4 
Contents 
PAGE 
Artificial mulches 46 
Table 18. — Effect of mulching on soil moisture, 1912 47 
Table 19. — Effect of mulching on soil moisture, 1911 48 
Loss of water from the soil 49 
Depths to which crops have used moisture 50 
Table 20. — Depths to which crops have used moisture. Summer 
tilled land 52 
Table 21. — Depths to which crops have used moisture. Summer 
tilled land 53 
Effect of weeds 55 
Tables 22-27— Effect of weeds on soil moisture, 1907-1913 56-60 
Chart VI— Effect of cultivation and weeds, 1908 61 
Chart VII. — Use of available water by a corn crop 62 
Table 28. — Use of water from soil by spring wheat, 1913 64 
Chart VIII. — Showing available moisture (above 8 per cent) and 
its use by the crop 65 
Chart IX. — Showing available water (above 8 per cent) and its 
use by the crop 66 
Charts X, XI, XII, XIV, and XV.— Moisture content of plats con- 
tinuously cropped to spring wheat 68-74 
Chart XI. — Moisture content of plat continuously cropped to 
spring wheat (1908) 69 
Table 29. — Effect of capillarity on soil moisture. Alfalfa on 
bench land 75 
Table 30. — Effect of capillarity on soil moisture 77 
Table 31. — Water required to produce one pound of dry matter 
of various crops 78 
Water required to produce one pound of dry matter of various crops.. 78 
Climatic conditions 80 
Fig. 1. — Normal annual precipitation in Nebraska. Map showing 
rain belts 81 
Fig. 2. — Precipitation at North Platte, Nebr., by years, 1875-1913, 82 
Table 32. — Record of precipitation by months for thirty-nine years, 
at North Platte, Nebr., as reported by the United 
States Weather Bureau 83 
Table 33.— Daily precipitation from March 1 to June 30, 1908-1913, 84 
Table 34.— Daily precipitation from July 1 to October 31, 1908-1913, 85 
Table 35. — Daily mean temperature from April 1 to August 31, 
1908-1913 86 
Table 36. — Daily evaporation from April 1 to September 30. for the 
years 1908 to 1913 87 
Table 37. — Daily wind velocity per hour from April 1 to August 
31, 1908-1913 88 
