4 
COMPARATIVE EXPERIMENTS ON THE EFFECT OF 
The experiments were made in zinc cylinders open at both 
ends, 60 centimetres wide and i metre long. These were sunk 
in 6 lines, each of 8 cylinders, into the soil of a level field up to 3 
centimetres from the upper edge and very uniformly filled to a 
higbt of 70 centimetres with the yellow subsoil of our farm ; 
the soil was weighed in buckets and after discharging each bucket 
into the respective cylinder the soil was pressed in with a wooden 
instrument to avoid the formation of cavities and to obtain the 
same structure of the particles as exists under natural conditions. 
On the top of the subsoil there came 30 kilograms of our black 
topsoil freed with sieves from all rootlets and foreign materials, 
and previously mixed with precipitated calcium carbonate (1000 
kilograms, per hectare) and potassium sulphate (200 kilograms, 
of potash per hectare). After letting this stand for some days, we 
added to each cylinder 1.413 grms. of nitrogen in the form of 
ammonium sulphate (50 kilograms, of nitrogen per hectare), and 
finally the phosphatic manure was applied several days before 
sowing. Each phosphate was applied in two quantities, a single 
and a double, and each quantity was given to 3 cylinders; each 
phosphate was accordingly tested on 6 different plots. Six 
cylinders symmetrically situated among the others, did not receive 
any phosphatic manure. The quantities applied, were as follows: 
Per cylinder Phosphoric acid per 
grams. hectare, kilograms. 
single 
dose. 
double 
dose. 
single 
dose. 
double 
dose. 
Double superphosphate. 
2.954 
5.908 
50 
IOO 
Precipitated calcium phosphate. 
7.22 
14.44 
75 
! 5 o 
Thomas phosphate . 
9-74 
19-48 
75 
150 
Steamed bor.e dust. 
7-35 
14.70 
60 
120 
Crude bone dust . 
8.607 
17.214 
60 
120 
I-taw crushed bones. 
7.828 
15-656 
60 
120 
Bone ash . 
9.276 
is.552 
100 
200 
Sowing took place on the 29th of October, 1890, the seeds, a 
variety of barley known as “golden melone ,” about 2 hektolitres 
per hectare, being distributed on the manured soil with the help 
of a perforated disk in distances of about 5 centimetres from each 
other. Over this we applied a covering of 5 kilograms of sifted 
