Arable News

  • Written by: Farmers Guide
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Fulfil sulphur requirements

Farmers who purchase nitrogen purely on the basisof price, without considering how to fulfil their crops sulphur requirement,are putting yield, quality and profitability at risk, according to fertilisermanufacturer GrowHow.

Despite above average yields for most areas forcereal harvest 2014, protein levels and grain selling prices were lower. As aresult, some growers have been sold cheap nitrogen this season in the form ofstraight urea, David Beck of GrowHow states. This could be a false economy asmany will not have fully considered the agronomic issues involved, particularlyureas in-effectiveness in the drier and warmer weather we have seen thisspring, its poor performance in higher protein achievement, the requirementfor more N applied as urea to achieve yield potential and also where sulphurapplications fit in the system. 

Farmers and their agronomists go to great lengthsto calculate nitrogen rates that are specific to individual crops and farmconditions. Using urea, which is highly weather dependent and according toDefra trials can lose up to 43% of its Nitrogen through volatilisation,particularly in hot, dry weather, is completely at odds with modern PrecisionFarming systems. Growers could therefore be risking their entire yearsproduction and profitability by relying on a product which, unlike AmmoniumNitrate, has been formulated for the ease and low cost of manufacture, ischemically unstable and has to undergo chemical change before it becomesavailable to the plant.

We have had reports of farmers who have purchasedurea being concerned about the dry weather this spring. Some have now purchasedadditional N as Ammonium Nitrate, rather than use the urea they had been soldto avoid risking compromises in crop performance, said Clive Deeley, GrowHowNational Advice Manager. Newer varieties like Skyfall, with high potential foryield and quality, require correct nitrogen rates, potentially above standard.Most important is the predictable availability of Nitrogen to the crop, whichcan only confidently be achieved with Ammonium Nitrate.

Another issue with urea is the question of where sulphurapplication fits into the system, so that you are applying the correct amountat the right time.

Sulphur is taken up into the plant at similartimes to nitrogen, so where large amounts are required it is advisable to splitthe recommended requirement. However, farmers who use urea to supply the cropsnitrogen requirements may have difficulty in applying the correct amount of sulphur.Some will use ammonium sulphate (21N 60SO3) to supply this nutrient, but thebalance between nitrogen and sulphur is just not right. If, for example, youare looking to apply 40kgN/ha as a first Nitrogen application in wheat, thenthe 114kgSO3/ha sulphur applied with this product would be way aboverecommended rates. Conversely a recommended sulphur rate of 50kgSO3/ha would leadto the under application of nitrogen, just 17kgN/ha.

Products such as GrowHow DoubleTop (27N 30SO3), sulphurGold (29N 20SO3) or SingleTop (27N 12SO3) offer a range of treatments tosupply timely crop needs in the correct ratio and to suit your farming system.

Farmers generally purchase nitrogen months inadvance of when it will be used and at that stage it is impossible to know whatthe weather conditions will be at the time of application. Given thesignificant investment of producing crops, it makes no sense to risk the entireseasons production on the basis of a relatively small apparent cost savingwhen they could use crop nutrition products which are part of a reliable, consistent,well-proven system and deliver guaranteed results.


  • Written by: Farmers Guide
  • Posted:
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