Permaculture gardening promotes biodiversity. It seeks to maximize the number of productive species of plant within a plot, not only to offer the gardener a diverse and vibrant number of crops to harvest for the kitchen, but also so that the ecosystem is itself is strong, with different plants performing different functions so that all can thrive. Permaculture design seeks to avoid any one thing – be it a species of insect, a ground cover plant or an extreme weather event – becoming too influential on a site, to the detriment of the other valuable parts of the ecosystem.
In contrast, much modern agricultural production is based on the opposite premise – cultivating monocultures. Think of vast fields of wheat or barley, plantations of a single species of fruit tree, or furrowed fields of a single vegetable crop. Modern commercial agriculture often seeks to increase yield – and so profits – by cultivating a single type of plant. The theory is that the farmer need only provide for the needs of a single species, with its individual characteristics, in order to grow a successful crop. And the economy of scale allowed by cultivating a single crop (by, for instance, requiring a single automated harvesting method) boosts profits for the farmer.
However, monoculture agriculture has significant negative impacts, impacts that must be alleviated if the ecological systems of the earth are not to be irreversibly damaged.
Eliminates Biological Controls
The lack of diversity in a monoculture system eliminates all the functions that nature provides to plants and the soil. It means that there is no range of insect species in a location to ensure that a single population does not get too large and damage too many plants. It means that there are no varieties of plant that naturally provide nutrients to the soil, such as nitrogen-fixing legumes, or ground cover crops that can be slashed and left to improve the nutrient content of the topsoil. It means that there are fewer species of microorganism and bacteria on the soil as there are fewer nutrients available for them to survive on, and it undermines the integrity of the soil by not having a variety of plants with different root depths.
More Synthetic Material Use
Having eliminated the natural checks and balances that a diverse ecosystem provides, monoculture production has to find ways to replicate some of them in order to protect the crop (and the profits from it). This inevitably means the use of large quantities of synthetic herbicides, insecticides, bactericides and fertilizers.
In attempting to prevent damage to crops by weeds, insects and bacteria; and to provide sufficient nutrients in the soil for the plants to grow, farmers use synthetic chemicals. Not only do these chemicals leave traces on plants that are intended for human consumption and so can enter the food chain, they are also routinely over-used so that a large proportion of the synthetic material remains in the soil, even after the crop has been harvested. Because of its inorganic mature, this material is not processed into organic matter by microorganisms. Rather it leaches through the soil, eventually polluting groundwater supplies, having the knock-on effect of altering ecosystems that may be at great distance from the original location where the chemicals were used. For instance, inorganic fertilizer runoff has contributed greatly to algal blooms in oceans and lakes, the growth of which starves water bodies and the organisms that live in them, of oxygen.
Furthermore, such chemical substances kill indiscriminately, meaning that all manner of wildlife, beneficial insects and native plants are affected by their use, depleting the vibrancy and diversity of neighboring ecosystems as well.
Changing Organism Resistance
Nature is, however, adaptable, and organisms are evolving resistance to these artificial insecticides and herbicides. Of course, the farmers want to continue to protect their crops, so new inorganic methods are continually being developed to combat the ‘threat’. More and more chemicals are being applied to monoculture crops and, in turn, affecting natural ecosystems detrimentally.
Besides the negative impact the overuse of chemical fertilizers has on the soil, monocultures are detrimental to soil health in other ways. Ground cover crops are eliminated, meaning there is no natural protection for the soil from erosion by wind and rain. No plants provide leaf litter mulch to replenish the topsoil, which would be eroded anyway. All of this combines to continually degrade the soil, often meaning that it becomes useable for agriculture. In some countries this means that forests are then cleared to provide new agricultural land, starting the damaging cycle all over again.
With no ground cover plants to help improve moisture retention in the soil, and the tendency for land planted with a monoculture to lack topsoil, which serves to increase rain runoff, modern monoculture agriculture requires huge amounts of water to irrigate the crops. This means water is being pumped from lakes, rivers and reservoirs at great rates, depleting this natural resource and affecting those aquatic ecosystems. This is on top of the pollution of water sources by agricultural chemicals.
Due to their scale, many modern monoculture farms are more akin to factories than traditional farms. Harvesting is generally performed by machines while, because the crop is intended for sale beyond the local area – sometimes nationally or even internationally – it requires large inputs of energy to sort, pack and transport it. These functions – along with the manufacture of packaging itself – use fossil fuel energy. In combination with the chemical fertilizers and pesticides, the industrialized mode of food production is a major contributor to climate change. It is also an incredibly inefficient way of using energy to produce food, taking an estimated 10 calories of fossil-fuel energy to produce just a single calorie of food energy.
At its simplest level, monoculture agriculture means a system that works against nature. Permaculture, however, seeks to work in harmony with nature. By putting permaculture practices in place, we can help to combat the harmful effects modern monoculture agriculture has on the planet.