Irrigation and Drainage Engineering

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A CASE STUDY OF MAI-SHAWSH AND MIDMAR SMALL SCALE IRRIGATION SCHEMES, IN MEREB SUB-BASIN, NORTH ETHIOPIA
(Hawassa University, 2017-10-16) GUESH HAGOS ASRESU
This study tries to evaluate the performance of small scale irrigation schemes using comparative indicators at Maishawsh and Midmar schemes, Mereb Sub basin, North Ethiopia. This study area has poor water management practice and not evaluated before using comparative performance indicators. To address the objectives of irrigation water use efficiency and on-field irrigation management performance of this study was field measurements related to canal discharge, moisture content determination of the soils, measurement of depth of water applied to the fields using two inches parshal flume, group discussion and informant interview to establish the cost of production and the price produced. The result of this study revealed that, the conveyance efficiency for Maishawsh scheme was 98.95%, 91.03%, and 75.21%, respectively for main lined, secondary lined and tertiary unlined canals of the scheme, and for Midmar scheme, it was 76.89% which was an earthen canal. The computed application, storage, distribution and overall scheme efficiency values are 60.8, 64.2, 93.40 and 46.7% for Midmar while they are 56.8, 70, 94.2 and 42.7% for Maishawsh schemes, respectively. The comparative indicators of agricultural outputs such as land productivity measured as outputs per unit command area and outputs per unit irrigated area are 3461.58 and 3512.8 US$/ha for Midmar while 3120.91 and 3032.46 US$/ha for Maishawsh respectively. The water indicators such as output per unit irrigation supply and Output per water consumed are 0.36 and 0.61 for Midmar while they are 0.25 and 0.54 US$/m3 for Maishawsh schemes respectively. The water supply indicators measured by, relative water supply and relative irrigation supply gave 1.8 and 1.85 for Midmar while they are 2.29 and 2.37 for Maishawsh schemes respectively. This implied that the amount of water supplied was sufficient for the water demand of both schemes. The original irrigable and command area was declined by 2% from the actual irrigated area in Midmar scheme. However, the actual irrigated area was expanded by 3% and 6% from original irrigable and command area in Maishawsh scheme respectively. The financial indicators measured by gross return on investment and financial self sufficiency for Midmar are 91.5 and 69% while they are 91 and 77% for Maishawsh respectively. Based on this result, Midmar irrigation scheme was slightly better than Maishawsh, the reason might be good water management at field level and Midmar water users pay for what they have consumed
COMPARATIVE PERFORMANCE ASSESSMENT OF MOJO ASHA AND ADANO SMALL SCALE IRRIGATION SCHEMES IN EAST HARARGHE ZONE, OROMIA REGION
(Hawassa University, 2017-08-06) EBSA MUSTEFA HAKIM
This study attempts to assess and cross-compare the performance of two small-scale irrigation schemes found in Oromia regional state namely, Mojo Asha and Adano irrigation schemes using comparative indicators. After collection of the valuable data from various sources, data analysis techniques were implemented for evaluating their performance using selected performance indicators such as conveyance efficiency, Application efficiency, system efficiency, water productivity and land productivity. The results showed that the average conveyance efficiencies of the two schemes were 83.41 % and 76.78 % at Mojo Asha and Adano respectively. It was lower at Adano than Mojo Asha scheme due to poor water management and irrigation structures’ deterioration. The maximum value of application efficiency found in downstream field of Mojo Asha scheme were 65.43 % and the minimum value was found in the Adano scheme at upstream field 40.45 % due to much amount of water was applied to the field without considering water requirement. The results of water use performance also indicated that the ratio of annual relative water supply were1.09 and 1.19 at Mojo Aasha and Adano schemes respectively, and ratio of annual relative irrigation supply were 1.12 and 1.27 at Mojo Aasha and Adano schemes respectively. The result indicated that water distribution is not tightly related to crop water demand or applying more than the demand. From analysis of agricultural performance the output results showed that the outputs per unit irrigation supply were 8.62 and 7.92 Birr/m3 at Mojo Asha and Adano schemes respectively. Whereas output per unit irrigation delivered were 10.78 and 9.70 Birr/ m3 at Mojo Asha and Adano schemes respectively. Outputs per unit command area in Birr/ha were 82501 and 96750 at Mojo Asha and Adano scheme respectively. Outputs per unit irrigated cropped area in Birr/ha were 55237 and 56437.5 at Mojo Asha and Adano schemes respectively. In case of water productivity Mojo Asha scheme was performing better than Adano scheme due to more productive use of irrigation water while land productivity was performing better at Adano than Mojo Asha scheme due to more intensive irrigation and better investment. Generally evaluation results of different indicators give information of performance level of the schemes that enables to transfer best practice to propose improvement measures.
COMPARATIVE PERFORMANCE ASSESSMENT OF MOJO ASHA AND ADANO SMALL SCALE IRRIGATION SCHEMES IN EAST HARARGHE ZONE, OROMIA REGION
(Hawassa University, 2017-08-24) EBSA MUSTEFA HAKIM
This study attempts to assess and cross-compare the performance of two small-scale irrigation schemes found in Oromia regional state namely, Mojo Asha and Adano irrigation schemes using comparative indicators. After collection of the valuable data from various sources, data analysis techniques were implemented for evaluating their performance using selected performance indicators such as conveyance efficiency, Application efficiency, system efficiency, water productivity and land productivity. The results showed that the average conveyance efficiencies of the two schemes were 83.41 % and 76.78 % at Mojo Asha and Adano respectively. It was lower at Adano than Mojo Asha scheme due to poor water management and irrigation structures’ deterioration. The maximum value of application efficiency found in downstream field of Mojo Asha scheme were 65.43 % and the minimum value was found in the Adano scheme at upstream field 40.45 % due to much amount of water was applied to the field without considering water requirement. The results of water use performance also indicated that the ratio of annual relative water supply were1.09 and 1.19 at Mojo Aasha and Adano schemes respectively, and ratio of annual relative irrigation supply were 1.12 and 1.27 at Mojo Aasha and Adano schemes respectively. The result indicated that water distribution is not tightly related to crop water demand or applying more than the demand. From analysis of agricultural performance the output results showed that the outputs per unit irrigation supply were 8.62 and 7.92 Birr/m3 at Mojo Asha and Adano schemes respectively. Whereas output per unit irrigation delivered were 10.78 and 9.70 Birr/ m3 at Mojo Asha and Adano schemes respectively. Outputs per unit command area in Birr/ha were 82501 and 96750 at Mojo Asha and Adano scheme respectively. Outputs per unit irrigated cropped area in Birr/ha were 55237 and 56437.5 at Mojo Asha and Adano schemes respectively. In case of water productivity Mojo Asha scheme was performing better than Adano scheme due to more productive use of irrigation water while land productivity was performing better at Adano than Mojo Asha scheme due to more intensive irrigation and better investment. Generally evaluation results of different indicators give information of performance level of the schemes that enables to transfer best practice to propose improvement measures.
