348 SOIL PHYSICS AND MANAGEMENT 



during the summer will make it sufficiently compact and a thin 

 stratum of two to four inches in depth mellowed somewhat by the 

 disk will provide an excellent seed bed. Wheat is sometimes seeded 

 in the standing corn and in such case no preparation is necessary. 

 The crop is handicapped, however, because the corn has left the 

 soil in poor condition in regard to moisture and plant food. 



The preceding table shows that deep, early plowing with working 

 till seeding time has given the greatest profit. 



The soil for wheat should be well drained. This is very essential, 

 especially in temperate regions where freezing and thawing occur. 

 The great objection to growing wheat formerly was the winter killing 

 caused by a poorly drained seed bed. 



2. Corn. The plowing for corn may be done either in fall or 

 spring and the production of the seed bed is somewhat different in 



Fro. 166. A Rood seed bed on stalk ground. 



the two cases. With fall plowing the ground should be disked or 

 worked in some way as early as possible in the spring to a depth of 

 three to five inches. This conserves moisture, raises the temperature 

 of the soil and destroys any weeds that may have started. This 

 disking should be continued at intervals of ten days or two weeks 

 until the time for planting. The object is to destroy as many 

 weeds as possible before the crop is planted, as cultivation for this 

 purpose is much more effective at this time. The disking should 

 be done deep to thoroughly aerate the soil and encourage the develop- 

 ment of plant food. Corn on fall-plowed land is said by some 

 farmers to " fire " easily. This " firing " may be due to two causes : 

 first, to lack of moisture, and, second, to lack of available nitrates. 

 Fall plowing, unless the soil is in good tilth, tends to dry out early 



