34 



the clover. Application at the rate of 4 to 5 cords to the acre only is 

 desirable. In connection with such applications of manure, materials 

 which supply phosphates, potash and perhaps also lime should be em- 

 ployed. During; the past few years large (juantities of phosphatic or 

 basic slag meal have been employed on the college farm at Amherst, 

 and with results which are eminently satisfactory. This slag meal should 

 contain about IG to 20 per cent of actual phosphoric acid. This acid 

 is not in so highly available a form as in acid phosi)hate or dissolved 

 boneblack. 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 

 large amount of lime, and this, while less effective in correcting the 

 faults of a sour soil than (juick lime, must prove valuable in helping to 

 prevent soils which have once been Ijrought into proper condition from 

 becoming sour again. On such soils as those at Amherst the applica- 

 tion of slag meal at the rate of some 500 or 600 pounds per acre in con- 

 nection with such dressings of manure as have been indicated 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 ver}'- 

 desirable form, but they are becoming increasingly scarce, aird are held 

 at prices which make them a relatively expensive source of that ele- 

 ment. 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 cloA'er than muriate of potash or 

 kainite. Experiments now in progress in Amherst are furnishing 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 me to wonder whether the magnesia 

 of the low-grade sulphate may not ultimately jjrove valuable. Cer- 

 tainly better clover is seldom seen than that produced on certain of the 

 fields of the college farm during the past year which have been during 

 the past few seasons top-dressed with basic slag meal and low-grade 

 sulfate of potash. If the high-grade sulfate of potash, however, is 

 selected for use in connection with manure in preparing for clover, it 

 is believed that an annual application at the rate of about 150 to 175 

 pounds per acre will supply the element potash in sufficient quantities 

 for clovers on most soils. These materials (basic slag meal and sulfate 

 of potash) should be mixed after the land has been plowed, spread 

 broadcast and harrowed in. 



Fertilizers inthout Manures. 



In some cases the farmer will desire to bring his soil into suitable 

 condition for clovers in rotation by application of fertilizers alone to 

 preceding crops. In such cases the materials which have just been 

 considered should constitute the main reliance, but they should be used 

 in connection with materials which will furnish nitrogen in sufficient 

 quantities for the preceding ci-ops. Both tlie slag and potash, how- 

 ever, must be used in somewhat larger (quantities, and the writer would 

 suggest as suitable for most cases basic slag meal 800 pounds anrl high- 



