BURNING OVER THE SOIL FOR CULTIVATION. 167 



be the most profitable crop, paying nearly all the ex- 

 penses that have been incurred for the improvement. 

 The moor will then be in such a condition as to produce 

 for several years a crop of oats or rye ; but it is best 

 not to exhaust the fertility of the soil too much, and 

 rather let it rest and enter upon a fallow of several 

 years, after which forest-planting may be commenced 

 successfully. At all events, the soil, by the several 

 burnings and cultivatings, will be chemically so much 

 changed that its obnoxious ingredients are destroyed, 

 and components favorable for plant-growth which for- 

 merly were locked up, become unlocked and efficient. 

 Precautions have, however, to be taken not to burn too 

 deep into the moor-ground, because only the heath plan- 

 tation should be destroyed, while the underlying inac- 

 tive elements which originated from the decayed aquatic 

 plants will be brought into use by the drainage. For this 

 reason the fires should run over the top soil as quickly 

 as possible, and, therefore, the ignition be made when 

 the weather is very dry and fresh winds are blowing. It 

 is true that then the ashes are lost, but the residue of 

 the coals is what stimulates the vitality of the underly- 

 ing soil. In order to prevent damages which may occur 

 when the fire penetrates too deep into the earth it is 

 advisable to close the ditches so as to keep the water- 

 table up to a desired height. 



