A vegetable grower tested three schedules for applying fertiliser to cabbage plants.
Each schedule supplied a total of 120 kg of fertiliser per hectare. The same variety of cabbage was planted on each plot on the same date. Drainage water was collected from the plots until the cabbages were harvested.
The table shows the results.
| Schedule | Timing of fertiliser application | Yield of cabbages in tonnes per hectare | Mean nitrate concentration in drainage water in mg per dm³ |
|---|---|---|---|
| A | 120 kg per hectare six weeks before planting | 31.2 | 14.0 |
| B | 120 kg per hectare when the cabbages were planted | 36.8 | 9.0 |
| C | 60 kg per hectare when planted and 60 kg per hectare four weeks later | 39.5 | 5.0 |
Describe what the results show about splitting the fertiliser application, rather than applying all of the fertiliser at one time.
A 12-hectare cabbage field produces 250 000 dm³ of drainage water per hectare during the growing period.
Calculate how much less nitrate would enter the drainage water from this field using schedule C rather than schedule A.
Give your answer in kg.
1 kg = 1 000 000 mg
The drainage water from the cabbage field enters a lake.
Explain how using schedule C rather than schedule A could affect the number of fish in the lake.
100 exam-style questions on Edexcel GCSE Biology 4.3 Selective breeding and genetic modification, covering 4.3.1 Selective breeding and its impact, 4.3.2 Tissue culture, 4.3.3 Genetic engineering overview, 4.3.4 Main stages of genetic engineering, 4.3.5 Advantages and disadvantages of GM organisms, 4.3.6 Agricultural solutions for a growing population, and 4.3.7 Evaluating genetic engineering and breeding. Each one has a worked solution and a mark scheme showing where the marks go.