Desirable Agricultural Experiments. 
269 
— pays as well as almost any crop that is grown, and better 
than most other crops. But it is equally clear that the atmo- 
spheric contribution of nitrogen obtained in an ordinary cropping 
rotation is not sufficient, as all good farmers supply their land 
with this important element by purchasing feeding stuffs or 
manures containing it. It is certain, then, that ordinary farm 
practice must be modified in order to obtain all the nitrogen 
that is needed from the air. But the necessary modification 
might possibly involve such a diminution of returns from the 
sale of crops or stock, or both together, that the nominally free 
supply of atmospheric nitrogen would prove a very costly one. 
To put the case in familiar imagery. Nature offers us an un- 
limited quantity of nitrogen absolutely free in her atmospheric 
market, but does not pay carriage ; and the freight, including 
service and terminal charges, is an unknown sum which may 
possibly exceed the value of the commodity. 
The problem before us is one of considerable complexity, so 
numerous are the points to be decided before it can be fully 
solved. M. Ville, in his usual summary fashion, has cut the 
Gordian knot by recommending the ploughing-in of green crops, 
an old-world system to which he has given the new, fantastic, 
and misleading name of “ Sideration.” It is astonishing that 
he should assume as a self-evident fact that the nitrogen ob- 
tained at the cost of a year’s rent and other expenses upon the 
area of crop ploughed in is obtained in the cheapest possible 
way, for the method would strike most practical farmers as 
probably the dearest. It may be the cheapest method in the 
long run, but it should be proved to be so before it is recom- 
mended for general adoption. M. Ville does give estimates of 
the cost and returns of his system, as compared with those of the 
old triennial rotation of two corn crops and a fallow ; but estimates 
will not suffice in a case of such vast importance, and, even if it 
were demonstrated that his system was superior in all respects 
to the one with which he compares it, we should still be with- 
out evidence of its superiority to better systems than the old 
three-course one. Moreover, M. VUle, with no fear of clover- 
sickness before his eyes, recommends the growth of clover 
every third year, his rotation being one of clover, ploughed in, 
winter wheat, and oats or spring wheat. The clover is to be 
manured with superphosphate, chloride of potash, and gypsum, 
the atmosphere supplying the nitrogen ; and the land thus 
manured is to be left to produce two white-straw crops without 
further manuring, as well it might be. The feeding of live- 
stock on the produce of arable land M. Ville deems a nuisance 
and an extravagance. When kept at all, he would have the 
VOL. m. T. s. — JO T 
