ARCHIVE: Fertiliser Manual (RB209)

Industrial ‘wastes’

The recycling of industrial ‘wastes’ to agricultural land is controlled by the Environmental Permitting Regulations. These Regulations allow the spreading of some industrial ‘wastes’ onto agricultural land under an exemption providing that certain conditions are met i.e. that they can be shown to provide ‘agricultural benefit’ or ‘ecological improvement’. The application of such ‘wastes’ must be registered with the Environment Agency who will supply advice on the Regulations and their interpretation. The typical nutrient content of selected industrial ‘waste’ materials that are commonly recycled to farmland are summarised below.

Paper crumble – total nutrients

Typical total nutrient content (fresh weight basis)

 

Dry matter (%)

Total Nitrogen
(kg N/t)

Total phosphate
(kg P2O5/t)

Total potash
(kg K2O/t)

Total S
(kg SO3/t)

Total Mg
(kg MgO/t)

Chemically / physically treated

40

2.0

0.4

0.2

0.6

1.4

Biologically treated

40

7.5

3.8

0.4

2.4

1.0

ND = no data
To convert kg/t to units/ton, multiply by 2.

Following the application of chemically/physically treated paper crumble nitrogen ‘lock-up’ commonly occurs due to the wide carbon: nitrogen ratio of the paper crumble which immobilises soil nitrogen. As a general rule, around 0.8 kg of inorganic nitrogen is required per tonne (fresh weight) of paper crumble applied to compensate for the nitrogen ‘lock-up’ in the soil. As biologically treated paper crumble has a lower carbon: nitrogen ratio, nitrogen ‘lockup’ is not usually experienced following land spreading.

Mushroom compost – total nutrients

Typical total nutrient content (fresh weight basis)

 

Dry matter (%)

Total Nitrogen
(kg N/t)

Total phosphate
(kg P2O5/t)

Total potash
(kg K2O/t)

Total S
(kg SO3/t)

Total Mg
(kg MgO/t)

Mushroom compost

35

6.0

5.0

9.0

ND

ND

ND = no data
To convert kg/t to units/ton, multiply by 2.

 

Water treatment cake – total nutrients

Typical total nutrient content (fresh weight basis)

 

Dry matter (%)

Total Nitrogen
(kg N/t)

Total phosphate
(kg P2O5/t)

Total potash
(kg K2O/t)

Total S
(kg SO3/t)

Total Mg
(kg MgO/t)

Water treatment cake

25

2.4

3.4

0.4

5.5

0.8


To convert kg/t to units/ton, multiply by 2.

 

Food industry 'wastes' – total nutrients

Typical total nutrient content (fresh weight basis)

 

Dry matter (%)

Total Nitrogen
(kg N/t)

Total phosphate
(kg P2O5/t)

Total potash
(kg K2O/t)

Total S
(kg SO3/t)

Total Mg
(kg MgO/t)

Dairy

4

1.0

0.8

0.2

ND

ND

Soft drinks

4

0.3

0.2

Trace

ND

ND

Brewing

7

2.0

0.8

0.2

ND

ND

General

5

1.6

0.7

0.2

ND

ND


ND = no data
To convert kg/t to units/ton, multiply by 2.

Typically industrial ‘waste’ materials are supplied to farmers with specific nutrient content data and advice on how to best manage these materials to the benefit of soils and crops.

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