1. Your slurry
Typical "book" values from AHDB's RB209. Real slurry varies — sample yours for a truer figure.
2. How you spread it
Phosphate and potash count in full. Nitrogen is the one that escapes to the air — spread it precisely and promptly and you keep more of it (and more of the money).
Fertiliser value of this slurry
Slurry value, in plain English
How much is slurry actually worth?
It depends on volume, type, dry matter and how you spread it. Typical 6% cattle slurry carries about £3–£4 of nutrients per cubic metre. Across a full store it adds up fast — which is rather the point.
Does it really replace bagged fertiliser?
Yes — the N, P and K substitute directly for bought fertiliser. Phosphate and potash are used almost in full over the rotation; nitrogen depends on how and when you spread. Target your low-index fields for the most benefit.
Why does my spreading method change the figure?
Nitrogen gases off as ammonia after spreading. A trailing shoe, dribble bar or shallow injection in spring keeps far more in the ground than a splash plate — so better kit pays for itself in retained nitrogen.
And the carbon saving?
Making nitrogen fertiliser is carbon-heavy — roughly 3 kg of CO₂ for every kg of nitrogen. Spread your own slurry instead and you simply never make those emissions. Free halo included.
Figures, prices, carbon & sources
Crop-available nitrogen is a share of total N depending on method (spring); phosphate and potash are valued in full. CO₂ saved is the manufacturing footprint of the fertiliser you don't buy.
Nitrogen available by method (spring):
Fertiliser prices (£/kg nutrient, AHDB GB fertiliser prices, early 2026) & carbon (kg CO₂e/kg nutrient, manufactured-fertiliser footprint, Carbon Trust / Fertilizers Europe range):
Sources: AHDB Nutrient Management Guide (RB209) Section 2; AHDB GB fertiliser prices; published fertiliser carbon footprints (CF Fertilisers / Fertilizers Europe). Cattle values anchored; pig values est; carbon figures are typical and for illustration.
For guidance only. Book values vary with dry matter, diet and dilution — sample your slurry or use AHDB MANNER-NPK for accuracy, and always spread to a soil and crop need (Farming Rules for Water). Prices and carbon figures move. Carbon equivalents are a rough, friendly illustration, not a certified audit. Staging build: pig figures await sign-off.