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.

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 THEFormula Equivalent to Ammonia(NH3)Per Cent Factor for calculatingFertilizerMaterial from Nitrogen Factor for calculatingFertilizerMaterial 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 aFormula Phosphorus (P)Per Cent Phosphoric Acid (P2O5)Per Cent Factor for calculatingFertilizerMaterial fromPhosphorus Factor for calculatingFertilizerMaterial fromPhosphoricAcid 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 calculatingFertilizerMaterial fromPotassium Factor forCalculatingFertilizerMaterial fromPotash Muriate of potash 41.5 50 Multiply by48 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.