Grass needs nutrition in order to perform well. Nitrogen is one of the most important engines for the growth of plants. However, mineral fertilisers are made from non-renewable sources using an energy-intensive process. Too much fertiliser also poses a threat to the ecosystem in surrounding ditches.
The selection of the right grass mixture for the purpose can make a difference here too. Some grass mixtures perform just as well with less nutrition. This means that fewer fertilisers are required without any sacrifices needing to be made in terms of quality.
In general, the nutrition requirements of a grass plant depend on:
- Its purpose: the demands of sports fields are different to those of golf courses or parks
- The species of grass: Lolium perenne needs more nutrition than red fescue
- The genetic variation: cultivars have varying nutritional requirements
Years of independent research carried out by STRI, based in Bingley in the United Kingdom, have shown that red fescue and hard fescue perform excellently on lawns and golf courses under low to very low input fertilisation. The research showed that the quality of the grass cover remained the same when fewer fertilisers were used. Mixtures and cultivars with a low input (60 kg N/ha/year) were compared with those with a standard input (120 kg N/ha/year). The research paid attention to the influence of less fertilisation on disease resistance, the development of annual meadow grass, turf density and also ball speed (including golf ball speed) and build-up of thatch on the turf. The research, which took several years, also demonstrated that, compared with the standard regime, the proportion of red fescue increased over the years when input was lower.
Figure 3: The change in the proportion of red fescue over time at two levels of fertilisation.
Source: STRI 2010 Trials
Figure 3 shows that the proportion of red fescue in the green when fertilization was carried out at standard levels was smaller than when fertilization was decreased. BAR Fescue produces a higher green quality at lower levels of fertilization.
The conclusion is that in reducing fertilization input from 120 to 60 kg/ha/year, the desired grass is maintained while 50% less fertilisation is required! On top of that, research shows that growth of annual meadow grass can be prevented.
There are also large differences with Lolium perenne. The first results of a trial to determine the effects of less nitrogen on the performance of sport cultivars, which started recently, are very promising and contradict the old doctrine that Lolium perenne requires a lot of nitrogen.