impact of agriculture specifically on the environment, and the sustainable use of resources might be …
Key Variables That Can Contribute To Environmental & Sustainability Issues In Agriculture
The clearing of land and forests, and conversion into farms and ranches
The use of synthetic fertilizers like nitrogen (that contain reactive nitrogen), phosphorus and potash fertilizers
The use of synthetic pesticides and herbicides
The use of non renewable water, and irrigated water
Issues related to livestock specifically, such as overgrazing, waste (like manure), and emissions (burping, farting, etc)
Intensive or unsustainable farming practices which don’t consider long term soil health, topsoil, and other potential long term consequences
General farming waste (like agricultural plastics for example)
Greenhouse Gas Emissions & Climate Change
There’s several ways that agriculture might contribute to a changing climate:
– The clearing of land of trees and vegetation (and sometimes forests) to convert them into farms, ranches and agricultural land (changing their land use)
One reason for this might be that trees and vegetation are a carbon sink
But, another reason is that changing the composition of the Earth’s surface can change the way it absorbs and reflects/releases heat. This can impact the greenhouse effect
– The use of synthetic fertilizers
Greenhouse gases are emitted from the use of synthetic 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
– The use of synthetic pesticides
Greenhouse gases that are emitted from the use of pesticides – both at the manufacturing stage, and at the usage stage.
Although, emissions from pesticides might be largely ignored right now in some agricultural GHG emissions data
– The farming of livestock
Greenhouse gases 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)
Livestock accounts for between 8% and 18% of greenhouse-gas emissions, depending on how you account for changes in land use (when the Amazon is cut down for pasture, carbon emissions rise). (economist.com)
– The farming of some types of plant based foods
– The miscellaneous use of fossil fuels in agriculture, as well as the generation of waste
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
It’s also worth noting that agriculture can 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 Clearing, & Change In Land Use
Different types of forests (and vegetation) can be cleared for new land uses
These new land uses might include agriculture, logging, palm oil plantations, cocoa plantations, and a range of other uses
Some of the impacts of deforestation and land clearing might involve:
– A change in the way land absorbs and reflects heat in the greenhouse effect
– Soils may dry out when trees are removed, due to a lack of shade and trees no longer being able to help with the water cycle (by returning water vapor to the environment)
– Desertification of land without trees
– Fluctuations in temperature
Land Degradation, & Soil Degradation
There’s many different types of land and soil degradation, but, physical and chemical degradation and contamination can be two of the broad categories
When it comes to agriculture, intensive and unsustainable farming practices can degrade the land and soil over time (the structure and the quality of the land/soil)
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, over irrigation, under irrigation, and irrigation with contaminated water, and more
wikipedia.org lists the forms and effects of land/soil degradation from agriculture in their resource
More than 60% of the world’s rangelands were damaged by overgrazing during the past half century
As much as 85% of rangeland in the western US is being degraded by overgrazing
Overgrazing is by far the most pervasive cause of desertification
[Irrigation from agriculture can also cause problems with soil:]
Soil can become over irrigated and cause problems with yields and soil health … [as well as] 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
Roughly a fifth of all the world’s pasture has been degraded by overgrazing
Pollution – Water Pollution, Air Pollution, & Land Pollution
There’s a range of ways agriculture can cause pollution, such as:
– Water Pollution
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 poorly managed livestock manure and waste.
Pesticide can also drift in the air and settle in nearby water sources.
Factory farms are the biggest contributors to polluted rivers and streams in the US
About 60,000 miles of streams in the US have fisheries impaired by feedlot pollution
Animal agriculture is a chief contributor to water pollution
– Air Pollution
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
– General Pollution
General Waste Generation, & Also General Waste Pollution
Agricultural waste is one of the main types of waste in the world
There’s a range of types of agricultural waste – pesticides, fertilizers, waste water, livestock waste such as manure, veterinary medicines, and general farm waste like plastic sheets used for drip irrigation (which allows better control over soil nutrients and moisture, as well as better rain and pesticide runoff), and other agricultural plastics
Plastic mulch is another underrated type of agricultural waste (a lot of it ends up in landfill, but the chemicals can leach into the environment, and it can break down into micro plastics)
On manure waste:
Manure produced by all farm animals in the US annually is roughly 10 times the waste produced by the human population
(Un)Sustainable Use Of Resources
Resources are used in different ways and for different purposes in agriculture.
Resource use in agriculture can sometimes be unsustainable, inefficient, or simply divert resources away from other means’ of production.
Some of the ways agriculture uses resources that can become an issue can be:
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
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)
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 (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.
Livestock uses a third of all available fresh water in most countries.
Livestock uses water inefficiently: you need about 15,000 litres of water to produce a kilo of beef but only 1, 250 litres for a kilo of maize or wheat.
