122 CAMPBELL'S SOIL CULTURE MANUAL 



and cause it to settle very firm as shown in the center 

 column of our illustration. The restoring of this mulch 

 is of vital importance, and the question of the proper 

 time in which the condition of the surface soil regarding 

 the per cent of moisture it still has, must be carefully 

 considered, that cultivation may be done at a time when 

 the greatest good may come from it. 



When we realize that under the conditions we are con- 

 sidering, following a heavy rain, the soil will lose from 

 its surface by evaporation under normal summer climatic 

 conditions from one and a-half to two quarts of water per 

 square foot each day. 



We certainly should grasp the importance of quick 

 action, but if we cultivate too quickly we may puddle 

 the soil and leave a very poor mulch, especially if the soil 

 be close and heavy. 



Again if the soil be slightly or quite sandy and we 

 delay the cultivation too long, and the surface soil becomes 

 quite dry, which it will much quicker than the heavy soil, 

 then we may have our soil too much on the order of dust 

 which is easily disturbed by high winds. All these things 

 must be watched and duly considered. 



Just as soon as the soil is dry enough so it will not 

 stick to the harrow or cultivator, it should be quickly 

 gone over, 



