In agriculture, monoculture is the method of growing only one type of crop in a field at a time. Monocultures make planting, managing, and harvesting crops easier and faster in the short term, often with the help of machines. However, monocultures are more likely to be affected by diseases or pests over time because they reduce the variety of plants and animals in an area and can use up soil nutrients quickly. Farmers can increase crop diversity by planting different crops in a sequence over time, such as through crop rotation, or by growing multiple crops together in the same space, such as through polyculture or intercropping. Monoculture practices are connected to negative effects on human health through several ways, including harm to the environment, more frequent pest and disease outbreaks, increased use of pesticides and herbicides, and reduced variety in diets, which can lead to health issues like heart disease and diabetes.
Monocultures are not only found in farming but also in other areas. For example, grass lawns are a common type of monoculture in homes. In tropical regions, large areas of single-species forests have grown more common due to global trade, affecting local communities.
A genetic monoculture happens when crops have very little or no genetic differences. This occurs when farmers use specific types of plants, called cultivars, created through selective breeding and other growing methods. These crops can be more easily affected by diseases that spread quickly across large areas, which can threaten food supplies for people who rely on them.
Alternatives to monoculture include agroecological practices, silvo-pastoral systems, and mixed-species plantations. These methods help protect biodiversity while keeping crops productive. They also help reduce risks to human and environmental health.
Agriculture
Agricultural monocultures are farming methods where only one type of crop is planted in a field. This practice is common in both intensive farming and organic farming. In monoculture systems, all plants in a field have the same planting, care, and harvesting needs, which can lead to higher crop production and lower costs. When a crop is grown in a well-managed environment, monoculture can produce more food than polyculture, which involves growing multiple crops together. Modern farming techniques, such as planting only one crop and using synthetic fertilizers, have helped reduce the amount of land needed to grow food, a concept called land sparing.
Monoculture and polyculture refer to differences in how crops are arranged in space. Similarly, monocropping (planting only one crop) and intercropping (planting multiple crops together) both describe spatial diversity. In contrast, monocropping and crop rotation describe differences in how crops are managed over time.
Monocultures of perennial plants, such as African palm oil, sugarcane, tea, and pine trees, can change soil chemistry. This can cause soil to become more acidic, degrade in quality, and develop soil-borne diseases. These changes can harm long-term agricultural productivity and sustainability. Poor irrigation practices on monocultures like soy can also lead to soil erosion and water loss.
As soil health declines, farmers often use more synthetic fertilizers on monocultural fields. This can lead to chemical runoff, which harms human health. For example, excess nitrogen from synthetic fertilizers can seep into groundwater and surface water, causing nitrate contamination in drinking water. This contamination is linked to serious health risks, such as methemoglobinemia (a condition that affects infants, called "blue baby syndrome") and the formation of harmful compounds like nitrosamines in the human digestive system.
Agricultural runoff can also harm aquatic ecosystems by adding too many nutrients to water, leading to eutrophication. This process causes harmful algal blooms (HABs), which produce toxins like microcystin. These toxins can accumulate in fish and shellfish, and consuming them can lead to liver damage, neurological issues, and gastrointestinal illness in humans.
Monocultures can also reduce biodiversity by limiting resources for native species, displacing them, and reducing genetic diversity. Large-scale oil palm plantations in Latin America, such as in Colombia and Brazil, have led to significant declines in mammal, bird, amphibian, and pollinator populations.
Monocultures often lead to more frequent disease and pest outbreaks because of low biodiversity. To address this, farmers use more pesticides, which further harm insect populations, pollinators, and human health. Rotating crops or using alternative farming methods can help reduce these risks.
Monoculture farming has social impacts, such as reducing opportunities for small-scale farmers and increasing health risks from pesticide exposure. Monoculture farming conflicts with traditional, more sustainable practices used by small-scale farmers. After pest outbreaks, over 600 million liters of pesticides are sprayed each year, contaminating nearby small farms and harming community health. This connection between monoculture, pesticide use, and health risks is highlighted by the One Health perspective, which shows how environmental and human health are linked. Long-term exposure to pesticides has been linked to health issues like Alzheimer’s disease, amyotrophic lateral sclerosis, brain tumors, leukemia, non-Hodgkin lymphoma, and various gastrointestinal, skin, and respiratory illnesses. Vulnerable groups, such as farm workers, their families, and nearby residents, are most affected by these risks.
Monoculture farming also influences human diets. The global expansion of monoculture has focused on staple crops like wheat, rice, soy, corn, and sugar. This has reduced dietary diversity worldwide and promoted foods high in calories but low in nutrients. This shift has led to lower intake of essential micronutrients, contributing to both nutritional deficiencies and overnutrition-related diseases like obesity and type 2 diabetes. Monoculture systems prioritize high-yield crops that are used to make processed foods, encouraging diets high in refined carbohydrates, sugars, and unhealthy fats. From a One Health perspective, these changes show how farming practices can reduce dietary diversity and harm human health.
