The first UK trials of a low carbon, slow release nitrogen fertiliser have revealed it can boost crop Nutrient Uptake Efficiency (NUE) by up to 20% and reduces the number of passes farmers have to make.
The trials, which were conducted in Wiltshire and Hampshire on spring barley and winter wheat by agrifood and grain marketing specialist Bartholomews, looked at the crop yield and quality achieved by Fertiberia’s DS+ Zero Impact fertiliser vs the farm standard.
DS+ Zero Impact is a nitric and ammoniacal nitrogen fertiliser which features a biodegradable coating around the granule to control nutrient release and prevent leaching, as well as a nitrification inhibitor that significantly reduces volatilisation.
It is manufactured using ‘green’ hydrogen produced from renewable energy sources, which reduces the overall carbon footprint of the fertiliser, helping farmers to meet their environmental obligations.
The spring barley trials took place in the 2023 growing season at Birdlymes Farm, near Salisbury utilising varieties Planet and Laurette.
A total of 28 different fertiliser treatments were tested per variety against the farm standard of 240 kgs N + 75 kgs So3, applied as Polysulphate, per hectare.
According to Andrew Stilwell, technical director and agronomist at Bartholomews, who conducted the trials, replacing farm standard using Fertiberia DS+ Impact Zero at the same N level produced no change in yield or crop quality.
This, Andrew said, confirmed the product performed ‘at least as well as the existing standard’. But he added large gains were observed when DS+ Zero Impact was used at lower levels.
Andrew added: “We conducted the trials to compared the DS+ to other equivalent products at same application rates and then at reduced application rates to observe the slow release in action.
“Where we applied DS+ at the same rate of N as farm standard, we didn’t see too much difference in either yield or grain quality, which shows the product performs equally as well as the existing standard.
“At reduced rates is where the most impressive result were generated, however. “We dropped rate of N by 33% compared to farm standard and what we saw was just a 0.4 t/h reduction in yield and no reduction in grain quality, which is a highly efficient outcome for the farmer, generating what is still a financially viable crop.
“When we cut N by 33% using the standard farm product, the yield drop of was 1.2 t/h, which demonstrates how effective DS+ is at lower application rates.
“The results were recreated across four trial plots, ensuring a high degree of statistical accuracy and robust findings.”
Andrew said the findings could be explained by an overall increase in NUE – by around 20% – brought about by the technology built into the fertiliser.
The biodegradable coating ensures the slow release of nutrients into the crop, providing high quality nutrition in line with the plants’ requirements rather than in a large flood of nitrogen which is then left to leach through the soil.
The nitrification inhibitor also ensured more N remained on the field and accessible for the crop, rather than being lost to volatilisation.
As the results are generated by applying significantly less fertiliser, farmers in the trial needed to make fewer passes, creating time and fuel efficiencies on farm.
Similar results were also observed at trials in Hampshire on Skyfall winter wheat, where applied at standard rates, DS+ Zero Impact achieved the same quality and yield compared to farm standard.
Andrew added the results of these initial trials seemed to demonstrate DS+ Zero Impact could generate a favourable economic return for farmers by reducing the levels of N applied to a field, while at the same time enabling them become more sustainable.
He said: “The coating and slow release, and the nitrification inhibitor built into the product, gives us far more efficiency from the applied nitrogen than we have observed before in other products.
“Couple this with the huge cut in carbon emissions required to make this product and you can see that it ticks a lot of the boxes farmers will need to consider for the future.”