E F FED I NOITAGIRRI TC L EVE SL TA EREFFID TN GR TWO H S EGAT S NO YI LE D DNA ETAW R P O YTIVITCUDOR F O OIN N U REDN UF WORR TAGIRRI I NO SYS M
(Hawassa University, 2018-12-07) T SS E EB K LE E HES BE O
W reta s ac r ytic si eht m tso eves er tniartsnoc of r arutlucirga l tworg h ni dira dna imes - ra di saera . oT evo r moc e iht ,s t eh er si a n ee d to esu ht e elbaliava wa ret yltneiciffe na d acimonoce lly w hcih si an tnatropmi ygetarts ot sserdda tneserp dna erutuf retaw deen . ehT S seidut ni ticifed girri ati no noitacilppa ot orpmi ve retaw vitcudorp yti a er detimil ni eht duts y aera . sihT yduts saw c detcudno ni arsiM k Az tenre reB b ere Wor ade ni etliS enoZ orf m ceD e rebm ot aM r hc / 20 71 / 81 ot etagitsevni ht e tceffe fo fed i tc oitagirri n slevel no dleiy dna retaw p ytivitcudor no O noin rednu worruf i irr g noita metsys . ehT tnemirepxe deniatnoc n eni tnemtaert s hcihw edulcni : lortnoc (0 % DI); 02 % ID dna 04 % DI evel l guorht tuoh org wt h ;segats 0 % ID , 02 % ID , 04 % ID dna 20 % ID ( .i e: ,laitini oleved p ,latnem dim dna etal segats ) ser p levitce y; 04 % ,ID 02 % ID , 0 % ID dna 02 % ID ( :e.i ni ni i ,lait latnempoleved , dim dna etal egats s), r evitcepse ly dna 20 % ID ta hcae htworg st sega ( e.i : ni laitini , poleved m latne , dim dna etal segats ), itcepser v yle erew dial tuo ni CR DB detacilper eerht emit s ehT . stluser iatbo n de detacidni taht d fe i i tc r noitagir slevel ereffid ni n segats htworg t dah yltnacifingis detceffa eht dleiy dna dleiy moc p tneno fo O noin ta (p ≤ 50.0 ). ehT tsehgih elbatekram blub dleiy (2 23.9 ah/not ) saw niatbo ed morf T1 ( lortnoc ) ihw ch saw detagirri yb 0 % ID el v le tuohguorht eht htworg gats e saerehw eht tnemtaert icer e dev 20 % ID el v le ta tal e htworg egats (T9) evag 29. 41 ah/not blub dleiy . T eh dleiy tluser deniatbo f mor T 1 ( ortnoc l) dah ton yltnacifingis nereffid t htiw T9 ( 02 % ID ta tal e htworg egats ). ehT wol e ts blub dleiy ( .51 23 /not ha) saw r edroce d morf T3 hcihw eviecer d 40 % DI el v le hguorht o tu eht htworg egats s . W reta ytivitcudorp (WP) saw dnuof id f tneref gnidneped no level fo w ta re noitacilppa . T eh tsehgih WP 9.9 gk /m 3 was deniatbo morf T2 ( 02 % ID tuohguorht eht worg th segats ) dna ti has 59.1 m/gk 3 retaerg WP naht T1 (8 gk /m 3 ) taht tog f llu girri a noit . tnemtaerT (T9) sah eht sehgih t RRM ( 37631 2. %) naht lla srehto stnemtaert . Th si yduts stluser rifnoc m de taht htiw icifed t noitagirri tcarp sei , ti si elbissop ot esaercni WP yb gnivas retaw dna esaercni ocni me f mor ecracs noitagirri retaw . T ,erofereh ti nac be er c dednemmo t tah ppa l gniy noitagirri retaw a t 02 % DI fo CWR ta la et htworg egats (T9) in 4 yad s noitagirri lavretni si cifineb i la rof gniniatbo mumitpo O in on dleiy dna esasercni retaw ytivitcudorp taht irb n sg rehgih imonoce c ter nru rednu racs ce taw er noitidnoc . ehT sremraf ni ecracs retaw r cruose e aera dluoc osla be T desu 2 ( ID % 02 fo C ts htworg tuohguorht RW a eg s) noitpo sa m evas ot o r
E F FED I NOITAGIRRI TC L EVE SL TA EREFFID TN GR TWO H S EGAT S NO YI LE D DNA ETAW R P O YTIVITCUDOR F O OIN N U REDN UF WORR TAGIRRI I NO SYS M
(Hawassa University, 2018-12-27) GAT SS E EB K LE E HES BE O
W reta s ac r ytic si eht m tso eves er tniartsnoc of r arutlucirga l tworg h ni dira dna imes - ra di saera . oT evo r moc e iht ,s t eh er si a n ee d to esu ht e elbaliava wa ret yltneiciffe na d acimonoce lly w hcih si an tnatropmi ygetarts ot sserdda tneserp dna erutuf retaw deen . ehT S seidut ni ticifed girri ati no noitacilppa ot orpmi ve retaw vitcudorp yti a er detimil ni eht duts y aera . sihT yduts saw c detcudno ni arsiM k Az tenre reB b ere Wor ade ni etliS enoZ orf m ceD e rebm ot aM r hc / 20 71 / 81 ot etagitsevni ht e tceffe fo fed i tc oitagirri n slevel no dleiy dna retaw p ytivitcudor no O noin rednu worruf i irr g noita metsys . ehT tnemirepxe deniatnoc n eni tnemtaert s hcihw edulcni : lortnoc (0 % DI); 02 % ID dna 04 % DI evel l guorht tuoh org wt h ;segats 0 % ID , 02 % ID , 04 % ID dna 20 % ID ( .i e: ,laitini oleved p ,latnem dim dna etal segats ) ser p levitce y; 04 % ,ID 02 % ID , 0 % ID dna 02 % ID ( :e.i ni ni i ,lait latnempoleved , dim dna etal egats s), r evitcepse ly dna 20 % ID ta hcae htworg st sega ( e.i : ni laitini , poleved m latne , dim dna etal segats ), itcepser v yle erew dial tuo ni CR DB detacilper eerht emit s ehT . stluser iatbo n de detacidni taht d fe i i tc r noitagir slevel ereffid ni n segats htworg t dah yltnacifingis detceffa eht dleiy dna dleiy moc p tneno fo O noin ta (p ≤ 50.0 ). ehT tsehgih elbatekram blub dleiy (2 23.9 ah/not ) saw niatbo ed morf T1 ( lortnoc ) ihw ch saw detagirri yb 0 % ID el v le tuohguorht eht htworg gats e saerehw eht tnemtaert icer e dev 20 % ID el v le ta tal e htworg egats (T9) evag 29. 41 ah/not blub dleiy . T eh dleiy tluser deniatbo f mor T 1 ( ortnoc l) dah ton yltnacifingis nereffid t htiw T9 ( 02 % ID ta tal e htworg egats ). ehT wol e ts blub dleiy ( .51 23 /not ha) saw r edroce d morf T3 hcihw eviecer d 40 % DI el v le hguorht o tu eht htworg egats s . W reta ytivitcudorp (WP) saw dnuof id f tneref gnidneped no level fo w ta re noitacilppa . T eh tsehgih WP 9.9 gk /m 3 was deniatbo morf T2 ( 02 % ID tuohguorht eht worg th segats ) dna ti has 59.1 m/gk 3 retaerg WP naht T1 (8 gk /m 3 ) taht tog f llu girri a noit . tnemtaerT (T9) sah eht sehgih t RRM ( 37631 2. %) naht lla srehto stnemtaert . Th si yduts stluser rifnoc m de taht htiw icifed t noitagirri tcarp sei , ti si elbissop ot esaercni WP yb gnivas retaw dna esaercni ocni me f mor ecracs noitagirri retaw . T ,erofereh ti nac be er c dednemmo t tah ppa l gniy noitagirri retaw a t 02 % DI fo CWR ta la et htworg egats (T9) in 4 yad s noitagirri lavretni si cifineb i la rof gniniatbo mumitpo O in on dleiy dna esasercni retaw ytivitcudorp taht irb n sg rehgih imonoce c ter nru rednu racs ce taw er noitidnoc . ehT sremraf ni ecracs retaw r cruose e aera dluoc osla be T desu 2 ( ID % 02 fo C ts htworg tuohguorht RW a eg s) noitpo sa m evas ot o r
