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. 
