[] [] [index]

  Composition of some fertilisers.

 

 

 

 

 

 

 

 

 

 

 

 

 

  Proportions in %

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N

P

K

Zn

MgO

Fe

Mn

Cu

Bo

Mo

SO3

CaO

 

Product

 

 

 

 

 

 

 

 

 

 

 

 

Comments

Growmore

7

7.0

7.0

 

 

 

 

 

 

 

 

 

Granules

Blood,fish, bone

5

5.0

6.5*

 

 

 

 

 

 

 

 

 

Slow (*K is added)

Phostrogen

10

10.0

27.0

 

1.3

0.4

0.02

 

 

 

 

 

y1995

Phostrogen

14

10.0

27.0

0.01

2.5

0.04

0.02

0.01

0.01

0

15

2

y2000 2% lime

Phostrogen

14

10.0

27.0

0.01

2.5

0.04

0.02

0.01

0.01

0

7.5

2

y2006 2% lime

Vitax

19

19.0

19.0

 

0.2

0.05

0.03

0.03

0.01

0

 

 

 

Vitax conifer/shrub

10

7.5

10.2

 

1.8

0.01

0

0

0.01

0.04

 

 

 

Vitax Q4

5

7.5

10.0

 

3

0.2

0.01

0.02

0.01

0.04

 

 

Different chelation

Miracle Gro

15

30.0

15.0

0.06

 

0.15

0.05

0.07

0.02

0

 

 

y1993

Miracle Gro

15

30.0

15.0

0.03

 

0.15

0.05

0.03

0.02

 

 

 

y2006

Miracle Gro outdoor

6

5.0

5.0

0

 

0.03

0.01

0.01

0.01

0

 

 

Liquid

Miracle Gro Azalea

9

14.0

19.0

 

3

0.5

 

 

 

 

 

 

Slow release

B&Q General Purpose

5

3.0

6.5

 

 

 

 

 

 

 

 

 

 

B&Q Fruit food

4

2.0

6.0

 

 

 

 

 

 

 

 

 

Liquid

B&Q plant food

12

10.0

27.0

 

2.2

0.4

0.02

 

 

 

13.8

 

 

B&Q rose

11

7.5

10.5

 

4.5

 

 

 

 

 

 

 

y1995

B&Q rose

5

5.0

10.0

 

0.3

0.02

0.07

0.04

0

 

 

 

y2000

B&Q rose

5

5.0

10.0

0

1

0.02

0.01

0

0.01

0

 

 

y2006

B&Q flower/bed

7

7.0

14.0

0.01

 

0.1

0.05

0.03

0.01

0

 

 

 

B&Q rhodo/heather

6

5.0

9.0

 

 

0.18

 

 

 

 

 

 

plus 0.18% chelated iron

B&Q liquid blood and bone

8

6.8

7.2

 

 

 

 

 

 

 

 

 

plus trace elements

Osmocote

14

13.0

13.0

 

 

 

 

 

 

 

 

 

temperature controlled release

Hoof and horn

13

 

 

 

 

 

 

 

 

 

 

 

Slow acting

Dried blood

11

 

 

 

 

 

 

 

 

 

 

 

Slow acting

Bone meal

4

18.0

 

 

 

 

 

 

 

 

 

 

7.8 P soluble slow

Magnesium sulphate

 

 

 

 

10

 

 

 

 

 

13

 

Epsom Salts MgSO4

Ammonium Sulphate

21

 

 

 

 

 

 

 

 

 

24

 

Sulphate of Ammonia (NH4)2SO4

Phosphorous pentoxide

 

14.7

 

 

 

 

 

 

 

 

 

 

Super- phosphate 7.6 P soluble P2O5

Potassium oxide

 

 

48.0

 

 

 

 

 

 

 

1

 

Sulphate of Potash 39.9 K soluble K2O

Lime/limestone

 

 

 

Dolomitic limestone contains magnesium in addition

CaO/CaCO3

Levington liquid

6

4.0

6.0

0

0.03

0.01

0

 

 

 

 

 

plus 2% chelated iron

Lev Tomorite

4

4.5

8.0

 

0.03

 

 

 

 

 

 

 

Liquid

Lev Flowerite

4

3.0

6.0

0.01

0.02

0.03

0

 

 

 

 

 

Different chelation

Sequestrene

 

 

 

 

6

2+1.2 +0.8

3.2

 

 

 

 

 

Different chelation

Miracid

30

4.4

8.3

0.07

 

0.3

0.05

0.07

0.02

0

 

 

Soil acidifier

Chempak Base

3.2

3.4

3.6

0.1

4

0.38

0.13

0.05

0.05

0

 

 

Compost base

Chempak 3

20

20.0

20.0

0.05

yes

0.2

0.02

0.01

0.02

0

 

 

Other ratios of NPK

Hydrangea color

 

 

 

 

 

 

 

 

 

 

 

 

Aluminium Sulphte/Iron Sulphate

A. Bowers Erica

5

4.0

7.0

0

0.01

0.2

0

0

0

0

 

 

 

Toprose

5

6.0

12.0

 

2.5

0.6

 

 

 

 

 

 

& gypsum(CaSO4)

Homebase Tom

11

6.0

18.0

 

1.4

0.8

0.03

 

 

 

10.8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.Percentages of soluble/insoluble vary. For example Growmore is labelled 7-7-7 for NPK,  but is actually 7-3.1-5.8 in  soluble form. It is therefore high in nitrogen, not balanced as usually considered. Also, most of what you see is the clay based carrier used for convenience of distribution.

2.Chelation processes vary, and are not always specified.

3.Price comparisons are difficult as dilution or distribution quantities vary.

4.Nitro-chalk = Calcium carbonate+ammonium nitrate

5.Nitrate of soda = sodium nitrate

6.The ROI Statutory Analysis is sometimes given. This seems to show a slightly lower NPK figure.

7.None of the values given imply value for money or recommended dilutions.

8. The constituents of some fertilisers have been changed over the years. The effects on plants are difficult to predict.

9. Seed and plant composts like John Innes already contain nutrients. Typical content of these and other manures can be found at: http://www.ihrs.ac.uk/courses/organic_market.html               This is from the Institute for Horticultural and Rural Studies at Hestercombe, Somerset.

10. The application of excess nutrient to a soil when it is not required is harmful. Always use sparingly, and preferably only when there is evidence that specific nutrients are needed. Seeds contain their own nutrients for germination.

 

  

                     Fertilisers


The content of many packaged fertilisers changes over time.  Perhaps it is in the light of improved knowledge about plant growth, availability of chemicals, restrictions on some substances or cost. Only the manufacturer would know. Some basic types contain the basic nutrients, some contain additional trace elements. The main problem with selection  is that without detailed testing of the soil, you don't know which chenicals are required to restore the balance. Experienced gardeners will observe the growth deficiencies of existing crops and assess what is needed.  There is a tendency to apply everything, but bear in mind that you might be applying too much of one or not enough of another. Over dosing does more harm than good.