UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 512 
Contribution from the Office of Public Roads and 
Rural Engineering 
LOGAN WALLER PAGE, Director 
Washington, D. C. PROFESSIONAL PAPER April 5, 1917 
PREVENTION OF THE EROSION OF FARM LANDS 
BY TERRACING. | 
By C. E. RaMser, Drainage Engineer. 
CONTENTS. 
Page Page 
TA ROMICELOME ys ee CE IR Sto 1 | Terracing—Continued. 
HIOEIISOUOLOSION Saas se oe eet a eee 2 The graded-ridge terrace................----- 21 
Methods of preventing erosion................- 3 The narrow-base form ...-.--- Pape meets 21 
Deep tillage and application of humus....... 3 ‘heybroad=hase)formeseesee ser. seeeeaeee 22 
WSCIORCOMOINCLOPS tesco cloat easier cee 4 Terraces with uniform grade.......-.....- 24 
ipracticeloslovel Gulpure ..6 22552. . caNss. 4 Terraces with variable grade.............- 27 
iRasturineand foresting-:- 2 -..-.s-s4es-eses 4 Outlets yee sew see ee ees cise Cee Merial Coe 28 
iniderdrainime se a eae ae ES 5 General discussione sees 2 eee eee eee 29 
Wscorniliside ditches ssc... 0a-4 ee ees 5 Comparison of terrace types. ----.-.--------- 30 
PROETAC HAC me nA he ea oe hole eA SER Ul 5 Laying off a terrace system..... Pi tena caee ge AUS 32 
Definition and classification of terraces....... 6 Construction of terraces.-......-.-..-.----.-- 35 
hoibench terraces oc ee See PL 7 Maintenance and cultivation of terraces...... 37 
Mitotevel-ridee terrace: 91-22 )ei2 es 10 | Reclamation of gullied lands................... 38 
The narrow-base form...........-....-.--.- iQ) |) SUH EEN coon) souadaosceanee ssacausoses acest 38 
The broad-base form. ......:252.2..-022--8 1194 
Generali discussion css u-= eae eee 18 
INTRODUCTION. 
The existence of vast areas of so-called worn-out hill lands 
throughout the United States may be attributed chiefly to soil erosion, 
due to the natural agencies of wind, frost, and rain. In most lo- 
ealities wind and frost, owing to their comparatively slow processés, 
play but a minor part in the depletion of the soil and the ultimate 
destruction of good farm lands. It is the failure of the soil to 
absorb the rain water which falls upon it that presents by far the 
most serious aspect of the problem. It is estimated! that the Poto- 
mac River each year carries off in solution about 400 pounds of solid 
1 Bulletin 17, North Carolina Geological and Economic Survey, p. 21. 
Notre.—This bulletin treats of terracing as a means of preventing erosion of hillside 
land. It describes the different types of terraces and points out the applicability of 
each to the yarious kinds of soil and topography. It discusses the principles of terrace 
design. While the investigations upon which the recommendations are based were made 
in the Southern States, the information is applicable generally to any State in the 
‘humid section. 
71775°—Bull. 512—17——_1 
