Chemical elements required for plant growth and development are divided into major elements and trace elements depending on the amount required.

The sixteen essential elements necessary for the nutrition of turf grasses are listed below [James Beard, 1973]

The elements Carbon, Hydrogen and Oxygen are obtained by the plant from the air and water in the soil and atmosphere and for all practical purposes are supplied in well aerated and watered soils in inexhaustible quantities.

The other essential plant nutrients must be obtained by plants from the soil. In actively managed turf areas the soil will generally not be able to keep up a sufficient supply of nutrients for adequate plants growth and development, thus additions in the way of fertilizers will need to be added.

Soil and plant tissue analyses are ways of predicting deficiencies.

Deficiencies can also be observed from changes in color or growth and development of the plant.

Turfgrasses required Nitrogen in the largest amounts of nutrients and in regular quantities. For this reason the fertilizer program should be primarily based around Nitrogen application.

In turf wickets most other nutrients need only be added in small quantities due to

1. There is little leaching through clay wicket soils
2. There is a high cation exchange capacity
3. The clay soil acts as a reservoir of nutrients (it could be thought of a fertilizer in itself).

As a guide for established wickets the following could be used.

Rate per Wicket (80 sq.m)

N 400g/month

P 200g/month

K 800g/month

Observation, soil and tissue analysis will provide more accurate information on the correct proportions and rates to be applied.

As Nitrogen is required in much larger quantities than other nutrients, N can be applied as a straight Nitrogen fertilizer in a variety of trade names. Agran (34% N), for example, for most of the year and as an NPK mix (e.g. Turf Special Mix) every four or five months.

By satisfying the Nitrogen requirements in this way, there will also be sufficient quantities of Phosphorus and Potassium.

E.G.

Agran (34% N) = Monthly rate required is 400g N per wicket = 1.2kg

Agran (0.4kg – 34/100)

Plus the Turf Special Mix of three applications per year.

Turf Special Mix = N 15%

P 2%

K 6%

Required N rate is 400g N per wicket per month = 3kg Turf Special Mix per wicket (0.4kg – 12/100)

At a rate of 3.3kg Turf Special Mix the amount of: -

K received per wicket is 3.3 x 6/100 = 0.198kg (198g)

If this application were to be made on three occasions per year the K & P requirements would be satisfied.

The above is merely to guide and should not be taken as actual. Consult the soil and tissue analysis results prior to fertilizer applications.