600 
Rotation of Crops. 
It may be observed, that the produce, even on the plots with 
superphosphate alone, was, where the roots had been fed on the 
land, about the average of the country at large under ordinary 
rotation— namely, from 36 to 33 bushels ; whilst, on the full 
manured plot, the produce was much more than this — namely, 
in one case 40|, and in the other 42§ bushels, where the roots 
had been removed ; and where they had been fed on the land, in 
one case 48f, and in the other 47| bushels. 
Thus, then, the effect on the succeeding barley of the full 
mineral and nitrogenous manure applied for the preceding tur- 
nips is very obvious ; whilst the effect, on the one hand of the 
removal of the root-crop, and on the other of the retention on 
the land of most of its constituents, is also very marked. The 
experimental results relating to the second crop of the course — 
the barley — so far fully confirm, therefore, the explanations 
which have been given of the beneficial effects of root-crops grown 
under the ordinary conditions of manuring, on the succeeding 
cereal grown in alternation with them. 
Examination of the results relating to the quantities of straw, 
and of total produce (grain and straw together), as given in the 
middle and lower divisions of the Table, will show that they fully 
bear out the general conclusions that have been drawn from a 
consideration of the produce of the grain alone. 
The Leguminous Crops (or Fallow). 
Table III. gives for the third element of the typical four- 
course rotation — the leguminous crops — the results obtained in 
each of the eleven years of the forty-four in which they were 
grown, in exactly the same form as those previously recorded 
for the turnips and for the barley. But, as in some of the years 
clover, and in others beans, were grown, the averages are here 
taken, not for the eight and for the two courses, as with the 
other crops, but, respectively, for the four years of the eleven in 
which clover was grown, and for the seven in which beans were 
grown. 
A glance at the Table brings to view some of the difficulties 
connected with the growth of these crops. Thus, although the 
scheme of the four-course rotation supposes the growth of red 
clover as the third crop of each course, that is once in four 
years, it has in fact only been grown four times in the forty-four 
years — namely, in the first, seventh, ninth, and tenth courses ; 
and when it failed beans were grown instead. It is, indeed, a 
matter of general knowledge and experience, that it is only on 
a few descriptions of soil that clover can be grown so frequently 
