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Validation of fertiliser manual (RB209) recommendations for grasslands - IF01121

The Fertiliser Manual (RB209) (8th edition, Defra 2010), provides industry standard recommendations for grassland in England and Wales. Recently revised, the nitrogen (N) recommendations for grassland were substantially changed and restructured. This project will provide an evidence base for validating and assessing the effectiveness of these recommendations for grassland farmers. The project brings together experienced scientific and industry expertise in grassland nutrient management and social sciences. ADAS will lead the project, supported by a Steering Group and working with Rothamsted Research North Wyke, the Centre for Rural Policy Research (CRPR) of Exeter University, Promar International, Hill Taylor Partnership and the Agri-Food and Biosciences Institute (AFBI), with support from industry sector representatives, the National Farmers Union (NFU), Agriculture and Horticulture Development Board (AHDB), Agricultural Industries Confederation (AIC), Professional Nutrient Management Group (PNMG) and British Grassland Society (BGS).

There will be 3 work packages (WP), each led by an experienced ADAS consultant. In WP1 using a structured telephone survey of c.600 grassland farmers, an email survey of grassland advisors/influencers, and an indepth evaluation of 10 case study farms (6 dairy, 4 beef&sheep), the CRPR of Exeter University will evaluate the use and impact of the RB209 recommendations, and also the expected impact of the Nmax limits that are part of the current NVZ Action Programme. The study will evaluate current farm practice and decision processes, as well as the technical content and ease of use of RB209. Any possible improvements will be identified and discussed with farmers/advisers at 3 focus groups (2 dairy, 1 beef & sheep) to obtain feedback. In WP2, field experiments will be undertaken in each of 3 years to validate the RB209 grass dry matter yield production values expected from recommended N rates under different conditions of Grass Growth Class (GGC, based on soil type, rainfall and altitude) and Soil N Supply (SNS, based on previous field history). Replicated N response experiments will be carried out under contrasting conditions of GGC and SNS (12 field sites over 3 growing seasons) to determine dry matter yield at 6 annual N rates (0-450 kg N/ha/year). In WP3, the new data will be used to assess the validity and effectiveness of the current Fertiliser Manual (RB209) recommendations, and to make outline recommendations for any revisions (if required).
2.2 Objectives

The overall aim of this project is to provide an evidence base for validating the Fertiliser Manual (RB209)
grassland recommendations in order to meet the requirements of the industry now and in the future.
Specific objectives covered by the core elements of the proposed project are:
1. To assess views of farmers and advisors on:
a. 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
b. The impact of the NVZ Action Programme Nmax limit.
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.
EVID2 Research Project Proposal Form (04/11) 7
3. To use the new information to assess how well the Fertiliser Manual (RB209) meets the needs of
grassland farmers in England and Wales.
Costed options
The above objectives do not include items identified as ‘Costed options’. These are identified separately in outline
and with indicative costs only. They are included in this proposal for consideration by Defra, and ADAS would
be happy to provide more detail if requested. The inclusion of these options recognises that a wide range of
research work (including experiments with grazing livestock and on grass/clover swards) is considered to be
necessary in order to comprehensively address the overall project objectives, but that there would be a high
total cost of all of this work together.
Project Documents
• FRP - Final Report : IF01121 Final Report 30-01-15   (616k)
Time-Scale and Cost
From: 2011

To: 2015

Cost: £509,678
Contractor / Funded Organisations
A D A S UK Ltd (ADAS), North Wyke Research, University of Exeter
Integrated Farming Systems              
Sustainable Farming Systems