Rotations. 
19 
Indirectly, also, the rotation adopted lias an influence on 
the tilth or friability of the soil. Though it is possible 1 to 
grow one kind of crop, like corn, continuously, where the soil 
only requires to be turned over with an ordinary furrow slice, 
the texture and filthiness of the land will deteriorate year by 
year, and even extra cultivation in the shape of hoeing, 
scarifying, &c., may not be sufficient. On the other hand, the 
introduction of a fallow crop gives an opportunity for deep- 
ploughing, thorough exposure to the frost and weather during 
winter, and a continuous series of cultivations while the crop 
is growing. By this means the tilth of the soil is improved for 
several years. 
That different kinds of cultivation — as for example deep 
versus shallow ploughing — are provided for the different 
crops is one of the indirect results of rotating crops — we 
are rotating the different varieties of cultivation at the same 
time. 
It must be noted that there are various ways of looking at 
a rotation or what constitutes a rotation. The outstanding 
rule being that no crop should be followed by the same crop 
the next year, we reduce the whole matter to a two-years’ 
rotation thus, as far as ordinary farming is concerned — corn ; 
other crop ; corn ; other crop ; and so on indefinitely. The 
corn (of whatever kind) is a more or less “scourging” crop, 
and we alternate it with a renovating or cleaning crop in the 
shape of bare fallow, roots, beans, clover, or grass, according to 
circumstances. Thus in the great majority of cases we are 
only rotating corn with something else, although the rotation 
is named according to the number of years intervening between 
the repetition of these intermediate crops. 
Apart altogether from a regular rotation of crops, that is, 
from a hard and fast cycle which repeats itself at an interval 
of so many years, there are many reasons why crops should 
be changed as to their sites from year to year, and we may 
classify and examine these in some detail. They may be 
divided into two groups — those due to the soil itself (a), and 
those due to circumstances outside the soil (b). We may take 
the former first in order and see what rotations do. 
A. 
1. Admit of better cleaning of the land. 
This is probably the oldest reason for changing a crop on 
the soil. In ancient times in our own country the “ infields,” 
that is the cultivated fields near the homestead in contra- 
distinction to the grazing “ outfields ” at a distance, were 
1 Mr. Prout’s system at Sawbridgeworth, Herts, is very nearly continuous 
corn, though an occasional fallow or clover crop is taken. — Editor. 
