Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D.C. 4 Vv November 22, 1916 
WATER PENETRATION IN THE GUMBO SOILS OF 
THE BELLE FOURCHE RECLAMATION PROJECT. 
By O. R. MatueEws, Assistant, Dry-Land Agriculture Investigations. i 
CONTENTS. 
Page. Page. 
MRErOGUCtION el Voce gle ane lc lode Aes!) 1 | Rate of movement of water in loose, sat- 
Description of the gumbo soil of the Belle (DULG MSO USA IS Ee eee Ree SADE pl TEN he 4 
Fourche Reclamation Project ............- 2 | Rate of movement of water in wet soil under 
Water capacity of the gumbo soil.........._. 3 heldvconditionsys: N00 8 0) oc oy ae Roe Ue 5 
Productivity of the gumbo soil........._.... 3 | Penetration of water into dry soil in the field -. 6 
Changes in the volume of the soil due to SUANINA DY te tet oe ye Ln ee Ai eh pe aCe 11 
wettineandidmying. i yee 3 
INTRODUCTION. 
The readiness with which water penetrates into any soil determines 
to a great extent the amount that will be available to crops. An ac- 
curate knowledge of water movement within a soil often furnishes 
an indication of the farm practices that will be most successful. 
Thus under irrigation the rapidity of water percolation may deter- 
mine in what way and at what time water may be most effectively 
applied. On dry land a knowledge of moisture movement often 
shows what results may be expected from different cultural methods 
calculated to increase the quantity of water entering the soil. 
_ The gumbo soil of the Belle Fourche (S. Dak.) Reclamation Proj- 
ect offers problems in water penetration materially different from 
those in soils of other types. These differences are due largely to its 
peculiar physical characteristics. 
This bulletin presents the results of certain studies of the penetra- 
tion of water into the gumbo soils of the Belle Fourche project. 
_ Knorr, working on the sandy loam soils at Scottsbluff, Nebr., 
found that plats irrigated in the fall were more moist and moist to 
greater depths in the spring than plats not fall irrigated. When 
‘Knorr, Fritz. Experiments with crops under fall irrigation at the Scottsbluff Recla- 
mation Project Experiment Farm. U. 8. Dept. Agr. Bul. .133, 17 p., 5 fig. 1914. 
99155°—Bull. 447—16 
