620 
Rotation of Crops. 
treatment of the previous root-crop, on the available supply of 
nitrogen within the soil for the succeeding barley is, therefore, 
throughout clearly traceable. 
Lastly, in regard to the nitrogen statistics of the barley 
crops, it is to be of served that, under whatever conditions of 
manuring or other treatment, and whether grown in rotation 
or continuously, there was generally three-fourths or more of 
the total nitrogen of the crop accumulated in the grain, that is, 
in the portion which is as a rule sold off the farm ; only about 
one-fourtli, therefore, remaining in the straw which is supposed 
to be retained on the farm. 
The Nitrogen in the Leguminous Crops . — The third division 
of the Table (VI.) gives the results relating to this point. 
Referring first to the amounts of nitrogen in the total bean 
crops (corn and straw together), it is seen that, under each of 
the three conditions as to manuring, there was from twice to 
twice and a half as much in the rotation as in the continuously 
grown beans. The details further show that the advantage was 
proportionally greater in the corn than in the sti’aw. 
It is next to be observed that the amounts of nitrogen 
taken up by the rotation beans were — without manure about 
36 lb. per acre per annum, and with superphosphate between 
40 and 50 lb. ; whilst with the mixed manure, containing 
nitrogen, there were in one case 63 - 6 lb., and in the other 70’2 
lb. In fact, both without manure and with superphosphate, 
the amounts taken up in the beans were much greater than 
in either the preceding roots or the preceding barley. With 
the mixed manure supplying nitrogen, they were also much 
more than in the preceding barley, but less than in the 
root-crops, to which the mixed manure had been directly 
applied. 
The point of greatest interest in the results is, however, 
that under each condition as to manuring, the clover took up 
very much more nitrogen than the beans, and very much 
more than either of the other crops of the rotation under 
parallel conditions. Thus, even without manure, the average 
amount of nitrogen in the two crops of clover was — in one case 
55 lb. and in the other 47 lb. ; with superphosphate it was 
124-5 and 144-6 lb. ; and with the mixed manure, containing 
both potash and nitrogen, in the one case 167 lb. and in the other 
168-4 lb. Or, taking the average amount of nitrogen in the 
six bean and two clover crops, there were — without manure 
41-5 and 38-9 lb. ; with superphosphate 6L5 and 72-9 lb. ; 
and with the mixed manure 89 - 5 and 94 - 7 lb. It is, indeed, to 
the occasional growth of clover, that the very large average 
