CHAPTER IV 



MANURES 



29. Plant Foods. 30. Artificial Manures. 31. Properties of 

 Artificial Manures, 32. Nitrate of Soda. 33. Muriate of Potash. 

 34. Phosphatlc Fertilizers. 35. Fresh Stable Manures. 36. 

 Belgium and Holland. 37. Mammal Experiments. 



29. Plant Foods. A manure is any substance containing 

 plant food which, when incorporated with the soil, decomposes 

 and takes such a form that it can be readily assimilated by 

 the plants. 



Most soils are generally well supplied with plant food, but 

 not always in a soluble condition. Changes of weather, heat, 

 frost, snow, and rain, together with good cultivation, assist 

 these several foods to dissolve or change until they are in the 

 state capable of being absorbed by the plant. 



The three essential plant foods in most fertile soils are 

 nitrogen, phosphoric acid, and potash. One or other of these 

 is occasionally and temporarily exhausted. Any one may be 

 restored to the soil again, but the farmer must exercise careful 

 observation to ascertain which kind is required. 



Occasionally lime is applied as a developer of the natural 

 plant food contained in heavy soils. " Fallen " lime is a 

 deliquescent. It readily absorbs moisture, dissolves acids, 

 opens up the soil and improves its texture ; it decomposes 

 decaying vegetable matter, which, in the process, generates 

 heat to the soil and simultaneously produces carbonic acid 

 and ammonia, both important plant foods. 



It is for each farmer to ascertain the specific food manures 

 requisite for the sustenance of flax on his own particular soils. 

 At the present time it is possible to learn, from various sources, 

 how to act precisely in each specific case. 



30. Artificial Manures. Artificial and chemical manures 

 are used because they contain plant food which is in a state 



31 



