Profit from CF N-Min sampling

Jon Birchall

Farmer: Jon Birchall, Hereford/ Shropshire

Crops Grown: Oilseed Rape

Variety: Incentive

N-Min: Used for 2 years

Yield Gain: 0.5t/ha

Margin Gain: £130 N/ha

Soil TypeSandy Loam

Fertiliser UsedNitram® and DoubleTop®

Fertiliser Saving: 40kg/ha


CF N-Min® on Oilseed Rape- Optimising Break Crops


Jon Birchall N-Min user“You have to be impressed with N-Min.  

Over the last two very different production years, it has helped us increase our yields and reduce our overall fertiliser spend. We went in with an open mind, but it has really opened our eyes and you can’t ignore the results we have achieved. CF N-Min is now an essential part of our business management moving forward.”

Jon Birchall

After two years of using N-Min, farm management adviser Jon Birchall is convinced of its benefits in oilseed rape.

In 2015 trials at the 600ha Sundorne Estate near Shrewsbury, which he manages through its agent Balfours LLP, N-Min increased yields by 0.5t/ha worth an extra £130/ha when compared to recommendations based on the RB209 fertiliser manual.

Across the farm he applied less Nitrogen and either maintained yields or managed to increase them.

In the more challenging year of 2016, trials showed he maintained yields at an impressive 4.63t/ha across both approaches but did so using 40kg N/ha less with the N-Min system than with the standard farm practice.

In a 32ha field which had received sewage sludge in the previous season N-Min showed 60kg N/ha which with a further 75kg N/ha as crop Nitrogen gave a total SNS of 135kg/ha.

The CF N-Calc used the SNS to suggest an application of 180kg N/ha, which was required to achieve a target yield of 5t/ha, as opposed to the existing farm practice policy of 220kg N/ha.

In 2017, CF N-Min and analysis of nitrogen needs and fine-tuning applications helped Jon hit protein specifications with all his milling wheat. With 170ha of milling wheat - and 66ha of Illustrious joins Skyfall for 2018 - balancing the relationship between variety, yield and quality is key.

“By and large we’re aiming for 10t/ha crops at protein spec between 12.5 – 14.0% with the lower end of this obviously being suitable for Warburtons,” he said.

Last year, the estate applied between 165kg/ha and 225kg/ha of nitrogen depending on the field and the result of N-Min testing.

"We decided to keep the final application at 40kg/ha as suggested by N-Min and N-Calc and applied it on 8 June. At harvest all crops hit milling spec,” he said.