Nutrient budgeting in the Ythan NVZ

The Ythan Project involved local people in protecting and enhancing the river Ythan. As part of this, AERU developed a whole farm and field level Nutrient Budgeting package for use on-farm. The objective was to produce a computer software package, for use by farmers and their advisers, that would determine the annual farm nutrient budget and provide key information on crop nutrient requirements. The specific aims were to:

  • To calculate the whole farm nutrient (N, P, K) surplus or deficit via the determination of the nutrient value of farm inputs minus the nutrient value of farm outputs in order to demonstrate nutrient recovery efficiency.
  • To provide a readily accessible means of assessing nutrient requirements for crops grown in the area on a field by field basis and the appropriate period for their application. The system will show the nutrient value of fertilisers and manures.
  • To show the nutrient surplus or deficit after application and post-harvest in order to provide a baseline for the following year.
  • To demonstrate to farmers the nutrient and financial value of manure and to provide information on the most appropriate application timing within the cropping cycle.
  • To provide a means for farmers to provide evidence that the nutrient policy of the farm is within the guidelines (set by SEERAD) for NVZs, and that closed periods have been observed.

The Ythan nutrient budgeting project was supported by the organisation behind the Ythan Project and the European Union.


Dr Andy Green


University of Hertfordshire
University of Hertfordshire, 2017.