EFFECT OF DEFICIT IRRIGATION LEVELS ON YIELD AND YIELD COMPONENTS OF SESAME (Sesamum indicum L.) IN BENA TSEMAY WOREDA, SOUTH OMO ZONE, ETHIOPIA
(Hawassa University, 2022-08-11) MEDHIN MADEBO MADA
Scarcity of water is one of the major constraints for the development of agriculture in arid and semi-arid regions. Hence, the effective use of available water by deficit irrigation is an alternative means to alleviate the problem and optimize the water productivity of crop in the region. The objective of this study was to determine the effect of deficit irrigation levels applied on yield, yield components and water productivity of sesame (Sesamum indicum L.). The field experiment was carried out at Bena Tsemay Woreda, Southern Ethiopia. The experiment was laid out in randomized complete block design with six irrigation treatments and three replications. The treatments were five water deficit irrigation levels (85%ETc, 75%ETc, 65%ETc, 55%ETc and 45%ETc) and full (100%ETc) as a control treatment. The result of analysis of variance showed that the different deficit irrigation levels applied had statistically significant (p < 0.01) effect on yield and yield component of sesame. Significant delay in flowering and maturity was observed as the water deficit level increased. The highest plant height, number of branch per plant, number of capsules per plant, number of seed per capsule, 1000-seed weight, aboveground biomass, harvest index and straw yield were observed under control treatment (100%ETc), while the lowest observed in 45%ETc treatment respectively. The maximum grain yield (2164.56 kg/ha) was observed under control (100%ETc), while the minimum (1377.37 kg/ha) was obtained from 45%ETc treatment level. From the mean result of grain yield it was observed that control treatment (100%ETc) significantly different from all treatments except treatment under 85%ETc. The highest water productivity (0.55kg/m3 ) was observed under 45%ETc, while the lowest (0.39 kg/m3 ) was at control treatment. From the result of study it was observed that the obtained yield response factor (Ky) was less than unity (Ky < 1), this indicates that sesame is tolerant to water stress. From the result of study it was observed that deficit irrigation under 75%ETc resulted in significant water saving and improved water productivity with insignificant yield reduction; therefore, sesame could be irrigated at 75%ETc in region with limited water resource condition
EFFECT OF DEFICIT IRRIGATION LEVELS ON YIELD AND YIELD COMPONENTS OF SESAME (Sesamum indicum L.) IN BENA TSEMAY WOREDA, SOUTH OMO ZONE, ETHIOPIA
(Hawassa University, 2022-10-27) MEDHIN MADEBO MADA
Scarcity of water is one of the major constraints for the development of agriculture in arid and semi-arid regions. Hence, the effective use of available water by deficit irrigation is an alternative means to alleviate the problem and optimize the water productivity of crop in the region. The objective of this study was to determine the effect of deficit irrigation levels applied on yield, yield components and water productivity of sesame (Sesamum indicum L.). The field experiment was carried out at Bena Tsemay Woreda, Southern Ethiopia. The experiment was laid out in randomized complete block design with six irrigation treatments and three replications. The treatments were five water deficit irrigation levels (85%ETc, 75%ETc, 65%ETc, 55%ETc and 45%ETc) and full (100%ETc) as a control treatment. The result of analysis of variance showed that the different deficit irrigation levels applied had statistically significant (p < 0.01) effect on yield and yield component of sesame. Significant delay in flowering and maturity was observed as the water deficit level increased. The highest plant height, number of branch per plant, number of capsules per plant, number of seed per capsule, 1000-seed weight, aboveground biomass, harvest index and straw yield were observed under control treatment (100%ETc), while the lowest observed in 45%ETc treatment respectively. The maximum grain yield (2164.56 kg/ha) was observed under control (100%ETc), while the minimum (1377.37 kg/ha) was obtained from 45%ETc treatment level. From the mean result of grain yield it was observed that control treatment (100%ETc) significantly different from all treatments except treatment under 85%ETc. The highest water productivity (0.55kg/m3 ) was observed under 45%ETc, while the lowest (0.39 kg/m3 ) was at control treatment. From the result of study it was observed that the obtained yield response factor (Ky) was less than unity (Ky < 1), this indicates that sesame is tolerant to water stress. From the result of study it was observed that deficit irrigation under 75%ETc resulted in significant water saving and improved water productivity with insignificant yield reduction; therefore, sesame could be irrigated at 75%ETc in region with limited water resource condition
