GP Klassik 20-5-8

GP Klassik 20-5-8

GP SPORT • UF PREMIUM TECHNOLOGY

Professional seasonal fertiliser with magnesium and iron for intensive turf colour

Short description: product section

GP Klassik 20-5-8 is a professional universal fertiliser for the entire growing season, from spring to autumn. Balanced NPK enriched with high magnesium (4 % MgO), sulphur (9 % S) and iron (1 % Fe) ensures intensive, deep colour and stable grass development. Three nitrogen forms, including UF technology (urea formaldehyde), provide long-term, even nutrition for up to 3 months.

The product is designed for professional care of sports pitches, golf courses and intensively used green spaces, as well as high-quality prestigious, ornamental and domestic lawns.

Key properties

Classic universal seasonal fertiliser for spring to autumn;

Three nitrogen forms: immediate, medium-speed and long-term (UF);

High magnesium (4 % MgO) supports chlorophyll synthesis and intensifies colour;

Increased sulphur (9 % S) supports efficient nitrogen use and protein synthesis;

Added iron (1 % Fe) gives deep, rich colour from the first days;

UF technology (urea formaldehyde) ensures biologically regulated, gradual nitrogen release;

Effective for up to 3 months after a single application;

Granule size 1.0–3.15 mm for dust-free, precise spreading.

Classic fertiliser for professional turf

GP Klassik is the core of the professional GP Sport programme. NPK 20-5-8 with magnesium, sulphur and iron provides long-term, stable nutrition at every growing-season stage.

20 % nitrogen comprises three chemical forms: ammonium (7.5 %), urea (7.5 %) and UF urea formaldehyde (5 %). This three-stage structure gives the following release pattern:

Ammonium nitrogen: immediate availability during the first days;

Urea nitrogen: medium-speed availability covering the first weeks;

UF nitrogen: biologically regulated release for up to 3 months.

Phosphorus (5 % P₂O₅) supports stable roots, while potassium (8 % K₂O) regulates water balance and strengthens stress tolerance.

GP Klassik's distinctive feature is triple reinforcement of turf aesthetics: magnesium (4 % MgO), central to chlorophyll; sulphur (9 % S), supporting photosystem protein synthesis; and iron (1 % Fe), involved in chlorophyll biosynthesis and enzymatic processes. This combination maintains intensive, deep colour throughout the effective period.

How does UF technology work?

UF technology (urea formaldehyde), known in German as Formaldehydharnstoff, is an advanced nitrogen form with slow, biologically controlled release.

Part of GP Klassik's nitrogen (5 % N) is bound in long polymer chains synthesised from urea and formaldehyde. Soil bacteria and fungi gradually break them down, releasing plant-available nitrogen. The rate depends on microorganism activity and environmental conditions, particularly soil temperature and moisture.

UF nitrogen in GP Klassik includes two subfractions:

Cold-water-soluble nitrogen (CWS, 2.1 %): medium-speed availability;

Hot-water-soluble nitrogen (CWIN/HWIN, 1.7 %): long-term nitrogen reserve.

This mechanism supplies nitrogen at a rate matching actual turf demand, without growth surges typical of fertilisers using only readily available forms.

Results of UF technology

Stable long-term turf nutrition for up to 3 months;

No growth surges, with even grass development;

Reduced nitrogen losses through leaching and emissions;

More efficient root nitrogen uptake;

Lower risk of local over-fertilisation;

Greater resistance to drought and intensive use;

Intensive, deep turf colour throughout the effective period.

Applications

Fundamental turf maintenance during spring, summer and autumn;

Fertilising sports and golf turf during the playing season;

Restoring intensive turf colour;

High-quality football pitches, golf courses, prestigious, ornamental and utility turf.

GP Klassik: application and parameters

Application rate and coverage (25 kg)

Application instructions

Calculate the area to be fertilised and measure the appropriate quantity of fertiliser at the chosen application rate.

Spread evenly on dry turf, preferably using a calibrated spreader.

Avoid overlapping spreading passes and locally exceeding the application rate.

Water after application (2–4 mm) to initiate nutrient dissolution and movement into the root zone.

Good professional practice

Apply during active growth with stable soil temperature and sufficient moisture.

Do not apply during prolonged drought without irrigation, or to frozen or waterlogged soil.

On larger areas, two passes in a cross pattern are recommended to distribute the granules evenly.

In professional programmes, repeat every 10–12 weeks according to use intensity and climate.

Application conditions

Do not apply during frost, drought or strong sunlight. Do not exceed the recommended rate. Note: the product contains iron. Avoid application near light-coloured surfaces (paving, façades, wood) because permanent staining may occur. Immediately remove residual granules from paths, shoes and pets' fur.

Declared composition

Role in the GP Sport programme

GP Klassik is the foundation of the professional GP Sport programme:

New establishment / overseeding / turf laying → GP Starter: high phosphate, rooting, up to 6 weeks

Spring / summer / autumn → GP Klassik: universal seasonal fertiliser, colour, up to 3 months

All season → GP Allround: balanced NPK formulation + trace elements, up to 3 months

Summer / early autumn → GP NK: high potassium without phosphate, up to 3 months

Late autumn → GP Finale: highest potassium with magnesium, winter hardening, up to 2 months

Frequently asked questions

When should GP Klassik be applied? Throughout the growing season from spring to autumn. Apply ideally during active growth with stable root-zone soil temperature above 8 °C.

How does it differ from GP Allround? GP Klassik has three nitrogen forms including UF, high sulphur (9 %) and iron, optimised for intensive colour. GP Allround has more balanced NPK (16-7-16) and a complete trace-element complex (B, Cu, Fe, Mn, Zn), for turf requiring broad-spectrum nutrition.

How soon does it work? The first response is visible within days through immediately available ammonium nitrogen. Urea nitrogen is released over subsequent weeks and UF nitrogen over up to 3 months.

Does turf need watering afterwards? Yes. 2–4 mm of irrigation initiates nutrient dissolution and supports movement into the root zone.

Does GP Klassik cause growth surges? No. Its three-stage nitrogen structure, including UF technology, spreads availability over time for stable, even development without surges.

Is GP Klassik suitable for domestic lawns? Yes. Although developed for professional sports facilities, it also performs well on prestigious, ornamental and domestic lawns, particularly where deep, rich colour and long-lasting action are valued.