Journal of Agricultural Research voi. xxm, No. 9 
740 
SUMMARY 
(1) The question of the effectiveness of mulching has been much 
disputed. Further study is desirable. The results of these experiments 
are reported in terms of averages from thousands of measurements. 
(2) An effective mulch of 1 inch of straw is capable of preserving 60 
per cent more moisture in the soil than is retained without mulching. 
(3) Straw is the most efficient mulch material used in the experiments. 
Then come hay, grass, wood shavings, and manure, in the order men¬ 
tioned. 
(4) The loss of moisture from the soil is correlated with the percentage 
of moisture retained by the mulch. An efficient mulch .must be con¬ 
stituted of material which does not absorb or retain moisture readily and 
which forms practically no capillary system in itself. An absorptive 
mulch can be used to an advantage provided it is turned under before 
the dry period begins. 
(5) The effectiveness of mulching and cultivation increases with their 
depths. 
(6) The rate of evaporation of soils under mulch varies according to 
their moisture contents. Finer soils lose more water. Clay that has 
been ground into a fine powder in the laboratory loses less water than 
loam. 
(7) Cultivation and mulching save more moisture, but the evapo- 
transpiration ratio is the least with no mulch or cultivation. 
(8) Fall plowing preserves more moisture than spring plowing. 
(9) Under field conditions, soil moisture is more variable. The 6-inch 
cultivation is not so efficient as the 4-inch. In the dry-farm regions, 
shallower cultivation is to be preferred to the deeper. 
LITERATURE CITED 
(1) Airway, F. J., and Clark, V. L. 
1912. A STUDY OF THE MOVEMENT OF WATER IN A UNIFORM SOIL UNDER ARTI¬ 
FICIAL conditions. In Nebr. Agr. Exp. Sta. 25th Ann. Rpt., [1911]/ 
12, p. 246-287. References, p. 287. 
(2) Bouyoucos, G. J. 
1915. EFFECT OF TEMPERATURE ON MOVEMENT OF WATER VAPOR AND CAPILLARY 
moisture in soils. In Jotir. Agr. Research, v. 5, no. 4, p. 141-172, 
11 fig. Literature cited, p. 172. 
(3) Briggs, Lyman J. 
1899. THE MOVEMENT AND RETENTION OF WATER IN SOILS. In U. S. Dept. Agr. 
Yearbook, 1898, p. 399-404, fig. 102-109. 
(4) -—and Lapham, Macy H. 
1902. CAPILLARY STUDIES AND FILTRATION OF CLAY FROM SOIL SOLUTIONS. U. S. 
Dept. Agr. Bur. Soils Bui. 19, 40 p., 5 fig. 
(5) Burr, W. W. 
1914. the storage and use of soil moisture. Nebr. Agr. Exp. Sta. Research 
Bui. 5, 88 p., illus. 
(6) Cardon, P. V. 
1915. TILLAGE AND ROTATION EXPERIMENTS AT NEPHI, UTAH. U. S. Dept. Agr. 
Bul. 157, 45 p. 21 fig. 
(7) Chilcott, E- C., and Holm, A. B. 
1898. soil moisture investigations for 1897. S. Dak. Agr. Exp. Sta. Bul. 
5$, p. 53-84, illus. 
(8) Cox, U. T. 
1905. a straw mulch in the orchard. In W. Va. Farm Rev., v. 13, no. 4, 
p. 18. Original not seen; Stockman and Farmer. 
(9) Fortier, Samuel. 
1909. soil mulches for checking evaporation. In U. S. Dept. Agr. Year¬ 
book, 1908, p. 465-472, fig. 22-28. 
