http://ir.bdu.edu.et/handle/123456789/11024 2001-01-13T05:52:41Z 2001-01-13T05:52:41Z TESFA, ASMELIE http://ir.bdu.edu.et/handle/123456789/16641 2025-03-18T06:32:51Z 2024-11-01T00:00:00Z

YIELD AND WATER USE EFFICIENCY RESPONSE OF ONION TO DEFICIT IRRIGATION IN SEKOTA WOREDA, EASTERN AMHARA ETHIOPIA TESFA, ASMELIE The increasing global population and water demand are creating pressure on the sustainable use of water sources, potentially reducing irrigation availability. Improving water use efficiency is crucial for addressing future water scarcity. A field experiment was conducted in Sekota woreda at Wolleh irrigation scheme to investigate the impact of deficit irrigation on yield and water productivity of Bombay red variety onion. The experiment was set using the randomized complete block design with nine treatments and three replications, involving 25% and 50% deficits at the development, mid, and late stages of onion growth, along with a control receiving 100% of the crop water requirement throughout the growing season. Crop water requirement was estimated using the CropWat model, and data analysis was conducted using the SAS statistical software method. The results indicated that deficit irrigation at different growth stages had significant effect (p≤0.01) on plant height, leaf length, bulb diameter, bulb length, marketable and unmarketable yield as well as biomass of onion. The maximum (25.2t/ha) and minimum (16.4t/ha) marketable yield were obtained from treatments receiving 100% and 50 % ETc throughout the growing season respectively. The highest CWUE of 6.39kg/ha was obtained from 50% ETc irrigation application. The severe yield reduction of 55.27% was obtained from 50% deficit at all stages excluding the initial stage which is establishing period. 25% deficit at development and late stage showed 6.36% yield reduction and saved 12% irrigation water. The maximum net income and maximum marginal rate of return was 684130.28ETB/ha and 969.66% obtained from treatments that irrigate 25%ETc deficit at development and late stage while applying full irrigation at mid or bulb formation stage. The study showed that increased water saving and water productivity were obtained from the 25% deficit irrigation at development and late stages followed by applying 100%ETc at development and only 75%ETc at mid and late stages respectively. Hence, applying deficit irrigation at recommended levels can reduce the problem of water shortage with no significant yield reduction. Key words: water productivity, onion, Sekota, marketable yield, wolleh, growth stage

2024-11-01T00:00:00Z MESSAY, ABERA http://ir.bdu.edu.et/handle/123456789/16640 2025-03-18T06:30:59Z 2024-11-01T00:00:00Z

EFFECT OF DEFICIT IRRIGATION AND MULCH ON WATER PRODUCTIVITY AND YIELD OF MAIZE UNDER RAISED BED PLANTING METHOD IN THE SEMIARID AREA OF WAG-HIMRA-ZONE, NORTHERN ETHIOPIA MESSAY, ABERA The soil moisture was the most limiting factors for crop growth especially in low land, aired or semi-aired area due to high evaporation and water scarcity. This experiment was conducted at Woleh irrigation scheme in Wag-himra zone; northern, Ethiopian in the 2023/24 irrigation season, to investigate the effect of deficit irrigation and mulch on water productivity and yield of maize under raised bed planting method. The experiment was arranged in a split plot using a randomized complete block design with three replications with eight treatments: conventional ridge sowing and furrow irrigated raised bed planting with three irrigation application levels (100%, 75%, and 50% of ETc). Pearl millet straw (6t ha−1) was applied as mulch. The test crop was an improved maize variety, BH-546. It was planted in two main plots, one with straw mulch and one without mulch. The spacing between the main plot, subplot, and blocks are 2m, 1m, and 1.5m respectively. The plot size was 3.75m x 3m for maize crop in Conventional Ridge Sowing on spacing between ridge and plant were 75cm and 25 respectively and furrow irrigated raised bed planting 60cm for bed and 30cm for furrow and 45cm is for between row and 25cm between plants. The amount of irrigation water applied was calculated using the CROPWAT8.0 model by using the required input data: crop, soil and climate data. The results clearly showed that the furrow irrigated raised bed sowing method with 100% ETc level and mulch produced the maximum grain yield (6.0t ha−1) and above-ground biomass (28.93t ha−1) comparable to the Furrow irrigated raised bed planting 75% ETc (5.87t ha−1 and 27.33t ha−1), respectively. However, the Furrow irrigated raised bed planting 75% ETc with mulch provided 24% and 28% water savings for both crop and biomass water productivity, respectively, compared to the Furrow irrigated raised bed planting 100% ETc with mulch. Additionally, the Furrow irrigated raised bed planting 75% ETc with mulch saved 75% of water and increased yield by 32% compared to conventional ridge sowing. These results confirmed that Furrow irrigated raised bed planting at 75% ETc with mulch improves yield and water productivity while saving water with minimal yield reduction. Keywords: Raised bed, mulch, planting method, crop and water productivity, and Pearl millet straw

2024-11-01T00:00:00Z HAIMANOT, FIKREMARIAM BELAYNHE http://ir.bdu.edu.et/handle/123456789/16639 2025-03-18T06:29:16Z 2024-10-01T00:00:00Z

