Certified Crop Advisor Practice Exam

Which of the following concepts of fertilizer recommendations increases soil fertility level most slowly?

1. Crop response

2. Crop sufficiency

3. Maintenance

4. Maximal yield

The correct answer is: Crop sufficiency

The concept of crop sufficiency focuses on providing the minimum amount of nutrients necessary to achieve adequate crop performance, which means that it prioritizes maintaining a level of soil fertility that is just sufficient for crop growth rather than enhancing it significantly beyond that point. This approach results in slower increases in soil fertility levels because it does not aim to build up nutrient reserves in the soil. In contrast, concepts such as crop response, maintenance, and maximal yield often require more aggressive fertilization strategies or practices that actively seek to improve soil fertility. For instance, crop response methods analyze how crops react to various nutrient levels and often involve applying fertilizers to optimize yields, thereby potentially increasing soil fertility more rapidly. Maintenance is about keeping nutrient levels at a stable point, while maximal yield focuses on applying fertilizers to achieve the highest possible crop production. Both of these approaches typically result in more significant and quicker boosts to soil fertility compared to the more conservative strategy of crop sufficiency.