Soil
Soil is very important in an ecosystem because it is a medium for plant growth, it controls the fate of water,and is used as a recycling system. The nutrients in soil are vital for plant growth. The three main nutrients are nitrogen (N), phosphorus (P) and potassium (K). Together they make up the trio known as NPK. Other important nutrients are calcium, magnesium and sulfur. Plants also need small quantities of iron, manganese, zinc, copper, boron and molybdenum, known as trace elements because only traces are needed by the plant.