296 SOILS AND FERTILIZERS 



The amount and kind of cultivation to secure the venti- 

 lation or aeration necessary for crop production must 

 be regulated according to the character of the soil, as 

 sand, clay, or loam, and the climatic conditions. The 

 cultivation which is given soils for moisture conserva- 

 tion also secures the proper aeration. 



In discussing the importance of a mellow seed bed, 

 King says ; 15 " When a mellow, open seed bed has been 

 prepared, and its temperature has been raised to the 

 proper point, should a rain fall upon it, that water will 

 tend to pass through its wide pores quickly to the 

 deeper soil, and without leaching it as badly as would 

 be the case were the soil more compact ; so that in 

 the early season when there is an overabundance of 

 moisture, it is best, for warmth, for aeration, and to 

 lessen loss of fertility by percolation, to have a mellow 

 seed bed." 



350. Preparation of Seed Bed without Plowing. - 



Loam soils which have been subjected to a systematic 

 rotation of crops ending with corn, need not be plowed, 

 but the seed bed for the succeeding grain crop can 

 be prepared simply by disking the corn land. Surface 

 tillage of the corn crop has sufficiently loosened and 

 aerated the soil and has caused an accumulation of 

 available plant food near the surface which would be 

 buried and be less available to the crop if the land were 

 plowed too deeply. On heavy clay lands this method 

 of preparing the seed bed is not advisable ; but on the 



