272 
Desirable Agricultural Dayperiments. 
stations simultaneously, care being taken to select a field of 
uniform soil and condition in each case, so as to avoid giving 
any advantage to either plan, it might settle the question as to 
the comparative advantages of ploughing- in and feeding-on 
nitrogen-accumulating crops. 
It would not in any way afiect the issue just mentioned if, 
at each station, a third piece of land in the same field were 
fallowed, and afterwards cropped in the same manner as the 
other two pieces. When scientific men talk of the waste of 
nitrogen incurred when land is fallowed, I strongly suspect that 
there is a “ missing link ” in the evidence taken into account 
by them. There is no doubt that a considerable quantity of 
nitrogen is lost in drainage water from a fallow ; but a great 
deal more available nitrogen appears to be gained. Dr. 
Mum’o’s valuable article on “ The Nitrifying Ferments of the 
Soil,” in the number of the Journal previously mentioned, shows 
that nitrification is promoted, while the destruction of nitrates 
is prevented, by the thorough aeration of the soil ; that 
nitrates are destroyed much faster than they can be produced 
where there is abundance of organic matter without aeration ; 
that nitrates are found in the greatest quantities in fallows ; 
and that the great stock of nitrogen locked up in the soil is 
some hundred or thousand times as great as the quantity of 
nitrates. These statements tend towards the vindication of the 
system of summer fallowing which has of late been frequently 
aspersed. It is an expensive luxury at the best, and I do not 
contend that it is often to be recommended, or that it is likely 
to prove equal for the purpose of nitrogen-accumulation to the 
ploughing-in or feeding-on of leguminous crops ; but still a 
trial, as above proposed, seems desirable. It may be said, 
perhaps, that summer fallowing is an exhaustive system in the 
long run, because, at the best, it only converts into available 
nitrates the inert nitrogen of the soil. But even if it does no 
more than this, is it not probable that, under an ordinary 
system of farming, there is a practically inexhaustible supply 
of organic matter in the soil for the production of nitrates? 
Certain it is that, on fairly good corn land, farmers are 
afraid of getting laid crops after a long fallow. This does 
not prove that fallowing does more than convert inert elements 
of fertility into an abundance or a superabundance of the avail- 
able elements of plant nutrition ; but it is strong evidence against 
the alleged loss of nitrogen, if a net loss be meant. 
The information to be derived from the experiments above 
described would be much more exact than it otherwise would be 
if the soil of each plot were so far analysed at the beginning 
