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Assessing Returns from Investments in two Agricultural Development Projects (Protected Agriculture and Modern Irrigation Systems) in the Sultanate of Oman
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... More specifically, CEA aims to enhance the yield quantity and quality of crop by controlling the environmental factors to be suitable for growing various crops, such as ornamentals, fruits and vegetables (Fogg et al., 1979). It was reported that greenhouses in Oman increased the productivity of land by 12 times compared with open-field farming (Tawfiq, 2009) and promoted the productivity of water by twice (Mazid, 2011). Because of these benefits, the number of CEA facilities in Oman significantly increased in the past 15 a (Mazid, 2011). ...
... It was reported that greenhouses in Oman increased the productivity of land by 12 times compared with open-field farming (Tawfiq, 2009) and promoted the productivity of water by twice (Mazid, 2011). Because of these benefits, the number of CEA facilities in Oman significantly increased in the past 15 a (Mazid, 2011). The most common cultivated crops in greenhouses in Oman are cucumber (90%), followed by tomato (5%-9%) (Mazid, 2011). ...
... Because of these benefits, the number of CEA facilities in Oman significantly increased in the past 15 a (Mazid, 2011). The most common cultivated crops in greenhouses in Oman are cucumber (90%), followed by tomato (5%-9%) (Mazid, 2011). Kiyumi (2009) considered monocropping of cucumber in greenhouses as one cause of some diseases. ...
High temperature and humidity can be controlled in greenhouses by using mechanical refrigeration cooling system such as air conditioner (AC) in warm and humid regions. This study aims to evaluate the techno-financial aspects of the AC-cooled greenhouse as compared to the evaporative cooled (EV-cooled) greenhouse in winter and summer seasons. Two quonset single-span prototype greenhouses were built in the Agriculture Experiment Station of Sultan Qaboos University, Oman, with dimensions of 6.0 m long and 3.0 m wide. The AC-cooled greenhouse was covered by a rockwool insulated polyethylene plastic sheet and light emitting diodes (LED) lights were used as a source of light, while the EV-cooled greenhouse was covered by a transparent polyethylene sheet and sunlight was used as light source. Three cultivars of high-value lettuce were grown for experimentation. To evaluate the technical efficiency of greenhouse performance, we conducted measures on land use efficiency (LUE), water use efficiency (WUE), gross water use efficiency (GWUE) and energy use efficiency (EUE). Financial analysis was conducted to compare the profitability of both greenhouses. The results showed that the LUE in winter were 10.10 and 14.50 kg/m2 for the AC- and EV-cooled greenhouses, respectively. However, the values reduced near to 6.80 kg/m2 in both greenhouses in summer. The WUE of the AC-cooled greenhouse was higher than that of the EV-cooled greenhouse by 3.8% in winter and 26.8% in summer. The GWUE was used to measure the total yield to the total greenhouse water consumption including irrigation and cooling water; it was higher in the AC-cooled greenhouse than in the EV-cooled greenhouse in both summer and winter seasons by almost 98.0%–99.4%. The EUE in the EV-cooled greenhouse was higher in both seasons. Financial analysis showed that in winter, gross return, net return and benefit-to-cost ratio were better in the EV-cooled greenhouse, while in summer, those were higher in the AC-cooled greenhouse. The values of internal rate of return in the AC- and EV-cooled greenhouses were 63.4% and 129.3%, respectively. In both greenhouses, lettuce investment was highly sensitive to changes in price, yield and energy cost. The financial performance of the AC-cooled greenhouse in summer was better than that of the EV-cooled greenhouse and the pattern was opposite in winter. Finally, more studies on the optimum LED light intensity for any particular crop have to be conducted over different growing seasons in order to enhance the yield quantity and quality of crop.
... Oman is the eighth highest date producing country in the world with more than seven million trees and over 200 varieties [51,54]. Table 8 shows the potential of date that may reach a sustainable level [53,55]. ...
... Potential of date in achieving sustainability level[53,55] ...
