8 FARM GRASSES OF THE UNITED STATES 
crop. This is largely due to the prevailing habit of 
leaving timothy meadows down after they have become 
unproductive. 
It is a remarkable fact that nearly all the grass lit- 
erature issued by the American experiment stations 
comes from those stations outside of the timothy re- 
gion. Inside this region the early introduction of 
timothy, red clover, and Kentucky blue-grass solved 
the grass problem in a manner satisfactory to the farmer 
before the establishment of the experiment stations, 
and these institutions have, therefore, devoted their 
energies to more pressing problems. The most im- 
portant grass literature from these States is to be found 
in the reports from early agricultural societies. These 
reports indicate that grass problems were at one time 
as important in the region in question as they now are 
outside of it. Nearly all the correspondence that 
comes to the office uf Grass and Forage Plant Investi- 
gations of the United States Department of Agriculture 
originates either in the cotton-growing States, where 
grass culture has been neglected, or in the arid and 
semi-arid West, where satisfactory grasses are yet to 
be found. 
Clover ranks next to ‘‘ other tame grasses’’ in the 
area devoted to it. The figures apply, of course, to 
the clovers when sown without timothy or other true 
grasses. The area devoted to clover is 4,104,000 
acres, or 7 per cent. of the total area of tame hay. 
The average yield of this class of crops is given at 1.3 
tons per acre. The clovers, particularly the common 
red clover (Trifolium pratense), are much more im- 
portant in American agriculture than these figures 
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