Chapter IX: Nitrate of Soda

Amount of exports 332 Date of discovery of nitrate deposits 333 The origin of nitrate deposits 334 Forbes and Darwin on the theory of their origin 335 Source of nitric acid in nitrate of soda 337 Guano theory of origin of nitrate of soda 337 Nitric acid in nitrate of soda probably derived from sea-weed 339 Appearance of nitrate-fields 340 The method of mining the nitrate of soda 341 Composition of _caliche_ 342 Extent of the nitrate deposits 342 Composition and properties of nitrate of soda 343 Nitrate applied as a top-dressing 344 Nitrate of soda encourages deep roots 344 Is nitrate of soda an exhausting manure? 345 Crops for which nitrate of soda is suited 346 Method of application of nitrate of soda 347 Importance of having a sufficiency of other fertilising constituents 348 Conclusions drawn 349

APPENDIX TO CHAPTER IX.

Total shipments from South America, 1830-1893 351 Total imports into Europe and United Kingdom, 1873-1892 351

CHAPTER X.--SULPHATE OF AMMONIA.

Value of ammonia as a manure 352 Sources of sulphate of ammonia 353 Ammonia from gas-works 353 Other sources 354 Composition, &c., of sulphate of ammonia 355 Application of sulphate of ammonia 356

APPENDIX TO CHAPTER X.

Production of sulphate of ammonia in United Kingdom, 1870-1892 358

CHAPTER XI.--BONES.

Early use of bones 359 Different forms in which bones are used 360 Composition of bones 362 The organic matter of bones 363 The inorganic matter of bones 363 Treatment of bones 364 Action of bones 365 Dissolved bones 368 Crops suited for bones 368 Bone-ash 369 Bone-char or bone-black 369

APPENDIX TO CHAPTER XI.
NOTE
I. Analysis of bone-meal 371
II. Analysis of dissolved bones 371
III. Composition of bone-ash 372
IV. Composition of bone-char 372

CHAPTER XII.--MINERAL PHOSPHATES.

Coprolites 373 Canadian apatite or phosphorite 374 Estremadura or Spanish phosphates 375 Norwegian apatite 376 Charlestown or South Carolina phosphate 376 Belgian phosphate 377 Somme phosphate 378 Florida phosphate 378 Lahn phosphate 379 Bordeaux or French phosphate 379 Algerian phosphate 379 Crust guanos 379 Value of mineral phosphates as manures 380

APPENDIX TO CHAPTER XII.

Imports of phosphates 381

CHAPTER XIII.--SUPERPHOSPHATES.

Discovery of superphosphate by Liebig 382 Manufacture of superphosphate 383 Nature of the reaction taking place 385 Phosphates of lime 385 Reverted phosphate 389 Value of reverted phosphate 391 Composition of superphosphates 391 Action of superphosphates 392 Action of superphosphate sometimes unfavourable 395 Application of superphosphate 395 Value of insoluble phosphates 396 Rate at which superphosphate is applied 397

APPENDIX TO CHAPTER XIII.
NOTE
I. The formulae, and molecular and percentage composition,
of the different phosphates 398
II. Reactions of sulphuric acid and phosphate of lime 398
III. Table for conversion of soluble phosphate into insoluble
phosphate 399
IV. Action of iron and alumina in causing reversion 399
V. Relative trade values of phosphoric acid in different
manures 400

CHAPTER XIV.--THOMAS-PHOSPHATE OR BASIC SLAG.

Its manufacture 401 Not at first used 403 Discovery of its value as a manure 403 Composition of basic slag 404 Processes for preparing slag 406 Solubility of basic slag 408 Darmstadt experiments with basic slag 410 Results of other experiments 413 Soils most suited for slag 414 Rate of application 414 Method of application 416

APPENDIX TO CHAPTER XIV.

Analysis of basic slag 417

CHAPTER XV.--POTASSIC MANURES.

Relative importance 418 Scottish soils supplied with potash 419 Sources of potassic manures 419 Stassfurt potash salts 420 Relative merits of sulphate and muriate of potash 421 Application of potash manures 422 Soils and crops suited for potash manures 423 Rate of application 423

CHAPTER XVI.--MINOR ARTIFICIAL MANURES.

Scutch 427 Shoddy and wool-waste 427 Soot 428

CHAPTER XVII.--SEWAGE AS A MANURE.

Irrigation 431 Effects of continued application of sewage 433 Intermittent irrigation 434 Crops suited for sewage 434 Treatment of sewage by precipitation, &c. 436 Value of sewage sludge 439

CHAPTER XVIII.--LIQUID MANURE 442

CHAPTER XIX.--COMPOSTS.

Farmyard manure a typical compost 446 Other composts 447