By Owilla B. P. O., Machungo, C., Wanjogu R.K.
National Irrigation Board
BACKGROUND
 Productivity of Kenya’s predominantly rain-fed agriculture is
declining hence the call for irrigation expansion.
 Kenya’s economy is sensitive agriculture by a factor of 1.6 (Owilla,
2009).
 Irrigation increases crop yields by up to 400% .
 Kenya is a water-scarce country with irrigation leading in
consumptive use of water
 Irrigation expansion must integrate WUE and WP (ASALs)
 Drip and sprinkler systems are superior WUE and WP, but no
trials have been done to quantify their water-saving potentials
under local Scheme conditions
OBJECTIVES
 Determine water use efficiency of different irrigation
methods in maize, NERICA 4, green grams, common beans,
dolochos beans, cow peas and soya beans in Mwea, Perkerra
and Bura Schemes
 Determine water productivity of maize, NERICA 4, green
grams, common beans, dolichos beans and soya beans in
Mwea, Perkerra and Bura Schemes under different irrigation
methods
METHODS
 Three treatments - drip, furrow and sprinkler- were used on
four crops (maize, green grams, commom beans, soya beans,
cow peas and rice) on plots of 3m by 3m; RCBD with 3
replications
 Plotting was done with each irrigation system installed then
the crops planted
 Volume of water used: measured using Parshal flume; and
application intervals determined by tensiometer; calibration
of discharge rate of drip irrigation kit and sprinkler system
 Standard agronomic practices carried out as recommended
TREATMENTS
 Irrigation system (IS)
o Drip system
o Furrow
o Overhead sprinkler
 Crops: Maize (DH04), Soya beans (Bossier), Common beans
(Mwezi moja), Green grams (N26), Rice (NERICA 4)
DATA COLLECTION
 Soil physical/chemical analysis at start and end of trial
 Meteorological data
 Volume of water used measured using Parshal flume and






application intervals determined by the help of tensiometer,
discharge rate of drip irrigation kit and calibration of
sprinkler system
Plant density
Crop vigor- plant height at 14 days interval
Time to 50% flowering
Time to 50% maturity
Days to harvesting
Yield in Kg/Ha
DATA ANALYSIS
 Analysis of Variance (ANOVA) using EXCEL STAT and
GENSTAT and mean separations using Least Significance
Difference (LSD)
RESULTS-Mwea
 No significant difference in IS/Crop applied to common
beans and dolichos (p=0.060; 0.30) with mean height
recorded at 53.14111±17.58777, LSD=75.67408 for drip,
48.20333±16.63171, LSD=71.56049 for furrow and in all the
3 diff types of irrigation 44.35±17.07635, LSD=73.47361
for sprinkler (fig)
RESULTS-Mwea contd.
 Effect of IS on common beans and dolichos beans not
significant (p=0.30 and 0.06 resp)
RESULTS-Mwea contd.
 Green grams
not significant within the diff types of
irrigation with mean height recorded at 27.89±9.80,
LSD=42.18 for drip, 26.74±9.96, LSD=42.85 for furrow, and
27.40±9.09, LSD=39.10 for sprinkler
RESULTS-Mwea contd.
 Water use on maize was significant at p=0.000781 between
the diff data collection dates but not significant within the
diff types of irrigation with mean height recorded at
84.43556±29.46249, LSD=126.7669 for drip,
71.43444±24.68121, LSD=106.1947 for furrow, and
75.06111±23.33954, LSD=100.422 for sprinkler
RESULTS-Mwea contd.
 Water use efficiency on Soya bean was significant at p=
0.004014 between the diff data collection dates but not
significant within the diff types of irrigation with mean
height recorded at 115.3078±88.74869, LSD=381.8548for drip,
38.71111±12.75699, LSD=54.88891 for furrow, and
37.22778±11.83406, LSD=50.91786for sprinkler (fig)
RESULTS-Mwea contd…
 Water use on Nerica 4 was significant at p= 0.005982
between the diff data collection dates but not
significant within the diff types of irrigation with
mean height recorded at 27.92444±8.180193,
LSD=35.19653 for drip, 27.60222±7.374973,
LSD=31.73195 for furrow, and 28.43111±8.608463,
LSD=37.03923 for sprinkler (fig)
RECOMMEMDATIONS
Two major implications for sustainable irrigation
management:
• Since irrigation methods affect various crops differently, (i.e.
different methods needed for different crops), irrigation
system design for a project should be guided by the proposed
crops , NOT vice versa
• Where a system has already been fixed, the crop combination
should depend on their performance under the method of
irrigation