234 



AGRICULTURAL ENGINEERING 



It also dispenses with many of the plates which must be 

 furnished with a planter that does not have the device. 

 Furrow-openers. The long shoe furrow-opener is in 



more general use than any 

 other type. It has good 

 penetration and is easy to 

 guide. Where there is 

 trash in the way, the stub 

 runner, which hooks un- 

 der the trash, should be 

 used. The single-disk 

 furrow-opener has good 

 penetration and should be 

 used in soil that often 

 becomes very compact 



Fig. 144. A corn planter with stub shoe before the CORl Can be 



furrow-openers. 



planted. It is quite im- 

 possible to make perfectly straight rows with the disk 

 planter. The bearings of the disks are subject to wear, and 

 the single disk throws the 

 earth to one side in open- 

 ing the furrow, making 

 the covering difficult. The 

 double-disk furrow-opener 

 offers additional compli- 

 cations without material 

 advantages. It is some- 

 times maintained that the 

 disk planter is of lighter F ig. 145. 

 draft. Even if this be 

 true, the planter under any circumstances is not a heavy 

 draft implement. 



"Wheels. The accepted type of wheel for corn planters 



A corn planter with disk fur- 

 row-openers. 



