A. Sheini-Dashtgol; Saeid Boroomand Nasab; AbdAli Naseri
Abstract
Introduction: Sugarcane fields of the southwest of Iran have heavy soil texture, high temperatures, hot and dry wind flow at spring and summer seasons. The electrical conductivity of irrigation water was considered about 1.1 dS.m-1, in basic designs of this irrigation method. In addition to sugarcane ...
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Introduction: Sugarcane fields of the southwest of Iran have heavy soil texture, high temperatures, hot and dry wind flow at spring and summer seasons. The electrical conductivity of irrigation water was considered about 1.1 dS.m-1, in basic designs of this irrigation method. In addition to sugarcane production, sugar is a fundamental good in the economic section of Iran. It has multiple use in food, medical and chemical industry, production of by-products such as feedstuffs, yeast and alcohol, wood and paper. Sugarcane requires lots of water during the growing period and sensitive to water stress and is not compatible with long duration of flooding. If groundwater rises and covers the root zone, crop yield decreases due to root rot. Significant benefits are identified in terms of increased yield, improved crop quality, reduction in applied water, and reduced agronomic costs for weed control, fertilization, and tillage. Improved water management is crucial for a sustainable future, and SDI will be one tool that is available to improve water productivity. The main advantages of SDI are related to water savings because water is applied directly to the crop’s root zone, which prevents losses due to direct evaporation from the soil and deep drainage, and, if properly managed, SDI allows for the maintenance of appropriate levels of soil moisture. Due to the water crisis in Iran, this study aimed to reduce the volume of consumed water and water productivity for sugarcane and sugar yield by managing water consumption using drip irrigation for the first time in the cultivation of sugarcane. Material and Methods: According to recent droughts and severe water crises in Iran, subsurface drip irrigation was implemented in sugarcane for the first time. It seems that water consumed in subsurface drip irrigation is less than other methods. Therefore, its effect was investigated by 15, 20, and 30 cm depths and 75 cm space of subsurface emitters and comparison with control, on water productivity and sugarcane yield. An experiment based on randomized complete block design was carried out at the Sugarcane Research and Training Institute of Khuzestan in the South-West of Iran. After harvesting the plant field (start Ratoon), soil samples were collected at 0-30, 30-60, and 60-90 cm depths. In order to measure the bulk density of soil, samples were collected from the undistributed samples with sampler cylinders, and the texture was determined by the hydrometer method. To assess soil moisture percentage, pressure plate was used for determining content in field capacity (FC) and permanent wilting point (PWP) (the results were 25.1% and 12.9%, respectively). Emitters were pressure controlled emitter type, anti-siphon and the pressure at the pump station was 4.3 bar, and emitters with a flow 2.2 liter-1 and the depth of emitters pipes were 15, 20, and 30 cm from the surface soil. Depending on irrigation frequencies and irrigation water acidity, acid was injected into the irrigation water to prevent clogging of the emitters. After a specified time, it was discharged from the network. Regarding the presence of algae in irrigation water, chlorine gas was used in acid filtration before irrigation in field capacity. Finally, the average quantity and quality functions and Water Productivity in subsurface drip irrigation were compared with compression irrigation. For data fitting and curves, EXCEL software was used, and SAS statistical software was used for statistical analysis. Also, to investigate the salinity distribution in drip irrigation, the mean soil samples were used during the sampling period. The figures were drawn using 8 Surfer software in two dimensions. In drawing the shapes, Craig’s introspection was used. Results and Discussion: High evaporation, air temperature, and relatively low quality of irrigation water are the most important limiting factors for sugarcane irrigation in Khuzestan. It seems that according to the research records, the irrigation of subsurface drops with proper management is successful. Therefore, for this purpose, the effect of planting depth of 15, 20, and 30 and a distance of 75 cm drops and to compare with the regular irrigation of sugarcane lands as control (control), on water productivity and sugarcane yield complete random blocks was applied. The results of the analysis of variance of quantitative traits showed significant effects of the planting depth of droplets, in terms of yield at the level of one percent and in terms of stem height traits, number of stems per hectare, and water efficiency per sugarcane and produced sugar, at the level of five percent. According to the results of qualitative traits, the effect of treatment of droplet implant depth in all traits was non-significant. At a depth of 20 cm, the highest efficiency of water production for sugarcane and sugar production were 1.6 and 0.73 kg / m3, respectively. The lowest water productivity for sugarcane and sugar produced in the control treatment was 4.2 and 0.51 kg / m3, respectively. As a result, water productivity in the treatment of selected index (planting depth of 20 cm) per sugarcane and produced sugar has resulted in an increase of more than 30% in water productivity compared to the usual irrigation of fields (control). The results of salinity distribution around the droplets also showed that under the conditions of irrigation of subsurface droplets with salt water, the lowest salinity values were always seen as a range around the droplets. With increasing distance from the droplets, the salinity increased. More salts The drops are concentrated in the streams on both sides of the drops, The highest salinity occurred at the bottom of the furrow, and the lowest salinity was found on the ridge, where the drip pipe was planted and on either side of which there were two rows of reeds. Conclusion: Subsurface drip irrigation is one of the most optimal irrigation methods that are almost unknown to sugarcane in the executive, research, and academic sectors, and has been implemented for the first time in sugarcane cultivation in Iran. Given the recent droughts and the crisis and water scarcity, and the importance of environmental issues, it will be invaluable to investigate further and apply them. In general, in this study, using a flow rate of 2.2 lit/hr and a space of 75 cm and an installation depth of 20 cm droplets, the highest quantitative and qualitative functions and the highest water productivity per sugar cane. And the sugar produced. Also, regardless of any deepening treatment, the drip irrigation system, compared to the conventional irrigation system, reduced water consumption by about 20% and water yield by 26% per sugarcane and sugar produced. According to the results and considering the uniformity of moisture distribution, soil surface salinity, lack of runoff, protection of the discharge pipe, removal of surface evaporation and sugarcane root development, depth of 20 cm, application of the discharge pipe with a distance of 75 cm drops on the hose with a flow rate of 2.2 lit/hr are recommended. Also, although the distribution of moisture onions is provided up to a distance of 80 cm, a shorter distance between the droplets, such as 60 cm with the above flow, needs further investigation.
