Water Application Methods - Practices of Irrigation and On-farm Water Management - page 44

Fig. 2.3 Schematic of furrow
irrigation system
Furrows
Water supply
The furrow method is an efficient system if properly managed, but a most ineffi-
cient one if improperly managed. For this method, fields must have a mild slope and
inflow discharge must be such that advance is not too fast and produce excessive
runoff losses, nor too slow to induce excessive infiltration in the upper part of the
field. Short blocked furrows with manually controlled water applications are prac-
ticed by traditional irrigators. Nowadays, long and precisely leveled furrows with
automated or semi-automated control have become increasingly popular.
2.3.3.2 Suitability and Limitations
Crop Suitability
Furrow irrigation is best used for irrigating widely spaced row crops such as potato,
maize, vegetables, and trees.
Soil and Topography
Loam soil is best suited for furrow irrigation. Sandy soils can cause excess infil-
tration at the upper end of the furrow, clay soils may need extra standing water to
infiltrate.
Steeper land compared to basin or border (mild slopy topography, 0.5-2%) is
needed to establish furrow irrigation. Undulated/zigzag topography is not suited for
this method.
Water Quantity
Depending on surface conditions, stream size used should be as large as possible to
move water through the field quickly without causing erosion.