POINTS IN ROTATIONS 89 
-be made beforehand, or a period will oceur when 
there is a lack of sufficient food. In the central 
states, the period likely to be most difficult to fill 
is the latter part of July and early August, espe- 
cially should the season be so dry as to prevent max- 
imum growth. To avoid interruptions, it is neces- 
sary, therefore, to plant a larger area and plan for 
a greater quantity of food than would be requisite if 
normal conditions prevailed. It is also necessary, 
if the land is to be fully occupied and maximum 
yields secured, that care be taken to follow the 
schedule of seeding and harvesting very closely. 
A difference of two or three days in the time of 
seeding, especially in spring, will very often make 
a difference of ten days in the time of harvesting. 
This is particularly true in the case of oats and 
peas. 
The period required for growing the crop to the 
proper stage, as well as the period during which 
crops may be useful for forage, will also vary to 
some extent; but if harvesting is begun early 
enough, as pointed out in the discussion of indi- 
vidual crops, the period of usefulness will range 
from six days to two weeks. For example, rye 
seeded at different times will in some seasons pro- 
vide excellent forage for fully two weeks, while in 
certain other seasons, especially if the early season 
is dry and hot, profitable feeding cannot be con- 
tinued for more than a week or ten days. The 
