Yield responses to applications of sulphur in recent years have varied from 0.2 to 1.9 t/ha. There are a number of features with regard to sulphur that help determine the optimum management approach.
Sulphur readily leaches
The crop available sulphate form of sulphur readily leaches through the soil profile, behaving similar to nitrate nitrogen. Applying all of the sulphur requirement for the growing crop in one application early is risky. All of the nitrogen is not applied in February / March as the risk of loss is too high, so why do this with sulphur?
Sulphur is required throughout the spring
Trials at Rothamsted Research Station have shown how a crop of wheat responds to sulphur right through March, April and May, confirming sulphur is required throughout the spring growing period.
Sulphur mobility in the plant is poor
Sulphur mobility in the plant is opposite to nitrogen. Such a feature explains why sulphur deficiency symptoms in crops always first appear in the young developing leaves. These young leaves turn yellow and plants become stunted.
Sulphur improves nitrogen use efficiency.
With sulphur based amino acids being the building blocks of plant proteins (fundamental for yield and grain quality), having sufficient quantities available throughout the season ensures the efficient use of nitrogen.
Through consideration of the points above it is clear that the ‘best practice’ approach to managing sulphur is one that delivers an even spread of plant available sulphur from February to June. This is most cost effectively achieved through applying a minimum of two applications of a nitrogen/sulphur grade that has the correct ratio of N and S to satisfy the crops requirement. Crop requirement will typically be between 50-75 kg SO3/ha which covers both oilseed and winter cereals. As well as satisfying the crops sulphur need, this also delivers improved nitrogen use efficiency, increasing the return on investment made into nitrogen.
The product YaraBela Axan matches these requirements, as well as having some of the lowest ammonia emissions, a new consideration in choosing your source of nitrogen as agriculture is tasked with contributing to cleaner air through the governments Clean Air Strategy.
The main advantage of YaraBela Axan is its spread-ability
“The main advantage of YaraBela Axan is its spread-ability” says Farm Manager Tom Garner of Scrivelsby Farms Ltd. “We are on 30 metre tramlines and find that YaraBela Axan offers the best quality and consistency allowing us to achieve uniform applications time and time again.
The key agronomic benefit is the 3:1 nitrogen to sulphur ratio
The key agronomic benefit is the nitrogen to sulphur ratio, at 3:1 it works for us across all our arable crops. It doesn’t interfere with the variable nitrogen applications we do through using the Yara N-Sensor as with this ratio we know whatever rate of nitrogen is applied the sulphur rate is ideally matched. I am a firm believer you get what you pay for, and I certainly get this with YaraBela Axan as the quality and consistency is second to none”.