|
| Loss due to use of gunpowder | 148 |
| Loss due to sewage disposal | 149 |
| Our artificial nitrogen supply | 150 |
| Nitrate of soda and sulphate of ammonia | 150 |
| Peruvian guano | 151 |
| Bones | 151 |
| Other nitrogenous manures | 152 |
| Oil-seeds and oilcakes | 153 |
| Other imported sources of nitrogen | 153 |
| Conclusion | 153 |
|
| APPENDIX TO CHAPTER III. |
| NOTE | |
| I. | Determination of the quantity of nitrogen supplied by rain, as ammonia and nitric acid, to an acre of land during one year | 155 |
| II. | Nitrogen in soils at various depths | 156 |
| III | Nitrogen as nitrates in cropped soils receiving no nitrogenous manures, in lb. per acre (Rothamsted soils) | 157 |
| IV. | Nitrogen as nitrates in Rothamsted soils | 157 |
| V. | Examples of increase of nitrogen in Rothamsted soils laid down in pastures | 158 |
| VI. | Loss by drainage of nitrates | 158 |
| VII. | Examples of decrease of nitrogen in Rothamsted soils | 159 |
| VIII. | Amount of drainage and nitrogen as nitrates in drainage-water from unmanured bare soil, 20 and 60 inches deep | 160 |
|
| CHAPTER IV.—NITRIFICATION. |
| Process of nitrification | 161 |
| Occurrence of nitrates in the soil | 162 |
| Nitre soils of India | 162 |
| Saltpetre plantations | 163 |
| Cause of nitrification | 165 |
| Ferments effecting nitrification | 167 |
| Appearance of nitrous organisms | 168 |
| Nitric organism | 169 |
| Difficulty in isolating them | 169 |
| Nitrifying organisms do not require organic matter | 169 |
| Conditions favourable for nitrification— |
| Presence of food-constituents | 170 |
| Presence of a salifiable base | 171 |
| Only takes place in slightly alkaline solutions | 172 |
| Action of gypsum on nitrification | 173 |
| Presence of oxygen | 173 |
| Temperature | 175 |
| Presence of a sufficient quantity of moisture | 176242 |
| Manures produced by the different animals— |
| Horse-manure— |
| Amount produced | 243 |
| Its nature and composition | 243 |
| Amount of straw used for litter | 244 |
| Sources of loss on keeping | 245 |
| How to prevent loss | 245 |
| Use of "fixers," and the nature of their action | 245 |
| Cow-manure— |
| Amount produced | 248 |
| Its nature and composition | 249 |
| Amount of straw used as litter | 248 |
| Sources of loss on keeping | 249 |
| Advantages of short dung | 249 |
| Pig-manure— |
| Amount produced | 250 |
| Its nature and composition | 250 |
| Amount of straw used as litter | 251 |
| Sheep-manure— |
| Amount produced | 251 |
| Nature and composition | 251 |
| Amount of straw used as litter | 252 |
| Methods of calculating amount of manure produced on the farm | 252, note |
| Fermentation of farmyard manure— |
| Action of micro-organic life in producing fermentation | 255 |
| Two classes of bacteria active in this work, aerobies and anaerobies | 255 |
| Conditions influencing fermentation— |
| Temperature | 256 |
| Openness to the air | 256 |
| Dampness | 257 |
| Composition of manure | 257 |
| Products of fermentation | 257 |
| Analyses of farmyard manure— |
| Dr Voelcker's experiments | 259 |
| Variation in composition | 259 |
| Amounts of moisture, organic matter (containing nitrogen), and mineral matter | 260 |
| Its manurial value compared with nitrate of soda, sulphate of ammonia, and superphosphate | 260 |
| Comparison of fresh and rotten manure— |
| The nature and amount of loss sustained in the process of rotting | 261 |
| Ought manure to be appliled fresh or rotten? | 262 |
| Relative merits of covered and uncovered manure-heaps | 263 |
| Methods of application of farmyard manure to the field— |
| Merits and demerits of the different methods | 265Mechanical functions of lime | 455 |
| Action on soil's texture | 455 |
| Lime renders light soils more cohesive | 457 |
| II. | Chemical action of lime | 457 |
| III. | Biological action of lime | 459 |
| Action of lime on nitrogenous organic matter | 460 |
| Recapitulation | 461 |
|
| CHAPTER XXI.—INDIRECT MANURES—GYPSUM, SALT, Etc. |
| Gypsum | 462 |
| Mode in which gypsum acts | 462 |
| Salt | 465 |
| Antiquity of the use of salt | 465 |
| Nature of its action | 465 |
| Salt not a necessary plant-food | 466 |
| Can soda replace potash? | 466 |
| Salt of universal occurrence | 467 |
| Special sources of salt | 468 |
| The action of salt | 468 |
| Mechanical action on soils | 470 |
| Solvent action | 470 |
| Best used in small quantities along with manures | 472 |
| Affects quality of crop | 472 |
| Rate of application | 473 |
|
| CHAPTER XXII.—THE APPLICATION OF MANURES. |
| Influence of manures in increasing soil-fertility | 474 |
| Influence of farmyard manure on the soil | 475 |
| Farmyard manure v. artificials | 476 |
| Farmyard manure not favourable to certain crops | 477 |
| Conditions determining the application of artificial manures | 477 |
| Nature of the manure | 478 |
| Nitrogenous manures | 478 |
| Phosphatic manures | 480 |
| Potash manures | 480 |
| Nature of soil | 481 |
| Nature of previous manuring | 482 |
| Nature of the crop | 483 |
| Amounts of fertilising ingredients removed from the soil by different crops | 484 |
| Capacity of crops for assimilating manures | 486 |
| Difference in root-systems of different crops | 488 |
| Period of growth | 489[Pg xxviii] |
| Variation in composition of cro
|
| Table III. Results of subsequent forty years | 562 |
| Tablel IV. Wheat grown continuously with farmyard manure (14 tons per annum) | 564 |
| Table V. Wheat grown continuously with artificial manures | 565 |
| Table VI. Experiments on the growth of barley, forty years, 1852-91 | 566 |
| Table VIII. Experiments on the growth of oats, 1869-78 | 567 |
| Table IX. Experiments on mangel-wurzel | 568, 569 |
| Table X. Experiments with different manures on permanent meadow-land, thirty-six years, 1856-91 | 570 |
| Table XI. Experiments on the growth of potatoes— average for five seasons, 1876-80 | 571 |
| Table XII. Experiments on growth of potatoes (continued)—average for twelve seasons, 1881-92 | 572 |
| _______________ |
| Index | 573 |
