Irrigation Agronomy

PROGRESSIVE DECLINE IN SUGARCANE (Saccharum Spp. HYBRID) YIELD AND OPTIONS FOR ADDRESSING THE PROBLEM AT WONJI SHOA SUGAR ESTATE, ETHIOPIA

2024-05-15T05:57:40Z

PROGRESSIVE DECLINE IN SUGARCANE (Saccharum Spp. HYBRID) YIELD AND OPTIONS FOR ADDRESSING THE PROBLEM AT WONJI SHOA SUGAR ESTATE, ETHIOPIA Alemayehu Dengia Layo; Prof Nigussie Dechassa; Dr. Lemma Wogi; Dr. Berhanu Amsalu Continuously declining yields of sugarcane have been the major challenge faced by the Ethiopian Sugar Industry. Over the last 70, 58 and 30 years, sugarcane yields have declined in Wonji-Shoa, Metehara, and Finchaa Sugar Estates by 48, 32 and 47%, respectively. However, to date, no comprehensive information has been generated on the root causes and management options of the decline in sugarcane yields. The objectives of this study were to identify the root causes of the progressive decline in sugarcane yields and suggest effective management strategies at Wonji Shoa Sugar Estate (WSSE). Therefore, the declining trends in yield were analyzed with respect soil type, variety and location by using long-term historical yield data (1954–2022) obtained from WSSE. To further comprehend the underlying causes of this decline, the changes in soil properties during the long-term intensive production of sugarcane were assessed through laboratory analysis of biosequentially sampled soils. Then, the minimum data set (MDS) and the key soil properties that exert a significant influence on cane yield were identified by using principal component analysis and stepwise multiple regression, respectively. Prevalence and changes in plant parasitic nematodes (PPNs) were also studied through soil and root sampling from various fields in the WSSE, and by conducting a pot experiment in a greenhouse. To manage the problem, the effectiveness of seven green manure crops were evaluated at WSSE under three methods of stool destruction in a split-plot design. Additionally, a simplified satellite-based approach for monitoring sugarcane plantations was evaluated by testing the accuracy of Landviewer Calculated Vegetation Indexes (LCVIs). Results revealed that 69% of the plantation fields were classified as "yield declining”, and the overall rate of the decline was 0.84 tons ha–1year–1. The rate of yield decline was significant in the older varieties, while non-significant in the newer varieties. Both Vertisol and Cambisol showed a significantly declining yield trends, despite the rate of decline was higher in the former than in the latter. The biosequential soil sampling result showed that organic carbon (OC), total nitrogen, available phosphorus (AP), exchangeable potassium (EcK), available sulfur (AS), zinc, and EC have significantly declined by 16%, 13%, 50%, 39%, 82%, 15%, and 58%, respectively, over the last seven decades. Additionally, the soil OC, AP, AS, and boron concentrations were below the critical values. The MDS of soil properties xxiv xxv at WSSE were identified to be silt, AP, EcK, OC, CEC, AS, sodium adsorption ratio, manganese and soil structural stability index, where the first three were found to play a dominant role in determining sugarcane yield. Furthermore, about ten genera of PPNs were detected in WSSE, of which four genera were newly identified. Over the long-term sugarcane production period, the population and diversity of PPNs increased by 36- and 4.5-fold, respectively. It was also observed that fumigation reduced the population of PPNs by 61% and produced 63% higher cane biomass than the unfumigated soil, suggesting the potential impact of PPNs on the observed yield decline. In the field experiment, cowpea, followed by lablab, dhaincha, and sunn hemp, were found to be the most effective green manures in terms of improving soil fertility and cane performance, with up to 17–20% yield advantage and 21–40% net economic benefits. The spraying method for cane stool destruction was nearly as effective as the cultivating out method. The satellite-based crop monitoring study revealed that the goodness-of-fit of the LCVIs to the sigmoid curve was significant, with 84–95% accuracy for all the indexes evaluated. The majority of the LCVIs also exhibited significant relationships with the yield and yield components of sugarcane. In conclusion, the long-term intensive production system has led to a significant reduction in the quality of soil, and most likely play a predominant role in the continuous decline in cane yields at WSSE. To mitigate this problem, green manuring and satellite-based crop monitoring offers a significant potential. Therefore, particular attention should be given to green manuring with legume plants such as cowpea, lablab, dhaincha, and sunn hemp after herbicide-induced destruction of sugarcane stools. It is also crucial to prioritize continuous replacement of outdated varieties, sustain the fertility of depleted soil, and optimize cultural practices particularly on fields with Vertisol soil types. The Sugar Estate should also adopt satellite-based crop monitoring which can enable plantation managers to take proactive measures before any significant damage occurs. 230p.

