The AHDB has updated the RB209 Nutrient Management Guide, which helps growers make the most of organic materials and balance the benefits of fertiliser use against the costs – both economic and environmental.
It’s the first revision based on the feedback of over 900 people that started in 2024.
Nutrient use efficiency was identified as the highest priority area by levy payers and RB209 will continue to provide robust, evidence-based information to assist with the reduction of input costs, without compromising yield or quality, says AHDB senior environment manager Amanda Bennett. “We have listened to what levy payers need from RB209 and have strengthened activity to provide adaptable guidance to meet the nutrient needs of a wide range of farming situations across the UK.
“While RB209 2026 is based on the latest available evidence, we have also invested in research to address some of the most critical knowledge gaps identified during the 2024 review.
“The conflict in the Middle East has refocused attention on fertiliser inputs and RB209 will continue to help farmers apply nutrients in the right place, in the right amount, at the right time, on a healthy soil.”
2026 RB209 updates include:
- Section 1. (Principles of fertiliser use and nutrient management) features improved pH and liming guidance
- Section 2. (Organic materials) accounts better for nutrient cycling. Specifically, it provides improved data on crop-available nutrients from numerous organic materials applied in various situations. The section also includes two new tables on nitrogen availability to crops after anaerobic digestate applications (from both food- and farm-based sources)
- Section 3. (Grass and forage crops) introduces more examples of nitrogen recommendations for different management patterns of grazing and silage
- Section 4. (Arable crops) includes several data refinements and layout improvements
According to the AHDB, the RB209 review identified numerous knowledge gaps associated with Section 3. Earlier this year, it AHDB commissioned a review of grass and forage crop information to recommend how to improve this section in subsequent editions and highlight requirements for further research.
The review also highlighted a demand for stronger guidance on cover crops. Consistency of cover crop information has already been improved in RB209 2026 (across Sections 1 to 4).
The AHDB has also commissioned several short projects since 2024 to address knowledge gaps. A key recent finding is that most nitrogen taken up by cover crops is usually released into the soil within two months of destruction, although release can take longer.
It is researching this further, looking at nitrogen release timings for specific situations, including consideration of destruction methods.
This year’s edition is available from the AHDB’s online catalogue: https://resources.ahdb.org.uk/
