In arid regions, agricultural yields have historically been limited more by phosphorus availability than by nitrogen availability. Certain desert shrubs, such as the creosote bush, exude organic acids from their roots that convert insoluble rock phosphates into a bioavailable form. Consequently, soil samples taken from the immediate vicinity of these shrubs show significantly higher concentrations of bioavailable phosphorus than soil from open areas just a few meters away. Nonetheless, agricultural crops planted directly adjacent to creosote bushes typically exhibit severely stunted growth.
Which one of the following is most strongly supported by the information above?
- AThe organic acids exuded by creosote bushes are directly toxic to most agricultural crops.
- BMost plants native to arid regions are capable of converting insoluble rock phosphates into a bioavailable form.
- In arid regions, a high concentration of bioavailable phosphorus in the soil is not sufficient to prevent agricultural crops from exhibiting severely stunted growth.Answer
- DIf a crop in an arid region is not planted directly adjacent to a creosote bush, it will not exhibit severely stunted growth.
- EThe severely stunted growth of crops planted near creosote bushes is caused by a depletion of soil nitrogen.
Answer
In arid regions, a high concentration of bioavailable phosphorus in the soil is not sufficient to prevent agricultural crops from exhibiting severely stunted growth.
The correct answer safely synthesizes the facts that soil near creosote bushes has high concentrations of bioavailable phosphorus, but crops planted there still exhibit stunted growth. This strictly proves that having an abundance of bioavailable phosphorus does not guarantee healthy, uninhibited crop growth.
Step-by-Step Solution
Key Concept
Synthesizing premises to form a safe, limited inference while avoiding unsupported causal assumptions.