. Soils, their properties and management . lly changesand undergoes improvement. Lines of seepage develop, 648 SOILS: PROPERTIES AND MANAGEMENT and the drain gradually increases in efficiency. In heavysoil and in soils having hardpan properties, several seasonsmay be required for this change in the soil to spreadthree or four rods from the drains. The problem is toremove the excess water from the soil at the maximumdistance from the drains in time to avoid serious injuryto the crop. 550. Construction of drainage trenches for tile. —Trenches should be as small as possible and yet i)ermitthe rea
. Soils, their properties and management . lly changesand undergoes improvement. Lines of seepage develop, 648 SOILS: PROPERTIES AND MANAGEMENT and the drain gradually increases in efficiency. In heavysoil and in soils having hardpan properties, several seasonsmay be required for this change in the soil to spreadthree or four rods from the drains. The problem is toremove the excess water from the soil at the maximumdistance from the drains in time to avoid serious injuryto the crop. 550. Construction of drainage trenches for tile. —Trenches should be as small as possible and yet i)ermitthe ready introduction of the tile. Unless the tiles to beused are of the larger sizes, the ditch should be madefrom twelve to fourteen inches wide, with vertical leveling instruments are employed, the courseof the ditch is staked out and the grade cord is stretcheda definite distance above the proposed grade line of theditch, to guide the workmen. In hand digging, the earthis thrown out with a narrow-pointed spade, the loose earth. Fig. 66.—Tools for ditchiiiK. (1) and (2), ditching spades for remov-ing the major inirt of the earth from the ditch ; (3), grading scoopused to finish the bottom of the ditch and the grade; (4), skek^tonspade adapted for use in very phistic soil; (5), shovel for removingloose earth; (6), hook used to place tile in deep, narrow trenches;(7), pick for loosening stone and hard earth. LAND DRAINAGE 649 is cleaned out with a round-pointed shovel, and the bottomis finished to a smooth, perfect grade by means of thegrading scoop, which also rounds the bottom of the trenchinto shape to receive the tile. (See Fig. 66.) Careshould be taken not to excavate the trench below thegrade line, so that the tile may have a firm bed. Horse and engine power are now very generally appliedto trench digging. Several types of plows drawn byhorses are available to loosen the soil, and some typesare arranged to follow the grade and to elevate the looseearth out of t
Size: 1824px × 1370px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidsoilstheirpr, bookyear1915
