Introduction
The aim of applying a turf fertiliser is to produce a hard wearing, uniform and dense turf, which is composed of desirable grasses.
The nutrient which has the most noticeable impact in achieving this is Nitrogen, which has a decidedly pronounced effect on grass growth. To ensure optimum growth is achieved, however, a balanced uptake of all the essential plant nutrients is required.
With the exception of Nitrogen (N), Phosphorus (P) and Potassium (K), most soils contain adequate amounts of plant nutrients for turfgrass growth. The actual amounts of N, P and K which are required will depend upon the grass species being encouraged, how well established the turf is, the soil texture and its current nutrient status, and whether clippings are boxed off or not.
Visual assessment of the turf quality can give a good indication of nutrient availability. However, to provide a more informed decision, soil tests are carried out to determine the levels of phosphorus and potassium on many areas, whilst on sand constructed facilities, magnesium may also be tested for.
Calcium and sulphur, as well as all the micronutrients, are usually present in the soil in suitable amounts and do not form part of a regular fertiliser programme for turf. The one exception to this is iron, which is used as a turf tonic to aid turf quality, but it does not usually have to be applied to ensure adequate growth takes place.
Extra care and diligence may need to be taken on high sand content facilities as many nutrients, including micronutrients, are prone to leaching in this type of situation.
The effects of the more important turfgrass nutrients
| Nutrient | Effect on turfgrasses |
| Nitrogen | Promotes leaf growth |
| Improves turf density | |
| Improves grass hardiness if not applied excessively or too late in the growing season | |
| Produces a darker green leaf | |
| Improves root development and turfgrass recovery from wear | |
| The main nutrient required by grasses | |
| Phosphorus | Promotes root development |
| Particularly required for seed development | |
| Encourages undesirable annual meadow grass at certain levels of availability | |
| Only required in limited quantities by turfgrasses | |
| Potassium | Involved with controlling the opening and closing of leaf stomata, assisting in drought resistance |
| It may improve overall turf quality | |
| Leaches out of sandy soils | |
| Required in intermediate amounts by turfgrasses | |
| Magnesium | Required for producing green colour in leaves as it is part of the chlorophyll molecule |
| Leaches out of sandy soils | |
| Normally adequate soil supplies, although may be required for high sand specification turf areas | |
| Iron | Produces a dark green to blackening effect on turf. It assists in chlorophyll synthesis |
| Acidifies the turf surface, improving disease resistance, reducing weeds and worms, discourages coarser grasses | |
| Adequate soil amounts, however, used as a turf tonic for improving turf, especially fine turf, quality |