Monocultures are large areas of land on which only one type of plant is grown. There are tree monocultures as well as crop monocultures. There are dangers associated with this approach to agriculture, especially environmental ones.
1. A monoculture is very vulnerable. It can be wiped out completely by one virus, fungus, destructive insect, or other disease. A farmer could lose his or her entire crop – and income – to one microbe.
2. Monocultures encourage more diseases, weeds, and destructive insects. These pests build resistance to the changeless nature of a monoculture, and their life cycles are never interrupted.
3. Because the natural resistance is so low in a monoculture, farmers must use greater and greater amounts of synthetic pesticides and fungicides to keep their crops alive and yielding. The environmental and health impacts of this kind of copious use of agrichemicals are significant.
4. Nutrients become depleted in soil that is used to grow only one type of crop year after year. Thus, farmers must step up the chemical fertilizers to keep getting crop yields.
5. The recent decline in honeybee populations has caused many to cast a critical eye on monocultures as a possible causal factor. Honeybees are prime pollinators, and only having one type of flower from which to gather pollen is completely unnatural (vast monocultures do not occur in nature).
Research in the UK has recently shown that bees’ immune systems need a variety of pollen sources to stay healthy. This theory does seem to hold water – it is well known that animal species of all sorts benefit from a varied diet. How healthy would you be if you ate only one food all the time?
Monocultures make heavy use of pesticides, exposure to which is implicated in the honeybees’ demise.
6. Erosion is a concern with monocultures. This is because the soil is so lifeless, and because there is no ground cover planted.
The Benefits of Crop Rotation
When crops are rotated, nutrients are replenished. It is recommended that farmers rotate nitrogen-producing crops such as legumes with nitrogen-using crops such as corn. There are other benefits as well.
- Rotated crops produce higher yields.
- The use of agrichemicals is reduced as plant disease and pest resistance increase.
- Erosion is decreased, especially when cover crops are grown with the main food crop. Farmers can also grow crops on legume sod, the roots of which hold the soil together and produce nutrients as they decay.
Monocultures simply do not occur in nature. That alone ought to give us pause as we consider how best to produce the food that feeds the world.