NURSERY PRACTICE ON THE NATIONAL FORESTS. 79 
bluntly pointed. A foot rest aids in probing hard soils. By forcing down this 
iron rod near gopher workings or a foot or two back of fresh mounds the open 
tunnel can be felt as the point breaks into it. The blunt end of the instrument 
is now carefully used to enlarge the hole, a bait or two is dropped into the 
run, and the probe hole closed. 
Baits need to be placed at only two points in each separate system or group 
of 10 to 30 mounds, which is usually the home of a single gopher. In our 
experience baits placed in open underground runs have invariably killed the 
gophers. The method has found great favor wherever it has been introduced. 
At the Converse Nursery, in California, wood rats, or " pack " rats 
(Neotoma), have been found responsible for a considerable part of the damage 
to transplants usually ascribed to rabbits. 
Wood rats eat little or nothing of the trees they cut, but carry the green 
tips into their nests to store away. These animals are rarely killed by any 
of the baits which have been described, though they pack away such baits 
readily enough. Effective results have been obtained by dusting baits liberally 
with finely powdered strychnine, as the rats are killed in packing them. Dry 
oatmeal biscuits one-half inch square and one-fourth inch thick, cut from a 
stiff dough of oatmeal and water, after rolling it in sheets, have proved to be 
especially successful baits. Raisins and whole corn may also be used. 
Though both cottontails and jack rabbits fall victims to poisoned oats during 
periods when their natural food is scarce, this poison can not always be relied 
upon to destroy them when it is most important to check their depredations. 
Green or ripening grain heads of barley or wheat are among the most attractive 
baits in summer. Soaked for 48 hours or more in a solution of 1 ounce of 
strychnine sulphate and one-eighth ounce of saccharine in 2 gallons of water, 
such baits have occasionally proved very successful. They should be used 
only in locations where live stock is not endangered. 
FERTILIZERS. 1 
The character of soil preferable for a nursery has been described, 
but such soils are not always to be found. Continuous raising of 
crops of trees, moreover, will eventually deplete even the best soils 
of the chemical constituents most essential for plant growth. It 
will also impair their physical qualities. Improvement of the soil 
by fertilization will accordingly be necessary. According to in- 
vestigations by von Schroeder, 2 the average quantity of nitrogen, 
potassium, and phosphoric acid (the three most essential plant foods) 
needed in one year by 1 to 3 year old spruce is about equal to the 
amount absorbed from the soil by a crop of corn, potatoes, or meadow 
hay. The physical and chemical qualities of a soil may be improved 
through the addition of manure, leaf mold, compost, or marl, and 
chemical fertilizers. Some of the chemical fertilizers, however, 
rapidly pass into solution and have no appreciable effect upon the 
physical quality of the soil. 
1 The information cited in regard to fertilizers is taken, but not wholly verbatim, from 
" Die Pflanzenzucht Im Walde," by Dr. Herman von Furst, and represents the views of 
German nurserymen. 
2 " Tharandter Forstliches Jarbuch," 1893-94. 
