190 AHTinC'lAL FORMATION OF WOODS. 



hoe, and harrowed so as to divide it linely. The nursery 

 operations can then be commenced, or the {ground, after 

 manuring, be used during one season for the cultivation of a 

 field crop, such as turnips, mangold-wurzel, or potatoes, so 

 that the additional cultivation may produce a further division 

 of the soil. After the removal of the crop, the ground is 

 ploughed and left fallow over a second winter, when it should 

 be quite ready to serve as a nursery. 



//. MnnuriiKi. 



On good soil plants can be raised foi- a number of years 

 without manuring, but sooner or later tliis becomes necessary. 

 Although the demands on the soil of a growing crop of trees 

 are comparatively small, yet, through the uninterrupted 

 grow'ing and removal of seedlings, considerable quantities of 

 various substances are taken out of it, wliich must be 

 replaced. At the same time our knowledge as to the kinds 

 and quantity of materials which must be supplied to the soil 

 is as yet deficient. 



Manuring, or amelioration generally, has for its object to 

 improve not only the chemical composition, but also the 

 physical qualities of the soil. If, at the outset, the soil should 

 not be of the proper consistency, it must be improved by the 

 admixture of sand to a stifi" soil, and by that of loam to an 

 excessively loose and light soil. At the same time, and at 

 any rate after a few years, the soil can be specially manured 

 by bringing into it stable manure, guano, bone dust, nitrates, 

 phosphates, potash, lime, or magnesia. All such manures 

 are however expensive, and, with a view to recovering a part 

 of the outlay, the soil may be used for one year for the pro- 

 duction of a field crop immediately after being manured. 

 This measure is further useful, because it gives the soil a 

 change of crop, while it receives at the same time a thorough 

 working. Scotch nurserymen, as a rule, act as follows : they 

 treat their nursery ground under a rotation of three or four 

 years, say ihree, tor forest plants, then they manure, take oil 



