274 
Desirable Agricultural Experiments. 
badly the cattle consuming roots might need more than their 
fair share of litter per acre, they must'not be allowed to have 
it. Expenses of all kinds would, of course, be charged to the 
piece of land in respect of which they were incurred. Two 
white-straw crops in succession would be grown on all the land 
without further manuring, and when the results for the third 
year had been recorded, the experiment would be finished. 
Although spring corn would come after roots in most rotations, 
it seems desirable to take wheat as the first white-straw crop, 
on account of its nitrogen-exhausting capacity. Barley may be 
suggested for the third year. At the end of the trial we 
should be able to compare the expenses and returns of the 
following divisions of forage crops and the two white-straw crops 
grown after each : — 
We should see whether either vetches or lupins, or both, had 
beaten swedes, financially, when all three were fed off on the 
land and followed by two white-straw crops ; and whether 
either or both of the leguminous crops had beaten either or both 
of the root-crops in respect of cattle-feeding and corn-growing. 
The value of this experiment, as of the one previously 
described, would be greatly enlianced if the soil of each plot 
were so far analysed at the beginning and end of the three- 
years period as to show the gain or loss of nitrogen in each 
plot. 
In my opinion this is by far the most important of the 
experiments which I have suggested, and it appears to me 
highly desirable that special efforts should be made to induce a 
number of agricultural associations to carry it out under uniform 
arrangements. That it would be no slight undertaking must 
be admitted ; but I do not know of anything that an association 
could do more likely to prove of service to farmers. In support 
of this plea Sir John Lawes and Dr. Gilbert may be quoted ; 
for, although the details of the experiment have not been sub- 
mitted to them, it is of a kind which they have recommended. 
In the article previously mentioned they say : — “ Now, however, 
that the character of the action (the fixation of atmospheric 
nitrogen) is more clealy understood, and it is certain that there 
is actual gain of nitrogen from sources external to the soil 
1. Vetches'' 
3. Swedes J 
4. Mangels^ 
2. Lupins ^ Fed on the land. 
6. Vetches [Fed away from the land, the manure 
6. Lupins I being restored. 
7. Swedes J 
being restored. 
