Abstract:
Water has been identified as one of the scarcest inputs, which can severely restrict agricultural
production and productivity unless it is carefully conserved and managed. A field experiment was
conducted under dry season conditions to investigate the effects of mulch types and water
application methods in furrow irrigation system on water productivity and yield of maize (Zea
maysL.) at Hawassa, Southern Nations Nationalities, and Peoples Regional State of Ethiopia.
Three types of furrow irrigation methods (alternate, fixed and conventional) and two mulch types
(plastic and straw mulch) and no mulch with three replications were used as two factors to
evaluate the yield and yield component including water productivity of maize in split-plot design,
in which furrow irrigation methods were used as the main plot together with the three mulching
techniques were used as sub-plot. Results indicated that different types of furrow irrigation
method had a very highly significant (p<0.001) effect on leaf area index, plant height, cob
length, cob weight with seed, aboveground biomass, grain yield, straw yield and water use
efficiency. Types of furrow irrigation method used highly significantly (p<0.01) affected
thousand seed weight and harvesting index. Moreover, maize growth, yield and yield components
including water productivity were highly significantly (p<0.01) influenced due to different mulch
types used except harvesting index (p>0.05).However, there was no interaction effect due to the
two factors studied (furrow irrigation method and mulching type).Significantly a higher growth,
yield and yield component of maize was recorded due to conventional furrow irrigation method
than alternate and fixed furrow irrigation method. Highest yield was scored (9003.8 kg/ha) from
conventional furrow irrigation water management method. However, higher water productivity
(2.43kg/m3) was obtained due to alternate furrow irrigation method. Moreover, higher growth,
yield and yield components including water use efficiency were obtained due to plastic mulch
than no mulch and straw mulch. Maximum grain yield (8088.9 kg/ha) and water productivity
(2.34kg/m3) obtained at plastic mulch condition , but the partial budget analysis revealed that
straw mulch was economically feasible for farmers than plastic mulch for maize at Hawassa
area. Therefore the present study suggests that, for maximizing grain yield under no water stress
scenario, irrigation of maize with conventional furrow irrigation methods could be used. On the
other hand, under limiting irrigation water condition, irrigation of maize could be done with
alternate furrow irrigation method with straw mulch application to minimize evaporation loss
and maximize water productivity of maize at Hawassa and similar agro-ecology and soil type.
