Campbell's 1902 Soil Culture Manual. 



29 



very heavy one. The part of the field that was cultivated previous to the 

 rain was left with the thick compacted crust made by the heavy fall of 

 water, which resulted in dissolving the loosened soil and settling it very 

 close, thus leaving the surface in the best possible condition for a rapid 

 movement of moisture to the surface and evaporation. Under the head of 

 Capillary Attraction we have explained this more clearly. The portion 

 not cultivated previous to the rain was gone over as soon after the rain as 

 conditions would permit, thus producing a perfect protection to the moist- 

 ure below, and bringing about the remarkable result referred to. While 

 these cases cited seem like extreme instances, under similar circumstances 

 you can look for similar results. When the reader begins to understand 

 the direct effect of these conditions it will then be quite clear why a light 

 crop was secured when a good crop might have been harvested. 



AS TO TIME OF CULTIVATION. 



The proper time for cultivating a field is one that cannot be fixed 

 without much thought, observation, and judgment by the farmer, especially 

 if he would get the best results. Always cultivate immediately, or as soon 

 after a rain as conditions will permit you on the field, and the soil is 

 suflBciently dried so that it will not adhere to the cultivator teeth, or tools 

 used. We do not mean by this that the soil should be absolutely dry on 

 the surface. It is an error to wait for that time, for the moment the sur- 

 face is apparently dry the crust begins to form. It is desirable to catch 

 the ground just before this time when all the soil is simply moist and then 

 there is a free and ready separation of all particles. In this condition the 

 cultivator runs the easiest, the mulch made the finest and lies up light 

 and loose. If the soil is a little too wet it settles, and not unfrequently 

 forms absolute and perfect connection with the firm soil below, steadily 

 carrying moisture to the surface. If too dry the cultivator produces an 

 imperfect mulch that gives us but little protection. 



Another and very important idea is that every moment's delay after 

 the soil reaches the proper condition causes you to lose water very fast. 

 It is at the rate of a quart or over per square foot per day providing it is 

 clear sunny weather, and even more in case of heavy south winds. The 

 more intense the heat the more frequent is it necessary to cultivate. A 

 very good rule is to watch the condition of the firm soil just beneath the 

 loose mulch or cultivated portion, and whenever the surface of this firm 

 soil begins to show dryness it is high time to commence cultivating again. 

 If the field is left too long during the extreme dry period the surface of 

 the solid soil beneath the mulch will begin to form a crust, practically the 

 same as is shown on the surface of the soil when uncultivated after a rain. 

 This is the result of the soil composing our mulch reaching a high degree 

 of heat, causing the moisture from the surface of the solid soil to form into 



