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applications of manure, materials which snpj)ly phosphates, 

 potash and perhaps also lime should be ein})loyed. During 

 the past few years large quantities of phosphatic or basic 

 slag meal have been employed on the college farm at Am- 

 herst, and with results which are eminently satisfactory. 

 This slag meal should contain about 10 to 20 per cent of 

 actual ])hosphoric acid. This acid is not in so highly avail- 

 able a form as in acid phosphate or dissolved bone black. On 

 the other hand, it appears to be more available than the 

 phosphoric acid in any of the phosphatic rocks, or even in 

 most of the forms of bone. Besides phosphoric acid, the slag 

 meal contains a largo amount of lime, and this, while less 

 effective in correcting the faults of a sour soil than quicklime, 

 must prove valuable in helping to prevent soils which have 

 once been brought into proper condition from becoming sour 

 again. On such soils as those at Amherst the application of 

 slag meal at the rate of some 500 or GOO pounds per acre in 

 connection with such dressings of manure as have been indi- 

 cated appears to be sufficient. In addition to the slag meal, 

 there will be needed on most soils to bring them into suitable 

 condition for producing clovers a fairly liberal application 

 of potash in some form, for this element the 4 or 5 cords of 

 manure will not supply in sufficiently large quantities for the 

 best results with clover. Wood ashes furnish potash in very 

 desirable form, but they are becoming increasingly scarce, 

 and are held at prices which make them a relatively expensive 

 source of that element. It is the practice on the college farm 

 to depend mainly upon some of the German potash salts ; 

 and, as has been pointed out in earlier articles on the hay 

 crop, sulfates of potash are found in the long run to give 

 much better results with clover than muriate of potash or 

 kainite. Experiments now in progress in Amherst are fur- 

 nishing an interesting basis of comparison between the low- 

 grade sulfate of potash and the high grade. The writer is 

 not yet prepared to recommend the low grade as superior to 

 the high grade ; and, since the latter furnishes actual potash 

 at the lower cost, it is his belief that it should usually be 

 selected. Comparative observations, however, on crops grown 

 on the two potash salts this year lead him to wonder whether 



