What can excessive nitrogen lead to in crops?

Excessive nitrogen in crops can lead to increased susceptibility to pests for several reasons. When nitrogen levels are too high, plants may produce an abundance of leafy growth at the expense of other structures, such as roots and flowers. This lush foliage becomes more attractive to certain pests, as they thrive on the ideal growing conditions nitrogen promotes.

Furthermore, overly nitrogen-rich plants tend to have weaker structural integrity, making them more vulnerable to pest infestations and diseases. An imbalance in nutrient levels can also disrupt the plant's natural defense mechanisms, weakening its ability to resist pest attacks.

The other options represent potential issues related to nutrient management, but they do not directly relate to the effects of excessive nitrogen as clearly as increased susceptibility to pests does. For example, improved fruit quality typically results from balanced nutrient levels, not excessive nitrogen. Decreased water retention is more often tied to factors like soil structure or moisture conditions rather than a high nitrogen content specifically. Finally, a deficiency of potassium can occur due to various nutrient imbalances, but excessive nitrogen itself does not directly cause this deficit; rather, it can create a competitive environment where potassium becomes less available to the plant. Thus, the link between high nitrogen levels and increased susceptibility to pests stands out as the primary concern.