The project use a novel on-farm 'Tramline Trial' approach that compares farm practice against 60kg N/ha more and 60kg N/ha less applied N to alternate tramlines. It is this large scale approach which will help to answer the question:
"To what extent is N application rate constraining farm yields?"
On a core set of six farms in Eastern England, tramline trials are being conducted across 18 fields per year for 4 years alongside small-plot N response trials to provide a structured dataset that can be used for validation. An associated network of around 12 farms across England and Scotland are also using the approach on three fields per farm to help provide a wider evaluation, gauge variability in field average N requirements, determine how the N optimum might be better predicted and gain feedback on how practical the approach is for others to adopt. Mr Giles Halfhead, of Sapperton Farms Lincolnshire is part of the whole evaluation process and has agreed to participate in the project for a second season, in 2015.
The first trials were successfully carried out in 2014, with positive feedback from growers, and some fields and farms showing large responses to the different N rates. However, it won't be until data is collected and analysed from more fields and seasons that definite conclusions can be drawn.