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ELEMENTS OF AGRICULTURE 



portance. It is especially adapted to warm climates, is 

 alkali-, drought- and heat-resistant. It grows throughout 

 the warm season if there is sufficient moisture. Hence, 

 it is possible to get two or three crops in Ontario, Canada, 

 while in Arizona eight crops are often harvested. 



Failures of alfalfa are usually due to one of the follow- 

 ing causes: drought, lack of drainage, weeds, lack of manure, 

 lime or inoculation. Sometimes failure is due to poor 

 seed or to dodder. 



Alfalfa is most likely to succeed on a porous, well- 

 drained soil, but it is successful on some clay soils. It is 



not a poor-land crop. If 

 the soil is not rich, an 

 application of 10 to 20 

 tons of manure should be 

 made before sowing it. 



It is more sensitive to 

 acidity than any other 

 farm crop. Probably half 

 of the soils east of the 

 Mississippi river require 

 lime for best success with 

 alfalfa. 



It is a tender plant 

 when young, and is not 

 likely to be successful if 

 sown with a nurse crop unless all other conditions are 

 very favorable. Nearly all experiments have shown that 

 it is safest to sow it alone. If the rainfall and soil are just 

 right, it may be successful when sown with wheat, oats, or 

 barley but there is much risk in sowing it this way. Fig. 98 



Alfalfa. Left, limed; right, not limed 



Weeds.-Left, limed; right, not limed 



FIG. 97. Influence of lime on alfalfa and 

 weeds on a farm where lime was needed. 

 Where limed there was no room for weeds; 

 when not limed the weeds were able to run 

 out the alfalfa. 



