Best Conditions o/ Soil for Plowing. 251 



knowledge of the needs and conditions. There can be no 

 "rule of thumb" fur plowing. 



As a general rule in humid climates the plow never 

 should go deeper than to turn over the surface or dark 

 colored layer of weathered soil. If deeper plowing is done, 

 turning up the un weathered subsoil, the productiveness 

 of the field will be reduced. 



It is very desirable to develop and maintain a deep soil; 

 this is clearly provied by the heavier crops which always 

 grow upon "back furrows" and the scanty ones which grow 

 in "dead furrows" as compared with the rest of the field. 

 When a soil is thin and the subsoil is close and heavy it is 

 only safe to deepen it gradually by plowing a little deeper 

 each year or two, turning under as far as possible coarse 

 manure, stubble and green crops to make the soil open and 

 form humus in it. 



Fall plowing may usually be as deep as the soil will per- 

 mit, down to 6, 1 or even 8 inches, but the cases are rela- 

 tively few where it is important to plow deeper than 6 or 7 

 inches. Where plowing is for small grains to be sowed at 

 once the depth may usually be shallow, 5 inches or less, as 

 these thrive best in a shallow seedbed. 



315. Best Condition of Soil for Plowing. There is a con- 

 dition of moisture peculiar to each and every soil at which 

 it will be left with the best texture after plowing, requiring 

 the least amount of finishing work to put it in final condi- 

 tion. If the soil is too wet the crumb structure so essen- 

 tial to a clay soil will be partly destroyed and the soil 

 puddled; if too dry the furrow slice will not shear in thin 

 layers and the soil will not be pulverized fine. The water 

 content should be such that the damp soil squeezed in the 

 hand will hold its form but will easily crumble to pieces 

 and not be at all pasty. 



Sod ground can always be plowed a little wetter than 

 corn, potato or stubble ground because the roots lessen the 

 danger of puddling and the shearing effect of the plow is 

 less. 



