Slow release fertilisers deliver healthier grass, healthier environments and healthier budgets
Landscapers should use specialist slow release fertilisers in favour of conventional compound products, not only to enhance the health and vitality of grass swards, but also to protect watercourses and to reduce the overall cost of landscaping projects. That is according to Richard Brown, Amenity Sales Manager for Germinal, who explains that slow release fertilisers offer greater stability and longevity compared to volatile, leaching-prone alternatives.
“As much as 70% of the UK’s land area drains into watercourses which are excessively polluted by nitrates,” Richard explains. “While the majority of these nitrates are derived from agricultural land, as much as 40% comes from non-agricultural green spaces such as parks, amenity spaces and sports pitches.
“As an industry we therefore need to do more to reduce nutrient losses, especially if we are to comply with the Environment Agency’s recommended good practice guidelines which state that the amount of fertiliser used for landscaping should be limited by carefully planning where it is needed and how it is applied.”
In order to reduce nitrate losses – and to ensure that the nutrients applied are of long-term benefit to the sward – Mr Brown recommends the use of specialist slow release fertilisers.
“Conventional compound fertilisers are extremely water soluble and are therefore more likely to be leached out of the rootzone during wet weather,” Richard continues. “In fact, depending on the soil type and rainfall intensity, nutrient losses via leaching and volatisation to the atmosphere can be as high as 60%.”
In contrast, slow release fertilisers which use more stable forms of nitrogen such as methylene urea and organic-based elements are much less likely to be washed from the rootzone and can remain available for uptake by plant roots for up to three months.
“Slow release fertilisers typically need both heat and water to breakdown,” Richard continues. “In effect, this means that products such as Germinal’s new GSR Tri-Phase 18-3.5-8 fertiliser only release their nutrients when the grass sward needs them. This produces a more even growth pattern, with none of the intense bursts of growth associated with frequent applications of compound products. The overall effect is a slower, more consistent supply of nutrients which results in a stronger sward which is better able to cope with and recover from wear damage and disease.”
Because plants are able to access a higher proportion of the nutrients supplied by slow release fertilisers, they can be spread at lower rates than conventional products. “As a result, despite a higher per kg cost compared to compound fertilisers, slow release nutrients offer better overall value for money, working out significantly cheaper when used across a full growing season,” Richard claims. “For landscapers and architects working to tight budgets, the economics therefore swing firmly in favour of using slow release products.”