1911.] PUBLIC DOCUMENT — No. 31. 33 



slowly, in which caso, in order to avoid injury to the plants 

 below, the eoeks shoiihl be moved. It is desirable^ as iu the 

 ease of clover, which is often similarly handled, to remove the 

 caps and (»})eii and turn ovov the cocks on the morning of a 

 good day, when it is judged to be sufficiently cured to be put in. 



Top-dressing Alfalfa. 



If the crop has been successfully inoculated, and the nodules 

 which have been referred to are abundant on the feeding root- 

 lets of the plants, it is not ordinarily necessary to top-dress 

 with materials furnishing nitrogen ; or at least, if such mate- 

 rials are at all required, as may be the case upon soils which 

 are naturally very poor and light, they should be used only in 

 moderate quantities. 



Top-dressing with mannre cannot as a rule be recommended, 

 for this will increase the tendency of grasses and clovers to 

 come in. It is better to depend upon chemical fertilizers, and 

 in order to secure large crops for a series of years the more 

 important mineral elements of plant food must be supplied in 

 abundance. The following mixture of materials is recom- 

 mended, per acre, annually : — 



Pounds. 



Basis slag- meal, 1,200 to 1,500 



High-grade sulfate of potash, 250 to 350 



Or, in place of the latter, low-grade sulfate of potash, 500 

 to 700 pounds. This mixture may be ap])lied either in the 

 autumn or in very early spring. 



Secondapy Value of Alfalfa. 

 Alfalfa, when successfid, as has been pointed out, is not onlv 

 a valuable forage croji, furnishing large yields of highly nutri- 

 tious forage in proportion to area, but is also a crop of much 

 importance because its introduction will mean much improve- 

 ment in the soils on which it is gTo^vn. Wherever alfalfa is 

 successfully cultivated the soils are sure to be rendered more 

 productive. This im])rovement is a consequence, first, of the 



