It may be safely concluded that a large portion of the water that falls as rain or snow may be stored in the soil to considerable depths (eight feet or more). However, the question remains, Is it possible to store the rainfall of successive years in the soil for the use of one crop? In short, Does the practice of clean fallowing or resting the ground with proper cultivation for one season enable the farmer to store in the soil the larger portion of the rainfall of two years, to be used for one crop? It is unquestionably true, as will be shown later, that clean fallowing or "summer tillage" is one of the oldest and safest practices of dry-farming as practiced in the West, but it is not generally understood why fallowing is desirable. Considerable doubt has recently been cast upon the doctrine that one of the beneficial effects of fallowing in dry-farming is to store the rainfall of successive seasons in the soil for the use of one crop. Since it has been shown that a large proportion of the winter precipitation can be stored in the soil during the wet season, it merely becomes a question of the possibility of preventing the evaporation of this water during the drier season. As will be shown in the next chapter, this can well be effected by proper cultivation. There is no good reason, therefore, for believing that the precipitation of successive seasons may not be added to water already stored in the soil. King has shown that fallowing the soil one year carried over per square foot, in the upper four feet, 9.38 pounds of water more than was found in a cropped soil in a parallel experiment; and, moreover, the beneficial effect of this. water advantage was felt for a whole succeeding season. King concludes, therefore, that one of the advantages of fallowing is to increase the moisture content of the soil. The Utah experiments show that the tendency of fallowing is always to increase the soil-moisture content. In dry-farming, water is the critical factor, and any practice that helps to conserve water should be adopted. For that reason, fallowing, which gathers soil-moisture, should be strongly advocated. In Chapter IX another important value of the fallow will be discussed. In view of the discussion in this chapter it is easily understood why students of soil-moisture have not found a material increase in soil-moisture due to fallowing. Usually such investigations have been made to shallow depths which already were fairly well filled with moisture. Water falling upon such soils would sink beyond the depth reached by the soil augers, and it became impossible to judge accurately of the moisture-storing advantage of the fallow. A critical analysis of the literature on this subject will reveal the weakness of most experiments in this respect.