Agriculturalists investigating cereal crop yields in controlled environments often use specialized liquid fertilizers containing essential macronutrients. The table below shows the crop yields obtained (expressed as a percentage of the maximum yield with all three nutrients present) when one of the three major nutrients—nitrogen, phosphorus, or magnesium—is omitted from the nutrient solution.
| Crop | No nitrogen | No phosphorus | No magnesium | All three added |
|---|---|---|---|---|
| Wheat | 48 | 65 | 78 | 100 |
| Barley | 42 | 68 | 81 | 100 |
| Oats | 52 | 60 | 75 | 100 |
| Rye | 46 | 72 | 84 | 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 magnesium?
A farmer grew another batch of wheat. With all three minerals added, the maximum yield obtained was 16 kg per m2. When grown with no nitrogen, the yield was 7.68 kg per m2.
Calculate the yield with no nitrogen as a percentage of the maximum yield. Show your working.
