Comparing Fertilizer Hypotheses

In an experiment to determine the effects of fertilizer on crop yield, two scientists, Dr. Smith and Dr. Jones, presented different hypotheses. Dr. Smith hypothesized that increasing nitrogen levels in fertilizer would enhance crop yield significantly. Conversely, Dr. Jones proposed that using organic fertilizers would have a more beneficial effect on crop yield compared to synthetic fertilizers.

Which hypothesis is primarily focused on the type of fertilizer used, rather than the nutrient levels it contains?