68 PREPARATION OF LAND FOR CORN 



seasons must be plowed thoroughly once a year to keep it in goo'd 

 physical condition, while in cultivated crops. Without good plow- 

 ing the land becomes hard, and increases the laber of planting and 

 cultivating. 



Depth of Plowing. Nothing definite can be said regarding 

 depth of plowing so far as immediate effect on the corn crop follow- 

 ing. However, common experience is that land can not be kept in a 

 good productive state by constant shallow plowing. The reasons 

 seem to be: (1) The humus and fertilizer applied is then limited 

 to the surface few inches. (2) The benefits to be derived from the 

 humus or fertilizer can not be fully utilized by the plant, as it does 

 not have sufficient roots in the surface three or four inches ; also the 

 surface may be too dry for considerable periods. (3) Constant 

 shallow plowing is apt to give a hardpan subsurface. 



Fall or Spring Plowing. Where heavy sod lands are to be put 

 into corn or manure is to be turned under, fall plowing is best, as 

 the vegetable matter decays more thoroughly. In other cases where 

 the corn follows corn or grain, fall and spring plowing give about 

 equal results. It is then largely a question of farm management. 

 On most farms it is convenient to do a part or all of the plowing in 

 the fall. 



On some heavy soils the fall-plowed land becomes too compact by 

 spring, necessitating replowing for the corn. In such cases spring 

 plowing is cheaper and advisable. 



Time of Spring Plowing. Three advantages have been estab- 

 lished regarding early spring plowing as compared with late spring 

 plowing : (1) The available plant food, especially nitrogen, will be 

 greater with early plowing, due to aeration and greater activity of 

 soil bacteria. (2) More moisture will be conserved, if the spring is 

 dry. ( 3 ) As a result the yield of corn is usually better. 



Preparation After Plowing. The principal objects of prepa- 

 ration after plowing are to pulverize and compact the soil well and 

 destroy weeds. 



Caution is needed in the case of certain very fine clay soils, which 

 when pulverized too fine are apt to run together in a hard crust after 

 heavy rains. On such soils tools that give a coarse preparation, such 



