Show TO PREVENT EROSION OF FERTILE LAND LANDI I TERRACING IS MOST r OST EFFECTIVE METHOD METHODI I E w t. ae f r v i tB h 1 i J 1 Terrace Bank Thrown Up With a Road Scraper Prepared by the United States Department Department Depart Depart- ment of ot Agriculture Erosion injures or practically ruins fertile land Bottom as well weil as hill lands suffer from the ravages of ero ero- sion Terracing Is the most effective method of stopping erosion Other means of reducing erosion that should be employed In connection with terracing terracing ter ter- racing are deep plowing growing cover crops plowing under organic matter contour plowing and under- under draining There are two distinct types of terraces terraces terraces ter ter- races the bench terrace and the ridge terrace The bench terrace Is particularly particularly particularly fitted for use on steep slopes while the ridge terrace Is especially adapted for use on moderate slopes The ridge terraces are divided Into two classes the narrow base and the broad base Both may be laid out level or with a fall along the terrace to carry the water off at a low ity The broad-base broad terrace can be cultivated and can be crossed readily by large farm machinery without In Injury Injury injury In- In jury to the terrace The narrow-base narrow terrace does not possess either of or these advantages and under ordinary circumstances Is less desirable than the broad-base broad t type peThe pe The broad-base broad ridge level-ridge terrace Is laid out absolutely level This more nearly meets the requirements of an Ideal terrace than any other type Its distinct advantage over a terrace WIth fall ran is that practically I none of the fertile parts of the soil are removed from the field It Is particularly particularly par par- suitable for use on open permeable soils The broad-base broad ridge graded ter ter- nce generally known as the Mangum terrace possesses all the advantages Jf f f. f the broad-base broad ridge level-ridge terrace wIth the exception n of the one sta stated ted in m the preceding paragraph It may mayI maye maySe Se Ie e used on any type of soil soli but Is recd recommended rec rec- for use only on soils where Jie he broad-base broad ridge level-ridge terrace without tile the drainage cannot be used successfully Erosion Is reduced to a minimum In the terrace channel b by carrying the water off ocr the field In a road goad shallow sheet at a low It ity It has been found that average soils are not washed much In broad broad- terrace channels where the me fall does trot not exceed 6 G inches in feet and It is recommended that this fall fail never be exceeded However even with this fall full some washing occurs and some rich soil particles are carried off the field Hence a graded terrace should be given Iven no more more fall than Is necessary necessary sary to remove the run off water without without without with with- out danger of the ten ace bein being over over- topped The terraces may be laid out with a uniform or a variable fall The best results are arc obtained where the variable fall tall Is used since It tends to prevent the concentration of the water water water wa wa- ter at the lower end of the terrace Also less washing occurs where the variable fall tall Is used The The provision for tor suitable outlets If Is h one of or the biggest problems In terracing tet ter- ter-j ter racing work Natural water courses make the best outlets outlets' Sometimes I It is necessary to construct ditches for fon use as outlets Where natural draws gullies s or roadside ditches are used they should be protected from erosion by building across them brush concrete con con- crete stop-plank stop or soil-saving soil dams The growing of grass gruss In draws used for outlets is especially recommended The work of laying off oil terrace should be done carefully preferably by an experienced man The best Instruments instruments In In- are the farmers farmer's small telescopic telescopic tele telex level and the engineers engineer's large level The plow and the V drag are most generally generall used for building up ter ter- races Other Implements sometimes used are the steel ditcher dUcher or the slip scraper the disk plow and md the road grader At crossings oti of draws and gullies the slip scraper Is Is' used to build up the high terrace embankment em em- It Is er very Important that the top of the terrace be built to the proper grade The upper terraces of ofa a n field should always s 's be built first Terraces require considerable care and attention particularly during the first year ear after they are built They should be Inspected after every heavy rain and an any breaks or weak weal places plaes repaired immediately The best results results results re re- are obtained when the crop rows are run parallel to the terraces In order to maintain the height and width of the terrace a cultivated terrace terrace terrace ter ter- race should be pl plowed wed at least once each year ear and the soil should be bo thrown to the center of the terrace rM ly w i q Aw x 4 rY x r AY 4 1 y Lines of Terrace Located by Plowing Two Furrows Together |