Increase of Manure by Turnips. 69 



of this extensive field of sheepwalk into arable 

 land, whence the finest samples of white peas 

 and barley are now produced, neither these nor 

 any other kind of corn could be obtained until 

 the surface had been well supplied with its 

 native crag. 



Such adventitious sources of fertilizing ma- 

 terials within the reach of the farmer, render 

 unnecessary the extent of green crops which a 

 less favoured neighbour is compelled to raise as 

 sources of manure. 



To place this in a clear point of light, let it 

 be supposed that the average produce of straw 

 is a ton an acre that of turnips, twenty-four 

 tons an acre. If the produce of the latter be 

 consumed with that of two acres of the former, 

 sixteen tons of manure will be obtained, while 

 the same quantity of straw only eaten by 

 cattle would produce but six tons, and that of 

 very inferior quality. Thus the farmer who has 

 sufficient turnips to consume his straw makes 

 manure in the proportion of eight to three with 

 him who has none. Hence it follows that, where 

 it can be accomplished, the turnip crop should 

 bear a proportion of one-third to that of the 

 grain ; on a supposition that two parts of the 

 straw are eaten with the turnips, and the re- 



