07 February 2019
Sulphur deficiency is now widespread across Northern Ireland. AFBI research has shown that dry matter yield losses of 30% are now occurring at 1st cut or 1st grazing as a result of sulphur deficiency. Lower protein levels in grass and silage are another consequence of sulphur deficiency, as sulphur plays an integral part in protein synthesis. The protein content of grass declines, and this not only reduces its value as a protein source for ruminants, it also hampers its ability to accumulate sugars and thus impairs its fermentation quality when ensiled. A shortage of sulphur in herbage (<0.2% S in DM) can also reduce the digestibility of forages. Rumen microbes require both nitrogen and sulphur to produce their own protein, and a shortage of S will therefore curtail important metabolic functions.
Sulphur deficiency can occur in spring on all soil types, regardless of whether or not slurry has been applied. The availability of slurry-S for spring grass is highly variable and often low, largely because variable amounts of sulphate (the plant available form) are converted into sulphide (a potential plant toxin) under anaerobic slurry storage conditions.
We should manage sulphur applications the same as N applications. If we apply all our sulphur in one application then we risk losing it to leaching. S leaching is wasteful but also very acidifying to soils. The ‘little and often’ approach to S applications does not have negative effects that ‘once off’ applications have. Similar to efficient nitrogen management, we apply the right amount of S as and when the plant requires it.
YaraVera Amidas is a urea based nitrogen (N) and sulphur (S) granular compound fertiliser from Yara, with 40% N and 14% SO3. Because it contains urea it’s well suited to spring use, delivering a stable and sustained supply of nitrogen in the weeks following application. 100% of the sulphur in Amidas is in the plant available form, unlike the S in organic manures. Therefore, you can rely on Amidas to provide a constant supply of sulphur over this critical spring period.
YaraVera Amidas has lower ammonia emissions than straight urea. The sulphur has an inhibitory effect on ammonia production during the conversion of urea to ammonium-N which is due to the Amidas granule containing both urea and S. This effect is not seen with blended urea and ammonium sulphate (AS) products. Because there is less ammonia lost, there is more N available for the crop to support grass growth, the S component has the double effect of reducing N losses while meeting the grass crops requirement for S to support higher grass yields.
Read more about YaraVera urea based fertilisers >