Your search found 2 records
1 Haileselassie, H.; Araya, A.; Habtu, S.; Meles, K. G.; Gebru, G.; Kisekka, I.; Girma, A.; Hadgu, K. M.; Foster, A. J.. 2016. Exploring optimal farm resources management strategy for Quncho-teff (Eragrostis tef (Zucc.) Trotter) using AquaCrop model. Agricultural Water Management, 178:148-158. [doi: https://doi.org/10.1016/j.agwat.2016.09.002]
Crop management ; Eragrostis tef ; Irrigation water ; Water productivity ; Models ; Farm management ; Strategies ; Crop yield ; Fertilizer application ; Sowing date ; Soil water characteristics ; Chemicophysical properties ; Rain ; Biomass ; Canopy ; Experimentation / Ethiopia / Mekelle
(Location: IWMI HQ Call no: e-copy only Record No: H047852)
(1.52 MB)
Teff is a major staple food crop in Ethiopia. Moisture and soil fertility are the two major factors limiting teff yield. Studies were conducted across three sites in Ethiopa [Mekelle (MK) in 2012 and 2016, Ilala (IL) in 2012 and Debrezeit (DZ) in 2009 and 2010]. The objectives of these studies were (1) to assess the response of Quncho-teff to different fertilizer and irrigation levels; 2) to quantify irrigation water productivity (IWP), and (3) to collect data to calibrate and validate AquaCrop model for simulating yield and evaluate optimal irrigation and sowing date strategy for Quncho-teff at different locations in Ethiopia. The different fertilizer levels were: 1) 64 kg N and 46 kg P/ha (N2P2); 2); 32 kg N and 23 kg P/ha (N1P1); 3) 0 kg N and 0 kg P/ha (N0P0) and 4) 52 kg N and 46 kg P/ha (N3P3). The four irrigation treatments were: zero (rainfed), two, four and full irrigation applications. Findings showed that full irrigation in combination with high fertilizer (N2P2) could give better yield. However, during abnormal rainfall, spreading the available fertilizer at a rate of 32 kg N and 23 kg P/ha may be preferable to applying 64 kg N and 46 kg P/ha. This study also indicated that the regional fertilizer recommendations for teff need to be revised taking in to account the soil characteristics, climate and irrigation water availability. The AquaCrop model was able to simulate the observed canopy cover, soil water, biomass and yield of teff satisfactorily. Canopy cover was simulated with normalized root mean square error (NRMSE), index of agreement (I) and R2 of 7%, 0.5 and 0.8, respectively. Soil moisture during the season was simulated with NRMSE of 11.4–15.7%, I of 0.99 and R2 of 0.85–0.9. Simulated final aboveground biomass values were in close agreement with the measured (NRMSE, 7.8%, I, 0.89 and R2, 0.66). There was also good agreement between simulated and measured grain yield with NRMSE, I and R2 values of 10.9%, 0.93, 0.80, respectively. Scenario analysis indicated that early sowing was the best option to maximize teff yield with the least amount of irrigation. Scenario analysis also showed that one irrigation during flowering stage could substantially improve irrigation water productivity (IWP) of teff and minimize the yield loses which could occur due to shifting of sowing date from early to normal. Two irrigation applications also substantially improved the yield and IWP of late sown teff. However, to get high yield, a late sown teff should receive at least four irrigation applications during the mid-growth stage of the crop. These results suggest that AquaCrop model can be used to identify optimal farm resource management strategies for teff production.
2 Araya, A.; Prasad, P. V. V.; Gowda, P. H.; Afewerk, A.; Abadi, B.; Foster, A. J.. 2019. Modeling irrigation and nitrogen management of wheat in northern Ethiopia. Agricultural Water Management, 216:264-272. [doi: https://doi.org/10.1016/j.agwat.2019.01.014]
Irrigation management ; Fertilizer application ; Nitrogen ; Crop production ; Wheat ; Crop yield ; Water productivity ; Soil chemicophysical properties ; Biomass ; Models ; Strategies / Ethiopia / Mekelle
(Location: IWMI HQ Call no: e-copy only Record No: H049197)
(1.10 MB)
Wheat (Triticum aestivum) is one of the most important staple food crops in Ethiopia. However, its production is limited by moisture and nutrient stresses. A field experiment was conducted in northern Ethiopia to: (i) evaluate the effects of irrigation and nitrogen (N) and phosphorus (P) fertilizer application rates on yield, biomass and irrigation water productivity (IWP) of wheat; (ii) calibrate and validate a crop model for simulating yield and biomass of wheat under different levels of nitrogen and irrigation applications; (iii) evaluate consecutive aboveground biomass accumulation as affected by different combinations of irrigation and N fertilizer rates. The Decision Support for Agro technology Transfer Cropping System Model (DSSAT-CSM) was calibrated and validated with experimental data. The calibrated and validated DSSAT-CSM was used to simulate wheat biomass, yield, and irrigation water productivity under rainfed and three irrigation scenarios: I0, rainfed; DI1, two irrigations from heading to flowering; DI2, four irrigations from heading to early grain filling; and DI3, six irrigations from heading to mid grain filling period in combination with nine N rates (0, 16, 32, 64, 80, 96, 112, 128 and 160 kg/ha). Simulation results showed that both irrigation and nitrogen applications positively affected wheat yield, biomass and IWP. Much of the increase in biomass and yield was due to increased N than to increased irrigation. Yield increased with increase in N application rates, however, at a diminishing rate yielding a curvilinear relationship. Four irrigation (DI2) starting from heading to early grain filling stage resulted in a yield similar to DI3, six irrigation applications from heading to mid grain filling stage. Simulations showed that two irrigation applications strategy (DI1) yielded relatively higher IWP (1.8 kg/m3 ) at the highest application rate of 160 kg N/ha. Further economic analysis would help to identify most efficient practices for wheat production in northern Ethiopia.
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