When it comes to advantages and disadvantages of subsurface agricultural drainage systems there is one very clear point for each argument; Advantage of Subsurface Agricultural Drainage Systems – There is no interruption of the field surface, wastage of land taken up for drainage systems or interference with farm machinery – okay, maybe that’s three advantages if you want to look at it that way.
Disadvantage of Subsurface Agricultural Drainage Systems –They are a much more pricey option than the relatively easy surface drainage methods. They also don’t work too well in heavy, largely impermeable clay type soils – okay, so maybe that’s two disadvantages.
Let’s take a look at the different types of subsurface agricultural drainage systems in more detail;
- Tile drains – first of all you’ve got to dig a narrow trench which needs to be at least 75 cm deep to prevent the tiles being crushed by heavy farming machinery above the surface. Then place a layer of tiles at the bottom of the ditch – porous type tiles definitely work the best and cover with soil. The water is moved thanks to gravity between the tiles.
- Rubble drains – work on pretty much the same principle as the tile drains using gravel or coarse stones. You’ve got to dig a narrow drain (V shaped works best) then fill them up with rubble and rough stones before covering with a layer of soil. This type of drain needs to be at least 90 cm deep.
- Mole drains – are useful in heavy clay type soils and need the use of a moling machine – usually 10 or 15 cm diameter a minimum of 75 cm beneath the surface of the land. These are commonly used in European agriculture.
- Drainage pumps – are often used in the United States as a means of reclaiming land at the bottom of rivers, lakes, irrigated lands, peat lands etc.