- Monoculture the practice of planting large areas with
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Monoculture the practice of planting large areas with
31) Monoculture, the practice of planting large areas with a single crop ________. A) always uses no-till techniques of plantingB) is typical of Native American farming techniquesC) is a development of industrial agricultureD) requires no artificial pesticides or fertilizersE) accounts for less than 1% of U.S. farmlandAnswer: C 31) 32) Seed banks (institutions that store and preserve seeds) are important for ________. A) protecting genetic diversityB) cash deposits for developing countriesC) protecting monoculture productivityD) providing farmers with the current yearʹs GM cropsE) loans to developing countries to promote organic agricultureAnswer: A 32) 33) It is more energetically efficient for us to eat more ________. A) plant-based foodsB) GM foodsC) herbivorous animals like cattle and chickenD) foods grown using IPM methodsE) carnivorous animals like fish and alligatorAnswer: A 33) 34) During the past half-century, global food production has ________ world population growth. A) fallen behindB) surpassed by several orders of magnitudeC) stayed about even withD) grown at a faster rate thanE) fallen to critical levels compared toAnswer: D 34) 6
Monocultures are large areas of land cultivated with a single crop, using methods that imply a high use of inputs such as agrotoxic chemicals and machinery. Monoculture crops and plantations have a host of social and environmental problems associated with their cultivation. In the South, monoculture plantations are large-scale and often produce bulk products for the export market, not for local use.
Monocultures include crops (food-based agriculture) and trees (plantations). Crops grown in industrial monocultures are cultivated for both food products (wheat, canola, corn, palm oil, sugar cane), animal feed and oils (soy, corn), and agrofuels (soy, canola, palmoil, jatropha, sugar cane), while tree plantations (eucalyptus, pine and acacia) are largely used for paper pulp, charcoal, timber and, increasingly, biomass (with the possibility that they will be used for agrofuels in future).
The social impacts of large-scale monocultures are often disastrous for communities who continue to grow local foods using sustainable practices. Small-scale farmers often cultivate local species which not only contain important minerals for the soils and for human health, but also have adapted to the local environment over many years. When small-scale farmers are confronted with industrial large-scale monocultures in their area, they are faced with water and other resources shortages, contamination from pesticide spraying and from GMO crops.
The takeover of land by monocultures also causes rural depopulation, destroying local community life and local economies. Monoculture plantations usually provide only temporary labour, for which workers are often hired from outside the region. Land grabbing and forced evictions of local populations are strongly linked to the expansion of monocultures.
By externalising social and environmental costs, monocultures are economically more profitable and therefore out-compete local producers. Markets become dominated by only a few multinational corporations that control the production, the financing, the trade and/or the input production.
All large-scale monocultures take a toll on the earth, one reason being that the growers view what were once local and natural plants and animals as weeds or pests. This upsets the local ecological balance, causing outbreaks of illnesses and negative feedback cycles. In the monoculture system, locally and naturally occurring plants and animals are merely seen as pests that have to be destroyed.
Growing so many homogenous plants in one area requires a lot of artificial chemical and mineral input. In nature, plants and animals feed each other the chemicals and minerals required to thrive. For example, leguminous plants fix nitrogen into the soil, a chemical required for growth, and animals provide fecal matter rich in minerals. Eliminating these natural cycles from a diverse ecosystem requires artificial fertilsers that are used to boost crop yields at a great expense to local biodiversity. Moreover, monocultures are particularly susceptible to disease, which can spread far more quickly over a large area covered by a single crop than in a biodiverse ecosystem. In order to fight these “weeds”, pests and disease outbreaks, cultivators will apply even more herbicides and pesticides to keep the plants growing.
Large-scale industrial monoculture with any plant has serious impacts, but the fact that monocultures are often non-native species adds another layer to the problem. Native species have adapted to the local environment over thousands of years and generally have developed a relationship with other plants and animal species which permit them to survive cooperatively. Non-native plants thus often require high amounts of water, energy or minerals to survive, which take a devastating toll on the hydro and soil resources as well as other plants and animals living in the area. For example, have you ever tried to grow a cactus in a rainy, cold climate, or a fern in a hot, arid climate?
While the climate crisis has become a business opportunity for polluters, it is often claimed that the quickest way to fix climate change would be to simply cover the earth with monoculture plantations that would absorb the carbon dioxide, but this could not be farther from the truth. To begin with, studies show that forests need to stand for many years before they lock-in carbon because most of the carbon is found in the soils. Plants breathe through their leaves and when the leaves fall to the ground they return carbon to the soil. The natural carbon cycle between plants, animals, the air, the oceans and the earth maintains a delicate balance. Monocultures are not forests/ecosystems and do not stand long enough to lock-in carbon in the soil. Moreover, monocultures inhibit soil carbon up-take by frequent tilling and pesticide use. The no-till or low-till methods often advocated by biotech companies as crops deserving climate subsidies are not a solution either because of all of the problems associated with GM crops.
The Clean Development Mechanism, the biggest offset scheme under the UNFCCC, allows projects that include monoculture plantations under the Aforestation/Reforestation track to sell carbon credits to polluters in the North. In addition, Reducing Emissions from Deforestation and Degradation (REDD) is a controversial scheme being implemented by the UNFCCC and the World Bank which does not differentiate between industrial tree plantations and forests. These tree plantations and land-related credits are being sold already in voluntary offset markets. Continuing to increase industrial tree and agriculture plantations anywhere, but especially in the South, to “offset” pollution in the North is not a solution to climate change!
Grassroots organisations and movements around the globe have been and still are fighting against the loss of their lands, water, forests and livelihoods as a result of the spread of industrial monoculture models – eucalyptus, pine, oil palm, rubber trees, soy and jatropha – and challenging this model which has profound impacts on food sovereignty, sustainable agriculture, access to land and water, biodiversity, climate stability, local plant knowledge including medicinal plants as well as Indigenous and local communities rights.
Large-scale monoculture plantations destroy the natural diversity of life. They are artificial, driven by profit and are environmentally and socially destructive.
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This type of farming goes against any form of traditional crops and growing food. The main technique is to replant the very same crop species in the very same field, with no other type of plant whatsoever. This is the basis of large-scale farm corporations that have been trying to control our food sources for decades. And, with the quantity of technology used – such as chemical fertilizers – the practice has become common, often usurping organic farming.
However, there are many downsides to this form of plant growing. Reusing the exact same soil, instead of rotating three or four different crops following a pre-determined cycle, can lead to plant pathogens and diseases. They adapt to the soil and attack the crops and the quantity produced eventually decreases. Furthermore, using pesticides and herbicides in the same field can have the same effect – the soil becomes used to it, thus needing other types or stronger insect and weed killers.
Afterwards, the use of these chemical products damages the land by infiltrating itself in the soil and, at times, is dragged by rainwater into the nearest body of water. Depending on where this land and water are located, wildlife that drink from it end up consuming these harsh killers and any life that made the body of water its habitat is affected – at times heavily – by the same products. If this body of water is a lake or river used for a city’s drinking water, then humans know an increase in cancer rates in that area.
With time, the land’s mineral value also begins to decrease. The quantity of food produced is, of course, impacted by this: we can produce less and of lesser quality this way. Eventually, the land will be depleted of all its minerals, and although this can take decades, the damage is irreversible. Even grass will refuse to grow there, and the farm needs to move to another location.
The answer to this craziness is to develop bot organic and permaculture farming, using ancient but tried, tested and true techniques of planting crops. Organic consists of using only natural pesticides and crop rotations, and permaculture tries to mimic the natural environment that these plants typically grew in before human intervention, which means that the plant will grow to its full potential by cultivating it in its preferred environment.
In a Nebraska field, thousands of acres of winter wheat stretch to the horizon. In California, workers pick strawberries in a field that has grown no other crop for the past eight years. And in Maryland, a single tomato plant grows in a single pot.
What do these have in common?
They could all fall under the phrase “monoculture.” Okay, that last one with the tomato is a bit of a stretch, but it’s an example that underscores how simplistic this discussion often plays out. Many critics of modern agriculture, including anti-GMO activists, point to monoculture as what Michael Pollan calls the “great evil of modern agriculture” and a major reason for the loss of biodiversity in agriculture. They say that biotech crops encourage monocultural farming.
So, what is “monoculture” and is it bad or is the issue more complicated?
Andrew Kniss, a plant scientist and weed expert at the University of Wyoming, is one of many scientists who think that the word doesn’t do the practices justice. On the surface, all monoculture means is that a farmer is growing just one crop in an area. By that definition, all crops are grown in monocultures except for those grown in the tiniest of farms or home gardens.
So, how big an area defines what is “monoculture”? And how many years must a crop be grown in a given field before it’s considered “monoculture”? Does monoculture actually reduce biodiversity?
What does the science say?
Most critics appear to use the term to suggest that something bad happens in single crop areas: blight, crop failure, or loss of biodiversity (in the form of native plants, pollinating insects, or microorganisms).
The Union of Concerned Scientists, under the leadership of its prior agricultural sciences director Doug Gurian-Sherman—who left UCS two years ago and now lobbies against crop biotechnology for the Center of Food Safety —has argued in a post entitled “Expanding Monoculture: 8 Ways Monsanto Falls at Sustainable Agriculture”, that monoculture reduces diversity and leads to a host of other problems.
Monsanto’s emphasis on limited varieties of a few commodity crops contributes to reduced biodiversity and, as a consequence, to increased pesticide use and fertilizer pollution. Large-acreage field crops—corn, cotton, soybeans, canola, and now alfalfa—make up the bulk of Monsanto’s products, in part because of the high cost of developing engineered traits. And the approach to agriculture that this product line encourages—monoculture, the production of only one crop in a field year after year—is not a sustainable one.
The piece is short of an understanding of the basic science of farming and long on ideology, say agricultural experts.
Consider crop rotation. Most organic food supporters point to crop rotations, which are required for organic certification, as an alternative to the ‘dangers’ of monoculture. But that’s a deceptive argument. Most large farms now rotate their crops as well, so rotating in an of itself does not address the question of the impact of monoculture. And just switching between crops in alternate years doesn’t bring the kind of genetic diversity that can prevent the downsides of mechanized farming.
Monoculture, incorporating crop rotation, can also have positive impacts. Just having one crop in the field allows mechanization of agriculture. Mechanized farming allows faster, efficient planting, weeding, and harvesting, which reduces the destruction of habitats–organic and agro-ecological farming has a yield lag averaging 15-45%. Scaled up to meet the growing global demand for food, smaller scare farming would result in clear cutting of forests and dramatically reduce biodiversity,
These potatoes in the second-generation Innate line of survived late blight in a test field in Pennsylvania. Unmodified potatoes were killed by the disease. via Simplot
leading to a sharp increase in greenhouse gases. Intensive farming also frees humans to discover other ways to spend our time and make a living.
Kniss also has made the point that a focus on genetic biodiversity in farming can help reduce the problems of monoculture while preserving its benefits. Examples such as the Irish Potato Famine shows what can happen when farmers depend not only on just one crop but on a crop that is genetically very, very narrow; they are vulnerable to disease. Planting genetically diverse potatoes (or any other crop) can help protect against the potentially negative impact of monoculture. And newly developed genetically modified crops, such as the Simplot Innate potato, have been specifically engineered to protect against the genetically narrowly focused potato blight. Other conventional and organically-grown potatoes are still vulnerable to the blight.
Anti-GMO activists have long claimed that genetic modifications are responsible for the extinction of species and losses of diversity that have been plaguing the planet for some 10,000 years now. They pushed through a critical set of precautionary principle-based claims critical of GMOs at the Cartagena protocol on biosafety to the convention on biological diversity.
