YIELD OF ALFALFA. 253 



land, in France, Italy and other lands where farm- 

 ing is carried to a high pitch of perfection. Irriga- 

 tion of alfalfa is only practicable where soils are 

 permeable so that any excess of moisture will read- 

 ily sink away, or else are thoroughly well under- 

 drained. 



Poverty of Soil a Factor. After all the most fre- 

 quent limiting factor in alfalfa production in the 

 eastern states is soil fertility. There is not enough 

 phosphorus in the land, or it lacks humus and bac- 

 teria, or it lacks abundant carbonate of lime. On 

 Woodland Farm I once applied phosphorus to an 

 alfalfa meadow set about three years, using acid 

 phosphate at the rate of about 250 pounds per acre. 

 Strips were left with no phosphate to test the effect. 

 Where additional phosphorus was given the land the 

 yield of hay was nearly doubled. Thus about $2 

 worth of fertilizer made a growth of about two tons 

 of hay per acre. This astonishing profit from the 

 use of phosphorus on alfalfa was the beginning of 

 regular use of phosphate fertilizers on new meadows 

 and old on Woodland Farm. 



The plain truth seems to be that along the 40th 

 parallel, in the region of the corn belt we ought to 

 mow at least four tons of alfalfa hay per acre and 

 could, by making our soils right, get six tons with 

 favoring seasons. 



