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Validation of Fertiliser Manual (RB209) recommendations for grassland

1 April 2011 - 31 March 2015

PI/s in Exeter: Professor Matt Lobley

CI/s in Exeter: Professor Michael Winter

Funding awarded: £ 53,930 (total funding of £ 509,678)

Sponsor(s): Department for Environment, Food and Rural Affairs (DEFRA)

About the research

In the absence of new data on phosphorus use in DEFRA's revised Fertiliser Manual (RB209), there is a need to test how well the new Nitrogen recommendations perform under current practical farm conditions. The outputs of the proposed project will help inform possible changes to the structure and nature of future industry standard Fertiliser Manual recommendations so that they can be adopted effectively, correctly and with confidence by farmers and their advisers, and to help in the development of appropriate policies for environmental protection including greenhouse gas emissions and water quality.

Specific objectives covered by the core elements of the proposed project are: 

1. To assess views of farmers and advisors on the Fertiliser Manual (RB209) grassland recommendations (especially nitrogen and phosphate), including awareness of the information, how it compares with current farm practices, how easy it is to understand, how it is used on farms, and to identify barriers to uptake and possible improvements.

2. To carry out a programme of field experiments to test the annual yield and fresh grass quality response of selected cut grass swards to different rates of manufactured nitrogen fertiliser under different conditions of Grass Growth Class (based on rainfall, soil type and altitude), field history (influencing Soil N Supply) and livestock production system (e.g. based on milk yield, concentrate use and stocking rate), and assess these data in combination with other relevant UK grass variety yield and nitrogen response data.

3. To use the new information to assess how well the Fertiliser Manual (RB209) meets the needs of grassland farmers in England and Wales.