N. Sedaghati; S.J. Hosseinifard; A. Mohammadi Mohammadabadi
Abstract
Unsustainable harvesting of agricultural water resources in the province of Kerman, has caused an annual average of one-meter drop in ground water levels. Surface irrigation methods in pistachio trees have low efficiency because of inherent characteristics and its incorrect application, as well as low ...
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Unsustainable harvesting of agricultural water resources in the province of Kerman, has caused an annual average of one-meter drop in ground water levels. Surface irrigation methods in pistachio trees have low efficiency because of inherent characteristics and its incorrect application, as well as low access to water resource in pistachio regions. Therefore under the current critical condition, basic development of pressurized irrigation systems is an effective step to raise water use efficiency in the pistachio orchards. In this research, two irrigation systems including conventional surface drip irrigation and subsurface drip irrigation (SDI) with two drip line depths (30cm and 50cm) with three levels of water irrigation in each treatment, including 40%, 60% and 80% of irrigation requirement of pistachio in surface irrigation system (2932, 4398 and 5864 m3/ha.year respectively) for four years, was studied. Growth and yield factors, water use efficiency (WUE) and water and salinity distribution in root zone were measured. The results indicated that 30cm installation depth was the best treatment. Between irrigation systems, amounts of 60% and 80% irrigation requirement don't have significant difference, but 40% irrigation requirement treatment, affected negatively on most of evaluated factors significantly. Therefore with regard to all evaluated factors in this research, subsurface drip irrigation with buried drip line at 30cm and 60% of irrigation requirement of pistachio in surface irrigation system, with water use efficiency of 0.290kg/m3 and 25% water saving in comparison with surface drip irrigation system, was the best treatment and recommended.
M. Jolaini; H.R. Mehrabadi
Abstract
Given the scarcity of water resources using modern methods of irrigation in agriculture will be inevitable. Today, process improvement, development and use of drip irrigation practices as one of the most advanced methods of irrigation in agriculture is increasing. So this study was conducted to determine ...
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Given the scarcity of water resources using modern methods of irrigation in agriculture will be inevitable. Today, process improvement, development and use of drip irrigation practices as one of the most advanced methods of irrigation in agriculture is increasing. So this study was conducted to determine the impacts of irrigation interval and drip irrigation method and their interactions on yield, water use efficiency and quality characteristic of cotton in Kashmar Agricultural Research Station, Khorasan Razavi Province. The study was carried out during 2006-2008. Experimental design was a completely randomized design with four replications. Treatments were included irrigation intervals (2, 4 and 6 day) and drip irrigation methods (surface and subsurface drip irrigation). The results showed that the irrigation methods had significant effect on Yield and Water Use efficiency (P≤ 0.01). There was significant difference between yield in surface and subsurface drip irrigation that was 3074 and 3988 kg/ha, respectively. Water use efficiency was 0.349 kg/m3 in subsurface drip irrigation that was greater than surface drip irrigation. The highest yield and water use efficiency in drip irrigation and subsurface irrigation 4 days, 4315 kg/ha and 0.375 kg/m3 respectively and the lowest with 2 days 3107 kg/ha and 0.265 kg/m3, respectively. Yields in irrigation intervals of 2, 4 and 6 days were 3491, 3725 and 3364 kg/ha, respectively, with no significance difference. The highest water use efficiency and yield were obtained in subsurface irrigation method with 4 days interval as 4315 kg/ha and 0.375 kg/m3 respectively, while the least water use efficiency and yield was obtained in surface irrigation method with 2 days interval as 3107 kg/ha and 0.265 kg/m3, respectively. Finally, using subsurface drip irrigation with irrigation every 4 days was chosen as the best treatment.
