Phosphorus: A Vital Non-Renewable Resource

Farming Futures WorkshopThursday, 11 November 2010

Matt Taylor: Environmental Scientist

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P15

30.97

Phosphorus=

Soils in the UK are naturally deficient in phosphorus

So we need to add phosphorus to supply plant needs

Historically livestock manures used, but more recently phosphate fertilisers

“We can get around declining oil production by using alternatives: but we have no

alternatives to rock phosphate”. Andy Barr, Farmers Weekly, June 2009

Source: Cordell, D., Drangert, J-O. and White, S. (2009).

We’ve used up the good stuff!!!

Overall phosphate application rate for Great Britain

British Survey of Fertiliser Practice (2009)

There is another way….

Organic materials: a valuable source of phosphorus

•Livestock manures

•Biosolids

•Compost

•Digestate (manure-based)

•Paper crumble (biological treated)

•Mushroom compost

•BioCompost

•etc.

Estimated quantities of organic materials recycled to land in the UK

Type Fresh weight

(million tonnes)

Livestock manure 90

Biosolids 3-4

Compost 1.3

Paper crumble 0.7

Digestate 0.1

Industrial ‘wastes’ 6-7

Typical total nutrient content of various organic materials (kg/tonne fresh weight)

Material type

Dry matter

(%)

Nitrogen

(N)

Phosphate

(P2O5)

Potash (K2O)

Cattle FYM 25 6.0 3.2 8.0

Pig slurry 4 3.6 1.8 2.4

Biosolids 25 11 18 0.6

Green compost

60 7.5 3.0 5.5

Paper crumble

30 7.5 3.8 0.4

The “Fertiliser Manual (RB209)”

In summary

Population growth will increase the demand for phosphorus fertiliser

Rock phosphate reserves and quality are declining

Farming in the UK is not sustainable without phosphorus: - We need to focus on the efficient use of

renewable resources, such as livestock manures, compost, biosolids, digestate etc.

Thank you!

Farming Futures WorkshopThursday, 11 November 2010

Any questions?