The Danger of Monocrops: Lessons from the Irish Potato Famine

crop duster field from shutterstock.com

This blog post was written by Margaret Riche, our Hunter College Public Service Scholar, in Spring 2012 - we rerun it today because it's such a great post. See our weekly series, Real Food Right Now and How to Cook It, for more on potatoes, and that other Irish favorite, cabbage.

Every March 17th, in honor of St. Patrick’s Day, some 80 million Irish descendants, scattered in countries all over the world, celebrate the heritage and history of their ancestors, making this once Catholic holiday a global celebration of Irish national culture. As one of the 12% of Americans who claim Irish ancestry, each year around this time, I find myself reflecting on the stories of my great-great grandparents and their difficult emigration aboard the perilous coffin ships to America. What would motivate someone to embark on such a dangerous journey, away from everything they knew and loved?

In a word, hunger.

While each immigrant story is different and contains its own unique lessons for modern life, in the case of the Irish Diaspora, one of the most useful takeaways lies in the tragic role that unsustainable agricultural practices played in leading to the mass starvation and exodus of the Irish people. Although it’s widely recognized that the Potato Famine of the 1840s was a significant cause of Irish emigration in the 19th century, its relevance in today’s world might be less obvious. However, an examination of the practice (and inherent dangers) of monocropping, which left the Irish potato so critically vulnerable to disease, paints a frightening portrait of the precarious position of many of the major crops grown today.

Much like modern day agricultural struggles, our understanding of this event is incomplete without a discussion of land acquisition and power, for monocropping – the practice of planting the same crop year after year on the same plot of land without rotation – was a last resort for the struggling Irish peasantry.

The story begins with the restrictive penal laws imposed by Great Britain, which occupied Ireland  and discriminated against Irish Catholics and prohibited them from owning and leasing land. While these laws were repealed by the Catholic Emancipation of 1801, the (generally Protestant) landowners were predominantly interested in raising cattle and grain and often refused to give up their land. British colonization transformed much of the Irish countryside from tillage plots to grazing land in order to satiate the British demand for beef.

Before being forced onto smaller plots of less desirable land and working for subsistence wages, Irish farmers grew a diversity of crops that often included barley, oat and flax. But left with limited resources, farmers increasingly relied on the hardy potato, which would grow in less favorable soil, was nutritionally adequate and could be grown in large enough quantities to feed an entire family on an extremely small amount of land.

While the potato itself is very diverse (three thousand varieties are found in the Andes Mountains alone), the Irish peasants relied on only one variety, the “lumper.” Genetic diversity was also limited because potatoes reproduce from enlarged underground roots called tubers, an asexual form of reproduction equivalent to cloning. Introduced as a garden crop by the landowning gentry, by 1840 the lumper was the dominant harvest for the entire country, and the sole significant source of nutrition for about 3 million people.

In August of 1845, a water mold called Phytophthora infestans (named from the Greek, “plant destroyer”) traveled across the Atlantic to the South of England and then to Dublin. The disease, which was later traced to the Toluca Valley of Mexico, had already decimated crops in North America. Carried by spores on the wind, the pathogen spread across Ireland and produced a symptom known as “blight,” which reduced hectare after hectare of Irish farmland into an odorous black rot, transforming the precious potato into inedible slime. The suffering that followed was monumental, with one in eight dying of starvation in the three years following 1845. Irish Catholic farmers often couldn’t pay their landlords and were evicted. Disease was rampant, with nutritional deficiencies weakening immune systems, and the desperate poor often contracting typhyus and cholera after eating rotten produce. Left with little to no recourse, hundreds of thousands flocked to crowded workhouses, neighboring countries and, like my great-grandparents, across the ocean to the Americas.

One of the bitterest truths about the Great Famine is the fact that it was avoidable. Unfortunately, we have not learned the lessons of history and monocropping is not a practice of the past; today, industrial agriculture employs vast monocrops with increased dependence on pesticides and synthetic fertilizers. The three most popular crops grown in the US – corn, soy beans and wheat – are all grown using the monocropping method. Farmers who plant these crops receive huge subsidies from the US government, and their crops end up in a vast array of products (and to feed livestock).

It’s a huge blow to biodiversity to monocrop large tracts of land season after season, but that is exactly what we're doing, and our food security is at risk because of it. The soil is being eroded and depleted of nutrients by overuse, producers rely increasingly on hazardous pesticides and synthetic fertilizers and crops are increasingly vulnerable to disease and natural disasters.

Looking to the future, there are many possible ways to create a sustainable and secure food system. The organic farming practices of biodynamic agriculture and permaculture, which use natural ecology as a guide, hold great promise for creating regenerative systems that are significantly less vulnerable to disease. A diverse food movement, comprised of rural and urban farmers, locavores, community gardeners, animal welfare advocates, CSA members, food professionals and concerned eaters is working to establish a sustainable, safe and equitable food system. As our momentum increases, so too do the possibilities, for as the old Irish proverb tells us, “Many a sudden change takes place on a spring day.”

Responses to "The Danger of Monocrops: Lessons from the Irish Potato Famine"

  1. Leslie Stempel

    Well written article, very informative. In China and other Asian countries the main crops are rice and soy. For years these crops have been a major food source. I wonder in years to come how the soil will be affected by planting only these crops and population growth

Leave a Comment

Comments are moderated and generally will be posted if they are on topic. You represent that comments submitted do not infringe upon anyone's rights including copyright, trademark, privacy or other personal or proprietary rights.


We need to make sure you're a human and not a spambot. Please answer the following question. What is 2 - 19 equal to?

By submitting a comment here you grant us a perpetual license to reproduce your words and name/website in attribution.