134 The Potato 



by spring-sown grain, which requires considerable work 

 early in the spring. The harrowing needed to place 

 fall-plowed land in condition for planting takes less 

 time than spring plowing and the harrowing necessary 

 to cut up the sod well. Harrowing must be deep and 

 thorough or the benefit of fall-plowing may be largely 

 lost. While there is some additional loss of moisture 

 from plowing a second time in spring, this later plowing 

 greatly reduces the amount of harrowing necessary and 

 makes certain that the soil is well pulverized to the 

 depth of the furrow. It is well to fall-plow land as 

 roughly as possible wdth the furrows-slice standing nearly 

 on edge. A rough surface catches the rains better, ex- 

 poses the soil better to the action of frosts and reduces 

 the damage by winds through the winter. Water is 

 saved in fall-plowed soil because the layer of sod or 

 trash at the bottom of the furrow prevents the water 

 in the subsoil from escaping as readily. Straw or manure 

 spread on the surface before fall plowing will usually 

 become rotted enough by spring to give little trouble if 

 replowed. The mellow soil with rotting organic matter 

 holds more water than unplowed land would, especially 

 in places like dry knolls. Clover sods rot quickly, but 

 sods of the grasses take longer. With spring plowing 

 only, it is beneficial to cut up the grass sods with a disk 

 harrow before plowing. The sod rots more quickly and 

 the soil settles together better so that the movement of 

 the water in the soil is not hindered. 



Earliness is a great advantage in spring plowing in the 

 northern states. An experiment by King at Wisconsin 

 showed that water equal to If inches of rainfall was 

 evaporated in one week in spring. Water evaporates 

 from the soil very fast in the first days of spring after 



