(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 applied _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 265 Setting it out in _heaps_ 265 Spreading it _broadcast_, and letting it lie 266 Ploughing it in immediately 267 Value and function of farmyard manure-- As a supplier of the necessary elements of plant-food 268 As a "universal" manure 269 Proportion in which _nitrogen_, _phosphoric acid_, and _potash_ are required by crops 269 Proportion in which they are present in farmyard manure 270 Farmyard manure _poor in nitrogen_ 270 Lawes' and Gilbert's experiments 271 How it may be best reinforced by the use of "artificials" 271 Indirect value of farmyard manure as a supplier of _humus_ to the soil 273 Its influence on soil-texture 273 Its influence in setting free inert fertilising matter in the soil 274 Rate at which farmyard manure ought to be applied 275 Lasting nature of farmyard manure 276 Its economic value 276