Nitrogen

Nitrogen is an important macronutrient for all plants as it is a major component of chlorophyll. Chlorophyll is essential for photosynthesis, the process by which plants convert sunlight to energy. Nitrogen is also a core component of amino acids, the building blocks of proteins, so is important for cell formation and growth of the plant. 

Nitrogen contributes to the green colour of grass, growth rate, density, and tolerance against pests and stress. Symptoms of nitrogen deficiency include yellowing of the grass and stunted growth. Sandy soils are prone to nitrogen deficiency as heavy rainfall may leache the nutrients from the soil. 

To maintain a healthy, green lawn regular application of nitrogen is essential. In Spring and Summer, when the grass plants are actively growing, higher levels of nitrogen can be applied. In Winter months, lower levels of nitrogen are needed in order to limit new growth, which weakens easily in cold conditions and becomes susceptible to disease.