Opportunities to increase future Nitrogen Utilisation Efficiency (NUE) through fertiliser product choice and the potential to reduce ammonia emissions will be the main focus of the CF Fertilisers stand at CropTec 2018.
Decisions around fertiliser use are becoming increasingly complex but growers still need to prioritise productivity and crop response, says the company’s arable agronomist Allison Grundy.
“The drive for growers is still to identify the optimum amount of fertiliser they need to deliver target yields and quality and then choose the N source that will produce the greatest economic return for them in their own individual situation.
“This doesn’t necessarily mean going for the lowest cost fertiliser option but instead choosing the product that will maximise nutrient recovery and deliver the best financial return. Such an approach usually minimises waste and reduces environmental risks, as well.”
In recent trials carried out by the independent research company Armstrong Ltd, using straight 34.5% N in the form of Nitram Ammonium Nitrate (AN) produced an extra 0.4t/ha of milling wheat over crops using a urea fertiliser as their only source of Nitrogen, she says.
“The trials showed AN outperformed urea with the extra margin over fertiliser costs at the optimum application rates being worth an extra £46/ha.
“Even where urea was used as an early application and then followed by Nitram, there was a 0.25t/ha drop in yield compared with crops given all their Nitrogen as AN.
“This means that even using urea in the often thought-of safe early application timing and following it with AN would have cost growers £34/ha over the full AN programme, which over 100ha of wheat adds up to a sizeable £3400 loss in gross margin.
“When comparing a full urea programme to a full AN one, the loss is even greater at £4600 over 100ha.”
Using high quality products like Nitram will also help reduce ammonia emissions – an issue likely to become increasingly important as Defra’s clean air act takes shape, she says.
“The new clean air guidelines clearly state that switching from urea to AN or inhibited urea should be a serious fertiliser consideration for growers because of the lower ammonia emissions associated with AN and, to a lesser extent, those from inhibited urea.
“With AN, Nitrogen is directly available to the plant as soon as it is applied, whereas with urea, Nitrogen release relies on the complex process known as hydrolysis, which is in turn reliant on interaction with soil bacteria and the environment.
“According to the definitive Defra research programme NT26 that looked into UK fertiliser use, volatilisation reduces the amount of urea Nitrogen available to cereal crops by an average of 22% but in the worst case scenario this was recorded at 43% and was even higher in grassland.
“In cereals, Defra reported losses of between 2 – 43% of the total urea N when applied to winter cereals and this is in the form of ammonia-N lost to the atmosphere.”
But growers looking to maximise Nitrogen recovery by the plant also need to be aware of the role of other nutrients in achieving this, Allison Grundy says.
“Sulphur is essential for the production of protein in milling wheat but it is also required to maximise the plant’s ability to take up Nitrogen.
“As atmospheric levels of Sulphur have fallen so much in recent years it’s important for all arable producers to address this if they want to get the most out of their Nitrogen.
“It is now generally accepted that yield response to Sulphur are typically around 10% in winter cereals, up to 50% in spring barley and in oilseed rape, which requires a higher level of Sulphur, increases in yield can be as much as 100% on very deficient sites.
“Correct levels of Phosphate and Potash are also important in allowing plants to get the most out of the Nitrogen applied.”
As well as getting the latest information of fertiliser choice, visitors to the CF Fertilisers stand at CropTec will also be able to take part in a ‘BASIS Knowledge Trail’ focused on fertiliser options.
The CF Stand can be found in Hall 1, stand 10 at CropTec.
Farmer Comments on fertiliser choice
Andy Rankin, farm manager, Westrope Farming Ltd, Woodbridge, Suffolk.
“Anything that gets in the way of crops getting the nutrients they need at the time they can make full use of them, be it as a result cheaper products with low Nitrogen utilisation, poor application performance or log-jams when it comes to machinery, is simply a waste of time and money.
“We’ve looked at everything over the years, but we know we can’t beat what good high quality Ammonium Nitrate based fertiliser can offer us.
“We’ve never entertained urea as it’s far too risky from a crop utilisation point of view, and liquid fertiliser application simply doesn’t give us the flexibility we need.
“In addition, I don’t think relying on hauling large volumes of liquid across the land just for fertiliser would really tie in with our commitment to paying greater attention to soil structure and minimising the potential damage we do from wheelings.
“Apart from a single base application of a liquid suspension fertiliser pre-planting on the root crops, all fertiliser requirements across all crops are taken care of by CF Nitram (34.5%N) and CF DoubleTop (27N + 30SO3).”
Richard Peck, sales and development manager, Sentry Farming
“Last year, we made the decision to switch from urea to Nitram (34.5%N) and DoubleTop (27N +30SO3).
“For me, it’s all about quality and these deliver exactly what you would expect from premium products. They are truly uniform, with no lumps or dust, the contents of every bag are the same and they spread consistently at up to 36m, whereas urea is limited to 24m.
“The fact that AN does not volatilise, gets into the soil more quickly and is taken up by the crop much more rapidly than urea was invaluable this season.
“The extended period of exceptionally cold, wet weather that lasted through until the end of April meant that when we were eventually able to get on the land, it was vital that Nitrogen was taken up by the crops very quickly, which would not have been the case with urea.
“Without AN working in our favour we would not have felt nearly as comfortable about the situation, in what has been the most difficult season that I have known in over 30 years of farming.”