Pesticides is an umbrella term for a multitude of chemicals like herbicides, insecticides, and fungicides that helps farmers control pests and weeds. In agriculture, herbicides make up 80% of all pesticide use. Pesticides allow farmers to protect their crops from pests that could potentially carry diseases. However, these chemicals also have many disadvantages as they are incredibly toxic to humans and other species and have caused extensive environmental damage.
Pesticides aren’t a recent invention. Humans have been protecting their harvests with the use of pesticides as early as 4,500 BC. Early Mesopotamian farmers implemented sulfur to dust their plants to deter pests and weeds. In 4,000 BC, some ancient peoples adopted poisonous plants to aid in ridding their fields of pests.
The first toxic chemicals emerged around the 15th century, when farmers applied arsenic, mercury, and lead to plants. In the 17th century, nicotine sulfate from tobacco leaves was discovered to be an effective insecticide. And, in the 19th century, chemicals derived from tropical vegetables were made available to farmers.
Arsenic-based pesticides remained the choice of farmers until the 1950s when DDT emerged on the market. However, after just 15 years, DDT was replaced by organophosphates and carbamates. Since 1975, pesticides derived from pyrethrin compounds have remained the dominant choice.
Until the first decade of the 20th centuries, pesticides were mostly unregulated. In 1910, the first legislation in the US passed, but in the next 30 years, the manufacture and sale of these chemicals became more widespread than before. The years between 1940 and 1950 are considered the start of the “pesticide era,” and despite the creation of the EPA and amendments to the pesticide law, the use of these substances has increased 50-fold.
Every year, 2.3 million tones of pesticides are used on farms across America. Developed countries account for 75% of the world’s pesticide use, though that percentage is growing in developing countries as well. This will only prove to be a detriment for climate change, and further endanger the habits of species across the globe while simultaneously affecting humans, whether they realize it or not.
Other methods can be used to rid crops of pests and weeds. The downside is that these practices are time-consuming and at times, less effective than using chemicals. However, they are much safer and guarantee minimal environmental impact.
The first is hand picking. It is considered the most effective method, but it also requires the most amount of work. Hand picking is beneficial because it allows farmers to inspect each plant individually and asses their needs. If there are pests, they can be brushed or disposed of.
The second method is using barriers and traps. Sticky traps are useful for tracking insect populations. Slug traps are a humane way to prevent them from getting to plants. Or, using newspapers or tarps to cover the soil around the plants prevents pests from burrowing to lay eggs that will then emerge as new bugs. Using a row cover allows sunlight, water, and air to reach the crops while shielding them from pests.
A natural pesticide is diatomaceous earth or DE. DE is a soft sedimentary rock that, when crushed, is similar in touch and appearance to talcum powder. When exposed to insects, they will die within 3-5 days. Additionally, a naturally-occurring bacteria called Bacillus thuringiensis, which is harmless to people, is an extremely helpful deterrent against different types of pests, depending on the strain used. Depending on the strain, Bt will only affect one kind of pest without harming others that come into contact with the bacteria.
Trap crops are plants that are purposefully planted to attract pests away from the main crop. It is a form of companion cropping. Examples of trap crops include alfalfa, mustard, and rye. Trap crops can be poisonous to bugs or prevent them from mating and spreading to other plants. Lastly, crop rotation can be used to disrupt the breeding cycle of pests. Alternating a variety of crops in the same fields prevents pests from using it as a breeding ground.
It is unclear if pesticides will ever truly be eradicated from traditional farming. Many farmers rely on it as a cheap and easy way to protect their fields. However, thanks to innovative agriculture, food can be grown in mass quantities without the use of chemicals. Hopefully as the trend of innovative agriculture grows and concern of the harmful effects of pesticides grows among consumers, it will become a thing of the past.