THE FOREST NURSERY 255 



27. The Use and Application of Fertilizers of Animal Origin. 



Fertilizers of animal origin are chiefly dried blood, tankage, 

 guano, hoof-meal, bone, and fish. The dung of domestic animals 

 is usually placed in a class by itself, as it is invariably mixed with 

 straw and other litter. Dried blood, tankage, guano, and hoof- 

 meal are particularly rich in available nitrogen, while bone and 

 fish are rich in phosphoric acid. All of the above are concentrated 

 manures of high market value and are chiefly used in nursery 

 practice to enrich low-grade fertilizers or for special purposes. 

 They are valuable for stimulating rapid growth in seedbeds when 

 applied just before the beds are formed or as a top dressing at the 

 beginning of the second year's growth. In the latter case, care 

 should be taken not to overstimulate growth by excessive appli- 

 cation. When applied before seeding, it is best to mix them thor- 

 oughly with the surface soil when the beds are formed. From 

 500 to 1500 pounds per acre should ordinarily be used, depending 

 upon the condition of the soil. A top dressing of fertilizers rich 

 in plant nutrients tends to hold root development near the surface 

 and to produce a root system well suited for transplanting. 



28. FARM MANURES. The dung of domestic animals varies 

 greatly in quality, depending upon its origin, the method of 

 storage, and the amount and kind of litter with which it is inter- 

 mixed. The richer the food of the animal in plant nutrients, the 

 more valuable the excreta as a fertilizer. The less the loss of 

 valuable constituents by exposure to rain and leaching and by 

 uncontrolled fermentation the better the quality. Farm manures 

 are the most useful fertilizers for general purposes that can be used 

 in nursery practice either alone or in combination with other mate- 

 rials composted with them. This is particularly true whenever they 

 can be obtained at reasonable cost. Not only are they rich in plant 

 food, but their large bulk makes them of superior value in improving 

 the physical condition of the soil. Cow manure is better than horse 

 manure because of its greater freedom from litter and the less 

 danger of its becoming " fire-f anged " during storage. Much less 

 time is required for its decomposition. 



Farm manures in the fresh state should be used in nursery practice 

 only when applied to farm crops or soiling crops in rotation with 

 nursery crops. When fresh farm manures are received at the 

 nursery, they should be rotted either out of doors in piles known as 

 compost heaps or under cover where loss from leaching is prevented. 



