Rotations. 
29 
ordinarily sown by itself for one year, and so to avoid 
failure from the growth of the same every four years, it is 
often requisite to add, say, fi lb. per acre of Italian rye-grass 
to make sure that there will be something to cover the ground 
if the clover fails, or, better still, a one-year temporary 
“ mixture ” is adopted. 
The difficulties met with in connection with swedes and 
clover occur with some other crops, but in lesser degree ; 
though it is only in cases such as these that any special steps 
have to be taken to meet the case, but these exemplify the 
rule that crops should be as far apart in a rotation as possible. 
The grass layer may not of course be put to the same use 
all over the country, though it is more largely confined to the 
wetter districts. The grass may be cut for hay or grazed by 
cattle, while in the southern districts the system of folding 
sheep within hurdles is very commonly followed, and with the 
best results. 
Moreover, a “seed layer” may take the form of laying 
away in lucerne or sainfoin for a series of years. In the 
southern and eastern parts of England, especially where there 
is some chalk or marl in the soil, it is customary to put fields 
down into either of these crops for a change, and thus a 
rotation becomes broken up as it were, and the land is put out 
of cultivation for a time. These crops will not thrive to 
perfection unless there is a superabundance of limestone in the 
soil or subsoil, and as they send down immense tap-roots they 
are independent of surface droughts and suit the drier south 
country very well. Sainfoin will not grow very far north, but 
recent experiments at the Kilmarnock (N.B.) Experimental 
Station have shown that lucerne will grow there very well as 
far as climate is concerned if the soil is naturally suitable, or 
made so by liming. 
The plants send down immense tap-roots and draw their 
sustenance from the deepest layers of soil or rock, and are 
usually left down for from five to ten years, according to 
conditions and cleanliness. The result is that on again 
breaking up the layer to resume a rotation of arable crops the 
soil is immensely enriched. 
Summary of Rotations as returned by 
Correspondents. 
Three Years' Course . — Three examples returned. 
(1) Potatoes or mangolds or mustard ; (2) wheat ; (3) oats. 
Two of the examples were on fen soil in Cambridgeshire : 
one on heavy land in Bucks. Clover or sainfoin, instead of 
potatoes, are alternatives mentioned by the correspondents. 
Four Years' Course. — Thirty-two examples returned. 
