Certified Crop Advisor Practice Exam

Extensive use of which of the following soil amendments is most likely to induce K deficiency?

1. Aglime

2. Compost

3. Animal manure

4. Cover crops

The correct answer is: Aglime

The choice of aglime as the correct answer is attributed to its primary role in correcting soil acidity by increasing pH levels and providing calcium and magnesium. While aglime is beneficial for soil health, its application can affect the availability of other nutrients, specifically potassium (K). When aglime is used extensively, the increase in pH can lead to conditions that reduce the solubility and availability of potassium in the soil. High soil pH can attract more cations that compete with potassium, such as calcium and magnesium, thereby potentially leading to K deficiency in plants. In contrast, compost and animal manure generally provide a more balanced nutrient source, including potassium. They enhance soil organic matter and overall soil health, thereby improving nutrient retention and availability. Cover crops, while not typically a direct source of potassium, help improve soil structure, organic matter, and nutrient cycling, which can support potassium availability rather than induce deficiency. Therefore, the extensive use of aglime is most likely to create conditions leading to potassium deficiency in the soil.