54 THE OLIVER PLOW BOOK 



add to that soil before it will produce. It is further 

 logical to assume that if the best growth takes place in 

 those pots that contain fertilizer or the plant food 

 elements which the farmer cannot hope to add to the 

 soil, it is unwise to plow the ground to that depth whether 

 he does it in the fall or spring. We often deceive our- 

 selves into thinking that soil plowed eight, nine, or ten 

 inches deep turns up soil fertility when it does not. 



As far as the writer has been able to learn, there have 

 never been experiments tried to prove that winter's 

 freezing unlocks soil fertility any more than that the 

 winter's freezing of certain soil particles such as clay, 

 has a tendency to flocculate the soil, or break it into 

 small particles, so that the fertility contained in the soil 

 is made more available. 



Obviously then, one must suppose that before deep 

 fall * or "spring plowing is indulged in it is necessary to 

 know whether the deep soil contains available fertility. 



The other important question to decide is whether or 

 not the plowing can be done so as to leave the ground in 

 the proper tilth and condition for plant growth. This 

 can only be determined by having a knowledge of the soil 

 and how to handle it to bring about conditions of tilth. 



The one great advantage of deep fall plowing over 

 deep spring plowing is that the fall plowing receives the 

 aid of t'ime, moisture and freezing to break up cloddy 

 formations that may have resulted from the plowing and 

 to compact the soil into a suitable condition for capillar- 

 ity to take place. In deep spring plowing, the ground 

 is often turned over in cloddy formations which are 

 detrimental to the compacting of the soil at the bottom 

 of the furrow on account of the depth at which it must 



