There is much ongoing discourse around the advantages and disadvantages of monocultural farming systems in the agricultural community today. It is mostly focused on how they contribute to environmental degradation and climate change, but also on how they play a role in feeding a growing global population expected to hit 10 billion by 2050. Agriculture is at a point where it is under pressure to become more sustainable, cut pollutants, and steward soil systems all whilst increasing its production to supply high volumes of food to rapidly growing urban areas. So how does this relate to monocultures? Let’s explore what this term means and the role it is playing in a changing food system.
What is a Monoculture?
Monocultures are farming systems in which only one single type of crop is grown in a field at a particular time, usually throughout an agricultural season. Monocultures have dominated most food production since the widespread mechanization of agriculture throughout the 20th century simplified the management of one crop at a time. According to findings from a study that analyzed FAO data, wheat, corn, soy, and rice cover a little less than 50% of global agricultural land, and are almost always grown as monocultures. As the alternative, polycultures are systems where two or more crops are grown together in a field at one time, and are a more traditional method of land management. Keep in mind that although monocultures will grow only one crop at a time, they may still rotate the crop that is planted in a field from year to year and still be called a monoculture. Monocropping is the term used to distinguish operations that continuously plant monocultures of the same plant species every year in the same spot without rotation.
Advantages of Monocultures
Monocultures evolved out of an industrialized food system that was trying to meet the needs and demands of a globalizing population and has provided the framework for our access to many food staples today. Some of the advantages this land management system has provided include:
Ease of management
The management of one crop at a time simplifies the business model for many farm managers and agribusinesses. The uniformity of a field planted with one single species means that all the preparation, inputs, crop maintenance, and harvesting are the same across a large area and less considerations need to be made about the needs of different species. Monocultures essentially make it very easy for farmers to farm, as they largely remove diversity and therefore remove the need to manage the more complex system linkages that come with it.
Yield maximization for grains
Monocultures that practice crop rotation from season-to-season are able to maximize the yields for certain crops that would be lower yielding if planted in an intercropping system with other plants of a different species. This is reportedly true for grains like wheat, oats, and canola, according to Washington State University.5 This is particularly true for prairie regions, where the climate favours the production of these types of crops over others, so minimal labor and inputs are required for a large crop yield. However monocultures that practice monocropping typically show decreases in yield over time due to soil degradation and erosion contributing to overall lower land fertility.
Higher revenues from specialized production
Specialization is key in a capitalist marketplace, and monocultures are hyper-specialized by nature, and often one farm will focus solely on the production of their monoculture-cultivated crop. Purchasing equipment, seeds, and general inputs tailored for one species can be done in bulk which is typically associated with lower prices. Farmers and professionals also gain highly specialized expertise about their specific crop, making them better equipped to deal with issues like pests or disease since they are working in a specific niche that doesn’t require broader knowledge about many species. Monocultures arose because they were seen to minimize costs, streamline production, and maximize profits, especially after the initial investment period, and from an economic standpoint this still holds true for many operations.
Highly responsive to technological innovation
For the same reasons that monocultures are more straightforward to manage, they are also easier to integrate with machinery and increasingly advanced technology: there are simply fewer variables at play. One crop species that is planted uniformly at the same time can be fertilized and harvested in one fell swoop by mechanized fleets that move sequentially down each row, without having to be programmed to account for other crops that may be at different stages of growth or have different nutrient needs. Uniformity is easier to manage and design for, and the rapid growth of monocultures in the late 20th century has gone hand in hand with the rapid technological advancements being made in agriculture.
Disadvantages of Monocultures
The key disadvantages of monocultures have slowly been revealed over the last several decades as environmental awareness and monitoring has reflected just how much industrial agriculture impacts local ecosystems. Despite the short-term benefits it provides from an economic standpoint, from a long-view and environment standpoint it contributes to:
Although most types of agricultural development require deforestation, monocultures specifically demand large parcels of land to be completely deforested and free from plant diversity for the uniform planting of one crop. The economic advantages of monocultures generally increase with the area of land cultivated, which is why they typically span many hundreds or thousands of acres continuously; necessitating deforestation in most regions. This is particularly concerning when old-growth forests that contain complex ecosystems are being eradicated at high rates to make space for monocultures; for instance in Borneo and Sumatra where ancient rainforests are being removed at rapid rates to make space for oil palm monocultures.
