TILLAGE AND EVAPORATION 155 
recent years that confirmation of this important 
principle has been obtained for the soils of the dry- 
farm region. Fortier, working under California con- 
ditions, determined that cultivation reduced the 
evaporation from the soil surface over 55 per cent. 
At the Utah Station similar experiments have shown 
that the saving of soil-moisture by cultivation was 63 
per cent fora clay soil, 34 per cent for a coarse sand, 
and 13 per cent for a clay loam. Further, practical 
experience has demonstrated time and time again that 
in cultivation the dry-farmer has a powerful means 
of preventing evaporation from agricultural soils. 
Closely connected with cultivation is the practice 
of scattering straw or other litter over the ground. 
Such artificial mulches are very effective in reducing 
evaporation. Ebermayer found that by spreading 
straw on the land, the evaporation was reduced 22 
per cent; Wagner found under similar conditions a 
saving of 38 per cent, and these results have been 
confirmed by many other investigators. On the 
modern dry-farms, which are large in area, the arti- 
ficial mulching of soils cannot become a very exten- 
sive practice, yet it is well to bear the principle in 
mind. The practice of harvesting dry-farm grain 
with the header and plowing under the high stubble 
in the fall is a phase of cultivation for water conser- 
vation that deserves special notice. The straw, thus 
_ incorporated into the soil, decomposes quite readily 
in spite of the popular notion to the contrary, and 