EFFECT OF DEFICIT IRRIGATION ON WATER PRODUCTIVITY AND YIELD OF COMMON BEAN (PHASEOLUS VULGARIS L.) AT MELKASSA, CENTERAL RIFT VALLEY, ETHIOPIA
(Hawassa University, 2020-10-12) ABERA TESFAYE TEFERA
The experiment was conducted at Melkassa Agricultural Research Center during off season under semi-arid climatic condition where moisture stress is higher. The study was under taken to evaluate effect of deficit irrigation on water productivity and yield of common bean (Phaseolus vulgaris L.).The experiment was split plot design with three common bean varieties as main plots and four deficit irrigation levels as sub plots all of which replicated three times. Four deficit irrigation levels 100%ETc, 85%ETc, 70%ETc, 55%ETc and three varieties SER-119, Bio fortified small seed-5, Awash-2 were used for treatment combination. The combined result indicates that there was a significant variation among treatments for yield, above ground biomass and water productivity. All common bean varieties were significantly affected under deficit irrigation levels. Consequently, highest yield (3.4 ton/ha) was obtained from irrigating 100%ETc followed by (3.2 ton/ha) with 85%ETc less yield reduction. In contrast the intermediate (2.8 ton/ha) and smallest yield (2.4 ton/ha) was obtained from irrigating 70ETc and 55%ETc.Water productivity was ranged from (0.83 kg/m3 ) at full irrigation to (1.33 kg/m3 ) at higher deficit irrigation. Based on obtained yield and water productivity, under a limited water supply situation where the goal was to gain highest possible yield of common bean and water productivity utilizing application of water from 70%ETC to 85%ETC at each irrigation event offers opportunities for water saving with yield reduction which was compensated by irrigating other area by saved water. The result of economic analysis shown that the highest net benefit obtained from irrigating full 100%ETc of the three common bean varieties. Based on obtained data the MRR was greater than 50% irrigating common bean with deficit irrigation 85%, 70% and 55% is economically feasible depending on accessibility of water
EFFECTS OF SALINE WATER AND IRRIGATION INTERVAL ON SOYBEAN (GLYCINE MAX) YIELD AND ALTERING SOIL PHYSICO-CHEMICAL PROPERTIES
(Hawassa University, 2018-07-06) ATALEL AWOKE
The declining availability of fresh water has become a worldwide problem, which maintains the development of alternative, secondary quality water resources for agricultural use. Several studies recommend that the need of attention for selected crops that can tolerate water and salinity stresses when saline water is used for irrigation. In this study, the effects of different irrigation intervals and salinity levels of irrigation water on Soybean yield and their impacts on soil physico-chemical properties were investigated using three irrigation intervals (I1 =3days, I2= 4days and I3= 5 days) with four salinity levels (S1= 4dS m-1 , 5dS m-1 and 6 dS m- 1 ) in a factorial combination using CRD with three replications. The result showed that salinity, irrigation interval and their interaction had shown highly significance effects (p<0.001) on number of pod per plant, number of seed per plant and grain yield of Soybean. The highest number of pod number (88.33), grain yield (2.31ton/ha) and number of seed per plant (172.33) was recorded from Soybean which was irrigated with the first salinity level, i.e. fresh water (S1) with irrigation interval of (3 days), S1I1;while the lowest pod number per plant (6.67), number of seed per plant (12.67) and minimum grain yield (0.034 ton/ha) were obtained from Soybean irrigated by salinity level four (S4) with 5 days irrigation interval (S4I3).Statistical analysis showed that salinity ,irrigation interval and their interaction showed highly significance effects (p<0.001)on electrical conductivity of soil. Irrigation with highest salinity level (S4) with five days of irrigation interval resulted in the salt accumulation in the root zone from 0.41 μS m -1 (before sowing) up to 13.73 μS/cm at the end of growing period and exchangeable Sodium of 0.2 cmol/Kg was found before sowing while 0.82cmol/kg was found after harvesting. Therefore, based on soil salinity and crop yield, irrigation interval of 3 days at lower levels of irrigation water salinities (up to 3 dS m-1 ) is suitable for soybean production in the study area. The study also showed that salinity and irrigation interval significantly affected the soil nutrients (p< 0.001) despite their interaction were not significantly affected on soil nutrients. Increasing the concentration of salt in irrigation water reduce availability of nutrients in the soil. Soil which was irrigated by salinity level four (S4=6dS/m) had lowest Organic Matter, Organic Carbon, Nitrogen (N), Phosphorus (P) and Potassium (K) content. Highest Organic Matter, Organic Carbon, N and P content were observed at soils which were irrigated by fresh water. This indicates that there is a need for giving attention for management of soil besides achieving Soybean yield production when saline water is used for irrigation.
