132 
IOWA ACADEMY OF SCIENCE 
Attempts have been made to improve a lawn by applications of 
manure. It was noticed that the manure quickly disappeared and 
did not have the effect on the soil that was desired. There was no 
marked change in color even after two applications of twenty-five 
tons of manure per acre. Experiments indicate that organic matter 
added to the lawn oxidizes directly, the amount of C0 2 given off be- 
ing equivalent to the amount of oxygen absorbed by the soil in closed 
vessels. The organic matter added to the lawn in its present condi- 
tion decomposes very quickly with little, if any, formation of humus. 
In this respect the lawn, which is a very dry natured soil, seems to 
act similarly to a dry earth closet. 
The mechanical analysis of the Tacoma lawn soil as published 
in the bulletin referred to is as follows : 
Conventional Names 
Sample I 
Sample II 
Per cent 
Per cent 
Fine gravel 
4.1 
2.5 
Coarse sand 
28.4 
32.5 
Medium sand 
10.8 
12.1 
Fine sand 
8.2 
8.0 
Very fine sand 
2.7 
2.3 
Silt 
29.2 
26.9 
Clay 
16.5 
15.5 
The Washington soils differ from this in having only half the 
amount of clay and considerably more fine and very fine sand. The 
percentages of silt are the same. In general the soils are somewhat 
similar. 
