Incompatibles in fertilizer mixtures (U. S. Dept. Agric).

The danger of indiscriminate mixing of fertilizing materials should be understood, and a diagram (Fig. 4) is given to indicate what combinations may be safely made of some of the more common materials.

Antagonistic Ingredients Of Fertilizers 26

In this diagram the heavy lines unite materials which should never be mixed, the double lines those which should be applied immediately after mixing, and the single lines those which may be mixed at any time.

Table for calculating raw fertilizer material required per ton by mixtures of given composition

Fertilizer Material as called for in a Formula

Per Cent of Nitrogen (N)

IN THE

Formula

Equivalent to Ammonia

(NH3)

Per Cent

Factor for calculating

Fertilizer

Material from Nitrogen

Factor for calculating

Fertilizer

Material from Ammonia

Nitrate of soda

15.0

18.2

Multiply by 133

Multiply by 110

Dried blood

12.4

15.0

161

133

Sulfate of ammonia

20.0

24.3

100

86.4

Cotton-seed meal

7.0

8.5

286

235

Table for calculating raw fertilizer material required per ton by mixtures of given composition. — Continued

Fertilizer Material, as called for in a

Formula

Phosphorus (P)

Per Cent

Phosphoric Acid (P2O5)

Per Cent

Factor for calculating

Fertilizer

Material from

Phosphorus

Factor for calculating

Fertilizer

Material from

Phosphoric

Acid

Acid phosphate

6.1

14.0

Multiply by 328

Multiply by 143

Basic slag

7.0

16.0

285

125

 

Potassium (K)

Per Cent

Potash (K2O)

Per Cent

Factor for calculating

Fertilizer

Material from

Potassium

Factor for

Calculating

Fertilizer

Material from

Potash

Muriate of potash

41.5

50

Multiply by

48

Multiply by 40

Kainit

10

12

200

167

Sulfate of potash

40

48

50

42

To mix a 2-8-6 fertilizer, i.e. a fertilizer containing 2 per cent nitrogen, 8 per cent phosphoric acid and 6 per cent potash, the quantities of raw material may be calculated as follows: —

2 X 133 = 266 lb. nitrate of soda 8 X 143 = 1144 lb. acid phosphate 6 X 40 = 240 lb. muriate of potash

1650 lb. mixture

If dried blood were used instead of nitrate of soda, it would be necessary to use 322 lb. of it to secure the required amount of nitrogen (2 x 161 = 322) in the ton. If the formula called for ammonia rather than nitrogen, the multiple would be 110 or 133 respectively.