EFFECTS OF SALINE WATER AND IRRIGATION INTERVAL ON SOYBEAN (GLYCINE MAX) YIELD AND ALTERING SOIL PHYSICO-CHEMICAL PROPERTIES
(Hawassa University, 2018-10-26) ATALEL AWOKE
The declining availability of fresh water has become a worldwide problem, which maintains the development of alternative, secondary quality water resources for agricultural use. Several studies recommend that the need of attention for selected crops that can tolerate water and salinity stresses when saline water is used for irrigation. In this study, the effects of different irrigation intervals and salinity levels of irrigation water on Soybean yield and their impacts on soil physico-chemical properties were investigated using three irrigation intervals (I1 =3days, I2= 4days and I3= 5 days) with four salinity levels (S1= 4dS m-1 , 5dS m-1 and 6 dS m- 1 ) in a factorial combination using CRD with three replications. The result showed that salinity, irrigation interval and their interaction had shown highly significance effects (p<0.001) on number of pod per plant, number of seed per plant and grain yield of Soybean. The highest number of pod number (88.33), grain yield (2.31ton/ha) and number of seed per plant (172.33) was recorded from Soybean which was irrigated with the first salinity level, i.e. fresh water (S1) with irrigation interval of (3 days), S1I1;while the lowest pod number per plant (6.67), number of seed per plant (12.67) and minimum grain yield (0.034 ton/ha) were obtained from Soybean irrigated by salinity level four (S4) with 5 days irrigation interval (S4I3).Statistical analysis showed that salinity ,irrigation interval and their interaction showed highly significance effects (p<0.001)on electrical conductivity of soil. Irrigation with highest salinity level (S4) with five days of irrigation interval resulted in the salt accumulation in the root zone from 0.41 μS m -1 (before sowing) up to 13.73 μS/cm at the end of growing period and exchangeable Sodium of 0.2 cmol/Kg was found before sowing while 0.82cmol/kg was found after harvesting. Therefore, based on soil salinity and crop yield, irrigation interval of 3 days at lower levels of irrigation water salinities (up to 3 dS m-1 ) is suitable for soybean production in the study area. The study also showed that salinity and irrigation interval significantly affected the soil nutrients (p< 0.001) despite their interaction were not significantly affected on soil nutrients. Increasing the concentration of salt in irrigation water reduce availability of nutrients in the soil. Soil which was irrigated by salinity level four (S4=6dS/m) had lowest Organic Matter, Organic Carbon, Nitrogen (N), Phosphorus (P) and Potassium (K) content. Highest Organic Matter, Organic Carbon, N and P content were observed at soils which were irrigated by fresh water. This indicates that there is a need for giving attention for management of soil besides achieving Soybean yield production when saline water is used for irrigation
EVALUATING THE PERFORMANCE OF AQUACROP MODEL IN SIMULATING THE PRODUCTIVITY OF POTATO (Solanum tuberosum L.) CROP UNDER VARIOUS WATER LEVELS AT DEBRE BIRHAN, AMHARA REGIONAL STATE, ETHIOPIA
(Hawassa University, 2019-10-22) TSEGAYE GETACHEW MENGISTU
Agricultural sector face the challenge to produce more yield with less water. In this regard, simulation models are basic tools in evaluating the effect of water on crop production. To address this need, FAO has developed yield responses to water model named AquaCrop, which simulates attainable yields of the major field and vegetable crops from their physiological and agronomic background perspective at farm level. The aim of this study was to evaluate the AquaCrop model performance on potato crop growth parameters under various water levels at Debre Birhan, Ethiopia. The AquaCrop is a user-friendly, easy to apply, accurate and robust model, and it addresses conditions where water is a key limiting factor for crop production. The experiment was arranged with Randomized Complete Block Design, with four replications under different water levels 100%, 85%, 70% and 55 % of crop water requirement of potato, which were simulated by the AquaCrop model. The results indicated that the simulated amount of irrigation water for 100% water level was 377.2 mm of water depth in growing season. The growth parameter and tuber yield were significant differences among the water levels at p < 0.05. The fresh potato tuber yield ranges from 35.25 ton/ha to 44.37 ton/ha was obtained in 55% and 100% water levels respectively. The water productivity ranges from 11.59 kg/m3 to 12.67 kg/m 3 was obtained in 100%and 55% water level respectively. Concerning its performance, the AquaCrop model simulated very well in the canopy cover, dry aboveground and tuber biomass and soil water content of the potato crop. The statistical indicators; Nash-Sutcliffe efficiency (NSE), Normalized Root mean square error (NRMSE) index of agreement (d) and Coefficient of determination (R 2 ) showed very well to excellent efficiency observed on dry aboveground and tuber biomass, there values were found to be in the ranges of 0.78 to 0.94, 35.50 to 16.30, 0.96 to 0.99 and 0.98 to 0.96 respectively. However, for soil water content before irrigation, which was found to be poor ranges 0.00 to -0.63, 10.2 to 10.8, 0.78 to 0.51, 0.45 to 0.03 were observed respectively.in the above order. From the results of the study can conclude in two scenarios: first, in case of water scarce area, it may be more profitable for a farmer to maximize crop water productivity instead of maximizing the harvest per unit of land. The saved water can be used to irrigate extra units of land. Second, in case of no water scarce area, it may be more profitable to maximize the yield harvest than crop water productivity. Under the first scenario farmers should adopt 70% of crop water requirement with a 10-days interval, which 16.65% saved water with 10.1% yield penalty over 100%. On the other hand, they should adopt 100% of crop water requirement within 10-days interval In the case of no water scarce area. The future studies shall consider various other stresses such as soil fertility and mulching
