Irrigation & Drainage Systems Engineering

The experiment was conducted during 2016 and 2017 cropping season. The study was conducted to evaluate sorghum legume intercropping pattern on selected soil chemical properties and yield of sorghumat Tulo and Chiro district, Western Hararghe Zone of Oromia Region, Eastern Ethiopia. The treatments were included two legume crops and four planting patterns (single row of Sorghum and double row of haricot bean (1S;2H) in sequence, single row of Sorghum and single row of haricot bean (1S:1H) in sequence, double row of Sorghum and single row of haricot bean (2S:1H) in alternate, double row of Sorghum and double row of Haricot bean (2S:2H) in alternate, single row of Sorghum and double row of cowpea (1S:2C) in sequence, single row of Sorghum and single row of cowpea (1S:1C) in sequence, double row of Sorghum and single row of cowpea (2S:1C) in alternate, double row of Sorghum and double row of cowpea (2S:2C) in alternate, Sole sorghum, Sole haricot bean (Awash-1) and sole cowpea (ILRI11114-accession number) with testing crop sorghum (chiro variety). The experiment was conducted in Randomized Complete Block Design with three replications. All necessary agronomic data were collected and analyzed by using Statistical Analysis Software version 9.0. Soil samples were analyzed by standard laboratory procedures. The results revealed that maximum sorghum grain yield (37.28qu/ha) obtained from 1S:2L pattern was higher than other planting patterns. Maximum grain yield of haricot bean and cowpea was recorded from1S; 2H and 2S:2L planting patterns respectively. Selected soil chemical properties were improved under intercropping system over sole sorghum. The highest LER (1.36) and the lowest LER (1.19) was recorded in sorghum/haricot bean and sorghum/ cowpea intercropping system. The highest total LER was recorded from single row of sorghum and double row of haricot bean (1S; 2H) in sequence. Highest net income accrued from planting patterns of1S; 2H in sequence. Therefore, based on the finding of the study, planting patterns of single rows of sorghum and double rows of haricot bean in sequence (1S:2H) could be recommended in mid land areas of Western Hararghe Zone and similar agro ecologies.

Water scarcity is among the major limiting factor that affects crop production in which efficient utilization of limited irrigation water is vital. A field experiment was conducted for two consecutive years at Kulumsa Agricultural Research Centre during the dry season based on the objective to determine the effect of moisture stress at different growth stages on yield and water productivity of wheat. Fifteen treatments combined and imposed at four growth stages were used in A Randomized Complete Block Design (RCBD) with three replications. The two years combined result indicated that moisture stress at different growth stages highly significant (P < 0.05) influenced plant height and grain yield of wheat. On the other hand, there was no significant (p > 0.05) variation among treatments on hectolitre weight, total kernel weight, and above-ground biomass. A maximum plant height of 70.5 cm was obtained when wheat is irrigated at the initial and development stages only. The highest grain yield (4.71 ton/ha) was obtained at control treatments where all the growth stage is irrigated which were followed by a treatment in which moisture stress happens only during the late season. On the other hand, the lowest grain yield (2.23 ton/ha) was obtained when wheat irrigated only during the late season, stressing the rest growth stages which leads to a reduction of 52.7% from the control treatment. Generally, the study showed that the grain yield of wheat was highly affected when moisture stress is imposed during the initial and development stages. In addition to this, the highest (4.71 ton/ha) and lowest (2.23 qt/ha) aboveground biomass were obtained at the control and when irrigation was applied only during the late season, respectively. The highest water productivity of 4.56 kg/m3 was obtained when only the initial stage is irrigated. Treatments that received lower irrigation water showed better water productivity especially when moisture stress was not imposed during the initial and development stages. Therefore, in areas where irrigation water is not limited, wheat should be irrigated during all growth stages and if there is limited water resource for irrigation water it could be irrigated only during the initial stages or initial and development stages to maximize water productivity.

Drought is a major environmental constraint affecting the growth and production of coffee. Selection of drought tolerant Arabica coffee genotypes an important way to mitigate climate change impacts on coffee production. A Study was conducted at Awada research sub-center in Sidama zone of south Ethiopia(6045’ N, 380 38’E and 1740 m.a.s.l) with the objective to screen drought tolerant Sidamo coffee genotypes. The experiment was conducted during 2011/12 and 2013 under a controlled condition in a rain shelter; it was laid down in a RCBD with three replications. Fourteen Sidamo coffee genotypes were subjected to two watering regimes, water stressed and well watered for 28 days. The genotypes were also evaluated under field condition during 2014 season at Korkie sub-station which is located 20 km south of Awada (6034 N, 38039’E and 1800masl). Results of the experiment indicated that there was high significant difference among the genotypes for extent of wilting, total dry matter, relative leaf water content and leaf retention capacity. C85238 shows high drought stress resistance with 1.58 scale value while c9744 indicated as sensitive to drought stress with 2.99 scale value.c9722 obtained the highest value 11.76 gram in total dry matter, c85237 obtained the highest leaf retention capacity 51.28% and c85257 obtained the maximum relative leaf water content. Significant difference was also observed in root to shoot ratio and stomatal conductance with highest values obtained by c974 and c75227 respectively The field evaluation indicated that plant height, canopy diameter, coffee yield and number of primary branch were significantly influenced at P<0.01 and number of bearing branches and leaf turgid weight were influenced by the genotypes at P<0.05 with c9722 scored maximum value 288.9 cm plant height, 76 NBB, 163.43 cm CD and 11.76 qt/ha coffee yield. There was strong correlation observed between extent of wilting scored at seedling stage and grain yield at field condition of genotypes (r = -0.80). Therefore from all the three year evaluations c979, c974, c85238 c9722, c75277 and c1377 performed better in resisting drought under both field and controlled conditions.

Agriculture is the main contributor to the Ethiopian economy. Water is a vital resource to sustain civilizations and pecuniary development and most importantly agriculture. The field experiment was conducted at Werer Agricultural Research center to evaluate the effects of drip and furrow irrigation under different irrigation levels on maize water use efficiency. The experiment was laid out in a split-plot design where drip and furrow irrigations were assigned as the main plot and irrigation levels (100, 85, 70, and 55% of ETc) were assigned in the subplot arrangement with three blocks. The interaction effects of irrigation system and irrigation levels have shown a highly significant (p<0.01) effect on water use efficiency. The highest (2.38 kg/m³) and the lowest (0.81 kg/m³) water use efficiency were recorded from the plots treated with drip irrigation at 100% ETc and Alternative furrow irrigation at 100% ETc treatments, respectively.

Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the combined effect of alternate wetting and drying furrow irrigation, conventional irrigation method and mulches on crop growth, yield and water use efficiency of tomato. The treatments of the experimental area comprised of two irrigation method (conventional and alternate furrow irrigation method) and three mulches (maize, soybean and wheat straw). The yield and yield-component characters in the mulched treatments for two of furrow irrigation method were significantly higher compared to those in the unmulched (bare soil) treatments. The yields of tomato were higher in conventional furrow irrigation method than alternate furrow irrigation method. The highest yield (82267 kg/ha for maize straw, 88004.5 kg/ha for soybean straw and 87074 kg/ha for wheat straw) was obtained at conventional furrow irrigation method. Soybean and wheat straw mulched treatment produced higher yield than the maize straw-mulched treatment. The highest water use efficiency of 16.221A kg/ha/m^3 15.978 kg/ha/m^3 was obtained with alternate furrow irrigation method under soybean and wheat straw mulch respectively. The study thus reveals that alternate furrow irrigation method with mulch has an explicit role in increasing the water use efficiency of tomato.