The absence of scientific certainty due to the insufficiency of relevant information and scientific knowledge concerning the extent of the potentially unfavorable effects of a GMO on the conservation and the sustainable use of biological diversity in the importing Party, including the risks that it involves for human health, does not hinder this Party to take, as it is appropriate, a decision on the import of the GMO in question.
Mainstream scientists, who were largely excluded from the drafting of this activist-inspired notion, challenge this statement as simplistic. Peter Raven, president emeritus of the Missouri Botanical Garden and international authority on plant biology, who was involved in the formation of the Convention:
The “so-called principle of biosafety is not based on any valid scientific principles, and working it up through the Cartagena Protocol…has given license to those who for personal reasons, presumably of a political nature, wish to vent their spleen.
Let’s review the critics’ major points:
- GMOs make us concentrate on only a few crops. Many anti-GMO activists claim that GMOs “reinforce genetic homogeneity and promote large-scale monocultures,” thus contributing to declines in biodiversity.
- Genetically modified crops grow in a dynamic environment and interact with other species of the agro-ecosystem and surrounding environment. As “biological novelties to the ecosystems,” a 2005 review paper by Maria Garcia and Miguel Altieri warned, GM crops may potentially affect the “fitness of other species, population dynamics, ecological roles, and interactions, promoting local extinctions, population explosions, and changes in community structure and function inside and outside agroecosystems.”
- GMOs push other crops out, forcing us to only grow corn, rapeseed, soybean, and canola, according to the Center for Food Safety.
- Thousands of acres of rainforest are cleared every day to make way for “monoculture genetically engineered crops,” warns the site Planet Earth Herald.
- In this video, activist philosopher Vandana Shiva discusses biodiversity as a spiritual commitment, claiming that while conventional practices give life, genetic engineering “is a death knell to biodiversity.”
Scientists aren’t convinced at what they say is Shiva’s ideologically-based critique. Let’s look at the numbers. Currently, about 7,000 plants are eaten by humans. Of those, just four provide half of all food production, and 15 species of plants provide two-thirds of all food produced on earth. Meanwhile, over the past 10,000 years, the rate of species extinction has accelerated, from about one species per million every year 10,000 years ago to hundreds of species per million per year today. While the planet has about 12 million species (of which we’ve named just under 2 million), species extinction—the destruction of biodiversity—is a legitimate concern. But what’s causing it? Genetically modified crops, using transgenic techniques, did not exist 10,000 years ago. But agriculture did.
When we first started breeding plants and animals and plowing land to grow these plants and animals, only a few million humans lived on the planet. Now there are just shy of seven billion. About 11 percent of the planet is used for cultivation, a process that always has involved the destruction of native habitats, removal of unwanted plants (weeds and otherwise), and the gradual disappearance of bugs, birds, and other animals that feed on both wanted and unwanted plants. No matter what the method: plowing, tillage, burning, pesticides or genetically engineered crops; all are involved in using land in a way that does not encourage biodiversity.
What is the real impact of GMOs on diversity?
So, are GMOs responsible for increased extinctions, plowing under of rainforest land, and infestations of invasive plants and animals? In short, no. Diversity depends on two things: habitat destruction and climate change.
By enhancing resistance to insects, weeds, fungi, and other pests, genetically engineered food has helped improve biodiversity in agricultural areas—or at least have decreased the rate of habitat destruction—by reducing pesticide use, increasing yields, and boosting crop quality (that is, with less damage by pests).
Researchers estimate that genetic engineering, because of higher yields, has saved more than 6.4 million acres of land from cultivation for grains and oilseed, and encouraged the adoption of conservation tillage practices (plowing and arranging farm acreage to preserve water and soil).
Genetic engineering can enhance ignored and hard-to-grow crops, and improve the yields of existing ones (again, reducing the amount of land needed for farming). Newer gene-editing techniques such as Zinc Finger Nucleases and CRISPR/Cas9 can precisely edit a plant genome and control expression of desired traits, without the need for splicing a DNA sequence from another organism. These technologies can be especially valuable in improving crop yield and quality in drought-ridden areas, using less soil.
And addressing drought is becoming increasingly important. Global climate change already is affecting food output, and will only make it harder to grow enough food for an additional two billion people by 2050. Genetic engineering of drought and flood resistant crops, or developing other crops that can adapt to climate shifts, is essential.
What does climate change have to do with biodiversity? Plenty—finding new genetic traits in cultivars can produce new plants that tolerate drought. And in some areas (some studies used forests as an example), we may be able to introduce new species in areas where climate change has made conditions challenging for older species. There’s much more need for science-based solutions to today’s agricultural problems instead of finger-pointing at GMOs or mechanized agriculture.
Andrew Porterfield is a writer and editor, and has worked with numerous academic institutions, companies and non-profits in the life sciences. BIO. Follow him on Twitter @AMPorterfield.
Ecology|by Bonnie Lavigne
What has monoculture ever done for us? Well, it created civilization, that’s what. Cultivating a few key crops enabled us to turn our minds and energies to things other than basic survival. Work diversified, allowing activities that did nothing to fill the belly, but that had other value, like creating beauty in music and art; building cities, power, and wealth; exploring human philosophy and examining the universe. With the cultivation of cereal crops and the domestication of animals, people settled and the evolution of civilization began.
So, is monoculture really such a bad idea? Why not celebrate it?
It’s Not Just About Farming Anymore.
The Free Dictionary defines monoculture in two ways:
1. The cultivation of a single crop on a farm or in a region or country.
2. A single, homogeneous culture without diversity or dissension.
We’ve come to associate monoculture with genetic uniformity, deep tillage, as well as pesticide and herbicide use. We think of it as an artificial system that wouldn’t exist in nature. This is partially true. Modern broccoli and kale couldn’t exist, as they are, in the wild. They’d provide a banquet for insects and disease in very short time. If lucky, there’d be enough genetic diversity for a few individuals to survive and seed, eventually returning the species to its wild state. But is that true for all crops? Why were crops like cereals the first to be widely cultivated? Why have these plants become our modern dietary staple around the world?
The second definition of monoculture is quite different. It may not be obvious, but our modern mono-“culture” goes hand-in-hand with our agricultural practices. It all boils down to economy of scale and something called Hotelling’s Law.
In 1929 Harold Hotelling described how manufacturers of consumer goods aim to satisfy the needs of the broadest segments of our populations. Niche markets can be profitable, but they’re smaller, more fickle and so less attractive to big sellers. This is why fast-food chains serve up meals that are so similar. It’s why trends happen—one chain will offer smoothies, for instance, and the next year or two all the competition sells the exact same item.
Harold’s law is also called “the principle of minimum differentiation” and can apply to everything from business to politics and ideas. Having one pioneer take on the risks of introducing something new, then waiting to see if they’re successful before following suit makes good economic and political sense. Unfortunately, for a healthy culture, we need the innovators and risk takers. An ultra-conservative society afraid to step outside the mainstream or even to voice an idea that may be unpopular leads to stagnation.
This focus on uniformity is well represented in agriculture, where Big Ag wants to make the biggest buck for the least effort. Big Ag is comprised of a relatively few food producers. Centralized production and food management create an economy of scale that increases the bottom line. This is paramount to big companies like General Mills, ConAgra, Cargill and Coca-Cola who are buying up smaller organic producers and now dominate the organic market in North America. One of the results of this lack of producer diversity is the desertification of the grocery aisle.
Natural Law: Where Does Monoculture Fit In?
There turns out to be many instances of naturally occurring monocultures in nature. Single plant species that have evolved to thrive in disturbed environments are the most likely to dominate an ecological niche. Flood and fire are two of natures more common means of causing mischief. Cereals and others that simultaneously produce large seeds that germinate and grow quickly are best able to survive such disruptions, and their dense growth habit naturally inhibits competition from other plant species. In the same way that we might grow a cover crop to damp down weeds, wild cereal crops crowd out most other species besides their own.
But wild cereals are not only better equipped to survive natural disturbances, they thrive on them. Wild relatives of wheat like einkorn form dense stands, and researchers testing yields discovered these grasses often produced as much seed per square meter as modern cultivated wheat. Wild emmer also grows in huge stands as dense as their cultivated cousins.
David Wood, a writer for LEISA Magazine, a publication promoting sustainable agriculture in India, defends natural monoculture citing many instances where it can be found in the wild. Natural monoculture occurs more often in marginal areas between land and water sources. An example is the wild rice that our Neolithic ancestors discovered when they first entered southeastern Asia, where regular flooding of rivers draining from the Himalayas nourished the swamps where wild rice grew.
Rice also produces large seeds and grows quickly, and so outperforms its competition in the continually disturbed environment of seasonal flooding. By taking advantage of this natural bounty and replicating the environment that supports it through terracing and diverting flood water, rice eventually became the staple diet for much of the world.
There are also examples of animal monocultures that thrive in nature. Wasps, bees, ants, termites, and mole rats all form colonies of sisters that are driven to forgo individualism for the sake of the family group. The unquestioned success of these animals in nature stumped Darwin, who regarded them as the biggest challenge to his theory that diversity within species drove evolution.
The millions of buffalo that once roamed the plains of North America were certainly not as closely related as hive insects, but they could be considered a natural monoculture. If you have a herd that is so large it covers the landscape to the horizon in all directions, it’s safe to say you have a single species dominating an environment. The thing that buffalo, insects, and wild cereal crops have in common though is genetic diversity within the species. This is even true of hive insects, although Darwin couldn’t have known that. Individual differences still drive natural evolution, whereas profits drive modern cultivated monoculture, with crops becoming less and less genetically diverse.
The Risks of Cultivated Monoculture
When we first started to scratch the ground and plant some seeds, the first crops we grew were already well represented in nature. They were grasses like wheat and rice that thrive as natural monocultures. We quickly began to grow other plant varieties and learned how fertilization and rotating crops kept the soil fertile and the plants healthy. The first successful crops we grew had a healthy genetic diversity, and cultivation enhanced that diversity. The potato has a single wild ancestor that was developed by early farmers into over a thousand sub-species. Most of these sub-species were developed to thrive in other areas with different pest and ecological pressures. This diversity can be a resource as our climate and environment changes.
The decline of genetic diversity within all species, both wild and cultivated, plant and animal, has scientists around the world ringing alarm bells. They warn of another collapse of a staple crop that could have devastating results. Examples of this already exist, a famous one being the Irish potato famine. In the 1500’s, the Spanish first encountered potatoes in the Andean highlands of the new world. Out of the thousands of cultivated species the Peruvians had developed, only a handful were introduced to Europe. One of these was the famous Irish Lumper.
The Lumper was grown successfully for three hundred years in Ireland and became the staple diet of the poor. But whatever genetic inventory was present in the original potatoes was lost over time as tubers were simply saved from season to season, creating generations of clones susceptible to disease. In 1845 the country was swept by a potato blight the Lumper had no defense against. As a result over a million people died of starvation.
Of the 80,000 edible plants in the world, 20 species such as wheat and corn provide 90% of the world’s food. Big Ag manipulates genes to enhance traits that create reliable and diverse products and profits, rather than to provide nutritious food or protect diversity. It’s not the agricultural industry driving the effort to create seed banks of endangered plants – it’s independent scientists, conservation groups and those farmers and homesteaders who save their own seeds, grow the older strains and raise rare heritage animals.
So, perhaps agricultural monoculture per se isn’t bad, as long as genetic variation within a species is protected, and the relationship of natural monoculture crops to their environment is understood and respected.
Monoculture in the Present: Oh! The Blandness of It All
We had the experience recently of visiting some friends in a new modern suburb and becoming quite lost. Of course not all the street signs were up yet and the place was a maze of cul de sacs and circular lanes flanked by houses that were all variations of a similar theme. We discovered what’s called “power centers”. These are outdoor malls with big box stores selling everything from electronics to bedding to furniture surrounding immense parking lots. Restaurant franchises were limited to about a dozen. To folks used to an eclectic mix of small single owner shops and family run restaurants, this landscape was a desert. No matter where we turned, the view was identical. The blandness of it all was breathtaking.