EVALUATION OF ALTERNATE, FIXED AND CONVENTIONAL FURROW IRRIGATION SYSTEMS WITH DIFFERENT WATER APPLICATION LEVELS ON ONION PRODUCTION IN DUBTI, AFAR
(Hawassa University, 2018-10-07) ZINABU AKELE DERBEW
Water scarcity is a major constraint for the production of food required in arid and semi-arid areas. Therefore, deficit irrigation and application of irrigation systems are important concerns to improve water productivity and sustained production in the areas with water shortage like lower Awash valley. A field experiment was conducted with the objective of evaluating the performance of alternate, fixed and conventional furrow irrigation systems under different water application levels on onion yield in Dubti, lower Awash basin. The treatments were three deficit irrigation levels of 50%, 75% and 100% of crop water requirements with three furrow irrigation systems of conventional, alternate and fixed furrow were laid out a factorial random complete block design (RCBD) with three replications. Data on plant growth and bulb yield were collected and analyzed. The result of the study indicated highly significant (α ≤ 0.0) differences for yield and WUE’s. The highest bulb yield of 25.46 ton/ha was obtained at 100% ETC with conventional furrow irrigation method. AFI 50% ETC water application level gave the highest water use efficiency. In contrast, the minimum water use efficiency was recorded with conventional furrow method with 100% water application level. CFI 100%, CFI 75%, and AFI 50% were not shown significant difference on yield which is 25.46 ton/ha, 24.88 ton/ha, and 24.54 ton/ha respectively, besides better water use efficiency of 8.39 kg/m3 was recorded from AFI 100%. In relative to the control CFI 100%, applying AFI 100% able to increase 0.868 ha net additional irrigable land per each hectare. Therefore, it can be decided that Alternative furrow irrigation with 100% ETC increased water use efficiency and can solve a problem of water shortage by improving WUE without significant reduction of yield.
EVALUATION OF ALTERNATE, FIXED AND CONVENTIONAL FURROW IRRIGATION SYSTEMS WITH DIFFERENT WATER APPLICATION LEVELS ON ONION PRODUCTION IN DUBTI, AFAR
(Hawassa University, 2018-10-21) ZINABU AKELE DERBEW
Water scarcity is a major constraint for the production of food required in arid and semi-arid areas. Therefore, deficit irrigation and application of irrigation systems are important concerns to improve water productivity and sustained production in the areas with water shortage like lower Awash valley. A field experiment was conducted with the objective of evaluating the performance of alternate, fixed and conventional furrow irrigation systems under different water application levels on onion yield in Dubti, lower Awash basin. The treatments were three deficit irrigation levels of 50%, 75% and 100% of crop water requirements with three furrow irrigation systems of conventional, alternate and fixed furrow were laid out a factorial random complete block design (RCBD) with three replications. Data on plant growth and bulb yield were collected and analyzed. The result of the study indicated highly significant (α ≤ 0.0) differences for yield and WUE’s. The highest bulb yield of 25.46 ton/ha was obtained at 100% ETC with conventional furrow irrigation method. AFI 50% ETC water application level gave the highest water use efficiency. In contrast, the minimum water use efficiency was recorded with conventional furrow method with 100% water application level. CFI 100%, CFI 75%, and AFI 50% were not shown significant difference on yield which is 25.46 ton/ha, 24.88 ton/ha, and 24.54 ton/ha respectively, besides better water use efficiency of 8.39 kg/m3 was recorded from AFI 100%. In relative to the control CFI 100%, applying AFI 100% able to increase 0.868 ha net additional irrigable land per each hectare. Therefore, it can be decided that Alternative furrow irrigation with 100% ETC increased water use efficiency and can solve a problem of water shortage by improving WUE without significant reduction of yield
HYDRAULIC MODELING AND FLOOD MAPPING OF HAROSHA RIVER WITH HEC-RAS AND HEC-GeoRAS MODELS IN TIGRAY, ETHIOPIA
(Hawassa University, 2017-03-10) MULUGETA TAREKE ABEBE
The Harosha river catchment is found in Tigray region in Raya Valley. This study area is surrounded by Waja and Tumuga catchment in the south and Harosha, Limeat and Harle catchment in the North and also it is the upper south part of the Raya valley catchment. The area is also dominated by undulating terrain with relatively steep to moderately steep and flatter slopes in the downstream of the catchment. Harosha flood plain has been vulnerable to high flooding from rainfall during rainy season. Also the main causes of these damages are land use changes from years to years and the main objective of this study is to estimate peak flood for various return period and prepare flood inundation mapping that can be used as decision support system for future intervention. The data used for this study was annual daily maximum rainfall, DEM, land use land cover map, and soil map and the flood frequency analysis of annual maximum daily rainfall was analyzed. The SCS rain fall-runoff method, HEC-RAS, HEC-GeoRAS and ArcGIS environment are used to determine the peak flood for different return periods. The simulation result for return period of 5, 10, 25, 50 and 100 year floods magnitude are 347.4, 383.7, 420.8, 443.6 and 463.1m 3 /s respectively. The maximum flood hazard and flow depth maps for a return periods of 5, 10, 25, 50 and 100 year are 84.6 and 3.36; 86.1 and 3.84; 86.9 and 4.35; 87.1 and 4.91; and 87.7 hectare and 5.89 m respectively with a maximum velocity of 4.6 m/s.
