276 



SEEDING AND PLANTING 



14. Covering the Seed in the Drills. The depth of soil cover- 

 ing should be from 1 to 4 times the average diameter of the 

 seed, depending upon the locality and the character of the soil. 

 Deep covering is more acceptable on sand and loam than on clay 

 soils. It is also more acceptable in regions having a dry atmos- 

 phere. Dry soils permit a deeper covering than wet soils. 



Walnut, oak, and other broadleaved species sown in large, wide- 

 spaced drills are usually covered by means of the hoe or rake. 

 Special implements have been devised for covering shallow, 

 closely-spaced drills. Among them the Spitzenberg seed coverer 1 

 has already been introduced into the United States from Europe. 

 It is recommended as an effective and practical implement for 

 rapidly covering shallow drills (Fig. 60). 



FIG. 60. Spitzenberg seed coverer. 

 a. Open metal roller for covering the seed. 

 6. Solid wood roller for firming the soil. 



15. Drill Machines. A number of machines have been con- 

 structed which mark the seedbeds, sow and cover the seed in 

 a single operation. European foresters Spitzenberg, 2 Hacker, 3 

 Hermann, 4 and others have constructed practical drill machines 

 for use in forest nurseries. The Spitzenberg machine is useful in 

 sowing large seed-like fruits such as the oak and hickory. It can 

 be adjusted for density of seeding and depth of covering. The 

 machine is operated by two men, one going ahead and drawing it 

 across the bed by means of a rope and belt over the shoulder, and 

 the other operating and guiding it from behind. . The Hacker 

 machine is for sowing coniferous and other small seed in shallow, 

 closely-spaced drills crosswise of narrow seedbeds. It is operated 



1 Spitzenberg, G. K.: Die Spitzenberg'schen Kulturgerathe. 2. Aufl., 

 S. 60. Berlin, 1898. 



2 Ibid. 



3 Hacker, R.: Hacker'schen Gastensaatmaschine. (Centralblatt f. d. 

 gesamte Forstwesen, S. 135. 1891.) 



4 Hormann, Forstamtsassessor : Ein neues Saegerat. (Forstw. Central- 

 blatt, S. 622-628. 1903.) 