We finally got to where we were going, but it took a phone call and some determined navigational skills to make it. Although the house turned out quite nice and it was a great visit, we were never happier to leave a neighborhood.
Have you ever purchased one of those gift cards you can pick up in drug stores and other places that are good in several different restaurants? Take a look at these. All of these restaurants are owned by the same company who bundle purchase incentives for any of their outlets onto one card. All the meats and produce are acquired, warehoused, processed according to the menus of the restaurant franchise, then distributed to each location. If you think you’re eating different fare at different restaurants, you’re not. It’s the same food, just repackaged.
Monoculture is well represented even on those colorful, well stocked store shelves. Look at the store brands and no-name brands in your grocery aisles and read the labels. There are many that contain exactly the same ingredients as the big name brand items do. The generic apple juice you buy at a discount is identical to the one you pay premium for in the bright branded label. It’s often sourced from the same supplier and packaged in one facility. Only the labels are switched.
We may think we’re buying diversity, but we’re not. What are we missing in this bland landscape? Independence from the tyranny of ever growing corporate power centers? Lack of competition to provide value? Some nutritional element processed out of our food? Protection against another potato famine, or perhaps worse?
If there’s a flaw in the system, who do you turn to?
Polyculture: Can We (Should We) Return?
Polyculture by definition is a system of agriculture that understands, respects and works within parameters set down by nature. It involves crop rotation, multi-cropping, companion planting and encouraging beneficial insects. Its goal is to increase the genetic diversity within a species. It’s more labor-intensive than artificial monoculture. Although not all crops are organically grown, farmers and homesteaders who follow polyculture practices are more often interested in sustainable farming growing crops for their disease resistance, nutritional and flavor value. None of these things are generally attractive to Big Ag.
If you grow a variety of crops and are careful in their management, a small farm can provide for much of your nutritional needs. A collective of farms and gardens can provide for the nutritional needs of the areas around them. Polyculture is the answer to eating local. Artificial monoculture, on the other hand, is highly attractive to Big Ag. Their attention is on creating efficient channels moving raw materials to manufacturing plants to grocery chains. Their advertising is directed to the end user – you and me – but their product is designed to withstand their process, not to feed us. They manipulate nature rather than work with it.
But, monoculture doesn’t have to be this way. There are examples from around the world where monoculture works. Many single-crop farms rotate their fields and grow a single species with genetic depth. In China, a study reported in Nature magazine revealed that planting several varieties of rice in the same field increased yields by 89%. Pesticides were no longer needed because crop diversity created a 94% decrease in disease.
It isn’t the waving fields of wheat or corn that are the problem. It’s a system that has at its core a love of profit over people. Cereal crops are natural choices for monoculture. Most other plants are not. If you grow a single crop and keep an eye on genetic diversity within the species and its natural relationships within its environment, you can grow a healthy harvest that’s good for you and for the planet. We’ve been doing this since the very beginning of farming.
It’s only recently we’ve elbowed Mother Nature aside to replace whole ecosystems with artificial, genetically uniform crops. Yes, growing the staples we’ve come to rely on did create civilization and all the technology, art and luxury we enjoy today. But the modern trend toward the desertification of our food supply just might be the undoing of all that.
Monocrops: They’re a problem, but farmers aren’t the ones who can solve it.
There are two sides — active, vocal sides — to just about every food-supply issue on the planet. Are genetically modified organisms, organics, pesticides or conventional livestock good or bad? Depends whom you ask. There is one issue, however, that gets universally bad press. Nobody, but nobody, defends monocrops.
I’m not exactly going to step into the breach — this month, monocrops; next month, Stalin! — but I think any discussion of our food supply has to include a look at just what monocrops are, why farmers sometimes choose them, and the degree to which they’re risky.
A monocrop is exactly what it sounds like. A monogamist has one spouse, a monoglot speaks one language and a monocrop is one plant growing in the same place, year after year.
There are two problems with monocrops. The first is that they are not conducive to good soil health. The second is that, when all your eggs are in one basket, you’re vulnerable to a devastating loss; think Irish potato famine. Half of our 300 million farmed acres are planted with corn and soy, and that’s a very big basket.
Of the two issues, famine sounds scarier, but it’s actually less likely to be a problem. Tim Griffin, director of the Agriculture, Food and Environment program at Tufts University’s Friedman School of Nutrition Science and Policy, says our vulnerability is limited, mostly because we don’t eat those crops directly. An event like the drought of 2012 affects meat and dairy (and ethanol) prices, but humans still have plenty to eat. He also points out that staple crops such as corn, soy, wheat and rice provide most of the world’s calories, so it makes sense that they take up a big slice of our farmland.
Soil health is another matter. Growing only one plant tends to deplete the soil’s nutrients over time, and leaving fields bare for the winter can hasten erosion. Monocrops also provide a friendly home for pests that happen to like that crop, since it shows up reliably, every spring.
“There’s a consensus that monocrops are bad,” says Griffin, but not all monocrops are the same, and a monocrop today isn’t necessarily an arid wasteland tomorrow. Take the mother of all monocrops: the wheat that has been grown continuously in English fields since the 1840s. In some areas, the wheat stalks were left in the fields. In others, they were removed. “They have data on characteristics of the soil that go back to 1840,” Griffin says, “and they show that growing wheat for 175 years is a bad idea, and removing the straw is worse, but it reaches an equilibrium.” That equilibrium isn’t as productive as well-managed cropland, but neither is it a dust bowl.
If monocropping is unequivocally bad for soil health, why would farmers choose to do it? Most of the time, here in the United States, they don’t. Steven Wallander, an economist with the United States Department of Agriculture, tracks which crops are grown on what land, and it turns out that the vast majority of land under cultivation supports a rotation of two or more crops. The most recent data indicate that 16 percent of corn, 14 percent of spring wheat and 6 percent of soybean acreage is continuously planted with one crop over a three-year period.
Much more common is what I’ll call a duocrop. Although precise numbers aren’t available, Wallander says it’s reasonable to estimate that more than half of our corn acres are in a rotation that includes soybeans. I asked Griffin how much better that duocrop is than a monocrop. “It’s a little better,” he said, unenthusiastically. He points out that you still have the problem of crops being planted in the spring and harvested in the fall, with fields bare over the winter. “Ecologically, and in terms of soil management, it’s still a simple system.”
So why do it? Wallander and Griffin have the same answer: economics. Planting only one or two crops can make sense for some farmers in some situations. “There’s an economic advantage to specialization,” says Griffin. “One of the reasons for the duoculture is that the equipment for corn and soy is identical. If you add one more crop, and grow wheat, just that one change requires a specialized planter.” He adds that there are marketing concerns. The farmer who takes corn and soy to a local grain dealer might not have an outlet for potatoes.
It strikes me, though, that if you want to know why farmers do something, it makes sense to ask farmers. Garry Niemeyer grows corn and soy on 2,100 acres in Illinois, and he sometimes plants corn continuously because he can yield 230 bushels an acre, which makes corn more profitable for him than soy. He’s perfectly aware that continuous planting will degrade his soil, and he rotates in other crops before that happens. “Two years of corn and one year of soy works pretty well for us,” he says.
Richard Wilkins also grows corn and soy, as well as a variety of vegetables, on the Delmarva peninsula, and all of his 1,000 acres get rotated. Some of them are in a corn-soy rotation, for the simple reason that those acres aren’t irrigated and can’t support other crops. When irrigation isn’t a problem, says Wilkins, something else is. “There are parts of the country where farmers might grow other crops if the market provided for them to be able to do it,” he says. “And there some regions in the Midwestern states that do have some vegetable production, but there are different types of soil,” some of which don’t lend themselves to growing vegetables.
Soybean plants grow in Illinois. Many farmers rotate soybean and corn crops, planting them in alternate years, because they can be grown using the same equipment. (Seth Perlman/Associated Press)
Maintaining soil health is the central tenet of organic farming, but I’ve never met a farmer, organic or conventional, who wasn’t concerned about it. Crop rotation, even if it’s just the two crops, is one way farmers of commodity crops are balancing the need to keep their farms healthy with the need to grow the plants they can sell. According to the USDA, no-till systems, which help prevent soil erosion and nutrient runoff, are on the rise, and about a quarter of corn acres, and almost half of soy acres, are farmed that way. Although the USDA doesn’t track cover cropping (planting an interim crop like rye grass or clover, specifically to enhance soil health), every source I spoke with says it appears to be on the rise.
Still, a system in which two crops dominate is distinctly sub-optimal, and it’s perfectly reasonable to point to monocropping as a problem. What isn’t reasonable is expecting farmers to lead the charge for change. “Farmers will produce what the market asks them to produce,” says Wilkins, and I think that’s the crux of the issue. A complex series of factors, from government subsidies to consumer preferences, has built a food supply with an almost insatiable appetite for corn and soy.
If farmers can’t change things, who can? I can think of two ways to start tackling our monocrop problem. The first is to re-jigger farm subsidies (and regulations on ethanol; 30 percent of the corn crop goes to fuel), which could change the economic reality for farmers. The second is to cut back on our consumption of the meat and processed foods that most of our corn and soy goes into. Worried about monocrops? Look in your pantry, and see if you can’t help solve the problem.
Haspel, a freelance writer, farms oysters on Cape Cod and writes about food and science. On Twitter: @TamarHaspel. She’ll join today’s Free Range chat at noon: live.washingtonpost.com.
Guest Author: Andrew Kniss, Associate Professor, Weed Biology & Ecology University of Wyoming | Follow him on Twitter: @WyoWeeds
This is an older essay that previously appeared on Control Freaks, but it’s an evergreen topic so we thought it deserved another look. It appears here by permission of the author.
Pollan was referring to a Grist article by Nathanael Johnson, which was a response to Amy Harmon’s excellent piece in the New York Times. Both of their articles are worth reading (as is some of the controversy around one of Michael Pollan’s other recent tweets on the issue), but I’d like to stick with Pollan’s criticism of monoculture. Michael Pollan has been blaming monoculture for the problems of modern agriculture for quite some time.
“I still feel that the great evil of American agriculture is monoculture.” – Michael Pollan
Pollan may be the most recognizable, but he is certainly not the only one to blame monoculture for many of the problems of modern agriculture. This is a pretty common refrain from the anti-GMO camp, and also from many folks who are just not big fans of conventional agriculture. There are even some who claim to be allergic to monocultures. So is monoculture evil as Pollan says? Well, it may depend on what you mean by monoculture.
What’s a monoculture?
The biggest problem with monoculture might be your interpretation of the term. How, you might ask, could there be multiple interpretations of the word monoculture? I mean, there are very few words in the agricultural vocabulary that are as intuitive as the word monoculture.
Mono: single + culture: the tilling of the land.
Put them together, and it is pretty clear that a monoculture is the tilling of the land for a single crop. And most dictionary definitions reflect this intuitive meaning.
- The cultivation of a single crop in a given area – WordNet
- The use of land for growing only one type of crop – Dictionary.com
- The cultivation or growth of a single crop or organism especially on agricultural or forest land – Merriam Webster
One plant in a pot. A monoculture?
One plant in a pot. A monoculture?
So if you grow a single crop, you are growing a monoculture. Simple as that. The problem with this term is the scale. How much “given area” or “land” is required before we call it a monoculture? How long must a single crop be grown on the same area of land before it is considered a monoculture? The word is very imprecise. It seems to be used far more often by people criticizing modern agriculture than those who actually practice agriculture; I presume it is due to the non-specificity of the term. It doesn’t really convey enough information to be very useful to practitioners. It is the scale of the monoculture (both temporal and spatial) that determines whether monoculture is useful or problematic (or both) from an agronomic point of view.
