As the poultry litter is subjected only to incineration, the elements in Cropkare are only those that were in the litter. However, every batch of Cropkare is sampled and analysed for nutrients and metals. This regular monitoring gives the user confidence in the product.

Whilst poultry litter can simply be applied to land, regulations apply to the products of incineration if they are to be used as a fertiliser. To comply with regulations, and to provide confidence to users, the metal concentrations in Cropkare are regularly measured and results compared with statutory application limits. In the table below, application rates of metals in Cropkare (based on analyses of four shiploads) are compared with statutory limits set by the Sludge (Use in Agriculture) Regulations. In all cases, even at high rates of application of Cropkare, applications of metals are much smaller than the limits.

 

Metal application rate (g/ha/year)

Cropkare applied (kg/ha):

250

500

750

1000

Statutory limit
(average per year over ten years)

Arsenic

0.9

1.8

2.6

3.5

700*

Cadmium

0.3

0.6

0.9

1.2

150

Chromium

4.2

8.4

12.6

16.7

15000*

Copper

73

146

218

291

7500

Lead

2.9

5.9

8.8

11.7

15000

Mercury

0.3

0.5

0.7

1.0

100

Nickel

3.8

7.7

11.5

15.4

3000

Zinc

416

831

1247

1663

15000

* Limit stated in the Code of Practice for Agricultural Use of Sewage Sludge.

The incineration of the poultry litter in the power station destroys all pathogens that were present in the poultry litter.

Cropkare has no smell so application does not cause odour problems.