EFFECT OF DIFFERENT LEVELS OF SUPPLEMENTARY IRRIGATION ON YIELD AND YIELD COMPONENT OF MAIZE (zea mays L) AT TEPPI, SOUTH WEST ETHIOPIA

2024-01-02T06:56:36Z

EFFECT OF DIFFERENT LEVELS OF SUPPLEMENTARY IRRIGATION ON YIELD AND YIELD COMPONENT OF MAIZE (zea mays L) AT TEPPI, SOUTH WEST ETHIOPIA Zinaw Asaye; Tilahun Hordofa (PhD) Maize (zea mays L) is one of the most important cereal crops grown in Ethiopia. Field experiment was undertaken on clay loam soil at Teppi national spice research center, Ethiopia during 2013/2014 cropping season with the objectives of investigating the effect of supplementary irrigation on yield and yield component of maize for achieving maximum crop yield in rain fed agriculture during belge season. The experiment was laid out in RCBD (Randomized Complete Block Design) with three replications. Treatments include seven levels of supplemental irrigation treatments and a control irrigation receiving no supplemental irrigation. The irrigation water was applied when the soil moisture depleted reached 55% of total available water (p=0.55). The supplemental irrigation levels had shown a highly significant (p<0.01) effect on grain yield of maize and gave increased water use efficiency. However, the treatments did not affect leaf area. The supplemental irrigation levels had also a significant (P<0.05) effect on days to tasseling, silking and days to maturity. The maximum yield of 67 q/ha was recorded from 100% ETc (Crop Evapotranspiration) which was not significantly different from 75% ETc and the minimum yield of 25q/ha was gained from rain fed treatment. In terms of water use efficiency rain fed treatment had the highest crop water use efficiency which has significantly different from all other treatment. Yield response factor (Ky) was separately calculated for the growing season and was found to be 1.25 the highest value and 1.05 the lowest value. Therefore, it is recommended that to apply 75% ETc which gave 6.16 ton/ha which improve WUE (Water Use Efficiency) without significant reduction of yield. 78

EFFECT OF DEFICIT IRRIGATION AND MULCH LEVELS ON YIELD COMPONENTS, YIELD, AND WATER USE EFFICIENCY OF HOT PEPPER (Capsicum annuum L.) IN HARAMAYA DISTRICT, EASTERN ETHIOPIA

