Amenity Turf Category J

This has a minimum height setting of a mower of 150mm and a maximum recommended height of vegetative growth of 200mm. Occasionally the grass will also be cut shorter for silage. This category of turf will typically be cut every 2 to 4 weeks, with a slight increase in frequency to every ten-days during peak growth periods. It is used for turf areas within airfields so as to minimize hazards to aircraft from birds. It will be cut with either a rotary mower, flail mower, reciprocating knife mower or even a forage harvester and clippings may either be collected (especially if any vertical take-off type aircraft use the airfield) or let fly and returned to the surface.

The desirable grass species will be quite varied depending on the soil type in particular, but a typical grass seed mixture would have about 50% of the harder wearing perennial ryegrasses and smooth stalked meadow grasses, combined with 50% of Chewings fescue. The aim would be to have very good grass coverage of whatever the desired grasses where required, being at least 85% ground cover (with total ground cover being at least 95%). Intermediate amounts of weed presence are allowed up to a total of 10% of the total ground coverage, as well as intermediate amounts of disease infection (up to 10% of the ground cover).