SPRING VERSUS FALL PLOWING 67 



respond to this treatment are the heavier types, as the 

 clays. Fall plowing, if followed by surface cultivation, 

 conserves the water by checking the evaporation, and the 

 land is left in a better condition to retain the moisture. 

 When fall plowing is done it will be found to be generally 

 better to delay the surface cultivation until the following 

 spring, especially on heavy clay land. If clay land is left 

 ridged, when fall plow r ed, an irregular surface is exposed, 

 and the rain is held in the furrows and a better opportunity 

 is given for the water to sink into the subsoil. 



Fig. 19. — The Osborne disk harrow. (International Harvester Com- 

 pany of America.) 



When the soil is not plowed until in the spring there is a 

 greater loss of water by evaporation during the winter and 

 early spring. Besides the loss of water by evaporation the 

 soil has not been able to store up as much water from the 

 rains and the snows during the winter, because it has been 



