Controlled Release Fertilizers

29 March 2016
  • Whastsapp

Growing strong, dense and healthy sportsturf doesn’t happen by chance. Three of the key factors for keeping sportsturf surfaces in top condition are selecting the best fertilizer, applying it at the right time and at an appropriate rate. Get these essentials right and turf will stay uniform and green and weather many challenges including attack from pest and disease. Having stronger, more resilient surfaces also means pitches and courses can be played on for longer in the season, keeping the players happy too.

As part of an integrated turf management approach, controlled release fertilisers (CRF’s) can play a very valuable part in an annual turf maintenance programme.

CRF’s use specific technologies which allow nutrients to be released over a set time period, in a controlled way. By allowing Nitrogen to be released slowly, CRF’s are a much more efficient and effective fertilizer option. Conventional fertilizers tend to generate soft growth flushes which can cause nutrients to be washed away by rain and leached from the soil. With CRF’s allowing for a more measured release of nutrition, the result is even turf growth and a consistency of turf colour lasting right through the season.


ICL has a comprehensive range of controlled release fertilizers, including SierrablenPlus which uses well-established Poly-S and resin-coated PACE technologies.

With Poly-S, the Nitrogen granules are first coated with sulphur (a plant nutrient in itself) and then with a unique, degradable polymer membrane. Once moisture permeates the outer polymer membrane and Sulphur coating, Nitrogen is released.

PACE resin-coated fertilizers contain more than one nutrient. ICL-SF’s unique vegetable-based resin membrane ensures the plant receives a steady dose of Nitrogen, Potassium and Phosphorus. When applied to turf, the granule absorbs moisture from the environment which gradually dissolves the nutrients within it. When soil temperatures are above 6°C, pressure begins to build within the granule forcing the nutrients out through the semi-permeable resin coating.

Depending on the thickness of the coating, the rate at which nutrients are released will vary, but the effects can last from two to three months, up to nine months. Major increases in soil temperature, pH or moisture levels don’t create severe fluctuations in the release patterns either which means there’s always steady growth and the turf stays healthy and green, even in warm and wet conditions.

More cost-effective

Professional turf managers responsible for sports pitches and golf courses are always on the look-out for cost efficiencies. When used correctly, CRF’s can deliver significant cost savings per hectare over the year, in terms of the amount of fertilizer used and in terms of any associated labour and storage costs. Using a more efficient product, less often, means there’s far less to store and transport over the season and as there will be fewer, less frequent applications, less watering and less mowing so labour costs should also be reduced.

Reduced environmental impact

Independently conducted research has shown that CRF’s significantly reduce leaching losses of N compared with conventional and organic fertilizers. By supplying just the nutrients at the right time, CRF’s reduce the risk of waste by preventing nutrients from leaching from the soil, especially during times of heavy rainfall and from freely-draining, sand-based root zones. This makes using CRF nutrition a more efficient and a more environmentally-friendly choice.

For more information about the comprehensive range of controlled release fertilizers available from ICL, please contact your local technical advisor.