Water Application Methods - Practices of Irrigation and On-farm Water Management - page 45

Attainable Efficiencies
When using properly designed row slopes, row lengths, set times, stream sizes, and
a reuse system, furrow irrigation efficiency can be high as 90%.
Labor and Energy Requirement
To establish the furrow, some labors are required. After that, the least labor required
among the surface methods. If the system is automated, the labor requirement is
reduces to minimum.
Required Depth of Irrigation Application
If only little water is to be applied per application, e.g., on sandy soils and a shal-
low rooting crop, furrow irrigation would be most appropriate (However, none of
the surface irrigation methods can be used if the sand is very coarse, i.e., if the
infiltration rate is more than 30 mm/h).
Cost and Economic Factor
Major initial cost in furrow system is the construction of furrows. The cost is directly
related to the number of furrows (i.e. furrow spacing), volume of soil to be removed,
and the unit labor/instrument charge.
Level of Technology
Furrow irrigation, with the possible exception of short, level furrows, requires accu-
rate field grading. This is often done by machines. The maintenance - plowing and
furrowing - is also often done by machines. This requires skill, organization, and
frequently the use of foreign currency for fuel, equipment, and spare parts.
Advantages and Disadvantages
Advantages
(i) developed gradually as labor or economics allows
(ii) developed at a relatively low cost after necessary land-forming activities are
accomplished
(iii) erosion is minimal
(iv) adaptable to a wide range of land slopes
Limitations
(i) Not suitable for high permeable soil where vertical infiltration is much higher
than the lateral entry
(ii) Higher amount of water is required, compared to sprinkler or drip irrigation
(iii) Furrows should be closely arranged