An agricultural researcher investigated the growth of sunflower seedlings (Helianthus annuus) in sand culture irrigated with different mineral formulations. Three batches of seedlings, each starting with a mean dry mass of 0.12 g, were grown under identical light and temperature conditions for 21 days.
The table below outlines the growth results for each batch:
| Batch | Nutrient solution supplied | Mean dry mass at start in g | Mean dry mass after 21 days in g |
|---|---|---|---|
| X | Complete Hoagland's solution | 0.12 | 1.85 |
| Y | Nitrogen-free solution | 0.12 | 0.35 |
| Z | Magnesium-free solution | 0.12 | 0.62 |
Explain the differences in the growth (measured as mean dry mass) of Batch X compared to Batches Y and Z.
