Performance Evaluation of Irrigation Projects - Practices of Irrigation and On-farm Water Management - page 125

If a 2.0 cusec supply source irrigates 50 ha land, the duty of the flow is 50/2.0 =

25 ha/cusec.

Crop Productivity/Yield Rate

Crop productivity (CP) refers to the yield per unit area. That is,

Y
A

CP = (4.25)

where

CP = crop productivity, (t/ha)

Y = yield from specific area, A (t)

A = area irrigated with the available supplied water source (ha)

Yield per hectare is the traditional way of representing the performance of agri-
cultural enterprise. It is of interest to irrigators too. Sometimes it can give a false
impression of efficiency, when other inputs of production are not being used, or not
provided at right amount and/or right time.

Water Productivity (WP) or Water Use Efficiency (WUE)

For a single crop,

WP = (Total dry matter or seed yield)/(Water used by the crop) (4.26)

For yearly basis,

WP = (Total production of all the crops)/(Total water used by the crops)

Here, “total water” represents “rainfall + irrigation + soil moisture depletion from
the root zone.” Different crops should be converted to equivalent one specific crop.

Irrigation Water Productivity (IWP)

Irrigation water productivity is defined as

Y
IW

IWP = (4.27)

where

Y = Total dry matter or seed yield, t/ha

IW = Irrigation water applied to the crop, mm

IWP = Irrigation water productivity, t/ha-mm

It can also be expressed in yearly basis.