SEEDING MACHINERY 



suits are given from experiments made at the Iowa ex- 

 periment station : 



Distance Distance Total 



Kind of Apart at No. of covered Draft Draft 



Drill Disk Drill Rows Disks in Feet in Pounds per Foot 



No. 4. Double 8" 10 6.7 450 67.1 



No. 5. Single 8" 10 6.7 460 68.6 



Neither of the above drills was provided with any form 

 of covering device other than chains. It is to be noted 

 from the above tests that the single-disk drill requires 

 more power than the double-disk in pulverizing the 

 ground, but the difference is small. 



162. Calibration. The scales or gages placed upon 

 drills and seeders to indicate the amount of seed drilled 

 per acre are not as a rule to be depended upon for great 

 accuracy. If they are correct at first, there is a tendency 

 for them to become inaccurate as the drill becomes old. 

 The operator should make calculations of the ground 

 drilled and the amount of grain used, and in this way 

 check the scale of the drill. Drills calibrated have shown 

 the scale to be in error as much as 25 per cent. 



163. Clean seed. The drill is displacing, to a large ex- 

 tent, the broadcast seeder because the farmer desires to 

 place all of the seed in the ground and at the proper 

 depth. With the broadcast seeder, where various meth- 

 ods of covering of the seed are resorted to, the seed can- 

 not be covered a uniform depth. Practically all fall seed- 

 ing is now done with drills, and the broadcasting is used 

 for the seeding of spring grains alone. Experiments at 

 the Ohio, Indiana, North and South Dakota stations give, 

 without an exception, better results from drilling, the in- 

 creased yields for the drilling being from 2 to 5 bushels. 

 In order to have a drill do its best work, great stress 

 should be laid upon the fact that all grain should be clean 