Loss of biodiversity
By their very nature, monocultures are the opposite of diverse. One species is grown over a large area, sometimes thousands of acres, and pesticides are applied to eradicate the growth of weeds or any species that threaten the production. This creates an obvious lack of biodiversity, which in turn can cause food chain and ecosystem collapse for native species of flora and fauna. The loss of many keystone species has been associated with monoculture expansion, which in turn has an effect known as the ‘trophic cascade’ and results in the endangerment or total extinction of many native, wild species. To reference the example above, expansive oil palm monocultures have resulted in the habitat loss and subsequent endangerment of many native species like the orangutan.
Decline in pollinators
The application of glyphosate, and particularly neonicotinoid, pesticides over large areas has been associated with a huge decline in bee populations globally. Colony collapse disorder (CCD) has been a trend since the early 21st century, and there is a mounting pile of evidence that widespread pesticide use is playing a key role. These types of pesticides are characteristically used in large-scale monocultures, particularly for corn. But this isn’t the only factor, the lack of diversity creates less variability in the diet of surviving bees, and they end up lacking the healthy bacteria that contribute to a nutritious and long-lasting food source for their colonies.
The management of monocultures is largely dependent on the frequent applications of synthetic chemicals, like pesticides and fertilizers, over large areas to control weeds and pests and encourage crop growth. Although many of these synthetic inputs are deemed necessary for the widespread production of certain cash crops, the rates of usage and subsequent contamination of local watersheds from run-off has serious consequences. Fertilizer runoff has been directly correlated with the development of algal blooms and the subsequent creation of hypoxic dead zones that leave aquatic areas devoid of marine life. Beyond groundwater and watershed systems, air pollution from methane, nitrous oxide, and carbon dioxide emissions are also major issues with large scale monocultures, particularly cattle operations.
Susceptibility to pest immunity and devastation
It is commonly known amongst ecologists that diversity fosters resilience, with multiple barriers and feedback loops that naturally limit the damage one single pest or disease pathogen can do to a diverse population. The absence of species diversity in monocultures has made them, in a way, sitting ducks to devastation from host-specific pests and diseases that suddenly have acres and acres of uninterrupted food and breeding ground with no natural controls. This is even more of a concern in monocultures that practice monocropping, and end up supporting multiple generations of the same insect pest in one area with devastating effects. The consistent spraying of pesticides has actually boosted the aggressiveness of many pest species that have adapted and become resistant to these inputs, worsening the original situation.
Soil compaction and erosion
The automation of agriculture and the predominant use of large, heavy machinery in monoculture management has created extensive soil compaction. The loss of soil microbial diversity and soil structure is also associated with monocultural systems, where one plant species feeds on their specific nutrient and mineral preferences, leaving the soil depleted of certain nutrients with no way to restore them through diverse plantings. Similarly, the planting of one species over a large area creates a much more unstable root structure, as only one type of root system is present to anchor the soil and it becomes more susceptible to erosion and topsoil loss over time. Monocultures will also harvest all their crop within a specific time frame, leaving huge expanses of bare soil exposed to the elements sometimes for the entire winter (if they do not practice cover cropping) leading to high rates of erosion and eventual desertification.
Decrease in land fertility and livelihood instability
All of the above disadvantages combined have already led to many farmers growing commercial monocultures to experience a yield decline as their practices have surpassed peak production and they are now farming on increasingly desertified and eroded land. The loss of overall soil fertility and the growing immunity of pests and weeds to glyphosate pesticides means an inevitable turning point is reached where the traditional model of industrial monocultures is no longer a feasible farming technique. This unfortunately leads to a disproportionate amount of risk being borne by farmers and agricultural managers as their livelihoods become increasingly unstable with a loss of soil fertility and yield losses. Monoculture farmers also have all their eggs in one basket and depend on the success of one specific species, making them very vulnerable to losing their entire crop and revenue in one season from a specific pest, disease or weather event.
