How do fertilizers and pesticides affect crop yield?

Fertilisers and pesticides increase crop yield by providing essential nutrients and protecting crops from pests and diseases.

Fertilisers are substances added to the soil to supply essential nutrients that plants need for growth. These nutrients include nitrogen, phosphorus, and potassium, which are vital for plant development. Nitrogen promotes leaf and stem growth, phosphorus is essential for root development and flowering, while potassium aids in overall plant health and disease resistance. When these nutrients are deficient in the soil, plant growth is stunted, leading to reduced crop yield. Therefore, by replenishing these nutrients, fertilisers help to increase crop yield.

Pesticides, on the other hand, are chemicals used to kill or control pests that can damage crops. These pests include insects, weeds, fungi, and other organisms that feed on crops, reducing their yield. By killing or controlling these pests, pesticides protect crops from damage, thereby increasing their yield. However, it's important to note that excessive use of pesticides can lead to pest resistance, where pests evolve to become immune to the pesticides, rendering them ineffective.

Moreover, both fertilisers and pesticides must be used judiciously. Overuse of fertilisers can lead to nutrient pollution, where excess nutrients run off into water bodies, causing harmful algal blooms and depleting oxygen in the water, which can kill aquatic life. Similarly, overuse of pesticides can harm non-target organisms, including beneficial insects and other wildlife, and can also contaminate water sources.

In conclusion, while fertilisers and pesticides can significantly increase crop yield, their use must be carefully managed to minimise environmental harm.