Rotation of Crops. 
595 
stituents being available, there was a large increase of produce 
due to the supply of nitrogen in the manure. 
The figures in the middle division of the Table show that the 
produce of leaf as well as that of roots was increased by super- 
phosphate, and that it was still further increased by the mixed 
manure containing nitrogen. 
The next point is to consider the effects of the other con- 
ditions besides those of different manure supply ; that is, the 
removal of the root-crop, or the feeding or the spreading of it 
upon the land ; also whether, in the third year of each course, a 
leguminous crop was grown, or the land was fallowed. 
It is seen that, without manure , whether clover or beans 
were grown, or the land were fallowed, there was even rather 
less average produce of roots over the eight years where they 
had been fed on the land, than where they had been carted off; 
but with such very small crops the differences are immaterial, if 
not accidental. 
On the superphosphate plots, where the produce was much 
higher, and where there would, therefore, be more loss to the 
land by removal, the crops were materially better on the fed 
portions of the plots. 
On the mixed manure plots, on the other hand, with nearly 
twice as much produce as with superphosphate alone, there would 
be still greater difference between the condition of the land 
where the roots were carted off and where they were fed on ; 
but there was very little difference in the average produce of 
the root crop. 
It will be seen further on, that the higher condition of the 
land where the more highly manured roots were fed upon it had 
a very marked effect on the succeeding cereal crops, and espe- 
cially on the immediately succeeding barley. This was the case 
on both the superphosphate and the mixed manure plots. 
The difference of effect on the average produce of the root- 
crop, by fallowing, or by growing beans or clover, in the third 
year of each course is, in the comparable cases, practically 
immaterial under each of the three different conditions as to 
manuring. 
Before passing from Table I. it is to be observed that there 
was higher average produce over the tenth and eleventh courses 
with superphosphate and potash, soda, and magnesia, than over 
the preceding eight courses with superphosphate alone. But, as 
there was also increase in a greater degree with the mixed mineral 
and nitrogenous manure over the two than over the eight years, 
it is obvious that the character of the seasons had a good deal to 
do with the result. It is noticeable, however, that on the plots 
with potash, soda, and magnesia, as well as superphosphate, in 