Mitigating the Adverse Effects of Monocultural Systems
Precision agriculture has the ability to mitigate and reduce some of the more harmful effects of monocultural systems with data-based systems that can pinpoint exact needs and reduce wastage and pollution of the local environment. Although many farmers and agribusinesses are looking to transition to polyculture systems, those remaining monocultures can be improved with some of these strategies:
Variable Rate Application & Irrigation (VRA & VRI)
The soil compaction and pollution associated with large scale monocultures can both be reduced through the integration of variable rate applications, which removes the application of unnecessary inputs and therefore the unnecessary movement of tractors with spraying equipment around fields. Customized VRA maps look at geospatial data to analyze which specific areas need inputs and in what quantities, avoiding the traditionally wasteful approach of broadcasting the same input over an entire area. These maps can be uploaded to machinery and tractors which are capable of carrying out very exact applications of inputs only where they are needed, avoiding dead zones and accounting for the topography and drainage of the landscape.
As previously mentioned in this article, monocropping is a separate practice often associated with monocultures where crops are not rotated year to year. When a monoculture is monocropped, many of the disadvantages are exacerbated and particularly soil quality and overall land fertility take a serious plunge. Monocultures that are rotated every season to encourage microbial and nutrient diversity in the soil and interrupt the generational breeding cycles of pests are best for both farmers and the land and are overall more sustainable to operate in the long term.
Integrated pest management
Integrated Pest Management, or IPM, has been exploding in the AgTech sector with multiple startups and companies looking to move away from glyphosate pesticides and move toward alternative products, such as biorational pesticides. Biorational products, like Bt pesticides, are not chemically based but use living biological controls, such as the microbe Bt, to eliminate the larvae of pests without having the same destructive effects on soil biodiversity. Bt pesticides are just one example of many biorational products making use of naturally occurring bacteria and fungi, and there are other companies taking a different direction with pheromone-based control. The manipulation and spraying of pest pheromones interfere with the reproductive cycles of various pests by messing with their mating patterns on a species-specific level. This means these interventions affect only the pest of interest and leave the rest of the ecosystem relatively unaffected. The use of IPM strategies and technologies on a monoculture scale has the potential to mitigate some of the detrimental effects that this practice has on pollution, and on pollinator and soil diversity.
Renewable energy-powered machines and equipment
The use of electric vehicles and renewable energy in monoculture operation is an important part of guaranteeing their longevity in the agricultural system, as almost every global sector is shifting away from fossil fuel dependency. The use of drones and highly efficient spraying equipment, along with smart devices and machines, can reduce the pollution and movement of machines to be only where and when necessary.
Increase edges and spaces for wildlife and biodiversity corridors
The overall reduction in operation size, or at least the creation of more edges and corridors, in monocultures may also be key in making them less destructive to local biodiversity and forests. Many species of flora and fauna make use of the edges and borders of different land types for shade, different food sources, or a means of transport through a landscape. Forested wildlife corridors through large monocultures could greatly improve the conservation efforts of native species by giving them a pathway to move through the fields without being vulnerable to exposure, and forested areas provide a net cooling effect to the surrounding landscape.
Cover cropping is a traditional method of preserving soil structure and preventing soil erosion throughout the winter that is not commonly utilized in commercial, western systems. Alfalfa, clover, and various legumes are popular cover crops that can be sown in the autumn before the first frost and then used as a green manure in the spring, adding rich organic matter to the soil once it has thawed. Cover cropping can be easily implemented in monocultures with much of the same equipment and provides protection, insulation, and organic matter to already fragile soil systems.
The Future of Agricultural Systems: Polycultures
The future of sustainable agriculture is a general movement away from traditionally intensive monocultures towards more diverse and resilient polycultural systems. But for remaining monocultures, or those selective monocultures that have been proven to produce higher yields for grains and other similar crops, the adoption of cover cropping, crop rotation, soil building, and the breaking of thousands of acres into patches with forested corridors is essential. Much AgTech is actually designed to function very well around polycultures as well as monocultures, for example VRA and VRI technologies that have been designed for diverse needs and specificity. Polycultural landscapes that include agroforestry and native plants are more feasible to grow large quantities of food today than they were before with advanced mapping technology, and they also diversify income streams and create contingency plans for farmers previously dependent on one crop. Accessibility of appropriate technologies is the most important step moving forward, and investments need to be directed at the creation of sustainable solutions targeted specifically for the environment and farmers’ needs to avoid making the same mistakes that have been made in the past.Whats