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The subsurface field drainage systems consist of horizontal or slightly sloping channels made in the soil; they can be open ditches, trenches, filled with brushwood and a soil cap, filled with stones and a soil cap, buried pipe drains, tile drains, or mole drains, but they can also consist of a series of wells.
In drainage research the collection and analysis of field data is important. [ 5 ] In dealing with field data one must expect considerable random variation owing to the large number of natural processes involved and the large variability of plant and soil properties and hydrological conditions.
In addition, land drainage can help with soil salinity control. The soil's hydraulic conductivity plays an important role in drainage design. The development of agricultural drainage criteria [3] is required to give the designer and manager of the drainage system a target to achieve in terms of maintenance of an optimum depth of the water table.
Various geotechnical engineering methods can be used for ground improvement, including reinforcement geosynthetics such as geocells and geogrids, which disperse loads over a larger area, increasing the soil's load-bearing capacity. Through these methods, geotechnical engineers can reduce direct and long-term costs.
Practically, wheat does not require irrigation because it develops deeper roots while during the maturing period a dry soil is favorable. The analysis of cumulative frequency [6] of climatic data plays an important role in the determination of the irrigation and drainage needs in the long run.
Vertical drainage systems are drainage systems using pumped wells, either open dug wells or tube wells. Map of a well field for subsurface drainage with radial flow across concentrical cylinders representing the equipotentials. Both systems serve the same purposes, namely water table control and soil salinity control.
Tilling the soil, or tillage, is the breaking of soil, such as with a plough or harrow, to prepare the soil for new seeds. Tillage systems vary in intensity and disturbance. Conventional tillage is the most intense tillage system and disturbs the deepest level of soils. At least 30% of plant residue remains on the soil surface in conservation ...
The primary method of controlling soil salinity is to permit 10–20% of the irrigation water to leach the soil, so that it will be drained and discharged through an appropriate drainage system. The salt concentration of the drainage water is normally 5 to 10 times higher than that of the irrigation water which meant that salt export will more ...