HYDRAULIC MODELING AND FLOOD MAPPING OF HAROSHA RIVER WITH HEC-RAS AND HEC-GeoRAS MODELS IN TIGRAY, ETHIOPIA
(Hawassa University, 2017-10-27) MULUGETA TAREKE ABEBE
The Harosha river catchment is found in Tigray region in Raya Valley. This study area is surrounded by Waja and Tumuga catchment in the south and Harosha, Limeat and Harle catchment in the North and also it is the upper south part of the Raya valley catchment. The area is also dominated by undulating terrain with relatively steep to moderately steep and flatter slopes in the downstream of the catchment. Harosha flood plain has been vulnerable to high flooding from rainfall during rainy season. Also the main causes of these damages are land use changes from years to years and the main objective of this study is to estimate peak flood for various return period and prepare flood inundation mapping that can be used as decision support system for future intervention. The data used for this study was annual daily maximum rainfall, DEM, land use land cover map, and soil map and the flood frequency analysis of annual maximum daily rainfall was analyzed. The SCS rain fall-runoff method, HEC-RAS, HEC-GeoRAS and ArcGIS environment are used to determine the peak flood for different return periods. The simulation result for return period of 5, 10, 25, 50 and 100 year floods magnitude are 347.4, 383.7, 420.8, 443.6 and 463.1m 3 /s respectively. The maximum flood hazard and flow depth maps for a return periods of 5, 10, 25, 50 and 100 year are 84.6 and 3.36; 86.1 and 3.84; 86.9 and 4.35; 87.1 and 4.91; and 87.7 hectare and 5.89 m respectively with a maximum velocity of 4.6 m/s.
IMPACTS OF CLIMATE CHANGE ON RAINFED MAIZE PRODUCTION IN RIFT VALLEY LAKES BASINS OF ETHIOPIA; HAWASSA AS CASE STUDY
(Hawassa University, 2017-10-07) KINDE NEGESSA DISASA
Agriculture is mainstay of Ethiopian economy. Developing country like Ethiopia suffers from effects of climate change, due to their limited economic capability to build irrigation projects to reduce climate change impact on crop production. This study evaluates climate change impact on rainfed maize production in rift valley lakes basins of Ethiopia. First, outputs of 15 General Circulation Models (GCMs) under two emission scenarios (SRA1B and SRB1) are statistically downscaled by using LARS-WG software. Probability assessment of bounded range with known distributions is used to deal with the uncertainties of GCMs’ outputs. These GCMs outputs are weighted by considering the ability of each model to simulate historical records. The study result indicates that LARS-WG 5.5 model is more uncertain to simulate future mean rainfall than generating maximum and minimum mean temperatures hereby GCMs weight difference for rainfall mean is 0.83 whereas weight difference for minimum and maximum mean temperatures is 0.09. AquaCrop, version 4 developed by FAO that simulates the crop yield response to water deficit conditions, is employed to assess potential rainfed maize production in the study area with and without climate change. The study results indicate minimum and maximum temperatures absolute increase in the range of 0.34 0 C to 0.580 C, 0.940 C to 1.80 C and 1.420 C to 3.20 C and 0.320 C to 0.560 C, 0.910 C to 1.80 C and 1.340 C to 3.0350 C respectively in the near-term (2020s), mid-term (2055s) and long-term (2090s) under both emission scenarios. The expected percentage change of rainfall during these three time periods considering this GCMs weight difference into account ranges from -2.3 to 7%, 0.375 to 15.83% and 2.625 to 31.1%. Maize yields are expected to increase with the range of 3.63% to 7%, 5.39% to 14.08%, and 6.83% to 15.61%, during the same time periods. Unlike many studies in the world this study result show that maize yield increased in coming three time periods under both emission scenarios. Due to rainfall increase with temperature increase maize yield is expected to increase in future for this study area by using only rainfall. In conclusion, the results indicate that climate change will respond positively to climate change impact on maize yield production for this district if all field management, soil fertility and crop variety improved; but since there is rainfall variability among the seasons planting date should be scheduled well to combat water stress on crops
MPACTS OF CLIMATE CHANGE ON RAINFED MAIZE PRODUCTION IN RIFT VALLEY LAKES BASINS OF ETHIOPIA; HAWASSA AS CASE STUDY
(Hawassa University, 2017-10-18) KINDE NEGESSA DISASA
Agriculture is mainstay of Ethiopian economy. Developing country like Ethiopia suffers from effects of climate change, due to their limited economic capability to build irrigation projects to reduce climate change impact on crop production. This study evaluates climate change impact on rainfed maize production in rift valley lakes basins of Ethiopia. First, outputs of 15 General Circulation Models (GCMs) under two emission scenarios (SRA1B and SRB1) are statistically downscaled by using LARS-WG software. Probability assessment of bounded range with known distributions is used to deal with the uncertainties of GCMs’ outputs. These GCMs outputs are weighted by considering the ability of each model to simulate historical records. The study result indicates that LARS-WG 5.5 model is more uncertain to simulate future mean rainfall than generating maximum and minimum mean temperatures hereby GCMs weight difference for rainfall mean is 0.83 whereas weight difference for minimum and maximum mean temperatures is 0.09. AquaCrop, version 4 developed by FAO that simulates the crop yield response to water deficit conditions, is employed to assess potential rainfed maize production in the study area with and without climate change. The study results indicate minimum and maximum temperatures absolute increase in the range of 0.34 0 C to 0.580 C, 0.940 C to 1.80 C and 1.420 C to 3.20 C and 0.320 C to 0.560 C, 0.910 C to 1.80 C and 1.340 C to 3.0350 C respectively in the near-term (2020s), mid-term (2055s) and long-term (2090s) under both emission scenarios. The expected percentage change of rainfall during these three time periods considering this GCMs weight difference into account ranges from -2.3 to 7%, 0.375 to 15.83% and 2.625 to 31.1%. Maize yields are expected to increase with the range of 3.63% to 7%, 5.39% to 14.08%, and 6.83% to 15.61%, during the same time periods. Unlike many studies in the world this study result show that maize yield increased in coming three time periods under both emission scenarios. Due to rainfall increase with temperature increase maize yield is expected to increase in future for this study area by using only rainfall. In conclusion, the results indicate that climate change will respond positively to climate change impact on maize yield production for this district if all field management, soil fertility and crop variety improved; but since there is rainfall variability among the seasons planting date should be scheduled well to combat water stress on crops
