228 NORTHEAST EXPERIMENT FARM. 
much cut up by roads, ditches, and plots, are classed into 
four groups of approximately equal productivearea. As new 
land is cleared, it is classed in with one o1r the other of 
these groups as circumstances dictate. The rigid four year 
sequence is seldom followed on any of these fields, but the 
crops are always planned to bring the field back into its 
place inthe rotationif they depart from it. If theclovercatch 
should fail,a second graincrop would be raised, and the fields 
seeded down again, but allowed to remain only one year, in- 
stead of two in meadow. Should it bedesirable to plow un- 
der the second crop of clover, the field would either be 
brought into meadow again a year sooner and allowed to lie 
three years or an extra grain or cultivated crop would be 
raised on it. Millet has sometimes been raised in place of 
potatoes, and other changes made. The possibility of such 
modifications makes the system elastic enough to meet any 
condition that may arise, and at the same time the general 
plan can be closely followed, guess work done away with 
and the numerous beneficial results of rotation be perma- 
nently secured. The main point is to have a general plan to 
suit the conditions of the farm, and then work steadily to- 
wards it. Examples have been given ot three, four and five 
years rotations, and of two rotations on the same farm. 
These are only a few of the many plans that may be adapted,. 
but the simpler they are the better. The four year rotation 
of cultivated crops, grains and meadow two years, lends it- 
self to more changes and conditions than any other, which 
is why it was adapted, or rather forced itself upon the ex- 
periment farm. The proportion of the various crops raised 
under this rotation seems to more nearly and easily approx1- 
mate the general needs of the farmers here than other 
rotations. In fact, it serves as the type of rotation in this 
section and all other successful rotations are mere modifi- 
cations of this one. To test the effect of different methods of 
rotation in a thorough manner both on the composition of 
the soil and the yields produced, twenty-four plots were laid 
in 1900, on each of which a different rotation was started. 
Sixteen of these include grass in a three four or five year 
course. The others are planned without grass depending on 
manure, or the plowing under of rye for fertilization. Some 