What are the problems associated with monoculture production?
It has been my experience that most who criticize monoculture production don’t usually provide many details about why monoculture is a problem. And more importantly, they rarely provide specific, practical suggestions for improvement. So I think it is important to discuss these issues and place them in context. First, though, it is important to recognize that there are many good reasons to grow crops in monoculture. Monoculture is a practice that has allowed many technological advances in crop production. Having only one crop in the field increases our ability to mechanize planting, weeding, and harvest. And the mechanization of agriculture is the reason a majority of the population in developed countries do not still work on a farm. Without mechanization, growing your own food is often a necessity, not a hobby.
Some notable historical examples of widespread monoculture:
- The Irish potato famine. Potatoes reproduce vegetatively (not by seed) and therefore most potatoes grown in Ireland in the 1830s and 1840s had identical genetics. ‘Irish Lumper’ potato was grown extensively, and also happened to be extremely susceptible to late blight (caused by Phytopthora infestans). Potatoes had become the primary food source for the poor, and when the disease was finally introduced to the region, massive crop failure was inevitable. Nearly the entire potato crop in all of Ireland was susceptible to the pathogen. In the 1840s, late blight devastated the potato crops throughout the country; many people starved, and the population of Ireland crashed.
- Victoria oat blight. The oat variety ‘Victoria’ was bred to be resistant to crown rust, a problematic disease in oats. By 1945, well over half of US oat production had Victoria oat as a parent line. Then a new fungal pathogen came along, and it turns out that Victoria oats were highly sensitive (the pathogen was later named Victoria blight). It turned out the same gene that resulted in resistance to crown rust (interestingly, due to a hypersensitive response), also resulted in high susceptibility to Victoria blight. Because so many of the oat varieties had this particular gene, losses were widespread.
- Texas Male Sterility. In order to make corn hybrids, breeders must have a male parent and a female parent growing in close proximity. It is also necessary to have the male plants provide the only source of pollen. To ensure the females don’t self pollinate, the female plants are de-tasseled, so only the desired male parent plants produced pollen. Corn de-tasseling is expensive and labor intensive (and a generally not-fun job). Then the Texas cytoplasm (cms-T) was discovered (cms for cytoplasmic male sterile, and T for Texas). Use of cms-T meant there was no need to de-tassel the corn. Because the cms-T made it so much easier to produce hybrids, up to 90% of the US corn crop contained cms-T in the late 1960s and early 1970s. But along with male sterility, the cms-T also resulted in dramatic susceptibility to Bipolaris maydis or Southern Corn Leaf Blight (SCLB). Which meant 90% of the US corn crop was extremely susceptible to SCLB. Corn yield losses over a 2 year period were dramatic, and use of cms-T was rapidly discontinued.
Certainly, these examples illustrate a fundamental problem with large monoculture over a large geographical region (the spatial scale). But even more than that, they illustrate what can happen when we rely on extremely narrow genetics within a crop that is grown on a large scale. They all tell the same basic story: over-reliance on a single genotype is a bad idea, because it makes the entire crop susceptible to a single pest outbreak. If there were multiple varieties of potatoes being grown (instead of only Irish Lumper), and some of them were less susceptible to late blight, perhaps the Irish potato famine would have been avoided. If there were multiple sources of male sterility in use in corn, widespread losses due to SCLB may never have happened. One of the first things most agronomy students learn is that using diverse genetics minimize problems like these.
Widespread planting of uniform genetics is at least part of what Pollan (and others) don’t like about monoculture. He says as much in a 1998 article, when he mentions monoculture being “exquisitely vulnerable” to pests.
Organic farmers like Heath have also rejected what is perhaps the cornerstone of industrial agriculture: the economies of scale that only a monoculture can achieve. Monoculture — growing vast fields of the same crop year after year — is probably the single most powerful simplification of modern agriculture. But monoculture is poorly fitted to the way nature seems to work. Very simply, a field of identical plants will be exquisitely vulnerable to insects, weeds and disease. Monoculture is at the root of virtually every problem that bedevils the modern farmer, and that virtually every input has been designed to solve. – Michael Pollan, Playing God in the Garden
In addition to pest vulnerability, Pollan makes a couple other interesting references in this passage. Pollan’s comment that “monoculture is poorly fitted to the way nature seems to work” implies that there are no natural ecosystems in which a single plant species dominates. This is simply not the case. I’ve seen relatively undisturbed habitats in the Big Horn Basin of Wyoming that contain almost no plants other than greasewood (Sarcobatus vermiculatus). And saline sites where nothing but foxtail barley (Hordeum jubatum) grows. And riparian areas where only common reed is present. Again, this is an issue of scale; if you zoom in to an acre, there is a naturally-occurring monoculture. If you zoom out far enough, you’ll see other plants in the community. But this is exactly what we see in crop production in most regions also; within a particular field there may only be a single crop, but if you zoom out, you see different crops, nearby riparian areas, pastures, etc.
Winter wheat and pinto beans growing in the same field.
Notably, Pollan’s definition of monoculture also goes beyond the spatial scale and incorporates the temporal scale (“year after year”). Steve Savage has previously recognized that those critical of “monoculture” are often referring primarily to this temporal aspect; growing the same crop year after year in the same field. Crop rotations would not be considered “monoculture” by many of these critics, even though only a single crop is grown at a time within a field. Although organic farmers get a great deal of well-deserved credit for the diverse rotations they commonly use, crop rotation is still a major (although apparently under-recognized) part of conventional agriculture as well. For example, over 80% of soybean growers in the U.S. use crop rotation for pest management. Perhaps these rotations are not as diverse as they should be. Lack of crop diversity (both spatially and temporally) is certainly a valid concern. Savage suggested that with respect to the temporal aspect, critics of modern agriculture should avoid using the term monoculture altogether, and instead discuss “diverse rotations” and “non-diverse rotations”. This would eliminate the ambiguity, and instead allow an actual discussion of some of the real problems caused by a lack of diversity in crop rotations.
So how do we fix the problems of monoculture?
Researchers at Iowa State University have proposed one possibility: strip intercropping. It is a really neat idea that provides some balance between the benefits of monoculture, and the benefits of polyculture. But it presents some unique problems as well. Some pest outbreaks may actually be worsened in this system. A primary reason for crop rotation over time is to break pest life cycles; a sugarbeet pest that cannot survive on corn or dry bean, for example, will be reduced in a three-year rotation of these crops. However, if we employ strip intercropping, there will be sugarbeet in the field each year of production, providing the opportunity for the pest to build up and be worse than in a conventional crop rotation. I suppose one could argue that Pollan is correct when he says “Monoculture is at the root of virtually every problem that bedevils the modern farmer,” but only because that is how modern farmers grow crops. If modern farmers universally adopted polyculture, a new set of (equally bad) problems would result. And then polyculture would be at the root of virtually every problem farmers faced.
For some perennial crops (like tree crops and vineyards), a diverse crop rotation over time is simply impossible. It takes years for these crops to become productive, and they are extremely costly to establish. Perhaps we could inter-plant other species between tree rows or vines to reduce monoculture. But it is unlikely that this would actually aid in the management of many pests, as the susceptible hosts would still be present in a relatively high density. Adding diversity to the genotypes grown is only helpful if there are resistance traits found within the species. Some pests, like the citrus greening pathogen/vector (the pest that Amy Harmon wrote about in the NY Times), have a broad host range that includes most citrus crops, and there is currently no known natural source of resistance within these species. So reduction in this monoculture would be unlikely to help the situation much. Which, in my opinion, makes Michael Pollan’s claim that the “real problem to which GM is “the solution” is monoculture” is simply false in many contexts.
Are monocultures problematic? Sure, if the geographic or temporal scale is large enough. But the problems solved by using monoculture on a field-scale tend to far outweigh the problems they cause. Is there room for improvement? Absolutely. And there are many researchers who are attempting to do just that. For example, I am beginning a new 5 year project to look at how diverse crop rotations and tillage may impact the development of herbicide resistant weeds. But long-term field research like this is expensive. And public investment in agricultural research has stagnated or declined in the last decade. The problems associated with monoculture production won’t be solved simply by complaining about monoculture. And “simple” solutions like diverse crop rotations, polyculture, or use of biotech crops may solve some issues associated with monoculture, but they will exacerbate others issues. As is often the case in agriculture, the problems attributed to monoculture are far more nuanced and complex than most critics realize.
So I’m in favor of a genuine discussion about the problems commonly attributed to monoculture production. And I hope to help develop practical, economical ways to combat those problems. It just isn’t as simple as calling monoculture evil. To paraphrase Churchill, my opinion is that monoculture is indeed the worst possible way to grow crops, except for all the others that have been tried from time to time.
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How to practice Integrated Pest Management?
Prevention and suppression of harmful organisms
Crop rotation; inter-cropping
If you plan to grow the same crops regularly, you will need to rotate them. Different crops needs particular nutrients in the soil and use these up at a particular level in the ground. At the same time, each kind of plant attracts its own particular pests and diseases, which soon become established around the crop. If you grow the same kind of crop in the same place season after season, the nutrients that the plant needs are quickly exhausted, the plants grow weak and stunted and quickly come under attack from waiting pests and diseases. Crop rotation is important if the rotation reduces inoculum. Crop rotations should be observed since there are many pathogens that survive on numerous types of both living and dead plant materials. Some crops, such as sorghum, pearl millet and maize, may drastically suppress weed population and reduce its biomass. Pearl millet may exhibit residual weed suppression in the following crop. It is obviously necessary to evaluate which rotations can be grown successfully in the agro-ecological zone to maximize yield and pest control.
Use of adequate cultivation techniques
Burning plant residues and ploughing the soil is traditionally considered necessary for phytosanitary reasons: to control pests, diseases and weeds. In a system with reduced mechanical tillage based on mulch cover and biological tillage, alternatives have to be developed to control pests and weeds and Integrated Pest Management becomes mandatory. One important element to achieve this is crop rotation to reduce the pest-risks associated with monocultures, interrupting the infection chain between subsequent crops (different sowing dates and distances between fields with the same crops) and making full use of the physical and chemical interactions between different plant species. Synthetic chemical pesticides, particularly herbicides are, in the first years, inevitable but have to be used with great care to reduce the negative impacts on soil life. To the extent that a new balance between the organisms of the farm-ecosystem, pests and beneficial organisms, crops and weeds, becomes established and the farmer learns to manage the cropping system, the use of synthetic pesticides and mineral fertilizer tends to decline to a level below that of the original “conventional” farming system (see section on Conservation Agriculture).
Where appropriate, use of pest resistant/tolerant cultivars and standard/certified seed and planting material
Plant breeding has resulted in the development of a large number of varieties that are resistant to several kinds of diseases. Breeding is based on access to plant genetic resources, which can be conserved in the field and in gene-banks. Wild cultivars have low economic benefits in most cases, but often show resistance to locally occurring biotic and abiotic stresses; and cross-breeding of these varieties can result in the development of varieties that can perform better, by out-competing weeds, without the application of large doses of pesticides. A sustainable seed system will ensure that high quality seeds of a wide range of varieties and crops are produced and fully available in time and affordable to farmers and other stakeholders. Access to certified seeds will improve the uptake of farmers of higher-yielding varieties which can withstand stress and thus decrease environmental problems that are caused by use of pesticides (see section on Seeds and Plant Genetic Resources).
Diseases: Control or Management?
