BULLETIN OF THE BUSSEY INSTITUTION. 117 
By 81 kilo- By 47 kilo- Hence each square 
grammes of grammes of ruta- Total. should receive 
ruta-bagas. baga leaves. about 
Grms. Grms. Grms. QGrms. 
i - ) re 2] 150 393 400 
Phosphoric acid 81 61 142 150 
Nitrogen . 200 about 150 350 200% 
The purpose of the mixtures was: Ist, to produce, if possible, crops 
as large as any that had been previously obtained upon the field by the 
use of farm-yard manure; 2d, to determine which of the available 
sources of potash is to be preferred ; 3d, to try which of the phos- 
phatic and nitrogenous manures that had been employed in 1871 and 
1872 were best suited to use with the potash compounds ; and 4th, to 
get a set of results from mixed fertilizers that could be compared with 
those already obtained by the use of simple fertilizers and with those 
that had been obtained with farm and stable manure. 
It may here be said that the experiments actually tried with mixed 
fertilizers were only a part of those originally planned. It was found 
at the time of planting that the preparation and proper application of 
such a variety of materials required a very large expenditure of skilled 
labor, —so much, indeed, that it was altogether impracticable to 
apply a considerable number of mixtures that had been proposed. 
The character of some of the fertilizers employed might perhaps have 
been improved upon. Thus the mixtures of low-grade superphosphate 
of lime and rough nitrogenized matters that were used in several in- 
stances are manifestly ill adapted for the preparation of precise and 
definite mixtures. But since these materials had been used of neces- 
sity for the experiments of 1871 and 1872, at a time when no simple 
superphosphate could be procured, it was thought best to continue to 
use them in the manner indicated in the tables: that is to say, an 
amount of each of the phosphatic manures sufficient to supply the re- 
quired phosphoric acid was taken in each instance, and a certain 
allowance was made for the nitrogen that the material contained, as 
will be seen from the variations in the amounts of sulphate of ammonia 
and nitrate of soda that were applied to the several squares. The 
last-named chemicals were, commercially speaking, pure. The mix- 
tures tried and the amounts of crops obtained by their use will appear 
_ from the following tables. The arrangement of the squares and their 
* Less nitrogen than the theoretical amount was purposely taken. 
