Developing a software tool (Manner-NPK) to estimate crop available nitrogen, phosphate and potash from organic materials

The Problem:

MANNER (MANure Nitrogen Evaluation Routine) version 3.0 was released in 2000. The decision support system produced a quick estimate of the fate of manure nitrogen (N) following land application. MANNER was designed to be easy to use and require only a few simple inputs (readily available to most farmers and their advisers).

Feedback from the large number of farmers (particularly livestock farmers) and consultants who used MANNER (more than 10,000 copies of version 3.0 have been distributed) highlighted a number of areas for improvement and enhancement.

These included:

• The facility to predict phosphate (P₂O₅), potash (K₂O), magnesium (MgO) and sulphur (SO₃) supply from organic manures
• The ability to estimate manure nutrient supply where more than one manure application had been made to a field during the same cropping year
• Calculation of the economic value (£/ha) of a manure application
• Conversion of laboratory dry matter nutrient analyses to a fresh weight applied basis
• Information on additional manure types (e.g. duck manure, sheep manure and dirty water)

Project Aims:

• To improve the MANNER user interface to make it easier to use
• To update the technical specifications – for example, NVZs regulations

Approach:

ADAS consulted with the project partners and expert testers, and updated the program. The new version was tested before its release.

Results:

Released in 2013, the updated MANNER-NPK can provide a quick estimate of crop available nitrogen, phosphate and potash supply from applications of organic manure. MANNER-NPK is applicable in England, Wales, Scotland and Northern Ireland. The version of MANNER–NPK produced as part of this project is available from Planet4Farmers.

2025 news:

A new online nutrient management planning tool, which covers England, Scotland and Wales, was tested and rolled out by Defra during 2025. The tool can record fertiliser and manure applications. It can also be used to plan nutrient use, with fertiliser recommendations (for all major nutrients and lime) based on the Nutrient Management Guide (RB209). It creates downloadable plans in PDF format and replaces the PLANET and MANNER-NPK planning tools. There is no legal requirement to use it.

Create a nutrient management plan (a free RB209-powered tool from Defra)