PLOWING 129 



series of years, and so was like hard pan. It was 

 that undercrust of soil which we find upon most of 

 our soils, underlying the usual plow depth, caused 

 to some extent by the passing of the bottom of 

 the mold board plow through the soil. This man, 

 by actual measurement, was breaking up this soil 

 to an average depth of three inches. When asked 

 by the author why he did not plow deeper, he re- 

 plied that when he adjusted his plow to plow a 

 greater depth, or so that it would penetrate the 

 hard soil underneath the depth of three or more 

 inches, his horses could not pull the plow. It was 

 a case of lack of motive power, so he set his plow 

 to do shallow plowing. And it may be of inter- 

 est to know that the corn grown upon this shallow 

 plowed soil did not average ten bushels to the 

 acre. 



Experimenting with riding gang plows of two 

 twelve-inch bottoms, plowing in average soils as 

 to compactness, the author has found that such 

 plows, plowing to a depth of five, or six inches, can 

 be easily drawn by four average farm horses ; but 

 when set to plow seven, eight, or nine inches, the 

 minimum depth to which any soils should be 

 plowed, the drawing of these plows becomes a dif- 

 ficult task. 



In the past five or six years the author has ex- 

 perimented with, and has investigated the break- 

 ing of the soil with modern gasoline and steam 

 tractor plows, and he has found the same condi- 

 tion to obtain with most every one of these plows 

 that he has operated upon his farms, or seen op- 

 erated. As long as their plows were adjusted to 

 plow five or six inches in depth, their engines 



