SOILS THAT NEED DRAINAGE

Articles In This Section:

· WATER, AIR, AND BACTERIA

· SOILS THAT NEED DRAINAGE

· DRAIN OUTLETS

· SURFACE AND UNDERGROUND DRAINS - Part 1

· SURFACE AND UNDERGROUND DRAINS - Part 2

The need for drainage arises in most intensely cultivated areas, but more especially in the following circumstances: (a) flat lands or basins in which water from adjacent lands collects; (b) lands adjoining higher slopes where the formation allows the water that soaks into the higher ground to seep farther to the lower levels; (c) lands that are subject to periodical overflow of lakes and rivers; {d) flat lands that rest upon an impermeable stratum of rock or clay; (e) lands that are watered artificially, and where it is essential that the surplus water should readily escape. In suburban gardens the necessity for drainage often arises from, or is increased by, the interference with natural flow of subsoil moisture caused by roadways, large underground drains, sewerage excavations, and the like; (/) unduly acid peaty soils.

A garden should not be made until efficient drainage has been established. It would be foolish to spend time, money, and exertion unnecessarily in laying even a simple system of drains, but most gardens will need some such preparation. An easy test can be made by digging holes in scattered parts and leaving them open for further observation. They should be about two feet deep, and will be more informative in the wet season than in the dry, for in the former they will fill after heavy rain, partly by catchment and partly by soakage, and if they do not empty within twelve or, at the most, twenty-four hours after cessation of the rain, they will show that artificial drainage should be established. In dry weather they should be filled with water and refilled after a few hours. The water should disappear within twelve hours.

It is never safe to assume that sloping ground is well drained, for water is sometimes held up by the formation of pockets in the underlying soil.

Surface drainage may be useful in diverting great rushes of water from storms or floods, but open ditches to carry away surface water are not to be recommended as a general rule. Harmful erosion of the best layers of the soil is caused and often a hard crust is left, excluding air. Valuable purposes are served by water percolating through the soil.