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 ...
Read More
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.
hossein dehghani; Hamidreza Haji Agha Bozorgi; ali asghar ghaemi
Abstract
Introduction: Creating a uniform and adequate moisture in the root zone is one of the most challenging issues in irrigated lands. Use of irrigation systems with high water efficiency, such as sub-surface drip irrigation is recommended as a solution to reduce water losses. Information on soil ...
Read More
Introduction: Creating a uniform and adequate moisture in the root zone is one of the most challenging issues in irrigated lands. Use of irrigation systems with high water efficiency, such as sub-surface drip irrigation is recommended as a solution to reduce water losses. Information on soil moisture variation is an important factor for managing and designing a subsurface drip irrigation system. This study was conducted to evaluate the soil moisture variation for different irrigation regimes in a pistachio orchards equipped by a subsurface drip irrigation system (SDI).
Materials and Methods: This study was carried out in a two-hectare of 10 years old pistachio orchard located in Semnan province, Iran ( located at 35°28ˊ N, 53°12ˊE and elevation of 1160 m above sea level) during the 2012-2013 growing season. The climate of the studied area is hot desert having an average annual precipitation of approximately 110 mm. Daily meteorological data such as the temperature, relative humidity, wind speed, rainfall, and solar radiation were collected from a meteorology station in farm. The soil was sandy loam textured with average field capacity and permanent wilting point of 12.23 and 5.01%, respectively. Subsurface drip irrigation system was equipped by EuroDrip Company emitters (PC2), inline, to a distance of 80 cm and with a discharge of 26.2 Lit/ hr installed at a depth of 40 cm. In this study, a factorial experiment in split plot design was used with three replications. Three irrigation treatments i.e. control (I1), Irrigation based on irrigation requirement (I2) and I2 plus leaching requirement (I3), and changes in the moisture front were investigated by weight sampling between two drip lines, between the trees rows, on the drip line and out of the drip line of each row, before and after irrigation and in development, middle and late season.
Results and Discussion: For the evaluated irrigation systems, increased levels of irrigation regime resulted in increased moisture content in the root zone. The higher average soil moisture (16.6 %) was measured after irrigation under I3. The I1 irrigation regime did not significantly change the soil moisture content in upper part of emitters before and after irrigation event. Average soil moisture content at different depths showed that the soil moisture content in 75 soil depth was significantly higher than that in 25 and 50 cm soil depth, which can be attributed to higher root water uptake by root in 0-50 cm soil depth. Bilateral impact of irrigation regimes and soil depth showed higher soil moisture content (19.3%) under I3 and 75 cm soil depth which may lead to deep percolation. Bilateral impact of irrigation regimes, soil depth, and time before and after irrigation event also resulted in higher soil moisture content (22.5 %) in 75 cm soil depth after irrigation under I3. The lowest soil water content (10.5 %) was measured in 25 soil depth before irrigation under I1.
Conclusion: The results of this study showed that I2 and I3 irrigation regimes did not show water shortage during growth season (before and after irrigation), but the I1 irrigation regime caused water scarcity. Therefore, the formation of continuous moisture profiles with low moisture in I1 irrigation regime was caused as a result of low irrigation during this period. Accumulation of moisture at depth of 50-75 cm from the soil surface, even under low irrigation conditions I1 irrigation regime, implies that irrigation time is not suitable for irrigation regimes. In general, in order to improve the irrigation management, it is necessary to reduce the irrigation intervals and have a more appropriate distribution of moisture in the soil profile.
Mohammad Jolaini; mohammad karimi
Abstract
Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. ...
Read More
Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. Several studies showed that drip irrigation is an effective method for enhancing potato yield. Fabeiro et al. (2001) concluded that tuber bulking and ripening stages were found to be the most sensitive stages of water stress with drip irrigation. Water deficit occurring in these two growth stages could result in yield reductions. Wang et al. (2006) investigated the effects of drip irrigation frequency on soil wetting pattern and potato yield. The results indicated that potato roots were not limited in wetted soil volume even when the crop was irrigated at the highest frequency while high frequency irrigation enhanced potato tuber growth and water use efficiency (WUE). Though information about irrigation and N management of this crop is often conflicting in the literature, it is accepted generally that production and quality are highly influenced by both N and irrigation amounts and these requirements are related to the cropping technique. Researches revealed that nitrogen fertilizers play a special role in the growth, production and quality of potatoes.
Materials and Methods: A factorial experiment in randomized complete block design with three replications was carried out during two growing seasons. Studied factors were irrigation frequency (I1:2 and I2:4 days interval) and nitrogen fertilizer levels (applying 100 (N1), 75 (N2) and 50 (N3) % of the recommended amount). Nitrogen fertilizer was applied through irrigation water. In each plot two rows with within-and between-row spacing of 45 and 105 cm and 20 m length. The amount of nitrogen fertilizer for the control treatment was determined by soil analysis (N1). In all treatments, nitrogen fertilizer applied in 5 times until flowering stage. Potassium, phosphorus and microelements applied according to the soil analysis results. The subsurface drip tape was used for irrigation. Tapes with 300 µm thickness, 30 cm dripper spacing and 4 lit/hour discharge were applied. Tapes buried at 20 cm soil depth before planting. Water amount was measured by the volume meter at each irrigation treatment. Water amount calculated based on crop water requirement and plot area and irrigation frequency. On maturity stage, 8 m of two central rows of each plot harvested for determining tuber yields. Water use efficiency was calculated as the ratio of the tuber yield to the total consumed water volume. Statistical analysis was performed using MSTAT-C software. Means were compared by Duncan's multiple range tests at 0.05 and 0.01 significant levels.
Results Discussion: Results of combined analysis showed that yield and water use efficiency (WUE) did not affected by irrigation frequency. Yield and water use efficiency affected by nitrogen level (p
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 ...
Read More
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 ...
Read More
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.
