Monocultures

Monocultures refer to the mass cultivation of a single species of organism, or the cultivation of a species with little to no genetic variation within the group.

Why it matters

Humans have been growing fields of the same crop for centuries, whats the big deal?

Much of humanity's agricultural practices are rooted in efficiency and production, as well as habit. However with a rapidly changing global climate it is vital for our continual health to evaluate the strengths and weaknesses of our current food production systems.

While fertilizers and pesticides work in the short term, critical evaluation of the sustainability of modern agriculture enables better food security for years to come.

BIODIVERSITY

When measuring the nature of ecosystems, ecologists often use the word biodiversity to quantify and describe the variety of living things in any context. This diversity can refer to variations within a species. or even the variety of species in an ecosystem.

Generally, conservation research seeks to find ways to preserve the biodiversity of any habitat. This is because human intervention has led to a significant decline in the number of species worldwide. It is estimated that anywhere from 30-50% of all land on Earth has been modified by humans²². Resource exploitation, pollution, and introduction of non-native organisms have all contributed heavily to this statistic.

Biodiversity and Agriculture

When comparing levels of productivity to biodiversity many researchers find a positive correlation. This is not universal for all environments however, but studying what enables an environment to be productive is vital for optimizing agricultural practices. Especially as the world’s natural resources continue to diminish.

Current mainstream agricultural practices utilize large populations of plants with little diversity to maximize production. Given what is known about nutrient cycling and with data collected from field soil samples, current agriculture has had a tremendous toll on natural resources¹⁸²⁰. This fertilizer then is washed away as run off, causing a myriad of harmful effects such as algal blooms¹⁹. These blooms then have the potential to cause mass die-offs and even harm humans¹⁹. Alternate solutions are in short supply, but assessing the cost and benefits of moving to polycultural systems can mitigate the issue of resource exploitation.

Nutrient Cycling

Nutrient cycling the movement of vital molecules necessary for different aspects of life through a local or global ecosystem. This process describes how nitrogen, phosphorus, carbon, potassium, and many other atoms move through the soil, rivers, oceans, plants, animals, and air. In a stable ecosystem these nutrients are for the most part recycled or diminished and replenished through any variety of factors. Human disturbance has shifted the cycle of nutrient flow, removing nutrients from many ecosystems and introducing more nutrients to others¹⁸¹⁹. This can occur on purpose or accidentally, and also includes the introduction of non-native species which utilize or excrete nutrients in a way that alters the ecosystem¹⁵.

Fertilizer and animal manure run off are the primary sources of nutrient pollution in the US. Safely managing this run-off and reducing the need and production of pollutants may find their solution in polycultural systems. Often the most limiting nutrient in fields is soil nitrogen, which is a large component of industrial fertilizer. Cycling through, or growing at the same time, “N-fixing plants” offers a promising alternative that is often used in many farms⁵. The process relies on a plant species that harbors nitrogen-fixing bacteria that can convert atmospheric nitrogen into soil nitrogen. Most plants cannot utilize atmospheric nitrogen so nitrogen-fixing plants yield a promising solution to nutrient pollution if implemented on a larger scale.

Risks

Given the history of large scale crop failure, the current dependence on large scale farms is a disaster waiting to happen.

The most commonly cited mass famine is often the 1845 Irish Potato Famine. Over the course of seven years an organism known as P. infestans demolished half of the vital potato crop. This in turn lead to the starvation and dealth of over a million people, with another million leaving their home as refugees. In the US, corn accounts for over 95% of all feed grain produced and used. While it is unlikely an event as severe as the Irish Potato Famine will occur anytime soon, destruction of this feedgrain has the potential to send millions of farmers in to debt and impact the global economy.

Another mass blight is currently observed in Colombia with the fungus Fusarium. This fungus infects bananas and its spores hide in soil where they remain for decades. The Gros Michel banana strain was already wiped out in the 1950s by this fungus. Current banana production relies on Cavendish clones, which have already been show to easily succumb to the blight. The lack of genetic diversity between each banana clone is thought to be the leading contributor in these infectious outbreaks.

The 2020 Coronavirus pandemic serves as a reminder that the potential for wide spread disease is ever present and rarely 100% predicable. Current farming practices utilize risk and reward, which has the potential to cause disaster at any given time.