. Productive soils; the fundamentals of successful soil management and profitable crop production. Soils. METHOD OF DRAINAGE 113 2. Subsurface Drainage.—When the damaging water is in the soil, or when the water-table^ is too high, "subsurface'' or ''under- drainage'' is necessary. This may be done through the use of open ditches and underground or covered drains. 3. Vertical Drainage.—Occasionally water standing in upland depressions and on some flat upland fields may be given a chance to escape by making openings through the tight soil, or subsoil, so that the water may move downward int
. Productive soils; the fundamentals of successful soil management and profitable crop production. Soils. METHOD OF DRAINAGE 113 2. Subsurface Drainage.—When the damaging water is in the soil, or when the water-table^ is too high, "subsurface'' or ''under- drainage'' is necessary. This may be done through the use of open ditches and underground or covered drains. 3. Vertical Drainage.—Occasionally water standing in upland depressions and on some flat upland fields may be given a chance to escape by making openings through the tight soil, or subsoil, so that the water may move downward into an open and dry soil below, if such a substratum is to be found. 4. Combined Methods Necessary.—It is generally necessary to combine different methods of drainage. On nearly all large areas the best combination for thorough drainage is large open ditches for outlets, and underground drains. Under certain other con- ditions a surface-run combined with underdrainage gives best. FiQ 47 —Dead furrows as drams On tight soils, especially on fields having littlo slope, surface drainage may be had by plowing m narrow ' lands " up and down the gentle slopes The surface water drams from the back furrows to the dead furrows, thence down the dead furrows and off the field J?, back furrow, D, dead furrow (See Fig 68 ) results. In many large areas effective drainage is accomplished only through the combined use of open ditches, underdrains and surface-runs (Figs. 48 and 50). Method of Drainage Depends Upon Why Land is Wet.—^The only reasonable and safe way to begin any efforts towards drainage is to ascertain why the land is wet, and this knowledge should determine the manner and system of drainage to be employed. In most cases it is easy to determine when surface drainage is needed; but underdrainage is too often overlooked. On many a field the farmer never suspects a lack of drainage to be the cause of low crop yields. To eliminate any guessing in ascertaining
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectsoils, bookyear1920