2023-03-16T08:19:36Z

EFFECT OF DEFICIT IRRIGATION AND MULCH LEVELS ON YIELD COMPONENTS, YIELD, AND WATER USE EFFICIENCY OF HOT PEPPER (Capsicum annuum L.) IN HARAMAYA DISTRICT, EASTERN ETHIOPIA Addis Hailu Demo; Kibebew Kibret (PhD) The increasing scarcity and competition for irrigation water demands for adoption of innovative practices that increase efficient water use. In the context of improving water use efficiency, there is a growing interest in deficit irrigation which provides a means of reducing water consumption while minimizing adverse effects on yield. A field experiment was conducted at Haramaya University to investigate the effects of deficit irrigation and straw mulch levels on yield components, yield and water use efficiency of hot pepper (Capsicum annuum L). The experiment was laid out in a randomized complete block design in factorial arrangement with three levels of irrigation (100%, 75% and 50% of ETc) and four levels of straw mulch (0, 3, 6 and 9 tonnes of vetiver grass straw per ha) in three replications. The output of CROPWAT model indicated that the highest seasonal water requirement of hot pepper was 275.66 mm at 100% ETc, while the lowest was 137.83 mm at 50% ETc. The analysis of variance revealed that the interaction effects of deficit irrigation and straw mulch levels on growth (p < 0.05) and yield (p < 0.01) parameters were significant. The highest marketable yield (12.36 t/ha) was obtained from an experimental plot treated with combined application of 100% ETc and 6 t/ha straw mulch, while the lowest (4.66 t/ha) was obtained from plots that received 50% ETc irrigation and no mulch. Water use efficiency was also highly significantly (p<0.01) influenced by the interaction effects of deficit irrigation and straw mulch levels, with the highest (6.65 kg/m3 ) and the lowest (3.25 kg/m3 ) values recorded from the plots that received 50% ETc irrigation and 9 t/ha straw mulch, and 100% ETc irrigation and no mulch, respectively. The Partial budget analysis revealed that combined application of 75% ETc irrigation and 6 t/ha straw mulch is the most attractive management in economic terms since it gave the highest net benefit. Therefore, in terms of marketable hot pepper yield, economically attractive and water use efficiency, irrigating with 75% ETc combined with 6 t/ha straw mulch can be recommended for profitable production of hot pepper in the study area and others with similar agroecology. 92p.

EFFECT OF DEFICIT IRRIGATION AND MULCH LEVELS ON YIELD COMPONENTS, YIELD, AND WATER USE EFFICIENCY OF HOT PEPPER (Capsicum annuum L.) IN HARAMAYA DISTRICT, EASTERN ETHIOPIA

2022-03-28T06:01:27Z

EFFECT OF DEFICIT IRRIGATION AND MULCH LEVELS ON YIELD COMPONENTS, YIELD, AND WATER USE EFFICIENCY OF HOT PEPPER (Capsicum annuum L.) IN HARAMAYA DISTRICT, EASTERN ETHIOPIA Hailu Demo, Addis; Kibret, (PhD) Kibebew The increasing scarcity and competition for irrigation water demands for adoption of innovative practices that increase efficient water use. In the context of improving water use efficiency, there is a growing interest in deficit irrigation which provides a means of reducing water consumption while minimizing adverse effects on yield. A field experiment was conducted at Haramaya University to investigate the effects of deficit irrigation and straw mulch levels on yield components, yield and water use efficiency of hot pepper (Capsicum annuum L). The experiment was laid out in a randomized complete block design in factorial arrangement with three levels of irrigation (100%, 75% and 50% of ETc) and four levels of straw mulch (0, 3, 6 and 9 tonnes of vetiver grass straw per ha) in three replications. The output of CROPWAT model indicated that the highest seasonal water requirement of hot pepper was 275.66 mm at 100% ETc, while the lowest was 137.83 mm at 50% ETc. The analysis of variance revealed that the interaction effects of deficit irrigation and straw mulch levels on growth (p < 0.05) and yield (p < 0.01) parameters were significant. The highest marketable yield (12.36 t/ha) was obtained from an experimental plot treated with combined application of 100% ETc and 6 t/ha straw mulch, while the lowest (4.66 t/ha) was obtained from plots that received 50% ETc irrigation and no mulch. Water use efficiency was also highly significantly (p<0.01) influenced by the interaction effects of deficit irrigation and straw mulch levels, with the highest (6.65 kg/m3 ) and the lowest (3.25 kg/m3 ) values recorded from the plots that received 50% ETc irrigation and 9 t/ha straw mulch, and 100% ETc irrigation and no mulch, respectively. The Partial budget analysis revealed that combined application of 75% ETc irrigation and 6 t/ha straw mulch is the most attractive management in economic terms since it gave the highest net benefit. Therefore, in terms of marketable hot pepper yield, economically attractive and water use efficiency, irrigating with 75% ETc combined with 6 t/ha straw mulch can be recommended for profitable production of hot pepper in the study area and others with similar agroecology. 92p.