Coping with plant diseases in the field is relatively difficult because the causal organisms (bacteria, MLO, fungi, virus and nematodes) are very small and cannot be seen moving around like insects or rats. The most important first step in thinking about diseases is to realize that diseases must be managed not controlled. What is the difference? Management means a complete set of activities that support each other. Management means that these activities are carefully planned and are implemented over several seasons, not controlled within a single season. Management included control methods for prevention, and control methods to slow down epidemics; diseases will never be completely eradicated – only populations reduced to very low levels. Management usually needs the cooperation of several farmers working together to reduce overall disease in an area. Management requires someone who can observe larger areas of disease incidence and levels of infection.
Weeds reduce yields by competing with the plants for sunlight, moisture, and soil nutrients. Weeds may affect farming in many ways. For example, fertilizer applied might not increase yields in weedy fields because weeds absorb nitrogen more effectively than many rice plants. Also weeds are harmful because they may be alternate hosts for insect and disease pests of the main crop, and provide shelter for rats. Usually weed problems are more serious in upland and rainfed areas than in irrigated lowlands. If weeds are left to grow in the field they can significantly reduce yields. Knowledge of the behaviour of weed species is often lacking in the basic information available for weed control in most developing countries. Control measures are generally adopted to reduce weed infestation at certain phases of the crop cycle and not to bring about a sustainable reduction of the infestation. In order to know when is the right time to implement control methods to reduce weed species productivity, knowledge is required concerning: weed productivity; time of germination/emergence; and the period of fruit-setting and/or emission of first vegetative organs. These studies also provide information on the negative or positive influence of certain biotic and abiotic factors on weed growth and development (see section on Integrated Weed Management). Weed management must focus on the control of weed species, not only to avoid competition but also to prevent further build-up of weed seed bank in soil and eventually reduce it.
Field sanitation and hygiene measures
The pathogens that spread plant diseases and weeds can easily be spread by farmers and their machinery, as well as other people that visit farm fields. Although many pathogens are naturally present in the environment, they can also be spread by humans (faeces, clothing and machinery) and through inputs (mainly irrigation water). The main causes of contamination by pathogens that can be harmful to humans are the use of animal manure or sewage waste as organic fertilizer and the presence of animals in production areas. Composting of static piles and earthworms do not guarantee that micro-organisms have been inactivated. Wastewater and municipal wastes should only be used if effective disinfecting systems are available. Other ways of reducing the spread of potential plant diseases and weeds is to regularly clean farm machinery and clothing. Proper field sanitation and hygiene measures are an easy way to prevent diseases from spreading, but should always be combined with other measures, such as crop rotations and intercropping.
Protection and enhancement of important beneficial organisms
The configuration of the landscape can help to improve habitat for beneficial organisms for pest control and pollination (see section on Pollinator Management). Many ways exist of increasing these organisms, such as conservation of keystone species/structures and natural habitats. In rice systems, natural pest protection can be increased by small rows of certain crops that attract the beneficial organisms in (or at the border) the fields. For other crops, larger fragments of natural habitat (e.g. Agroforestry) are needed. Attention should also be given, where possible, to have a landscape that reduces the risk of the easy spreading of plant diseases. This means that borders between crops have to be established, based on the height and the distance that the pathogens/weeds can travel. Overall, a higher biodiversity will reduce the risk of pest outbreaks, whereas it will also benefit the biological processes that are needed for agricultural production and create diversification of income and risks (see section on Agricultural Biodiversity).
Monocultures: The Myth…the Reality…the Future
By leading farmers to focus on a small number of highly lucrative seeds, genetically modified organisms (GMOs) foster the spread of monocultures. As a result, they erode biodiversity and actually put humanity at risk of famine through increased crop vulnerability to disease.
“Very simply,” in the words of Michael Pollan, “a field of identical plants will be exquisitely vulnerable to insects, weeds, and disease. Monoculture is at the root of virtually every problem that bedevils the modern farmer…”
Monocultures—large areas planted with the same type of crop—predate the development of GMOs by decades if not centuries. That’s because the real driver of monoculture farming has been mechanized agriculture. Planting and harvesting of crops are faster and more efficient if farm equipment is working on a single crop, rather than a collection of different ones—a polyculture.
Although we don’t have to accept everything mechanized agriculture has resulted in to date, it is hard to overstate its benefits. When my grandfather was farming in Illinois in the 1930s, he did so literally with horsepower. At that time perhaps 25 percent of the state’s population was engaged in agriculture. Today that figure is less than 2 percent. By exponentially increasing productivity, mechanized agriculture has unleashed a huge pool of labor that has built new industries for the country. At the same time, it has greatly increased the affordability of food. The result has been a complete transformation of society—from rural to urban and to far higher levels of national wealth and food security.
GMOs, which began entering the market in the late 1990s, have simply been incorporated into the modern farming practices, including monocultures, that mechanized agriculture has helped drive. GMOs, however, can also be incorporated into other kinds of farming practices, such as those often employed in less developed parts of the world. Indeed, GMOs are being used today by millions of smallholder farmers in countries across Asia and Africa.
Conversely, the inherent efficiencies of monocultures are so compelling that many non-GMO farmers—including those who favor organic methods—also rely on them. That organic lettuce and kale you may be eating could well be the product of monoculture farming.
Finally, it’s important to understand that monocultures exist in two dimensions—time and space. That’s because no matter how many acres of corn or soybeans or some other crop a farmer may plant, he or she faces a new decision about what to plant the following year. Such decisions are based on field history, crop rotation, and market demand. If corn prices are low, for example, a farmer may choose to plant more soybeans or wheat or another crop, depending on the location. In other words, at least for row crops, there is more flexibility and diversity built into the system than the word “monoculture” implies. Orchards and vineyards, on the other hand, do operate on much longer timescales—grapevines for as long as 50 to 100 years.
Corn and soybean fields may look the same as you drive by on the interstate or fly over the “I-states” (Indiana, Illinois, Iowa), but they are in fact incredibly genetically diverse. And that diversity is actually increasing.
Consider corn. In the mid-1990s when Monsanto first entered the seed business in that crop, 90 percent of hybrids were produced from male and female plants of largely U.S. origin. The commercial gene pool was relatively narrow, using less than 10 percent of the global corn gene pool. Since then, however, a combination of advances—in molecular breeding techniques, the use of DNA markers, computing and more—have enabled us to incorporate ex-U.S. strains of corn into our own. As a result, the majority of our new corn hybrids today contain genes from “foreign” corn—varieties grown in Mexico, Brazil, Argentina, Asia, and Europe.
We are, in short, using more of corn’s global gene pool—and dramatically expanding the genetic diversity in farmers’ fields.
With biotechnology, we can add even more genetic diversity by incorporating foreign genes from other plants and microbes. A leading U.S. corn hybrid that contains the SmartStax® trait package, for example, introduces eight such genes into the crop. These genes and others provide protection against insects, weeds and drought. Within a decade, corn hybrids may contain 20 to 30 of these new, helpful GMO traits.
A few more points relating to the impact of GMOs on genetic diversity:
- Farmers are acutely aware of the importance of diversifying their plantings. When growing corn, U.S. farmers typically plant four to seven different hybrids to manage field variability, disease and insect resistance, and harvest dates.
- Insecticide sprays may kill a broad array of insects—including beneficial ones—as well as soil organisms. GMO crops that carry built-in protection against harmful insects dramatically reduce the need for insecticide sprays and thereby enhance biodiversity. By better protecting the corn roots from insect feeding and damage, the GMO traits also make the crop more drought resistant.
Skeptical? In 2010, the National Research Council (NRC) released a comprehensive assessment of the effect of GM crop adoption on farm sustainability in the United States. The NRC is the operating arm of the National Academy of Sciences and the National Academy of Engineering, which in turn are made up of some of the top scientists and engineers in the country. Among the report’s conclusions:
Generally, GE crops have had fewer adverse effects on the environment than non-GE crops produced conventionally. The use of pesticides with toxicity to non-target organisms or with greater persistence in soil and waterways has typically been lower in GE fields than in non-GE, nonorganic fields.
- Finally, the use of GMO herbicide-tolerant crops has resulted in widespread adoption of conservation tillage, which has a huge beneficial impact on soil biodiversity. Instead of tearing up their fields with big, fossil fuel-burning tractors, farmers can control the weeds on an acre with herbicides that fit in a soda can. Energy use and greenhouse gas emissions are slashed along with water loss from soils.
In short, the allegation that GMOs foster vulnerable monocultures is false. The truth is that GMOs are making both our crops and our farms more biodiverse – and more sustainable.
As recently as the mid-1990s, Hawaiian papayas were on the verge of extinction from a viral disease. What saved them? As this New York Times story reports, a GMO variety that resists the virus that was annihilating it.
Now the banana is threatened by a soil fungus called “Panama Disease” or, alternatively, “Fusarium Wilt”. What could save it? A GMO variety that resists that fungus.
Likewise, the U.S. citrus industry is facing a looming crisis of “citrus greening.” What could save it? As this New York Times story reports, a GMO variety of oranges that resists the bacteria that destroys it.
In all these cases, biotechnology provides solutions to problems fostered by monocultures—solutions that would enable us to keep using these crops to nourish millions of people and support the livelihoods of large numbers of farmers. And in the near future, the increased utilization of data science and precision AG tools based on satellite imagery, drones, robotics and sensors will provide additional ways to manage and enhance monoculture production.
Should we turn our backs on these solutions because some critics oppose monocultures, when those monocultures are a product of agricultural methods that have fed more people better than ever before and have helped create our increasingly prosperous modern world?
And should we turn our back on those solutions when they actually increase—not decrease—the genetic diversity in our environment?
The answer speaks for itself.
Early in the morning after a hot cup of coffee, Jim climbs up onto his tractor, turns the key, and drives to the edge of his vast corn fields. The arms of the spray boom unfold, creating a wingspan of 120 feet. As Jim drives down designated rows, a combination of water and chemicals sprays over his crops coating everything, but killing only pesky weeds (“Crop Sprayer”, n.d.). While most perish under the harsh conditions, a few weeds survive. Application after application, season after season, more weeds survive. Attempting to save his corn yields while still making some profit, Jim increases application rates and dates. However, as time goes on, nothing seems to help. The pesky weeds outsmarted the old farmer, leaving him in despair (“How Pesticide Resistance Develops”, n.d.).
Jim, like thousands of farmers across the country, is experiencing negative aspects of monoculture, or the agricultural practice of growing a singular crop species in which all plants are genetically similar or identical over vast acres of land (“Biodiversity”, n.d.). Despite high yields and relatively low input prices, growing just one species of crop on many acres of land creates major pest problems. Current American agricultural policies covered by the Farm Bill incentivize the overproduction of commodity crops, such as corn, wheat, soybeans and cotton, in monoculture systems. When the Farm Bill originated during the Great Depression, however, its goal was to preserve the diversified farm landscape. At the time, surplus ran high but demand fell low, driving crop prices into the ground. Farmers struggled to make mortgage payments. Fearing that farms would be forced out of business, President Roosevelt passed the Agricultural Adjustment Act, which paid farmers to not cultivate a certain percentage of their land. This successfully reduced supply and increased prices, keeping the market afloat (Masterson, 2011). Following the stabilization of crop prices, the Farm Bill became a permanent piece of legislation in 1938. For the next forty years, farmers continued to grow both staple crops (corn, wheat, and oats) and specialty crops (fruits and vegetables), as well as livestock (Haspel, 2014).
