Getting Started After The Cold – A Granular Fertiliser Trial
‘Cold Start’ fertilisers have become more common in recent years. Indigrow undertook the challenge of finding our which early season fertilisers performed best after a cold winter.
We undertook a series of trials in Sweden, known for it’s cold, snow covered winters to evaluate the effectiveness of our fertilisers for use as a first post-winter fertiliser.
We evaluated our products against a series of common products available on the market. The products included in the trial were those seen below:
| Product | Analysis | Form of Nitrogen | Form of Iron |
| Indigrow ImpactPlus Accelerate 14-0-12 | 14-0-12 | 1.2% organic, 10.2% ammonium, 2.6% urea | |
| Indigrow ImpactPlus All Round 5-5-15 | 5-5-15 + 3% MgO + 4% Fe | 1.7% organic, 1.7% ammonium, 1.6% urea | 4.0% carbonate |
| Indigrow ImpactPlus Perk 4-0-14 | 4-0-14 + 10% Fe | 0.5% organic, 3.5% urea | 5.0% sulphate, 5.0% humate |
| Indigrow Impact CGF 25-5-10 | 25-5-10 + 2% MgO | 1.2% ammonium, 23.7% urea | |
| Indigrow Humik N25 25-0-0 | 25-0-0 | 0.6% organic, 5.0% ammonium, 19.4% urea | |
| ICL Invigorator Plus | 4-0-14 + 2% MgO + 8% Fe | 4.0% ammonium | 8.0% sulphate |
| ICL Cold Start | 11-5-5 + 8% Fe | 5.6% ammonium, 5.4% urea | 8.0% sulphate |
| Compo Fertilis Speed | 18-5-10 + 2.5% MgO | 5.0% nitrate, 13.0% ammonium |
The application was made on 6th April when air temperature was 6°C. There was still frost evident below 10cm. Applications were made in dry conditions and irrigations was applied 6 days later on 12th April. The trial site was first cut on 28th April.
The graph below shows the weather conditions throughout the trial including rainfall (blue bars), minimum temperature, average temperature and maximum temperature.
All of the readings were taken with an NDVI Meter (normalised difference vegetation index). NDVI Meters emit a brief burst of red and infrared light – the amount of light reflected back from the plant is measured. The sensor displays the measured value in terms of NDVI (ranging from 0.00 to 0.99). The strength of the detected light is a direct indicator of the density vegetation of the vegetation cover.
The graph highlights the success of Impact Accelerate 14-0-12, Impact CGF 25-5-10 and Humik N25 25-0-0 when used as a ‘cold start’ fertiliser.
These trials show that there is no benefit of having Nitrate in a ‘cold start’ fertiliser. Products which contain no Nitrate perform equally as well or better.