The appropriate choice of nutrients and the form, method and timing of fertilizer applications are vital in minimising losses caused by mowing, leaching and volatilization, among other factors.
That was one of the key messages presented by Everris at Turf Science Live, a two-day hands-on event organised and co-presented by Everris, Jacobsen and Syngenta at De Vere Carden Park, near Chester, in early July.
Manning one of seven stations visited in turn by turf managers, Everris's International Technical Manager, Stuart Staples, stressed the importance of optimising turf fertilizer inputs to minimise pressures on budgets, the environment and the growing plant.
"Everris has developed a unique programme of integrated turf treatments and practices known collectively as iTurf, providing a tailored approach to individual turf management needs," he explained. "Within the programme, we are able to offer expertise and solutions to a wide variety of turf problems. This enables turf managers identify the ideal product and apply it at the ideal rate and ideal time, in the ideal place and ideal turf conditions across a range of sports and amenity situations. We call it the 'five i principle'."
Choice of nutrient is critical to avoid excessive losses due to physical, environmental and biological factors, a point highlighted by co-presenter Colman Warde, Everris's Country Manager for Ireland.
"It is vital that the plant receives all of the essential macro and micro nutrients required for strong, healthy growth and keeps receiving them over time," he said. "Our experience, and that of many turf managers, is that a little but often approach works best, applying appropriate nutrient levels at selected times of the year to suit the growth stage and the season. However, it is very important that the correct product is applied at the correct time and at the correct rate."
By way of examples, he said that soil pH levels can have an adverse effect on nutrient availability, while too much potassium can inhibit the plant's take up of calcium, magnesium and nitrogen, hence the reason why Everris offers an extensive range of different fertilizer products and analyses to suit the season and growth stage.
"But little and often does not have to mean frequent applications," he stressed. "Everris has developed slow and controlled-release fertilizers that will do the job for you, using patented technologies that ensure nutrients are released over extended periods, bringing optimum benefits while minimising potential losses. High analysis fertilizers that release in a slow or controlled release way will actually deliver less to the plant than a low analysis conventional fertilizer and help to avoid boom/bust cycles of nutrient delivery."
An 18 month trial conducted by Everris in conjunction with STRI compared results from two fertilizer programmes with equivalent NPK inputs, one being a conventional granular fertilizer, the other being Everris's SierraformGT slow-release micro-granular fertilizer.
Although the conventional fertilizer produced good top growth, root development was restricted. There was also increased incidence of the turf disease Microdochium Patch, which is more prevalent when foliar growth is excessive and potassium levels are inadequate.
By comparison, turf that had been 'spoon fed' with slow-release SierraformGT displayed much better root growth and plant vigour, with an accompanying reduction in the soil surface pH level making conditions less favourable to disease.
Concluding the presentation, Stuart Staples advised turf managers to be wary of fertilizers that promised nutrient delivery over unrealistic extended periods.
"All Everris controlled-release fertilizers are Quality Control tested in the laboratory at a consistent temperature of 21 degrees Celsius, and field tested to ensure the product performs for the stated longevity," he explained. "Some other companies calculate the longevity of nutrient release at lower temperatures, which means that in practice the product will have a shorter longevity than claimed on the label."