Farmers growing greenhouse vegetable crops often use liquid fertilizers to maximize their crop yields. These fertilizers usually contain three major mineral nutrients: nitrogen, phosphorus, and potassium.
The table below shows the crop yields obtained (expressed as a percentage of the maximum yield with all three nutrients present) when one of these three nutrients is missing from the fertilizer.
| Crop | No nitrogen | No phosphorus | No potassium | All three added |
|---|---|---|---|---|
| Tomato | 42 | 75 | 62 | 100 |
| Cucumber | 55 | 82 | 68 | 100 |
| Sweet Pepper | 45 | 64 | 70 | 100 |
| Eggplant | 50 | 58 | 71 | 100 |
State the mineral nutrient that has the greatest overall effect on reducing crop yield when it is missing.
Explain why this nutrient has such a significant effect on plant growth and yield.
Based on the table, which crop is most affected by the lack of potassium?
A farmer grew another batch of tomatoes. With all three minerals added, the maximum yield obtained was 15 kg per m215\text{ kg per m}^215 kg per m2. When grown with no nitrogen, the yield was 6.3 kg per m26.3\text{ kg per m}^26.3 kg per m2.
Calculate the yield with no nitrogen as a percentage of the maximum yield. Show your working.
