Blue Bags Grow Better Crops


Investing in latest technology helps North Yorkshire farmer to optimize Nitrogen use and crop yields.


Neil Welburn ISARIA Farmer



A North Yorkshire producer is reaping the benefits after using the latest precision farming technology to optimise fertiliser application and significantly increase both yields and profit.

Neil Welburn, who farms in partnership with his wife Deirdre, son Chris and daughter Claire at Cross Hill Farm, Balne, is one of the first producers in the UK to use ISARIA.

The system is the latest in variable-rate application technology, automatically altering Nitrogen inputs according to conditions.

Mr Welburn first trialed the technology in 2014 on 250 hectares of owned, rented and share-farmed land used for wheat, barley and oilseed rape.

He has since used ISARIA on crops grown on a wide range of soil types – from light sands and loam to very heavy clay and black peat, while also carrying out a further 1,000ha of contract spreading. 

Mr Welburn said: “The aim of investing in the ISARIA precision input system was not necessarily to use less Nitrogen but to use it more effectively by applying it to those areas where it will produce the greatest benefit.

“In the past I have done this as best I can by manually varying the tractor’s forward speed and spreader settings based on my experience and the appearance of the crop.

“ISARIA uses two infra-red sensors to scan the crop ahead of the tractor, calculate the optimum application and automatically vary the amount of fertiliser which the spreader puts on. I have been amazed how accurate, versatile and easy the system is to use, and by the results which it produces. There is no doubt that it represents the way forward.”




Mr Welburn uses ISARIA in conjunction with a 24m KRM Bogballe M2W twin-disc fertiliser spreader equipped with a weigh-cell and Tempo Tracker and mounted on a New Holland T6150 Auto Command tractor.

To prepare the machine he initially scans the crop to enable the system to establish a baseline. In oilseed rape and barley this involves scanning the best and worst areas of the field. This generates a figure for the scanning index, the aim being to maintain the figure in the green-zone on the in-cab display.

He then inputs details of the crop’s current growth stage, the next growth stage at which fertiliser will be applied, the type of crop, target yield, any correction figure that may be required and the percentage Nitrogen content of the fertiliser.

The spreader will then calibrate itself automatically within the first 20m to 30m of travel in the field, although the operator can vary the application rate manually by plus or minus 5%, up to a pre-set level.

Mr Welburn said: “Sometimes it is difficult to get used to the idea that the machine is making key decisions, but you just have to learn to trust what it is doing and leave it alone.

“Using ISARIA didn’t actually make any difference to the total amount of fertiliser that we used during the season but what it did ensure was that what was applied was used more efficiently and effectively, which generated higher yields. 

“One crop of oilseed rape was grown on a field which had no manure applied for some years. I would probably have put on 380kg/ha of 34.5% Nitram, yet ISARIA decided that it needed 451kg/ha.

“On another field where the straw had been chopped and muck applied for many years, I would probably have applied 210kg/ha of AN, yet ISARIA cut the rate back to 177kg/ha. When we harvested both crops, the one that had received the lower rate yielded 3.68t/ha, while the one which received the higher rate produced 3.73t/ha. There was significant difference in fertiliser use but a negligible difference in yield because ISARIA had made the crop so even.

“In another 25-acre wheat field where the soil types ranged from burn-off sand to heavy clay ISARIA varied the Nitrogen rate accordingly and we harvested an average of 9.45t/ha.”


ISARIA yield potential maps



A key part of farming using ISARIA is to know the exact level of Nitrogen in the soil, which can be done using CF Fertiliser’s N-Min and N-Calc service. The test is the only one available that measures not just how much Nitrogen is present in the soil, but also the amount of Nitrogen predicted to become available to the crop during the growing period (Additional Available Nitrogen).



CF Fertiliser is part of a consortium of businesses that is leading the ISARIA project – undertaking field tests and research to create software that is tailored to all conditions in the UK.

Allison Grundy- CF Fertilisers Agronomist "As the UK's leading fertiliser manufacturer, CF Fertiliser is keen to support new technology which has the potential to improve nutrient use efficiency and improve both the yield and quality of crops.  The system has exciting potential and will be developed for other crop inputs such as Plant Growth Regulators".