During the latter half of the 20th century, American agriculture experienced an overhaul. The Green Revolution during the 1960s increased crop production through the introduction of synthetic fertilizers, pesticides, high-yielding crop varieties, and farm equipment mechanization (Mills, n.d.). Farm size dramatically increased over time; since the 1980s, the average number of acres per farm increased by over 100% (DePillis, 2013). Farms consolidated, resulting in 20% of farmers producing 80% of agricultural outputs (Mills, n.d.). New practices, combined with new additions to the Farm Bill, changed the way farmers managed risk (Haspel, 2014). One such addition included the Marketing Loan Program, which revolves around a set price agreed upon by Congress. If crop prices fall below a certain point, the U.S. government will reimburse farmers the difference. This reimbursement program encourages farmers to increase production regardless if they need to or not. The more they grow, the more money they make, even if it lowers current market crop prices (Riedl, 2007). In 1996, for example, Congress increased the price point of soybeans from $4.92 to $5.26 a bushel. To capitalize on the situation, farmers planted 8 million more acres of soybeans, dropping soybean market prices 33% (Riedl, 2007). Despite the price drop, farmers actually made more money through the reimbursement program. The Farm Bill promotes overproduction which saturates the market with product and artificially lowers prices.
In addition to overproduction, industrial monoculture predisposes farms to pest problems. To keep up with intensified production, farmers increased pesticide and fertilizer usage, crop density, and the number of crop cycles per season, but decreased crop diversity (Crowder & Jabbour, 2014). Overcrowding genetically uniform plants allows pests to spread through fields with relatively little resistance, compared to a more diverse array of species (“Biodiversity”, n.d.). Perhaps the most infamous account of pests sweeping through a field occurred in Ireland during the 1840s. Irish farmers grew a single variety of potatoes. In 1845, the potato late blight fungus destroyed nearly half of the potato crop, and continued to kill more and more for seven years (“Irish Potato Famine”, 2017). Just like fields during the Irish Potato Famine, modern monocultures risk infestation at any moment.
The inherent issues of pest management in monoculture systems will be exacerbated by the effects of climate change. Increases in average temperature creates a favorable environment that support larger pest populations. All insects are cold-blooded organisms, meaning that their body temperatures and biological processes directly correlate to environmental temperatures (Petzoldt & Seaman, 2006; Bale & Hayward, 2010). The reproductive cycles for pests such as the European corn borer, Colorado potato beetle, and Sycamore lace bug depend on temperature (Petzoldt & Seaman., 2006). Due to higher average temperatures, these reproductive cycles require less time (Petzoldt & Seaman, 2006). For example, the Sycamore lace bug saw drastic time reductions in egg development. At 19˚C, Sycamore lace bug eggs required 20 days to fully develop, but at 30˚C, eggs reached full maturity in 7.6 days (Ju et al., 2011, p. 4). Warmer average temperatures allow faster reproduction rates of pests, leading to a significant increase in pest populations. As pest populations grow in size, so does the threat to monoculture farming.
Higher average temperatures will not only shorten the reproductive cycles of insects, but will also limit the pest control mechanisms of winter. 2015 was the warmest winter on record, and 2016 was not much cooler. On any given day throughout 2016, states across the country experienced daily temperatures up to 12.1˚C warmer than normal (Samenow, 2017, Chart II). As a result of climate change, scientists expect milder winters to continue. The National Weather Service predicts the winter of 2017 will be consistently warmer than usual (Samenow, 2017). Insects lack a method to retain heat, forcing crop pest to develop survival strategies during winter. Insects fall into two categories, freeze-tolerant and freeze-avoiding, both which remain dormant throughout the winter (Bale & Hayward, 2010). Milder winter temperatures will have varying effects on species of crop pest, but overall a 1-5˚C increase will decrease thermal stress in both freeze-tolerant and freeze-avoiding insects (Bale & Hayward, 2010). The southwestern corn borer is one species that benefits from milder winters. During summer of 2017, farmers in Arkansas reported higher numbers of southwestern corn borers (SWCB) following the mildest winter recorded in 2016. To combat SWCB, farmers across the state deployed pheromone traps. The traps captured 300% more SWCB moths per week during the 2017 season compared to previous years. (Studebaker, 2017). Mild winters will help crop pests survive through the winter, increasing the potential for crop infestation and damage.
Warmer winters will also drive pest populations northward into uncharted territories of farmland. The United States Department of Agriculture (USDA) classifies similar climatic regions into hardiness zones to help farmers determine which crops will thrive in their area. Over the past thirty years, increasing temperatures associated with climate change have shifted hardiness zones towards the north. For example, the USDA now classifies northwestern Montana as a zone 6a instead of 5b. Crops such as ginger and artichokes can now successfully grow in this region (Shimizu, 2017). Similarly, more pests can thrive in more northern locations. Beetles, moths, and mites are moving towards the poles at a rate of 2.7 kilometers per year (Barford, 2013). Additionally, fungi and weeds are moving north at a rate of 7 kilometers per year (Barford, 2013). As these ranges grow, farmers need to develop new strategies to control pests they have never encountered. Climate change will unleash a myriad of changes in crop pests: their reproduction rate, winter survival rate and ranges all increase as temperatures rise. To adapt to these changes, farmers have many options, each with their limitations.
The most common strategy to combat pests in monoculture productions is to increase pesticide application rates per acre. Theoretically, more pesticides will kill more pests. However, that solution losing practicality due to the more subtle effects of climate change. Pesticides efficacy decreases as the global temperatures rise. Detoxification rates, or the time required to breakdown a pesticide to render it unharmful to weeds, decrease with increasing temperatures (Matzrafi et al., 2016, p. 1223). A 2016 study, for example, determined that climate change negatively affected the effectiveness of two common herbicides, diclofopmethyl and pinoxaden. At low temperatures (22-28˚C) diclofopmethyl and pinoxaden prevented the growth of any weeds. However, at high temperatures (28-34˚C) 80% of weeds survived diclofopmethyl application and 100% of weeds survived pinoxaden application (Matzrafi et al., 2016, p. 1220, 1223). Applying larger quantities may work initially, but as the overall global temperature continues to rise, pesticides will become less and less effective. Farmers will not be able to afford the quantities needed to control pests.
While current pesticides are losing their ability to kill crop pests, new, more effective pesticides are millions of dollars and years away from development. In 2016, developing a new pesticide required almost 11 years of research and carried a price tag of $287 million dollars. Technological advancements will not be developed fast enough to defend monocultures from the risk of change (“Cost of Crop,” 2016). Consequently, farmers will apply higher quantities of the same pesticide in hopes to control the pest issue. Pesticide cost estimates, under a 2090 climate change model, predict that there is a direct correlation between increasing temperatures and increasing pesticide cost for crops such as corn, cotton, potatoes, and soybeans. In some areas, pesticide usage costs will increase by as much as 23.17% by 2090, aggressively cutting into profit margins (Chen & McCarl, 2001, Table VII).
While farmers attempt to mitigate the negative consequences climate change has on pesticides by increasing usage, further issues arise. Pesticide resistance occurs following repetitious applications of the same pesticide to a field. With each pesticide application, a select few pests survive. They pass on their resistance genes to their offspring, and more individuals survive pesticide application in the subsequent generation. Eventually, the pesticide stops controlling the pest, and crop damage occurs (“How Pesticide Resistance Develops”, n.d.). Currently, there are over 500 reported cases of pesticide resistance and over 250 cases of insecticide resistance worldwide (Gut, Schilder, Isaacs, & McManus, n.d.; “International Survey”, 2017). The most infamous case of pesticide resistance occurs within Roundup Ready crops. Scientists genetically modified crops such as cotton, corn, and soybeans to tolerate glyphosate applications, which is the generic name for the common household weed-killer Roundup. Farmers can spray entire fields with glyphosate and kill everything except the crop itself (Hsaio, 2015). In the United States, 90% of soybeans and 70% of corn grown are Roundup ready crops. The prevalence of Roundup ready crops exposes the drawbacks of monoculture systems. For example, over 10 million acres of farmland in the United States have been afflicted by Roundup resistant pests such as pigweed (Neuman & Pollack, 2010). The increasing rate of Roundup resistance has the potential to dramatically interrupt food security of United States.
As climate change increases the prevalence and range of pests and decreases pesticide efficacy, American farmers will begin to lose their ability to control and maintain its current production levels. Monoculture farms expose themselves to higher risks of pest infestations as well as pesticide resistance. The best strategy for maintaining a stable food supply is to transform American agriculture from monoculture systems to sustainable, diversified farms with a variety of specialty crops. Generally speaking, the more diversified agricultural land is, the more resilient the land is to climate change and other disturbances (Walpole, et. al, 2013). Monoculture fields lack biodiversity, which hinders natural pest control. Unwanted species can spread throughout entire fields with relative ease due to an abundance of their host species and lack of natural predators. In diversified fields, however, pests encounter more resistance when attempting to invade a field; more natural pests and predators, known as biological controls, limit their movement (Brion, 2014).
Diversified farms may already have natural biological controls in their ecosystem, although they can be introduced to farms as well. Biological controls prove to be more cost effective and environmentally conscious than chemical control. Both methods take roughly ten years to develop, but biological controls are much cheaper. In 2004, it cost only two million U.S. dollars to develop a successful biological control, whereas it took $180 million U.S. dollars to develop a successful chemical control. Furthermore, biological control development are 10,000 times more successful than chemical control development, largely in part due to the directed search for biological agents versus the broader search for chemical agents. Most importantly, biological controls exhibit very little to no risk of resistance and harmful side effects, whereas chemical controls have a high risk of resistance and many side effects (Bale, van Lenteren, & Bigler, 2008).
In addition to increasing biodiversity and biological controls, diversified farms use different management practices than monoculture farms. Diversified farms tend to use less synthetic chemical pesticides per unit of production than conventional farms, according to a National Resource Council study (Walpole, et. al, 2013). They also produce more per hectare than large-scale plantations. As stated in a 1992 agricultural census report, diversified farms grew more than twice as much food per acre than large farms by cultivating more crops and more kinds of crops per hectare (Montgomery, 2017).
To mitigate the effects of climate change on American agriculture, the U.S. government must alter its agricultural policies to promote diversified farming. Removing commodity crop subsidies and reallocating that money to farms that practice diversified farming techniques will decrease overproduction in monoculture operations that rely on heavy pesticide usage. Farmers will no longer be able to produce a single crop at maximum volume and continue to make a profit because programs like the Marketing Loan Program will no longer exist. In turn, this will help alleviate pesticide resistance caused by overuse and climate change. Farmers who grow a variety of specialty crops will be rewarded for their environmental stewardship through monetary compensation, similar to how mono-cropping farms used to receive subsidies.
The United States would not be the first country to remove crop subsidies. In 1984, New Zealand removed their crop subsidy program. Like the United States, New Zealand had subsidized as much as 40% of a farmer’s income throughout the 1970s into the early 1980s (Imhoff, 2012, p. 103). Farmers took advantage of government programs similar to the Marketing Loan Program in the U.S. by producing more, therefore receiving more subsidies. During the 1984 election, however, the winning party ran a platform to remove subsidies. The elimination of subsidies from the budget caused no major food shortages like supporters of the U.S. Farm Bill claim would happen. Instead, New Zealand saw an increase in efficiency. For example, the total number of sheep fell following 1984, but weight gain and lambing productivity increased. The dairy industry in New Zealand also saw drastic increases in efficiency, bringing production costs for cattle to the lowest in the world (Imhoff, 2012, p. 104).
In addition to more efficient farms, there is an interesting aspect of subsidy removal brought light to in the New Zealand case. After the 1984 repeal, pesticide usage reduced by 50% (William, 2014). If the United States adopted a similar practice to New Zealand, but instead reallocated commodity crop subsidies towards diversified farming practice, there would be an influx of more efficient and productive farms that could feed the nation while using less pesticides.
