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N-Min System delivers 1.5t/ha more wheat than standard farm practice with use of high quality Nitram.

Focusing on improved Nitrogen (N) recovery has a profound effect on wheat yields at J. T. Peach & Son’s Lincolnshire farm despite the challenging growing conditions of 2018, with the extra production representing an improvement of £172/ha in MOFC.

“I was pleasantly surprised by the wheat yields in a very difficult year when national trend for yields was 8- 0% lower. The CF N-Min test fields produced much higher yields than we have been used to. We were 12% up, so the actual difference between what I had expected and what we achieved was 20%. I can only attribute that to the Nitrogen recommendations and the N-Min testing.”


It was Arthur Baldwin, Area Manager for fertiliser distributor ACT Ltd, who advised Chris to consider N-Min testing two fields for the initial trial. Both were very similar in terms of being Grade 1 silt but also very different in terms of previous cropping. ‘

  • Post Office Field’ had high levels of residues from the previous crop of broccoli.
  • In contrast, daffodil bulbs grown on ‘Black Hole Drove’ during the three previous years had received only a small amount of base fertiliser in the spring after planting and when they were lifted in July 2017 left very little crop residue.

Both fields were tested using the unique, patented N-Min test that enables farmers to optimise N utilisation by making the most of Additional Available Nitrogen (AAN), with the aim of balancing Nitrogen inputs to achieve the maximum economic output,” he explains.

Developed over 30 years with leading research organisations, CF N-Min measures both the amount of Nitrogen in the soil at the time of testing (Soil Mineral Nitrogen or SMN), but also what will become available to the crop between the spring and harvest, the AAN. This is adjusted to account for the Nitrogen which will be supplied from the soil at depths of 60cm to 90cm, with allowances made for leaching losses, deposition and uptake efficiency. The CF Fertilisers’ N-Calc programme ensures that yield and quality aspirations are met, allowing for changes in economic circumstances, minimising the environmental impact of crop production and ensuring that the investment in Nitrogen is fully utilised taking the guesswork out of fertiliser calculations.”


The results showed a wide variation in Soil Nitrogen Reserves:

  • For Post Office Field the N-Min result was 149, giving an SNS of 179, a figure which even surprised Arthur
  • At Black Hole Drove the N-Min was just 44 and the SNS 74 reflecting the fact the field had been into bulbs and received no additional Nitrogen for three years.

Based on this information and a target wheat yield of 12t/ha, Arthur produce recommendations for both fields, 87kgN/ha for Post Office giving a total fertiliser cost of £48/ha and 238kgN/ha, costing £132/ha, for Black Hole Drove. The mean of £90/ha for the two fields was substantially higher than the £72/ha it would have been under the farm’s previous blanket rate N application, with all Nitrogen applied being CF Nitram (34.5%N) at £190 per tonne.

Arthur explains. “The exceptionally dry spring and summer ultimately meant that yields from both fields were less than they might have been, but nevertheless they exceeded previous average yields. Post Office, the high-residue field, yielded 9.6t/ha while Black Hole Drove, the low-residue field, produced 8.7t/ha, giving a mean of 9t/ha, significantly more than the 7.5t/ha for the standard farm programme.”

The average Margin Over Fertiliser Cost (MOFC) was £1420/ha where N-Min was used, compared with £1248 for the standard farm programme, justifying the cost of using the N-Min service many times over.

Chris Peach says “From what I have seen so far CF N-Min is an excellent management tool which provides scientific information on which to plan fertiliser applications more confidently and more accurately, so we will use N-Min again this year.”