Abstract:
Maize (zea mays L) is one of the most important cereal crops grown in Ethiopia. Field
experiment was undertaken on clay loam soil at Teppi national spice research center, Ethiopia
during 2013/2014 cropping season with the objectives of investigating the effect of
supplementary irrigation on yield and yield component of maize for achieving maximum crop
yield in rain fed agriculture during belge season. The experiment was laid out in RCBD
(Randomized Complete Block Design) with three replications. Treatments include seven levels
of supplemental irrigation treatments and a control irrigation receiving no supplemental
irrigation. The irrigation water was applied when the soil moisture depleted reached 55% of
total available water (p=0.55). The supplemental irrigation levels had shown a highly
significant (p<0.01) effect on grain yield of maize and gave increased water use efficiency.
However, the treatments did not affect leaf area. The supplemental irrigation levels had also a
significant (P<0.05) effect on days to tasseling, silking and days to maturity. The maximum
yield of 67 q/ha was recorded from 100% ETc (Crop Evapotranspiration) which was not
significantly different from 75% ETc and the minimum yield of 25q/ha was gained from rain
fed treatment. In terms of water use efficiency rain fed treatment had the highest crop water
use efficiency which has significantly different from all other treatment. Yield response factor
(Ky) was separately calculated for the growing season and was found to be 1.25 the highest
value and 1.05 the lowest value. Therefore, it is recommended that to apply 75% ETc which
gave 6.16 ton/ha which improve WUE (Water Use Efficiency) without significant reduction of
yield