14 THE HANDBOOK FOR PRACTICAL FARMERS 



is attached to the share. When the shin of the plow is sharp, 

 especially on fallow ground in good condition, colters are of little 

 service, and the jointer in particular is objectionable owing to 

 the increase in draft. 



There are two types of turning plow, the moldboard and the 

 disk. The former is in most general use and is adapted to the 

 widest range of soil conditions. The disk plow is especially 

 suited to hard, dry soil and does particularly well where there is 

 much rubbish or vegetation to be turned under. It is not adapted 

 to sod land or to soil that is very stony. 



On hard soil the disk plow is more efficient than the moldboard 

 plow for the draft consumed. 



Subsoiling. — Subsoiling is the operation of breaking up the 

 subsoil without turning it to the surface. A special plow is used 

 in the bottom of the furrow behind the turning plow. Subsoiling 

 is practiced most safely in the fall. Unsatisfactory results are 

 likely to follow subsoiling in the spring. 



Deep-tilling implements. — An intermediate implement between 

 the turning plow and the subsoil plow is the Spalding Deep- 

 Tilling machine. This is of the solid disk type. There are two 

 disks, one behind and below the other. They are carried on a 

 sulky frame, and by proper adjustment the soil can be worked 

 twelve to sixteen inches deep. Its use appears to be relatively 

 more safe than would be plomng with the moldboard plow to the 

 same depth, for, although the subsoil is stirred, it is only partly 

 thrown to the surface and mixed with the topsoil. In order to 

 accomplish the mixing of the right proportions of subsoil with 

 the soil, special attention must be given to the relative amount 

 of cutting done by the two disks. 



After plowing, the soil should usually be worked down and 

 pulverized at once. At that time the lumps are most easily 

 pulverized, and by leveling and fining the surface moisture is 

 saved. In the case of fall plowing this practice is not recom- 

 mended, as the rough surface holds the snow during the Avinter 

 and is less subject to puddling during the spring thaws. 

 Cultivators stir the soil. For rapid Avork some type of harrow 

 is generally used. 



The harrow is a broad, many-toothed implement, generally 

 without wheels or guiding handles. There are three main tj^pes 

 of harrows : the spike-tooth, the spring-tooth, and the disk. The 

 spike-tooth harrow is light, and is therefore suited to rather 

 clean soil in fairly good condition. The spring-tooth harrow 

 draws to the ground better than does the spike-tooth harrow. 



