ARCHIVE: Fertiliser Manual (RB209)

Summary of Main Changes from Previous Edition


Overall presentation

  • To make its use as easy as possible, the layout of the Manual, Section and Appendix numbers remain largely the same as those in the 7th Edition of RB209: Section 7 covers Biomass Crops and Section 8 covers Grass. However, every section has been fully revised, making use of all available peer-reviewed data and with full and comprehensive consultation.

General information

  • Section 1, describing the principles of nutrient management and fertiliser use, has been extensively revised. More information on meeting environmental objectives is included.

Soil Nitrogen Supply (SNS) Index system

  • The SNS system has been fully revised. Definitions of soil type have been made clearer and users are directed to a flowchart and a table to make identification easier. 
  • The SNS Index tables have been revised. Some crops, such as ‘Uncropped land’ (previously ‘Set-aside’) have moved down an Index.

Revised nitrogen recommendations

  • Optimum nitrogen requirements for all arable crops have been revised and those for wheat are now based on a breakeven ratio of 5:1 (cost of nitrogen as p/kg N divided by value of crop as p/kg yield or, put another way, 5 kg of grain are needed to pay for 1 kg N.).

Updated organic manures section

  • The Organic Manures section has been expanded to include nutrient contents for more types of livestock manures, biosolids, composts and some other organic materials that are commonly applied to agricultural land (‘content’ is used rather than the more accurate ‘concentration’ as this is common usage). 
  • The nutrient contents of livestock manures and biosolids have been updated and expanded guidance provided on their readily available nitrogen contents. 
  • MANNER-NPK has been used to provide updated guidance on crop available nitrogen. 
  • The table of excreta and nutrients produced during the period when livestock are housed has been updated. 
  • Enhanced guidance has been provided on the benefits of using bandspreading and shallow injection slurry application methods.
  • Advice on how to interpret laboratory analyses has been provided and manure sampling guidelines updated.

New approach to grassland recommendations

  • For grassland the amounts are based on a new systems based approach which helps determine the levels of fertiliser required to produce the grass needed in different farming systems at varying levels of intensity. This approach recognises that for many situations fertiliser application rates for grassland need not be based solely on the on-farm economic optimum. The grassland chapter in this Manual lists the main differences between the new approach and the grassland chapter in the 7th edition of RB209.

New recommendations for biomass crops

  • Recommendations for biomass crops are included for the first time.

Potatoes

  • Average nitrogen recommendations have decreased slightly. Phosphate and magnesium recommendations have been reduced, but there are slightly increased recommendations for potash.

Sugar Beet

  • Nitrogen recommendations have been increased slightly, particularly for an SNS Index of greater than 2. It has been made clear that, if growers want to achieve the optimum yield they will need to ensure that the P and K Index is at least 2.

Sulphur recommendations

  • An up-to-date map of sulphur deposition has been supplied by the NERC Centre for Ecology and Hydrology. 
  • The risk of sulphur deficiency is becoming more widespread. Recommendations for the diagnosis and prevention of deficiency remain the same but the need for sulphur fertilisers is emphasised.

Phosphate and potash recommendations

  • Emphasis is placed on maintaining soil target Indices and replacing offtake in harvested crops.
  • Build-up applications at Indices 0 and 1 have been increased slightly and run-down applications at Indices above target have been decreased.
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