Arable farmers who have traditionally shunned urea fertilisers should look again when covering next season’s nitrogen requirements.
New-generation stabilised N products are starting to gain momentum in the marketplace as they receive the backing of the UK’s bigger merchants. These products contain inhibitors to delay certain N conversion processes in the soil, reducing losses and allowing plants to exploit more of the nutrient, improving yields and quality.
However, not all products are the same and growers should do their homework to know exactly what they are buying, advises Gleadell’s fertiliser manager Calum Findlay.
“Unlike some other products in the market, Alzon 46 contains nitrification inhibitors. These lower the rate of conversion of ammonium, which is relatively stable, to nitrate, which is mobile.
“This means ammonium is retained for longer in the root zone, where it is available to plants. It also means smaller amounts of nitrate are released over a given period, which evens out supply and leads to a high efficiency of N use by the crop.”
The overall effect encourages root growth, reduces luxury uptake and excess green matter production and improves the availability of phosphorous and trace elements, Mr Findlay explains. This better efficiency is most marked in damp spring conditions when growers could potentially reduce rates.
As well as improving nutrition, Alzon 46 also benefits the environment by reducing both nitrate leaching and gaseous N losses, says Mr Findlay. “Depending on the weather and local conditions, the effect can last from four to 12 weeks.”
This means more fertiliser can be applied at any one time, potentially reducing the number of passes required to one for oilseed rape and one to two for cereals. “Alzon 46 is ideal for applying at high application rates, though these should be made before 1 May to reduce the risk of volatilisation,” he says.
Urease inhibitors contained in some alternative products delay conversion from urea to ammonium. While this reduces ammonia emissions, such emissions tend to occur mainly in tropical and sub-tropical conditions or on very light sandy or alkaline soils. In addition, the effect only lasts one to three weeks, notes Mr Findlay.
Urease inhibitors do nothing to slow the production of nitrates, he adds. “This means the advantages of ammonium nutrition are reduced and none of the other benefits of a more controlled nitrates release are realised either.”
Alzon 46 is tested and manufactured in Germany by SKW Piesteritz and marketed exclusively in the UK by Gleadell. This new technology has been developed specifically for the cooler northern European climate. The uniform, dust-free granules retain excellent spreading properties up to 32m, says Mr Findlay.
“More and more farmers are expressing an interest in Alzon 46, and its ability to bridge the gap between AN and urea. Given what it offers over material containing urease inhibitors, we expect that interest to grow.”
