This section is from the "Farm And Garden Rule-Book" book, by L. H. Bailey. Amazon: Farm and garden rule-book

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 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.

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