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).
globalagriculture.org indicates that in some parts of the world it’s no longer possible to substantially increase the production capacity of land in the area when it comes to agriculture (which impacts food production for a population)
About 50% of the habitable land on earth is being used for agriculture. However, compared to crops, livestock uses up a disproportionate amount of land compared to the % of the world’s caloric and protein supply that is supplies
One qualifier on this though is that livestock might be able to utilize a wider range of land compared to crops, which might need arable land or specific types of land to grow
Top soil is a resource used for agricultural production (and, especially fertile topsoil suitable for crops and other agricultural products that require the right soil with the right soil properties and characteristics)
When top soil is eroded by unsustainable farming practices, this might lead to issues with things such as agricultural production and yields in the future
Livestock Feed Requiring Resources To Make
Livestock require feed
A few of the potential sustainability issues with livestock feed is that a) it can take resources to grow or produce, b) some feed could be doing directly to humans for consumption instead of to livestock, which humans then eat as meat
According to different sources, livestock uses a significant portion of resources for their feed – roughly about a third of crops
Some small livestock and farm animals might be able to make use of waste and other by-products on the farm, or feed that isn’t as resource intensive.
On a global level …
About a third of the world’s crops are fed to livestock animals
About one third of the world’s commercial fish catch is fed to livestock through fishmeal and fish oil
Resources used in the production of livestock:
33% of world’s fish catch
38% of the world’s grain harvest
Just 55 percent of the world’s crop calories are actually eaten directly by people.
Another 36 percent is used for animal feed. And the remaining 9 percent goes toward biofuels and other industrial uses.
Read more about how much feed, and the type of feed beef requires in this guide
In the US …
70% of US grain production is fed to livestock
64% of US cropland produces livestock feed
Resources used in the production of livestock:
50% of all the water used in the US
70% of US grain harvest
80% of US corn harvest
Almost half of all energy expended in US agriculture
50% of all the antibiotics used in the US are fed to animals, and 80% of them are used to promote growth, not to treat disease
In the United States, just 27 percent of crop calories are consumed directly — wheat, soy, or fruits and vegetables grown in California.
By contrast, more than 67 percent of crops — particularly all the soy grown in the Midwest — goes to animal feed. And a portion of the rest goes to ethanol and other biofuels.
Other countries …
Resources used in the production of livestock:
60% of Brazil’s grain harvest
Chickens, pigs and other small animals can make use of waste and other by-products, eat worms or acorns, can complement food production and optimise the use of resources (globalagriculture.org)
Efficiency Of Converting Livestock Feed To Meat Or Protein
In addition to livestock requiring feed, there is consideration for how efficiently livestock convert that feed to meat or protein.
Chicken and pigs might be most efficient, followed by lamb, and beef might be least efficient. Some reports to indicate though that some herbivorous farmed fish can be more efficient than chicken and pigs.
The quality of the feed is a variable in conversion efficiency too – for this reason, conversion efficiency in places like America and Europe where grain is used might be higher than in some places in Africa where feed quality on rangelands is poor.
Grass or hay fed cattle may convert at the most efficient rates.
Since 1961, overall conversion rates for cattle have increased.
idtechex.com indicates poultry is the most efficient and cheapest meat to produce:
Poultry is cheaper to produce than other types of meat and chickens are the most efficient meat animal at converting grams of feed to grams of protein.
Poultry also has fewer religious restrictions on its consumption than meats such as beef or pork
Inefficient Source Of Nutrition (Meat vs Other Foods)
Beyond feed resources and feed efficiency, there’s the nutrition in the finished food product to consider.
One food product may be less nutrition efficient compared to another, or not contain specific nutrients another food product does.
Meat might be an inefficient source of protein and calories when considering the amount of resources it takes to make. Milk might be more efficient from a protein perspective.
Animals provide a third of the protein in people’s’ diets
Meat is an inefficient source of calories. It accounts for 17% of global calorific intake, but uses twice that amount of land, water and feed.
Milk is far more efficient than meat: it takes five times as much feed to produce protein in the form of meat than in milk.
Milk is more efficient as a source of protein than meat as well
globalagriculture.org indicates that ‘The production of meat, milk and eggs leads to an enormous loss of calories grown in fields, since cereals and oil seeds have to be cultivated to feed to animals’
idtechex.com indicates that (paraphrased) the meat industry faces sustainability issues as it uses a disproportionate amount of agricultural land compared to the total % calorie and protein share it provides globally
Meat is also an inefficient source of nutrition (idtechex.com gives numbers on the amount of energy required to produce 1 calorie for different types of meat)
If the world population continues to grow – a plant based diet may be better in terms of sustainably being able to feed extra people.
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
The impact of any agricultural process or product will differ depending on variables such as:
– The individual farm or agricultural operation
– The geographic region (different States or Provinces within a country, or different countries such as developed and developing countries)
– The agricultural practices usd (e.g. intensive agriculture vs more sustainable agriculture, or conventional agriculture, and organic agriculture)
– The conditions and resources available 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
Based on these variables and many others, agricultural products need to be assessed on a case by case, or individual basis.
Other Potential Effects Of Agriculture
For a balanced view on the potential effects of agriculture, these guides contain some of the other potential effects:
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