- Contour trenching
Trenches can be artificially digged along the contour lines. Water flowing down the hill is retained by the trench, and is infiltrating the soil below.
Immediate advantages are the following:
- The rain water does not immediately run off the hill,
- Water does not evaporate uselessly
- The water balance is enhanced
- Crops do not suffer later on from water shortage,
- Fertile soil particles are not lost by water and wind erosion.
Depending on the slope of the hill, the parallel trenches can be closer or further from one another.
Manually digged trenches are smaller. Machine digged trenches can be deeper. The dimensions, and the format of the trench should correspond to the local climate and soil conditions. The trench should be big enough to keep all the water; no water should spoil over the downhill border. The upside of the trench should be protected against erosion, by means of e.g. grass, shrubs, or fabric.
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