PERFORMANCE EVALUATION OF FIELD WATER APPLICATION ON FURROW IRRIGATION AT WONJI SHOA SUGAR ESTATE, ETHIOPIA
(Hawassa University, 2021-10-22) TSIGE MOHAMMED AHMED
Furrow irrigation is dominantly used method of surface irrigation in the large sugar cane irrigation projects in Ethiopia. This research was conducted to evaluate the performance of furrow irrigation with SIRMOD software by two point method and evaluate current performance of furrow irrigation system, identify the performance gaps and recommend means of performance improvement at Wonji Shoa Irrigation Estate. Three fields were selected according to soil type, furrow length and workability for measurement with field code 15, 52,108 which had furrow length of 64 m, 48 m and 32 m which was practice in the sugar estate. Different performance indicators were used to evaluate performance of furrow irrigation they were application efficiency, storage efficiency, application uniformity and deep percolation ratio. The estimated and simulation result obtained from the average application efficiency of the three selected fields (15, 52, and 108) were 74.42%, 41.19% and 64.12% and 74.39%, 50.20% and 75.18% respectively. The storage efficiency values for three selected fields were 100% for estimation and 99.11%, 99.67% and 99.65% for simulation respectively. The estimation and simulation average distribution uniformity of the three selected fields were 91.86%,90.78% and 89.86% and 92.44%,91.38% and 93.26% respectively and the deep percolation ratio for estimated and simulation were 25.35%,58.81% and 35.88% and 25.35%, 49.48% and 24.5 respectively . From the selected fields, filed 15 and 108 had better application efficiency with furrow length 64 and 32 respectively than the filed 52 with furrow length 48 m and the field 52 had low application efficiency and high deep percolation ratio. The result obtained from sensitivity analysis; discharge, cutoff time and length of furrow were highly sensitive to application efficiency and deep percolation ratio, whereas the slope of furrow had no effect on performance indicator in this study. The amount of water applied during irrigation event were more than the irrigation water required which indicates that large amount of water was being wasted due to poor irrigation water management practice. From the result of this study, it can be concluded that there were over irrigation problems
PERFORMANCE EVALUATION OF FURROW IRRIGATION IN BELLES SUGAR DEVELOPMENT PROJECT SUGARCANE FARM LEVEL, ETHIOPIA
(Hawassa University, 2017-08-12) ADUGNAW ASEFAW NIGATU
Evaluation of farm irrigation system plays a fundamental role in improving surface irrigation and in providing information used to advice irrigators how to improve their system operation. Furrow irrigation is one of the common methods of applying water to sugarcane at Belles sugar development project Sugarcane Plantation. The plantation is facing problems with respect to irrigation water management. This study was initiated with the objectives of evaluating the performance of furrow irrigation system at a farm level. To evaluate the performance of furrow irrigation system, a soil laboratory and field measurements (field layout, furrow geometry, time of cutoff, discharge) are made. The soil infiltration parameters „a‟, „k‟ and „fo‟ for each irrigation event are determined based on a two point approximation to volume balance method that incorporated modified Kostiakove Lewis infiltration function. Statically comparison of models outcome found the Win SRFR simulated model values provides good fitter than the SIRMOD simulation values to the estimated values. The analyses of the performance of the furrow irrigation in terms of application efficiency (Ea), distribution efficiency (Du), storage efficiency tail water Ratio (TWR), and Deep Percolation (DP) were done and found to be, the average application efficiency 62.1%, 65.3% and 68.5% for SIRMOD, estimated and WinSRFR simulated values; distribution efficiency 90.4%, 92.4% and 95.5% for estimated, SIRMOD and WinSRFR simulated value; storage efficiency 24.1%, 26.4% and 32.8% for SIRMOD, WinSRFR simulated and estimated values; TWR 31.2%, 34.2% and 37.9% for WinSRFR, estimated and SIRMOD simulated values, respectively and deep percolation ratio for all estimation is null. From the sensitivity analysis furrow slopes are higher sensitive than other parameters on influencing the application efficiency. The effects of furrow lengths are highly influencing on TWR. The effect of discharge influence on the storage efficiency also high with compared to others whereas the time of cutoff found affect the distribution efficiency.
PERFORMANCE EVALUATION OF FURROW IRRIGATION IN BELLES SUGAR DEVELOPMENT PROJECT SUGARCANE FARM LEVEL, ETHIOPIA
(Hawassa University, 2017-04-29) ADUGNAW ASEFAW NIGATU
Evaluation of farm irrigation system plays a fundamental role in improving surface irrigation and in providing information used to advice irrigators how to improve their system operation. Furrow irrigation is one of the common methods of applying water to sugarcane at Belles sugar development project Sugarcane Plantation. The plantation is facing problems with respect to irrigation water management. This study was initiated with the objectives of evaluating the performance of furrow irrigation system at a farm level. To evaluate the performance of furrow irrigation system, a soil laboratory and field measurements (field layout, furrow geometry, time of cutoff, discharge) are made. The soil infiltration parameters „a‟, „k‟ and „fo‟ for each irrigation event are determined based on a two point approximation to volume balance method that incorporated modified Kostiakove Lewis infiltration function. Statically comparison of models outcome found the Win SRFR simulated model values provides good fitter than the SIRMOD simulation values to the estimated values. The analyses of the performance of the furrow irrigation in terms of application efficiency (Ea), distribution efficiency (Du), storage efficiency tail water Ratio (TWR), and Deep Percolation (DP) were done and found to be, the average application efficiency 62.1%, 65.3% and 68.5% for SIRMOD, estimated and WinSRFR simulated values; distribution efficiency 90.4%, 92.4% and 95.5% for estimated, SIRMOD and WinSRFR simulated value; storage efficiency 24.1%, 26.4% and 32.8% for SIRMOD, WinSRFR simulated and estimated values; TWR 31.2%, 34.2% and 37.9% for WinSRFR, estimated and SIRMOD simulated values, respectively and deep percolation ratio for all estimation is null. From the sensitivity analysis furrow slopes are higher sensitive than other parameters on influencing the application efficiency. The effects of furrow lengths are highly influencing on TWR. The effect of discharge influence on the storage efficiency also high with compared to others whereas the time of cutoff found affect the distribution efficiency