Conserving Soil Moisture. 185 



eighth of the rainfall of the growing season of that lo- 

 cality. 



Nor was the saving of moisture the only advantage gained 

 by the early plowing, for the soil plowed last had dried so 

 extensively as to become very hard and lumpy, thus great- 

 ly increasing the labor necessary to fit it for planting. 



In another experiment to study the effectiveness of 

 early as compared with late spring plowing in conserving 

 soil moisture Fig. 57 shows how evident the effects were 

 to the eye. 



215. Disking or Harrowing Where There is Not Time to 



Plow. It often happens in the spring that hot dry winds 

 come on when there is not opportunity to get the ground 

 plowed in time to save the needed moisture and prevent 

 the development of clods. In such cases the use of tho 

 disk harrow, or even the ordinary spike tooth harrow, will 

 do very much to save the moisture and preserve the tilth 

 of the soil, if only the fields are gone over with these. The 

 disk harrow is one of the best of tools for early use in 

 the spring to work the soil and develop mulches. 



216. Corn and Potato Ground, Orchards and Gardens 

 Plowed Early in the Spring. Ground to be planted to corn 

 or potatoes, as well as the orchard and garden, should gen- 

 erally be plowed quite early in the spring and a consid- 

 erable time before it is intended to plant them. By doing 

 this, not only will moisture be saved but the development 

 of nitrates in the soil will be hastened and thus larger 

 crops secured on this account. It is only in the event of 

 long, frequent and heavy rains, following such early tillage, 

 that loss can result from such a practice. 



217. Effectiveness of Soil Mulches. The effectiveness of 

 soil mulches as means for diminishing evaporation varies 

 (1) with the size of the soil grains, (2) with the coarse- 

 ness of the crumb structure, (3) with the thickness of the 

 mulch and (4) with the frequency with which the soil is 