Agro-extractivism
Agro-extractivism is a type of resource extraction where foreign powers control agriculture in other countries. This control is driven by the large-scale growing and selling of agricultural products, often through the use of monocultures, which are large areas of land used to grow only one type of crop.
In the Global South, monocultures like sugar and coffee were first grown in the 1800s after European countries colonized these regions. These farms relied on enslaved labor, creating a pattern where foreign powers controlled agriculture in Latin America and the Caribbean. This system has led to the mistreatment of Black people and small-scale farmers, especially when foreign companies take over land for monoculture farming.
The widespread use of monocultures in tropical regions has harmed local small farms and indigenous communities. These communities face challenges such as less control over their food supply, less access to land and water, and fewer opportunities for hunting. Large companies often take over land through methods like forced removals, violence, or unfair land deals. Small farmers also struggle because they must meet demands from international markets, which can be affected by changes in prices or weather. If farmers fail to meet production goals or profit targets with large corporations, they may lose their land or face debt.
Monocultures are a key part of agro-extractivism because most of the crops produced are sent to large companies in developed countries for processing and sale. For example, after the North American Free Trade Agreement (NAFTA), agave production in Mexico tripled between 1995 and 2019 due to demand from the United States. In Paraguay, soy crops are heavily exported, with little to no nutrients returned to the soil. Over 46 million hectares of land in South America are used for soy farming, and more than half a million hectares of forest are lost each year to make space for crops. Major companies involved in agro-extractivism include Syngenta and Bayer (biotech), Los Grobo, CRESUD, El Tejar, and Maggi (landowners), and Cargill, ADM, and Bunge (grain and seed providers).
From a One Health perspective, monoculture farming harms soil health. Repeatedly growing the same crop drains soil of nutrients and reduces the variety of helpful microbes, making the soil less fertile. This forces farmers to rely on chemical fertilizers. Poor soil quality reduces the nutritional value of crops, which can lead to health problems in people who depend on these crops for food. In communities that rely heavily on staple crops, a lack of important nutrients like zinc or iron can cause malnutrition. This shows how soil damage from monoculture farming can directly affect human health.
Forestry
In forestry, a monoculture is a forest made up of only one type of tree. In many parts of the world, people plant monocultures to grow and harvest timber quickly. Because timber from these forests is often sold to other countries, this practice can be linked to extractivism, which takes resources from an area for profit. After forests are cleared, monoculture plantations have become more common because they are seen as a way to help the environment, such as by absorbing carbon dioxide and controlling gases in the air. Trees like eucalyptus, pines, and acacias are often planted in these forests, especially in tropical regions and parts of the Global South after rainforests are destroyed.
While these strategies may help reduce global climate change effects, they can cause harm to local environments and human health when considered through the One Health approach, which connects the health of people, animals, and ecosystems. Monoculture forests often use non-native tree species, such as eucalyptus or pine, which can replace natural forests. This change can lead to poor soil quality and disrupted water cycles, making it harder for local communities to access clean water and grow food. Even though these forests are intended to help the environment, they can harm the health of people, animals, and ecosystems in the areas where they are most used. This highlights the importance of using the One Health perspective to ensure fair and balanced climate change solutions.
Although monoculture forests are efficient for producing timber, studies show that forests with only one type of tree reduce biodiversity. Over time, this leads to fewer plants, animals, and insects, and makes the forest less healthy. Forests with low biodiversity are more likely to suffer from diseases, insect attacks, and environmental challenges, such as faster forest fires.
Monoculture plantations also affect people living in the areas where they are planted. In some parts of Latin America, these forests have caused people to move because of changes in water availability, poor soil, and fewer natural resources. While large-scale farming can create jobs, research shows that monoculture plantations often provide few employment opportunities, with most workers coming from outside the local area. The money earned from these plantations usually follows a pattern of short-term growth followed by decline, temporarily improving local income and quality of life until resources are used up, with profits rarely reinvested into the land.
Environmental changes caused by monoculture forests affect indigenous communities the most because these groups rely on the land for their way of life. These communities often lose access to their land when companies take it through unfair means, such as buying it without permission or forcing people off the land. This leads to the loss of rural areas, limits access to local people, and changes how communities grow food and live together.
Residential monoculture
Lawn monoculture in the United States was historically inspired by English gardens and manor-house landscapes, but its spread across American homes began more recently. The way lawns looked influenced how people designed their residential areas, with turfgrass becoming a common feature. Turfgrass is not native to the United States and needs a lot of care to stay healthy. At the local level, governments and groups like Homeowner Associations have encouraged keeping lawns neat and well-maintained, which can affect how much homes are worth. Disputes about how neighbors care for their lawns or control weeds have sometimes led to legal problems or conflicts between people.
