A NEW fertiliser guide says gross margin improvements of more than £100/ha are possible by more accurate recognition of the point at which applied nitrogen delivers the highest economic return.

Launched by CF, which has a plant in Billingham, the 12-page guide focuses on effective soil testing as a base for calculating nitrogen requirements and covers both feed and premium wheats plus oilseed rape and barley.

Alison Grundy, the company's arable agronomist, said: "We want growers to understand the importance of knowing precisely how much nitrogen they should be applying, not just relying on general guidelines.

"While RB209 is a great starting point, our studies suggest it is only accurate 35 per cent of the time so growers have to establish what nitrogen they have available in their soil and the crop if they are to make the best decisions."

The guide outlines the importance of identifying additional available nitrogen (AAN) as well as the more common soil mineral nitrogen (SMN).

"Most tests show SMN which is purely a reflection of how much nitrogen is in the soil at the time of testing and before significant crop uptake has taken place – but it is only part of the equation.

"What is of equal importance is the amount of nitrogen that will become available to the crop between the spring and harvest through ongoing mineralisation and this is called additional available nitrogen (AAN)."

Being able to calculate this seasonal release of soil nitrogen and estimated spring crop nitrogen enables growers to apply the exact amount of fertiliser needed to target optimum crop yield and quality. She said CF’s proven and patented N-Min test is the only soil nitrogen analysis available that includes this.

"Without understanding AAN you’re only getting half the picture and, more worryingly, you are likely to overestimate how much nitrogen you actually need to put on.

"In other cases, it could be that you actually need to apply more nitrogen to get the best yield and economic returns."

The guide includes numerous practical examples of N-Min use on-farm where yield gains of up to 1.0t/ha, fertiliser savings of up to 100kg/ha, and improved quality specifications have been achieved.

"As fertiliser is one of the biggest investments any farm will make, its correct use is essential. Use too little and you won’t realise your crop’s full potential – use too much and not only will you be wasting money, you’ll also be running the risk of lodging and serious environmental problems, too.

"Add in the increasing demands from buyers for evidence of environmentally sensitive crop production strategies and you’ll see why we believe precise use of nitrogen will become increasingly important in the years ahead."

She said that, following extensive work with the Carbon Trust, the full range of CF Fertilisers’ products now carry carbon footprints. In addition, the carbon footprint of Nitram has been reduced by 40 per cent since 2010.

"We are 100 per cent committed to producing the highest quality British made fertiliser products possible and providing the knowledge, services and customer support necessary to help growers get the best economic return possible from these.

"Correct testing and accurate on-farm applications are key elements in achieving this and we hope our new guide will help UK producers make the best-informed decisions around this."

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