JUNE 13, 1884. | 
those on the second section the same weight of corn- 
meal, while on the third and fourth sections the sheep 
had only the grass. The droppings of the animals 
were left on the land; and, as fattening animals re- 
tain practically none of the fertilizing ingredients of 
their food, these droppings were richer on the first 
and second sections by the amount of plant-food con- 
tained in the cottonseed-meal and corn-meal respec- 
tively. In the fall the land was sown to wheat; and 
in the spring, sections 8 and 4, on which no ground- 
feed was fed, were top-dressed with commercial fer- 
tilizers. Section 38 received fertilizers containing 
amounts of nitrogen and mineral ingredients equal 
to the nitrogen and ash of the 728 pounds of cotton- 
seed-meal fed on section 1; and section 4, in the same 
way, received nitrogen and ash equal to the amounts 
contained in the 728 pounds of corn-meal fed on sec- 
tion 2, 
Thus the four sections of this plot permitted a com- 
parison of the relative value for the wheat-crop, first, 
of stable-manure made from corn-meal and cotton- 
seed-meal respectively, and, second, between the 
value of stable-manure and a quantity of commer- 
cial fertilizers containing the same amounts of plant- 
food. Following the wheat, mangolds were grown 
in 1879, variously manured on the four sections. On 
section 1 they received stable-manure made from 
1,728 pounds of straw as litter, 5,000 pounds of man- 
golds, 1,250 pounds of wheat-straw, and 1,000 pounds 
of cottonseed-meal; on section 2, stable-manure made 
from the same amounts of food and litter, except 
that 1,000 pounds of corn-meal were substituted for 
1,000 pounds of cottonseed-meal. On plot 3 they 
received stable-manure made from the same quanti- 
ties of roots and coarse feed as were mentioned above, . 
but without either cottonseed- or maize-meal, and, in 
addition to this stable-manure, commercial fertilizers 
equivalent to all the ash, and two-thirds of the nitro- 
gen, of 1,000 pounds of cottonseed-meal. On plot 4 
they received the same stable-manure as on plot 3, 
and, in addition, chemicals equivalent to the ash and 
nitrogen of 1,000 pounds of corn-meal. 
Here, again, we havea comparison of stable-manure 
from different fodders with equivalent amounts of 
concentrated fertilizers. ‘The stable-manure, in this 
case, was made by steers which were fed in so-called 
feeding-boxes, in which all the excrements and litter 
were retained, and compacted by the movements of 
the animal. 
The mangolds produced on each section were 
weighed, and then fed out to sheep on the land. 
Following the mangolds came, in 1880, barley. This 
received no manure but the droppings of the sheep 
to which the mangolds were fed, except that section 
2 received the remaining third of the nitrogen of 1,000 
pounds of cottonseed-meal in the form of a top-dress- 
ing of nitrate of soda. 
In 1881 the barley was followed by grass, to be fed 
off by sheep as described, thus beginning the rota- 
tion anew. 
It will be seen, that, in the course of the four years’ 
rotation, each plot furnishes three tests, with as many 
crops, of the manurial value of cottonseed-meal as 
SCIENCE. 
VES 
compared with maize-meal, and of each as compared 
with an equivalent amount of concentrated fertiliz- 
ers. Moreover, since each one of the four plots is 
treated alike, three such comparisons can be made 
each year in different plots. Thus, by continuing 
the experiments for a series of years, it will be pos- 
sible to eliminate from the results, to a certain extent, 
the errors which may arise from unequal quality of 
the soil on the different sections, and also to judge 
how the character of the season affects the action of 
the manures. 
The subject is a very interesting one, and one 
which has received comparatively little attention 
experimentally. We know, indeed, with sufficient 
accuracy, the relations between the composition of 
food and that of the manure made from it. We 
know that in the manure of working, and of mature 
fattening animals, is found practically all the plant- 
food which their fodder contained. We know, that, 
in the case of growing animals and of those giving 
milk, more or less of the elements of plant-food pass 
into the new growth, or into the milk, and are lost 
to the manure; and we know approximately what 
proportions of them are thus lost on the average. 
With the necessary data as to amount and kind of 
food consumed, it is a comparatively easy task to 
compute the amount of valuable matters contained 
in the manure produced; but as to what modifica- 
tion the agricultural value of these matters may have 
undergone, and how it compares with the various 
forms of artificial fertilizers, we are comparatively 
ignorant. For example: we know that practically 
all the phosphoric acid of the food of a fattening 
animal passes into the excreta; but how the ma- 
nurial value of this phosphoric acid compares with 
that of the soluble, the reverted, or the insoluble 
phosphoric acid of a superphosphate, with that of raw 
bone, or of native phosphates, can be, at best, only 
conjectured. 
The Woburn rotation experiments promise to con- 
tribute to the solution of some of these questions. 
It would be premature to seek to draw definite con- 
clusions from the results thus far obtained; for only 
a considerable length of time can enable us to esti- 
~ mate the effect of continuous treatment, of the sort 
described, upon the yield of the several crops. At 
the same time, a brief statement of them may fur- 
nish some interesting suggestions. 
The following table contains the results, up to 
1882, in pounds per acre, of the experiments on man- 
golds, barley, and wheat. Under the head of manur- 
ing are included only the amounts of cottonseed- or 
corn-meal fed to the sheep, or their equivalents in 
commercial fertilizers. It should be understood that 
this was not all the manure used, as will be evident 
on comparing the detailed description of a rotation 
given above. 
In interpreting these results, there are some things 
which should be borne in mind. In the first place, 
we find in the reports of the above experiments, in 
the Journal of the Royal agricultural society, very 
meagre details as to their conduct. It is to be sup- 
posed that all four of the sections in each plot were 