Because turfgrass requires a lot of maintenance, there has been a growing need for chemical treatments, such as pesticides, herbicides, and insecticides. A study from 1999 found that in a sample of urban streams, at least one type of pesticide was present in 99% of the streams. A major risk of using lawn pesticides is that chemicals can enter homes through the air, clothing, or furniture. These chemicals can be more harmful to children than to adults.
In addition to chemical exposure, lawns made of a single type of grass, like turfgrass, can harm human health in other ways. They can increase the production of allergens, worsen urban heat islands, and use a lot of water. Grass pollen from uniform lawns has been linked to symptoms of allergic rhinitis and other health issues that can range from mild to severe. Lawns often replace trees in residential areas, reducing the cooling effects of tree canopies. This can make urban heat islands more extreme, increasing the risk of heat-related illnesses and stress on the heart during hot weather, especially for vulnerable groups like the elderly and young children.
Turfgrass lawns also require a lot of water to stay green, especially in dry areas. This puts pressure on local water supplies and increases reliance on outside water sources. The high water demand contributes to water shortages and lower water quality, as pollutants can be carried into water supplies through runoff. These conditions have been connected to reduced sanitation, waterborne diseases like cholera, and dehydration in communities with limited access to water. When viewed through a One Health perspective, these issues show how the way people use land can harm the environment and negatively affect human health and well-being.
Genetic monocultures
Monoculture refers to growing the same type of plant in a field or across a large area, meaning many plants share the same genetic traits. When plants in an area have similar genes, a disease they cannot resist may destroy entire crops. In 2009, a wheat disease called wheat leaf rust caused serious problems in Uganda, Kenya, and parts of Asia. After the Green Revolution, many wheat crops worldwide had similar genes, making them more vulnerable to diseases that threaten food supplies globally.
Genetic monoculture in food systems poses a major risk to food security. When staple crops lack genetic diversity, farming becomes highly susceptible to pests, diseases, and environmental changes. Outbreaks of disease or climate challenges can spread quickly, causing large crop losses, as seen in historical examples. These events directly impact human health, and the relationship between health and biodiversity is better understood through the One Health model.
In Ireland, reliance on a single potato variety called "lumper" led to the Great Famine (1845–1849). Potatoes were grown without genetic variation, and when a disease called Phytophthora infestans arrived from the Americas, the lumper variety had no resistance. This caused nearly all potato crops in Ireland to fail.
Before the 1950s, most bananas sold in the United States were the Gros Michel variety, which had small seeds and was easy to grow. However, because bananas were grown from plant parts rather than seeds, all plants had identical genes. This lack of genetic diversity made them vulnerable to Fusarium wilt, a fungal disease that spread in the Caribbean. By the 1960s, farmers switched to the Cavendish banana, which is also grown without genetic variation, leaving it similarly at risk from disease.
Monoculture can also involve raising a single breed of livestock in large-scale operations. Many farming systems focus on a few specialized breeds, which may reduce traits like disease resistance or fertility. In the 1990s, some Holstein calves died in their first six months due to a gene mutation that caused a health condition. This mutation was common in Holstein cattle worldwide, traced back to a single bull widely used in breeding. At the time, about 15% of Holstein bulls in the United States, 10% in Germany, and 16% in Japan carried the mutation.
Increasing genetic diversity by using plants and animals with different genes can make farming more sustainable. Crops with varied traits for disease and pest resistance reduce the chance of disease spreading, as neighboring plants may have genes that help them survive. This can improve crop yields and reduce the need for pesticides.
Alternatives to monoculture
Alternatives to growing only one type of crop, called monoculture, include using agroecology, silvo-pastoral systems, and mixed-species plantations.
Agroecology looks at the whole food system, considering how farming practices and their results affect people, the environment, and the economy. Even though large areas of the Amazon rainforest have been cleared to grow single crops like soy, corn, and cotton, many farms in Brazil run by Afrodescendant communities still use traditional agroecology methods. These methods help support the local community, protect the environment, and strengthen the economy. Practices that grow only one crop can cause serious harm to ecosystems, such as using harmful chemicals and damaging soil, which can be very hard to fix. However, modern farming methods that restore the land are helping to bring back crop rotation and natural ways to keep soil healthy, which improves biodiversity and soil quality.
Silvopasture is a traditional method that uses trees and plants in pastures to grow more food and raise more livestock. Adding plants like tree legumes to pastures has been shown to help pollinators like bees and butterflies, which supports biodiversity and food supplies. Silvopastoral systems also increase the variety of plants in pastures and provide better food for animals, leading to better results for both the economy and the environment, no matter the size of the farm.
Studies have shown that well-managed mixed-species forests can earn more money from selling timber than monocultures. These forests also store more carbon and support more plant and animal life, which could help reduce the effects of climate change and lower global carbon levels. However, mixed-species plantations are not used as often because some people believe they are more expensive and harder to manage.