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 

 I Die Pflanzenzucht Im Walde," by Dr. Herman von Furst, and represents the views of 

 German nurserymen. 



2 " Tharandter Forslliches Jarbuch," 1893-94. 



