Abstract:
The climate change, water shortage and increasing evapotranspiration highlights the need to
introduce water saving technologies for agricultural sustainability and crop production with a
minimum input of water, mainly in semi-arid region. This experiment was conducted at Werer,
Middle Awash Valley during the dry season of 2017/2018 to investigate the effects of mulching
materials and furrow irrigation techniques on maize yield and water productivity under
semiarid conditions. Split plot design with three replications, in which the irrigation
techniques (Conventional, Fixed and Alternate Furrow) were assigned to main plot and the
three mulching materials (no mulch, wheat straw and white plastic mulch), were to the subplot.
The analysis of variance revealed that both grain yield and water productivity were
affected by the main effect of furrow irrigation techniques and mulching materials (p≤ 0.05).
The conventional furrow irrigation (8193 kgha-1) and white plastic mulch (7930 kg ha-1)
resulted in the maximum grain yield. The alternate furrow irrigation (1.90 kg/m3) and the
white plastic mulch (1.69 kg/m3) resulted in the maximum water productivity. Grain yield of
maize recorded in conventional furrow was 16.28% higher than fixed furrow. Alternate furrow
irrigation increased water productivity by 44.21% as compared to the conventional furrow.
Plastic mulch increased maize grain yield by 11.08% and water productivity by 11.83% as
compared to no mulch. Maize irrigated by alternate furrow irrigation resulted in 10.5% yield
reduction as compared to conventional furrow irrigation. However, the 50% of water saved
could irrigate a total additional area of 1ha. The highest benefit-cost ratio of (1.20) and net
return of (49108 ETBha-1) were obtained from conventional furrow irrigation. Similarly, the
highest net return of (53028 ETBha-1) and benefit-cost ratio of (2.16) was recorded from no
mulch. Highest BCR, growth, yield and yield component of maize was recorded from
conventional furrow irrigation. However, the highest water productivity was obtained from
alternate furrow irrigation. Wheat straw mulch resulted in highest water productivity, better
yield and economically feasible for maize production at Werer. This suggests that for
maximizing grain yield under no water stress scenario, irrigation water could be used in
conventional furrow irrigation without application of mulch. Under limiting irrigation water
resource scenario and if the cost of irrigation water is high, irrigation could be done in
alternate furrow irrigation along with wheat straw mulch to minimize evaporation loss,
maximize water productivity and economically feasible for maize production at Werer and
similar agro-ecology and soil type.