The Fertiliser Manual

The main differences from the previous version are detailed below:

• Soil Nitrogen Supply – soil types have been clearer and some crops, such as uncropped land have moved down an index.
• Nitrogen recommendations – optimum N recommendations for wheat are now based on a breakeven ratio (BER) of 5:1 (previously 3:1). There are also tables to show adjustments according to changes in nitrogen price or crop value. 
• Organic Manures – This section has been expanded to include a larger number of manure types, including biosolids and composts. The nutrient contents of livestock manures and biosolids have been updated and Manner-NPK has been used to provide guidance on crop available nitrogen.
• Grassland recommendations – By far the largest change from the previous edition, the grassland recommendations are now based on the grass requirement for the farming system, rather than maximising the potential of grass. In this sense recommendations are based on milk yields, concentrate use and stocking rates.
• Biomass crops – These have been included for the first time
• Potatoes – Average nitrogen recommendations have decreased slightly, phosphate and magnesium recommendations have been reduced, however there is a slight increase in potash recommendations.
• Sugar beet – Nitrogen recommendations have increased slightly, especially at an SNS greater than 2.
• Sulphur recommendations – The sulphur deposition map has been updated by CEH Edinburgh. Although recommendations for sulphur remain the same, emphasis is placed on the need for sulphur fertilisers to represent the increasing risk of sulphur deficiency.
• Phosphate and Potash recommendations – Build-up applications at indices 0 and 1 have slightly increased, while run-down applications at high indices have decreased.

In reality, the differences between the old RB209 and the current Fertiliser Manual are very slight, although annoyingly the colour of the Arable and Forage section has been switched with the Vegetables section. The main difference is the date now present on every page, allowing each page to be individually revised over time, with new pages available to download from the Defra website. This should hopefully avoid the long, drawn out process of revision that occurred this time.

The Arable section has changed only very slightly, mainly due to wheat recommendations being based on a higher BER, accounting for the higher rates required by the newer varieties. There have been rates included for low SNS indices for the majority of soil types, which were previously greyed out as an unlikely occurrence.