Explain the role of fertilizers in farming and perform calculations related to crop productivity. Identify natural fertilizers from provided data.

Here are the answers to your questions: a) Explain why farmers need to use fertilisers. Farmers need to use fertilizers to replenish essential mineral nutrients (such as nitrates, phosphates, and potassium ions) in the soil that are absorbed by crops. This ensures that plants have sufficient nutrients for healthy growth, leading to increased crop yields and improved productivity, especially in intensively farmed areas. b) Calculate the % increase in productivity for ammonium nitrate. Step 1: Identify the productivity values from the bar chart. Productivity without fertilizer = 1000 kg/hectare Productivity with ammonium nitrate = 4500 kg/hectare Step 2: Calculate the increase in productivity. Increase = Productivity with ammonium nitrate - Productivity without fertilizer Increase = 4500 kg/hectare - 1000 kg/hectare = 3500 kg/hectare Step 3: Calculate the percentage increase. Percentage increase = ( IncreaseOriginal productivity ) × 100\% Percentage increase = ( 3500 kg/hectare1000 kg/hectare ) × 100\% = 3.5 × 100\% = 350\% c) Which forms of fertiliser used are natural fertilisers? The natural fertilizers listed in the diagram are Manure and Bone meal. d) Describe and explain how the use of fertilisers could have a detrimental effect on the environment. The use of fertilizers can have detrimental effects, primarily through eutrophication and groundwater contamination. • Eutrophication: Excess fertilizers, particularly nitrates and phosphates, can be washed off fields into rivers and lakes through runoff or leaching. This influx of nutrients causes rapid growth of algae, known as an algal bloom. When these algae die, decomposer bacteria break them down, consuming large amounts of dissolved oxygen in the water. This oxygen depletion can lead to the death of fish and other aquatic organisms. • Groundwater contamination: Soluble nitrates from fertilizers can leach through the soil and contaminate groundwater. High concentrations of nitrates in drinking water can be harmful to human health, especially for infants, potentially causing methaemoglobinaemia (blue baby syndrome). That's 2 down. 3 left today — send the next one.