The damage caused by chemical fertilisers is cumulative and long-term, therefore it is important to consider natural and sustainable methods of fertilising the soil.
Why use fertilisers?
We use fertilisers to increase the amount of nutrients in the soil, so that plants can grow. Typically present in fertilizers are one or more of the macronutrients nitrogen, phosphorus, and potassium - NPK. Any one of these is pretty much all a plant needs to grow, and do it fast.
There are two main types of fertilisers, organic and chemical. Organic fertilisers come from organic sources, such as, animal manure and plants. Chemical fertilisers come from inorganic materials, which undergo chemical treatments.
Chemical fertilisers allow farmers to produce more and high-quality crops in the short-term, but lead to fewer or poor quality crops in the long-term. The soil needs a balance of nutrients to remain healthy. While NPK can help plants and crops grow, simply adding them to the soil without keeping the balance can lead to big consequences.
Environmental issues caused by chemical fertilisers
One of the main environmental issues with chemical fertilisers is they leak through the soil into the groundwater and other water sources, leading to contamination. While NPK in small quantities is non-toxic, but a lot can disturb the balance of nature.
The dead zone
While nitrogen helps plants grow, it also creates a big problem. When it is in the water, it encourages the growth of plankton and other aquatic plants to excessive amounts. When they die, the process of decomposition eats up oxygen that fish and other aquatic animals need to survive. This disrupts the ecosystem of the area and the local fishing industry. Even when stopping the use of chemical fertiliser, nitrogen in the water can persist for many years, so it will continue to affect the environment even without adding more.
Nitrogen also contributes to the greenhouse effect. The main sources of nitrogen in the atmosphere in the form of nitrous oxide are power plants and cars, but using more nitrogen fertilizers than crop plants can absorb plays a significant role.
Acidic top soil
Chemical fertilisers can make the topsoil acidic, because nitrogen lowers the pH of the soil. If the soil is too acidic (pH lower than 5.5), it will yield less crops.
Human Health Issues Caused By Chemical Fertilisers
Lower Nutritional Value in Crops
Chemical fertilisers help plants to grow fast insead of them being healthy, resulting in crops with much lower nutritional value. Plants will grow on little more than NPK, but they will be missing or developing less of essential nutrients such as calcium, zinc, and iron. This can have a small but cumulative effect on the health of people that consume them.
Human health issues
Moreover, chemical fertilisers increase the risks of developing cancer in adults and children and adversely affecting fetal brain development.
Chemical fertilisers are cost-efficient and useful for short term, but they are also dangerous for both the environment and its inhabitants. Whether used on a farm or lawn, applying more than the plants can use to help them grow results in damage to the environment and human health. Because the damage caused by chemical fertilisers is usually long-term and cumulative, it may be wiser to consider natural and sustainable methods of fertilising the soil.