EVALUATING THE EFFECT OF DEFICIT IRRIGATION ON WHEAT YEALDS AND WATER PRODUCTIVITY ON FIELD EXPERIMENT AND AQUA CROP MODEL AT SHINA-HAMUSIT IRRIGATION PROJECT HAIMANOT, FIKREMARIAM BELAYNHE One of the most important simulation models in the field of water productivity (wp) management in the world is the Aqua crop model, which depends on many factors and conditions related to climate, soil. irrigation water etc. Aqua crop model program simulative vegetative growth, yield of wheat crops, biomass of wheat crop and irrigation water productivity. The objective of this study was to evaluate the effect of deficit irrigation on wheat yield, canopy cover, bio mass and water productivity. A field experiment was conducted to examine wheat yield response under different water application and validate Aqua crop at Shina -Hamusit project. The experiment was conducted with two plots of lands.. The water application levels for the crop at the field were considered 100 % and 50% application level in different growth stages. The agronomic parameters were collected (canopy cover, biomass and grain yield) to evaluate the crop yield response of the Aqua crop model. The canopy cover was analyzed by image tracker (LAI-2000) because Aqua Crop use canopy cover than leaf area index and above ground biomass was measured by cutting the plant within 19m × 29m area and oven dried by 550c for 60hr to determine green biomass . The result showed that the highest yield was recorded at full (plot one) irrigation (3.6 ton/ha), whereas minimum yield was obtained at plot two (2.78 ton/ha) which was subjected to a 50% water deficit during the whole-season (highly affecting the yield).The Stress of 50% at the mid-growth stage and stress 50 % of the full irrigation water requirement at all growth stage has significantly (α=5%) affected the canopy, biomass and wheat yield production. The Aqua Crop model achieved well in simulating the growth of biomass, canopy cover and yield of wheat for those of the treatments ( R2 = 0.83 for yield and 0.80 for biomass . RMSE values for yield and biomass was 0.72 ton/ha and 0.35 ton/ha respectively. This study shows that deficit irrigation at 50% stress through the entire crop growth period can bring more water productivity so as to projects can benefit by expanding irrigated land through saved water. Aqua crop model has a decent ability of simulating the yield of wheat for Shina-Hamusit Irrigation project. Key words: -wheat crop, validation, Aqua crop,calibration

2024-10-01T00:00:00Z CHALIE, WUBET TAYE http://ir.bdu.edu.et/handle/123456789/16638 2025-03-18T06:27:13Z 2024-07-01T00:00:00Z

Effects of Irrigation Levels and Fertilizer Rates on Nitrogen Productivity and Residual Soil Nitrogen of Forages at Robit Bata, Abay Basin, Ethiopia CHALIE, WUBET TAYE This study investigated the effects of irrigation, fertilizer, and forage variety on nitrogen productivity and residual soil nitrogen in Robit-Bata, Ethiopia. The experiment tested three irrigation levels (60%, 80%, 100% of available water), three fertilizer rates (manure 30 t/ha, urea 100 kg/ha, urea 300 kg/ha), and seven forage varieties (ILRI-16791, ILRI-16803, ArekaDZF590, ILRI-10871, ILRI-6765, ILRI-75 and ILRI-140). Data was collected over two irrigation seasons (2021 & 2022) and three rainy seasons (2020, 2021 & 2022). All the collected data were organized by MS Excel and subjected to ANOVA analysis using SPSS software, at a significance level of 5%. Mean comparisons for interaction effects were tested by using Minitab software. The highest dry matter yield (8.7 t ha-1), nitrogen uptake (131.2 kg N ha-1) nitrogen use efficiency (46 kg kg-1), and lowest nitrogen surplus (18.9 kg N ha-1) were observed under full irrigation (I100) treatment. However, the difference with deficit irrigation (I80) was not significant (P>0.05). ILRI-16791 with urea at 300 kg ha-1 exhibited the highest dry matter yiled (20.7 t ha-1) and nitrogen uptake (259.2 kg ha-1). However, the highest nitrogen use efficincy (138.8 kg kg-1) and lowest nitrogen surplus (-168.8 kg ha-1) were observed for ILRI-16791 with urea at 100 kg ha-1. In the rainy season, the three-way interaction effect of forage variety, fertilizer rate/types, and year was significant. Similar to irrigation season the highest dry matter yiled (50.7 t ha-1) and nitrogen uptake (760.5 kg ha-1) were recorded for ILRI-16791 with urea at 300 kg ha-1 in 2021 rainy season. Again, the lowest nitrogen suplus (-640.7 kg ha-1) occurred for ILRI-16791 with urea at 100 kg ha-1 in the 2021 rainy season. The interaction effects of fertilizer rate and irrigation levels on residual soil nitrogen were significant for the top 30cm soil layer. The highest residual soil nitrogen (117.2 kg ha-1) was observed for I60 with urea at 300 kg ha-1. ILRI-140 with urea at 100 kg ha-1, resulted the high residual soil nitrogen in rainy season. Generally, applying deficit irrigation (I80) with urea at 100 kg ha-1 for ILRI-16791 is recommended as an appropriate management practice for reducing inputs while achieving high resource use efficiency, forage quality, economic benefits and reduce environmental impact without compromising the dry matter yield. Additionally, using legume forages, especially ILRI-140 with low urea, can improve residual soil nitrogen, particularly during years like 2021 with favorable rainfall. Economic analyses comparing irrigation and fertilizer strategies, and exploring reduced urea with manure for ILRI-16791 are recommended for future research to guide farmers towards cost-effective and sustainable practices. Keywords: Irrigation, dry matter yield, nitrogen use efficiency, nitrogen uptake, nitrogen balance, residual soil nitrogen.

2024-07-01T00:00:00Z