192 ALFALFA FARMING IN AMERICA. 



thrive especially well in soils where the air can 

 penetrate easily. The bacteria supply alfalfa with 

 nitrogen. Thus deep plowing is equivalent to feed- 

 ing the alfalfa with extra nitrogen. The heaviest 

 growth of alfalfa that I have ever seen was on the 

 ranch in Utah where I once lived, the plants stand- 

 ing 48" high all over the field and very thick. The 

 underlying soil there was of loam, interspersed with 

 layers of loose sand and gravel, a soil that was too 

 easily drained, not very fertile, but well filled with 

 lime and other alkalies. With copious irrigation 

 that land produced enormous crops of hay. 



Deep plowing in a manner imitates such a condi- 

 tion by letting in the air and storing up more mois- 

 ture as well. Of course one must use judgment. If 

 his soil is of poor clay with only a thin skin of 

 vegetable mould on top one dares not bury that 

 deep under the clay and plant maize thereon, but 

 it is probable that he eould do it and plant alfalfa 

 with success, especially if the land was well drained 

 and limed. 



The water-holding power of deeply plowed soil 

 is about double that of unplowed, or shallow plowed 

 soil. This is important when it comes to getting 

 maximum crops of alfalfa hay. The lack of mois- 

 ture is usually the limiting factor in crop yield, a 

 fact not half appreciated as yet. 



How to Plow Deep. — I have done some experi- 

 menting on a hard clay soil with numerous small 

 round boulders or " niggerheads " in it in trying to 

 plow deep. It is not an easy task. In this especial 