Postharvest losses contribute to food shortages and ongoing food insecurity. Value addition in each aspect of agricultural produce creates more quality and adequate demand for the products. However, the growing market demand for quality and consistency in supply requires resources and necessary technical skills. There is a poor linkage between Research and Development institutions and the agro-value addition industry. Shortage of postharvest and value addition technical specialists and inefficient knowledge transfer from research stations to extension services are some constraints for needed outreach activities. Effective extension and training play a vital role in building capacity along the value chain by encouraging proper postharvest activities. In this article, the current postharvest value addition challenges are discussed with a specific focus on Oman. Furthermore, the strategies to be undertaken to enhance value addition processing and the need for increased institutional capacity building and technology transfer to achieve sustainability are discussed. It was recommended that targeted involvement be aimed at for better support for agricultural value addition in Oman.
... Sherif (2009) reported that UAE agricultural sector includes about 8435 greenhouses producing 0.101×10 6 t of vegetables which indicates the importance of protected agriculture in securing and meeting local demands. In Oman, greenhouses have significantly increased the production of cucumber, which is the dominant crop in greenhouses, with the yield being up to 24 folds that of open field (Mazid, 2011). The total cucumber production in greenhouses accounted for 96.0% of the total production. ...
This study aimed to explore the potential of developing a novel cooling system combining a greenhouse and an earth-tube heat exchanger (ETHE). In this system, greenhouse air is circulated through the underneath soil mass to use the deep-soil cooling effect. This was achieved through the following steps. First, soil temperature profile inside and outside the cultivated greenhouse was monitored for almost one year to study the possibility of using deep-soil coldness for cooling the greenhouse air. Second, a prototype ETHE was built to practically investigate the potential reduction in air temperature as the air flows inside the deep earth pipes. Third, a prototype greenhouse was erected to study the ETHE concept. Results from the first experiment revealed that soil temperature at a soil depth of 2.5 m inside the greenhouse offers good conditions to bury the ETHE. The soil temperature at this soil depth was below the maximum temperature (32°C) that most greenhouse crops can withstand. Results from the prototype ETHE showed a slight reduction in air temperature as it passed through the pipes. From the prototype of the integrated greenhouse and ETHE system, reduction in air temperature was observed as the air passed through the ETHE pipes. At night, the air was heated up across the ETHE pipes, indicating that the ETHE was working as a heater. We concluded from this study that greenhouses in arid climates can be cooled using the ETHE concept which would save a large amount of water that would otherwise be consumed in the evaporative coolers. Further investigations are highly encouraged.
... Climate control methods should be selected to suit the cultivated crop in order to avoid crop damage or loss and should be aligned with local climate conditions. Evaporative cooling pads are the most optimal means to control the greenhouse climate in arid areas (Mazid, 2017;Sabeh and Giacomelli, 2011). If the greenhouse is long, then the installation of a second pad is recommended for reducing temperature gradients. ...
Protected Agriculture (PA) presents a sustainable solution for food production in hot and arid environments. Harsh climate and the water deficit are obstacles to all year round cultivation. The greenhouse design should provide adequate control of its microclimate, such as temperature, relative humidity, CO2 concentration, and lightning depending on ambient conditions and the type of cultivation. This paper provides a thorough review of previous research on greenhouses design features, deemed important for efficient operation in hot and arid environments, such as dimensions, orientation, shapes, covering and shading materials. Effective greenhouse cooling methodologies and operation strategies to achieve and maintain satisfactory climate conditions in hot and arid conditions are investigated. Namely, natural and forced ventilation, evaporative cooling and fogging systems. Furthermore, the paper discusses the greenhouse control methods (field, remote, direct and combined) to monitor and regulate the indoor climatic parameters. Finally, the paper focuses on current greenhouse sustainable technologies and clean energy applications that contribute towards minimizing dependency on fossil fuels and leading to efficient water management. Namely, storage systems, humidification/dehumidification systems and Photovoltaic Panels. The future challenges facing the protected agriculture sector are identified. Suggestions of future scientific research and development topics are proposed. © 2018 Asian Agricultural and Biological Engineering Association
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