Here are why
Adding NPK fertilizer (Nitrogen-Phosphorus-Potassium) to the soil fundamentally alters the nutrient balance within the soil ecosystem. While the primary intention is to provide plants with the essential nutrients they need for growth, this action can also inadvertently affect plant health in ways that make them more susceptible to pests for several reasons:
1. **Rapid Growth**: High levels of nitrogen can lead to lush, rapid plant growth. While this might seem beneficial, it can actually weaken the plant. The rapid growth can result in softer, more succulent tissues, which are easier for pests to penetrate and feed on.
2. **Nutrient Imbalance**: Over-fertilization with NPK can lead to an imbalance in the plant’s nutrient uptake. An excess of certain nutrients can inhibit the absorption of others, leading to nutrient deficiencies. Plants with nutrient imbalances or deficiencies may be more stressed and less able to defend against pests and diseases.
3. **Attracting Pests**: The lush growth induced by high nitrogen levels can also make the plants more visible and attractive to some pests. Additionally, the excess nutrients can be exuded through the plant’s roots or leaves, attracting soil pests and foliar pests, respectively.
4. **Disruption of Soil Ecology**: Fertilizers can alter the microbiome of the soil, affecting the balance of microorganisms that could otherwise help to suppress pest populations. By disrupting these beneficial microbial communities, fertilizers might inadvertently promote conditions that favor the proliferation of pests.