Measuring Nutrients in Soil

This film shows how plants need nutrients such as nitrogen, phosphorus and potassium which they extract from soil. The amount of nutrients should be just right. If soil lacks nutrients plants cannot grow and fertilisers need to be added. But if too much fertiliser is added, the excess can leach into rivers and pollute them. 

Using a commercial testing kit, Dr Natalia Martsinovich measures how much phosphate nutrient is present in typical garden soil.