R22 TWENTY-FIFTH ANNIVERSARY REPORT. 
apparently, was the crop. Excellent lettuce, however, was pro- 
duced on the sandy loam by the use of commercial fertilizers alone. 
. No advantage was gained either on the clay loam or the sandy loam 
from the addition of sulphate of potash and acid phosphate when 
the soils had already received a heavy application of stable manure. 
The clay loam was composed of rotted sod from an uncultivated 
field; the sandy loam was from the side of a cultivated field where 
it had been drifted by wind. Analyses showed that the latter soil 
contained far less plant-food that was the case with the former. 
In comparing the various nitrogenous fertilizers in combination 
with stable manure, it was found that nitrate of soda gave the best 
result on a sandy loam. Dried blood was next with comparatively 
little difference in the crop. Sulphate of ammonia gave the poorest 
crop of all. On the clay loam the sulphate of ammonia gave the 
best results, with the dried blood the poorest of all. The variation 
in size of crop with the different fertilizers, however, was not 
so great on the clay loam as on the sandy loam. The general 
results were of interest in that they indicated that with light soils 
it is advisable to use commercial fertilizers, while with heavy soils, 
stable manure is more satisfactory. Perhaps the lesson that may 
be drawn from the results is quite as important as the results them- 
selves; that is, that the physical condition of the soil is quite as 
important a factor in determining the growth of a plant as the 
quantity of plant-food present. 
Later this work was carried further and a comparison made of 
the respective values of the different forms of nitrogenous com- 
mercial fertilizers.22 Lettuce was planted in boxes filled with the 
soils already described. To one series was added dried blood, 
dried blood and nitrate of soda to another, and sulphate of am- 
monia to a third lot. With each of these acid phosphate and 
muriate of potash were used. The quantity of each fertilizer was 
sufficient to exceed the needs of the crop. As compared with check 
lots in which no commercial fertilizer was used there was a de- 
cided increase in yield; but the use of commercial fertilizers alone 
‘proved inadequate for forcing the lettuce in a sufficiently short 
time to be profitable.’ On the clay loam, with no stable manure, 
a better yield was generally obtained where nitrate of soda was 
used than where either sulphate of ammonia or dried blood was 
used. On the sandy soils the results with dried blood were gen- 
erally superior to the results with nitrate of soda or sulphate of 
* Bul. 208; also in Rpt. 20:32T. 