Many states have begun to implement grant programs to promote diversified farming. In 2017, Massachusetts granted over $300,000 toward businesses and farms promoting diversification through specialty crop production. In concurrence with the USDA, Boston offered grants for projects aimed at improving Massachusetts specialty crops, which include fruits and vegetables, dried fruits, tree nuts, and horticulture and nursery products. In general, these grants support projects that help increase market opportunities for local farmers and promote sustainable production practices by giving money to diversified farms more funds. Community Involved in Sustainable Agriculture (CISA), for example, received a portion of this grant. With the money, CISA plans to provide financial support to specialty crop farmers in Western Massachusetts. The Sustainable Business Organization also received part of the grant, with which they hope to build relationships between specialty crop farmers and buyers. By removing barriers that prevent farmers and customers from doing business, the Sustainable Business Organization hopes to increase sales of specialty crops across New England (“Baker-Polito,” 2017).The United States federal government often looks upon states to make sure programs work on a smaller before the whole country takes after them on a larger scale. If the United States removes subsidies that encourage monoculture and reallocates that money towards diversifying crops on farms, American farmers could emulate programs like those in Massachusetts. By doing so, problems associated with pests and climate change will be mitigated.
Facing the adverse effects of monoculture agricultural systems and climate change, farmers and legislature must work together to diversify farms across the United States. The current monoculture overproduces food, leading to an increased use of pesticides, even by the mere increase of agricultural land alone. On top of this, increasing temperatures associated with climate change are threatening American agriculture as well. Warmer temperatures increase pest populations and decrease the efficacy of pesticides. Furthermore, overuse of pesticides is allowing pests to develop pesticide resistance, creating a snowball effect between pests, pesticide usage, and pesticide resistance. In order to preserve food security and mitigate the effects of climate change, the United States must remove commodity crop subsidies and reallocate the funds towards diversified farming practices. Doing so will decrease the need for pesticides while increasing crop yields. The fight against climate change will prove to be a challenging process, but collaboration between farmers and government will help ease the process and create positive change.
Julia Anderson – Animal Science and Sustainable Food and Farming
Emily Hespeler – Environmental Science
Steven Zwiren – Building and Construction Technology
Biodiversity and agriculture. (n.d.). Retrieved from https://chge.hsph.harvard.edu/biodiversity-and-agriculture
How a crop sprayer works. (n.d.). Retrieved from http://lethamshank.co.uk/sprayer.htm
Hsaio, J. (2015). GMOs and pesticides: Harmful or helpful? Available at: sitn.hms.harvard.edu/flash/2015/gmos-and-pesticides/.
Imhoff, Dan (2012). Food fight: the citizen’s guide to the next food and farm bill. Healdsburg, California: Watershed Media
International Survey of Herbicide Resistant Weeds. (2017). Retrieved from www.weedscience.org/.
Irish Potato Famine. (2017). Retrieved from http://www.history.com/topics/irish-potato-famine
Mills, R. (n.d.). A harsh reality. Retrieved from http://aheadoftheherd.com/Newsletter/2011/A-Harsh-Reality.html
MONO-CROPPING AND MIXED FARMING SYSTEM
This is the growing of only one type of crop (such as maize) on a piece of land. It could be for a season or for several years as in bush=fallowing farming. The system is also termed sole cropping.
Advantages of mono-cropping
1. It makes possible the use of machines in farm operation.
2. It leads higher productivity per hectare,
3. It also leads to specialization among farmers.
4. The control of weeds is easy. This is because herbicides can be used
Disadvantages of mono-cropping
1. It is risky because crop failure arising from pest, diseases or weather conditions will result in total loss of income to the farmer for that year.
2. The system encourages the rapid spread of pests and diseases on the farm.
3. Labour may not be efficiently utilized throughout the year.
4. It does not afford the farmer a variety of crops.
This is also called multiple cropping because it involves the planting, of more than one type of crop on the same farmland at in the farm. It is very common under subsistence agriculture and in are where farmlands are limited. read land tenure system of agriculture
Under mixed cropping, the farmer could practice any of the following
This is the growing of two crops together on the same land. The crop which was planted first is also harvest first while the one planted last remains on the plot to harvested later read about harvester here. An example is the growing of maize and together. Maize, which is usually planted first, is also harvest first. Maize is therefore said to be inter-planted with yam.
This is when two crops are grown together with the crop planted last being harvested first. Usually the c planted last has shorter lifespan than the one planted first, example is the planting of melon after yam has been plant The melon will be harvested first while the yam continues on plot. Yam is therefore said to be inter-cropped with melon.
Advantages of mixed cropping
1. It affords the farmer a variety of crops.
2. It serves as insurance against the failure of one type of crops.
3. It minimizes the spread of diseases and pests on the farm.
4. It enables the crops to make efficient use of soil nutrients.
5. The ensures efficient utilization of labour throughout the year.
Disadvantages of mixed cropping
1. It does not encourage the use of machines on the farm.
2. It may lead to rapid exhaustion of soil nutrients if legumes not included.
3. It is labour intensive.
4. Pests and disease agents may persist on the farmland. This is because there are always food and alternative hosts for them.
This is the practice of putting a farmland under cultivation continuously, that is from year to year.
It may take any of forms:
Planting annual crops which are replaced after harvesting. This means the land is cleared, tilled and cropped every season. This is common where land is scarce
(b) Permanent cropping: This involves planting and maintaining the crops, usually permanent crops continuously on the farm.
Advantages of continuous cropping
1 It reduces the cost of land preparation after the initial clearing and tilling.
2 It enables the farmer to construct permanent structures such as storage structures on the farm.
3 It tan be practiced where land is scarce.
Disadvantages of continuous cropping
1. The fertility of the soil is easily exhausted.
2. It leads to destruction of soil structure.
3. It encourages soil erosion.
4. Yields me normally reduced with increasing years of cropping.
5. It encourages build-up of crop pests and disease agents.
6. It required high amount of money to keep the land fertile and productive.
This involves the planting of different types of crop in different plots on a farmland during one season; and at the beginning of the next season, the crops are changed from their respective plots, while following a definite order or sequence. The system combines mixed cropping with continuous cropping and is mainly practiced by institutions of learning.
For crop rotation to be successful, certain principles must be followed
Principles of Crop Rotation
(a) The same type of crop should not be allowed to follow each other on the same plot. For example, maize should not follow maize.
(b) Crops that belong to the same group should not also follow each other on the same plot, e.g. cassava should not follow yam, or to follow maize.
(c) Crops that have deep roots like yam and cassava, should be followed with those that have shallow roots suclh as maize and groundnut.
(d) Crops that consume a lot of nitrogen such as the-cereal group should be followed by those that add nitrogen to the soil such as maize and the legume group,
(e) Crops likely to be affected by the same disease and/or pest should not follow each other on the same plot.
The number of crops involved in the rotation will determine the. type of rotation. Therefore, there could be a two-year, three-year, or four-year crop rotation.
How to Design a Four-Year Crop Rotation
(a) Divide the farmland into four plots.
(b) Choose the crops to cultivate.
(c) Plant one crop on each plot, making sure the principles guiding the adoption of the system are adhered to.
(d) At the end of one season, shift the crop from plot B to A, C to B, D to C and A to D as shown in Figure 3.2.1.
(e) Follow this sequence until the fourth year is reached.
Year Plot A Plot B Plot C Plot D
1 Maize Cassava Groundnut Yam and Melon
2 Cassava Groundnut Yam and Melon Maize
3 Groundnut Yam and Melon Maize Cassava
4 Yam and Melon Maize Cassava Groundnut
Figure 3.2.1: A Four-Year Crop Rotation,
Advantages of crop rotation
1. It helps to maintain soil fertility.
2. It makes efficient use of soil nutrients.
3. The farmer has access to a variety of crops.
4. It minimizes the spread of diseases and pests and helps to check weeds
5. It reduces soil erosion.
6. It leads to efficient utilization of labour.
7. It is a good practice where land is scarce.
Disadvantages of crop rotation
1. It is labour intensive.
2. Crop yields may decrease with years except additional manures or fertilizers are applied.
3. It leads to destruction of soil structure which may facilitate soil erosion.
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Agricultural biology topics
1. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
3. 52. SOIL MICRO-ORGANISMS
4. ORGANIC MANURING
5. FARM YARD MANURE
8. CROP ROTATION
9. GRAZING AND OVER GRAZING
10. IRRIGATION AND DRAINAGE
11. IRRIGATION SYSTEMS
12. ORGANIC MANURING
13. FARM YARD MANURE
16. CROP ROTATION
17. GRAZING AND OVER GRAZING
18. IRRIGATION AND DRAINAGE
19. IRRIGATION SYSTEMS
21. MILKING MACHINE
22. SIMPLE FARM TOOLS
23. AGRICULTURAL MECHANIZATION
24. THE CONCEPT OF MECHANIZATION
25. PROBLEMS OF MECHANIZATION
26. SURVEYING AND PLANNING OF FARMSTEAD
27. IMPORTANCE OF FARM SURVEY
28. SURVEY EQUIPMENT
29. PRINCIPLES OF FARM OUTLAY
30. SUMMARY OF FARM SURVEYING
31. CROP HUSBANDRY PRACTICES
32. PESTS AND DISEASE OF MAIZE- ZEA MAYS
33. CULTIVATION OF MAIZE CROP
34. OIL PALM
35. USES OF PALM OIL
36. MAINTENANCE OF PALM PLANTATION
99. RUMINANT ANIMALS
100. THE NERVOUS SYSTEM
101. THE NEURONS
102. A SYNAPSE ACTION IMPULSE REFLEX ACTION VOLUNTARY ACTION
103. THE CENTRAL NERVOUS SYSTEM
104. PERIPHERAL NERVOUS SYSTEM
105. THE REPRODUCTIVE SYSTEM MALE AND FEMALE REPRODUCTIVE SYSTEM
106. REPRODUCTIVE SYSTEM OF BIRDS
107. THE CIRCULATORY SYSTEM
154. PROTOZOAN DISEASES
157. RED WATER FEVER(PIROPLASMOSIS)
158. ENDO PARASITES
159. TAPE WORM
160. ROUND WORM OF PIGS
161. LIVER FLUKE
162. ECTO PARASITES
Advantages and Disadvantages of Monoculture
An agricultural practice which involves the cultivation of a single crop over a wide area for many successive years. It is practiced widely by farmers the world over. This Gardenerdy article weighs the advantages and disadvantages associated with monoculture farming.
An example of how monoculture can lead to disaster is the 1980s Grapevine calamity. California grape growers had to replant almost two million acres of vines, when their grape roots were severely affected by grape phylloxera (Daktulosphaira vitifoliae)―a new type of pests.
Monoculture farming is an agricultural method that involves planting one species of crop on the same piece of land repeatedly. Due to its implementation, farmers can yield large harvests with minimum utilization of resources. The ritual of growing the same crop for many successive years is known as crop monoculture. For example, in monoculture farming, rice will be grown only with rice, particular type of potato will be cultivated only with that type. In monoculture, same crop is grown in the same land year after year. The main purpose behind monoculture farming is to maximize the output and minimize labor required.
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The term monoculture or this technique is not just restricted to agriculture, it can be applied in other fields too. For example, raising one particular type of livestock on a farm, also in the field of computer science, wherein a group of computers are running the same software. It is extensively used in the field of farming, but other than that, it is adopted in forestry too. Same species of trees are planted in a particular area.
Examples of monoculture crops include corn, wheat, rice, clover, cotton. It also includes tea, coffee, different types of fruits, and rubber trees. Experts are of the view that monoculture farming is more of a curse than boon, particularly after the Irish Potato Famine of 1845. Along with its added benefits over traditional farming, it comes with its own set of dangers and risks. Let us take a closer look at each of them.
Advantages of Monoculture
- This approach to farming is fairly simple in nature, focusing all its needs and preference on one single crop species. Farmers just need to prepare the soil, and irrigate the land based on one crop. With monoculture, the field is in a better position to provide maximum output for a particular crop.
