After a rainfall, muddy water containing fertilizers and pesticides flows into waterways. Tim McCabe/USDA
What is it?
Growing crops, raising animals, and transporting and processing food products all fall under the essential aspect of agriculture, key to supporting the global population of eight billion (Worldometer, 2022). In order to keep up with the growing number of mouths needed to feed, as well as to improve efficiency, farmers use fertilizers and pesticides on their crops. Meanwhile, livestock create tremendous amounts of emissions. Altogether, if overused, these agricultural practices are harmful to the environment since they emit high amounts of pollutants. Unlike the typical types of pollution one may usually imagine, such as air pollution, agricultural pollution is created from an excess of nutrients in soil and water, and nutrients are not often considered as detrimental. Nevertheless, too much nitrogen and phosphorus concentrated in certain locations can have destructive consequences, yet not enough individuals realize to take sufficient action.
Why is it happening?
Agricultural pollution derives from a range of different sources, prominently through the application of nutrients onto farmers’ fields in the form of chemical fertilizers and animal manure. To begin, the widespread use of nitrogen and phosphorus-based fertilizers has allowed farmers to overcome the issues caused by monocropping and to consistently produce enormous yields of crops, but is considered to be one of the most significant sources of soil and water pollution. Nitrogen and phosphorus themselves are essential elements to all living organisms because they are a major part of amino acids, which form the proteins and genetic material that make up life. Replenishing the naturally occuring nutrients in farmland after the depletion of them due to planting the same crop year after year, which is known as monocropping, is an artificial process that damages the natural balance of nutrients in soil.
As the excess nitrogen makes its way into the atmosphere and reacts with bacteria to form nitrous oxide (N2O), one of the greenhouse gasses responsible for global warming, it can create smog that is harmful to other organisms, including human beings. Moreover, when plants do not fully absorb the abundance of nitrogen and phosphorus, these minerals are washed away from farm fields into water sources, including rivers, lakes and oceans, by precipitation, and can also leach through the soil and into groundwater over time. This continues setting a domino effect, as the process of eutrophication is achieved, and algae blooms thrive from the high concentrations of nutrients. Since the overgrowth of algae consumes most of the oxygen in water, as well as blocks the sunlight from reaching the underwater ecosystem that relies on it for energy, fish and other aquatic wildlife die off.
Furthermore, as the world’s consumption of meat grew from an average of 44 pounds per person each year in 1961 to 225 pounds of red meat and poultry per person annually in 2022, raising livestock has continued growing (Lindwall, 2022). The amount of animal manure in many farms attains the point where there is too much to fully use on fertilizing crops, nearly 1.4 billion tons of manure annually in the United States (Lindwall, 2022). Nevertheless, there is nowhere else to leave that accumulation, so an excess of animal waste is often applied beyond the ground’s natural absorption rate, contributing further to nutrient runoff into water sources.
In spite of all the disastrous effects of overusing fertilizers, farmers tend to continue employing the same processes since the low price of fertilizers results in massive yields and more income for them, and there still exists a lack of access to alternative solutions in developing countries. There is also an overall lack of awareness on this global issue because most of the population now lives in urban cities, where no one worries about agriculture. As always with complex environmental issues, individuals tend to stay with their current practices, until the day comes when the harmful effects of their actions are revealed and often it is too late to make a change.
Who is affected?
Although we are the ones creating this pollution, we aren’t the only ones feeling the effects of it. Animals are taking a significant blow compared to us. They are digesting these fluids from polluted waterways, which harm or kill them. Agricultural runoff can also cause algal blooms which deplete oxygen levels and kill aquatic animals. However, aquatic habitats aren’t the only area being effected, but land too. In fact, researchers have discovered that out of 41 grassland communities, the presence of fertilizer greatly weakened the biodiversity.
There are multiple alternatives to fertilizers that are being developed. Some natural alternatives include tree leaves, lomi dirt, weeds, egg shells, coffee grounds, manure, fish and more. Tree leaves can be tilled mixed, and then used as mulch. Lomi dirt is dirt created from food waste, which can be created through an electric composter known as Lomi. Weeds have large amounts of nitrogen within them, which support plant growth and can balance moisture within. However, they can become a nuisance if new weeds begin to grow. Egg shells contain lots of calcium , which can nourish plants and ensure a neutral soil acidity. Coffee grounds are used for the opposite, they increase the acidity of soil, but this can be useful for some crops. Manure is also a well-known alternative as it’s high in nitrogen and other nutrients. Fish scraps have actually been used to aid in plant growth for years. They’re packed with nitrogen and certain beneficial minerals. Finally, researchers have been using artificial intelligence, machine learning, and quantum computing to detect better fertilizer alternatives. If we wish to save the planet, fertilizers will need to evolve.