A scientist investigates how phosphate fertiliser, and the number of maize seeds planted per square metre, affect the yield of maize.
She adds different masses of phosphate fertiliser to fields containing different numbers of maize seeds, and measures the yield after a few months.
The table shows her results.
| Mass of phosphate fertiliser added in kg\text{kg}kg per hectare | Number of seeds planted per m2\text{m}^2m2 | Yield of maize in tonnes per hectare |
|---|---|---|
| 0 | 5 | 12.4 |
| 0 | 10 | 11.2 |
| 40 | 5 | 14.8 |
| 40 | 10 | 12.9 |
| 80 | 5 | 11.5 |
| 80 | 10 | 9.8 |
Identify the mass of fertiliser and the seeding density that produced the highest yield of maize.
Describe the effect that changing the mass of phosphate fertiliser has on the yield of maize.
Explain the effect that changing the number of seeds planted has on the yield of maize.