- Harvesting becomes fairly easy as the desired parts of the plant can be easily assembled without damaging other plants, which would be very difficult in polyculture. Chemical treatments is feasible, pests and diseases can be treated without having to worry about their side effects on other plants.
- It helps to keep down farming costs down, Farmers yield more output in less resources. Makes management pretty easy, machines and various methods can be utilized more efficiently and systematically.
- The knowledge of single plant species is sufficient for a good crop, farmers need not worry about other species, their cultivation methods, disease prevention, etc. Since the emphasis is on one plant, acquiring adequate knowledge or expertise is also easy.
- It is convenient for home gardeners who want to have a bigger harvest of a particular plant; suppose they want to save up on corn or barley to reduce their expenses. Growing a single large crop requires less investment.
- By grouping different plants together, farmers or gardeners have to cater to the fertilizer requirement of different plants. But with monoculture, they can easily use and apply one common fertilizer for all the plants.
- Planting same species of crop is much easier and faster process. Farmers can prepare garden beds and seed plants altogether. They just need to prepare garden beds for only one type of crop.
- Controlling pests and disease becomes relatively easy. Growers just need to use one pesticide for all the plants, because the diseases affecting them would be common.
- There is less competition for sunlight, nutrients, and space from other species. It helps to control other undesirable growth. It helps to maximize profits by planting crops which yields high gross margin.
- High gross margin crops are market-driven, and it’s easy to market such crops. Farmers particularly plants crop which can be consumed all year round, and also those which will thrive under all weather conditions.
- Monoculture does not support other flora and fauna. According to its definition, other plants should not be planted. We all need different environment to survive; likewise, animals continuously living in one environment will lack the feel of a natural habitat.
- If a particular disease or pest can affect one single plant, then it can possible affect all the other plants as they also will be vulnerable to their attack. An infected plant, in this scenario, will be surrounded by infected plants, which will lead to the destruction of the entire crop.
- Plants require multiple resources to thrive; however, if a crop is planted in the same field for extended periods, it limits its chance of taking advantage of other nutrients in the soil.
- One of the problems of monoculture farming is limited food options. For the sake of saving their resources, farmers plant one single crop, leaving consumers with few options to survive on, which can lead to malnutrition, especially in developing countries.
- Due to the cultivation of same crops over and over again, monoculture reduces the nitrogen composition in the soil. Once the land is used for one single crop, soil fertility diminishes at a faster rate.
- Because of diminishing soil fertility, farmers rely heavily on chemicals and technology to promote plant growth and production. Monoculture leads to environmental damage when the chemicals and pesticides make their way into ground water.
- Due to major crop failure, farmers can suffer high losses, which in turn would contribute to total market loss. Farmers depend on one type of production, so their income is also not stable.
- Monoculture results in less diversity of other species, this applies to both plants and animals. This, in turn is not good for the bio-diversity of that entire region.
- Monoculture is not advocated because repetitive use of fertilizers can lead to soil erosion, which makes it difficult for plants to grow.
- Planting crops over a large area can be time-consuming for a farmer. Not to mention the efforts and investment required to set up a complex irrigation system.
There won’t be any outcome if we simply sit and crib about the problems associated with monoculture farming. Solutions like polyculture, crop rotations, biotech crops might solve some issues, but again, there are some pros and cons related to them also. Researchers state that the trouble connected to monoculture farming is far more complex and grave to solve.
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15 Monoculture Farming Benefits and Disadvantages You Need to Know
Is Single Crop Planting A Good Or Bad Thing?
What is Monoculture Farming? Well, it is those large farm areas that only have one type of crop growing on them.
Monoculture Farming Basics
Why Do We Use Monocultures
Traditional methods of farming with multiple crop variations(polyculture) are not as efficient for getting harvested. So over the last 50 to 70 years, many farms have moved in favor of monoculture crops.
By switching to a single crop, it allows farmers to maximize the automation of agricultural machinery.
The original Monoculture technique involved planting a single type of crop, in the same field year after year.
The most massive monocrop operation I could find has been in use since the 1840s in England. Wheat has been grown continuously in these fields with no other crop types.
Where Monoculture Crops Get Used
Many of our monoculture fields in North America are not for humans. Most of the corn goes to feed livestock, and the creation of bioproducts(fuels, plastics, etc.).
It is believed that only about 20% of the corn grown in North America is used to feed people.
The demand for meat is one of the primary reasons for the mass-scale use of monoculture agriculture. Around 50 percent of soybeans and 60 percent of corn produced by the United States goes to feed our livestock.
Now that we got all that out of the way. Keep reading to see all the pros and cons we could find from single-crop farming.
Advantages of Monoculture Farming
The crop type selected by the farms will play to the natural advantages of the local climate and its soil conditions. By using proper selection methods, farmers reduce their chance of having weather conditions impact the yield of the crop.
Farms in the U.S and Canada commonly switch between corn and soy crops each year.
Soy is considered a nitrogen-fixing plant. It returns the nutrient to the soil. Corn, on the other hand, is essentially just a nitrogen stealer.
By alternating between these two crops, it helps to prevent over depletion of this vital nutrient and keeps our soil more healthy, reducing the number of fertilization chemicals needed.
Simplifies the Farming Process
The reduced complexity of raising a single crop is also proving to be highly beneficial to the farming process. Farms only need to learn about and take care of the specific needs of a single plant. Nutrient deficiencies are much simpler to notice and correct.
The farmer will not run into situations of plants requiring different nutritional mixes. So they can mix up one batch of fertilized water to feed the entire crop. Automating the watering of the fields is also now possible.
Easier Pesticide Selection
When the use of pesticides is required, you only have to find a type that will not harm one plant type. Only having to worry about one plant makes it easy to find suitable Pesticide/Herbicide.
Speeds up the Planting of the Crop
Since monocultures use a uniform crop determining the spacing to plant the seeds between one another can be easily calculated maximizing space use. Equipment only needs to be configured once and then can prepare the entire garden bed.
The farmers can then use a seed planting device to walk the fields depositing each seed in the ground. Knowing each plant will get optimal space it requires.
For people looking to maximize the yield of their crop, monocultures allow precise placement of plants.
Knowing how the crop will grow, there is less chance of plants overcrowding each other.
For some crops like grapes, overcrowing can results in mold problems next. Once mold sets in, it can be disastrous to the final usable yield.
Caring for the crop is significantly easier as any nutrient deficiencies are likely to appear in a large majority of the plants. The uniformity allows farmers to identify problems quickly. Quickly reacting to the crops problems ensures it can get the chance to grow to its full genetical potential.
By focusing on crops that can fetch the highest price with the smallest use of their land area can help farmers increase their profit margins.
From their perspective, it would make the most sense to focus on just this one crop type only.
Reduce Workforce Requirments
Because all of the agriculture equipment can get optimized to the specific crop, a large amount of the process can now be automated.
From placing the seeds, watering the fields, and even harvesting the end product machines can be included to reduce the amount of human work required to get performed.
Disadvantages of Monoculture
Why Are Monocultures Bad
Weaker Against Insect Attacks
If you have two fields(one monoculture, one polyculture) walk away and leaving them to their own defenses, the monoculture filed will attract a significant amount of more pests.
By adding a mix of different genotypes of the same crop species with varying levels of nutrient requirements, you can help prevent attracting as many insects.
Different genotypes of the same crop help to add diversity for the crop. While still keeping the consistency of the final product that will get sent to the consumer.
More farms are currently utilizing this practice, planting four to seven hybrid types to manage field variability, disease, insect resistance, and harvest dates.
When only a single type of crop gets planted in the same soil, certain nutrients become depleted over time.
Different crops require a different ratio of minerals.
Reduced soil health also increases the number of fertilizers a farm needs to use to add the required nutrient levels back into the ground.
By alternating crops or growing many different variations at once, you reduce consuming any one specific mineral.
Current estimates put our average soil depletion rates on monoculture farms at greater than 13 percent. Unfortunately, this percent is larger than the maximum amount we can replace naturally.
Monoculture Farming And The Environment
High use of Fertilizers
Many polycultures use ground cover crops and plants like legumes(nitrogen restorers) to improve the nutrient content of the topsoil and keep soil health continually at optimal levels. While with monocultures, the soil will continually degrade year after year. The land will continue to grow a monoculture crop every year.
But the nutritional value of the produce collected slowly degrades over time(as shown with specific English wheat field soil samples).
Alternating with different crops is a simple way to help to maintain the integrity of the soil in two ways.
The first is the different nutrient requirements of each crop. If one year a high nitrogen crop is grown, the next should use a plant that requires a lower level or even nitrogen or even better nitrogen helpers like legumes.
Legume crops, like jack beans and velvet beans, contain specific bacteria in their roots. The bacteria helps to convert the nitrogen captured from the air into a useable form of nitrogen in the soil(a natural fertilizer).
Doing this could also help reduce the number of fertilizers that would need to get used on the farm fields later.
Ideally, we want the root depths of the different plants planted each year to vary. By choosing plants with varying root depths, it is easier for the soil to stay healthier. By choosing plants with varying root depths, it is easier for the soil to regain its nutritional values year over year.
Water And Air Pollution
Because pesticides and fertilizers get used on the fields, it is causing harmful effects on our environment.
Nitrogen fertilizers break down into nitrates that travel easily through the soil. Moving easily through the soil increases the chance of it contaminating our groundwater where it can remain for decades.
Even some fields that do not use any fertilizers are still finding high levels of nitrogen getting leached from surrounding fields that use them.
Pesticides will leach both into our soil and also to parts of the plants(most commonly their laves). Groundwater contamination has been linked to gastric cancer, birth malformations, hypertension, and stomach cancer. These chemicals can also find there way into our waters, causing problems for aquatic life. Wildlife that drink from these waters can also get harmed.
Bees, in particular, are suffering from the mass use of monoculture agriculture practices.
Bee colony collapse caused by pesticides(used by many monocultures) has been rated as there number one cause.
A large amount of water is needed to irrigate the crops properly.
Since monocultures do not use any ground cover crops(more are starting to), they quickly lose large quantities of topsoil moisture, especially on a dry, hot sunny day.
All the water loss requires these fields to get watered many more times than their polyculture counterparts.
Fossil Fuel Reliance
Because of the scale of these farms and the amount of machinery used in the automation, they generally have a heavy reliance on fossil fuels.
The sorting, packaging, and transportation(from local to internal produce) will also require large amounts of energy.
The industrial model we currently use is resulting in high levels of greenhouse gas emissions because of this.
Over Production of Crops
The Marketing Loan Program states that if prices on certain crops fall below a specific price point, farmers will get reimbursed from the U.S. government.
With the addition of the policy, it has caused farmers to continue increasing production of specific crops.
In 1996 the soybean price point increased from $4.92 to $5.26 a bushel. As a way to capitalize on this, farmers planted an additional 8 million additional acres of soybeans. All this increased production caused the soybean market price to fall by approximately 30 percent. Despite this price drop farmers made significantly more money since the reimbursement program still paid them at a higher rate.
Because of these conditions, overproduction of certain crops will continue to happen. Overproduction causes market saturation and artificially lowers the price.
Unfortunately, it is not just GMO fields using this method either.
Many organic farms have seen the benefits Monoculture Farming has to offer. So now, many large scale organic farms are also starting to focus on larger areas with a single crop type.
Luckily most smaller organic farms will grow a more substantial variety of plants mixed in together.
More massive Industrial Monoculture Farms are also now commonly adopting the technique of using ground cover crops.
Many North American farms will use a variation of the monoculture technique where they will cycle between 2 or 3 crop Types. So the first year they might grow nothing but corn, the next nothing but soybeans, etc.
Each year the crop they grow will also use 4 to 7 different genetic variants of the same plant.
The rotation of different crops is to help prevent some of the adverse effects observed in England’s soil where Monoculturing gets used.