Irrigation
M. Emadi; M. Noshadi; A.A. Ghaemi
Abstract
Introduction: According to expantion of urbanization, it is necessary to create green space as the most important environmental factor in moderate cities. However in recent decades, shortage of water resources is one of the problems facing the expansion of green space especially grass type. Therefore, ...
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Introduction: According to expantion of urbanization, it is necessary to create green space as the most important environmental factor in moderate cities. However in recent decades, shortage of water resources is one of the problems facing the expansion of green space especially grass type. Therefore, the application of management methods such as deficit irrigation is very important. Development of green space requires sufficient water supply and according to the climatic conditions of our country, finding alternative methods and resources for effective irrigation and utilizing all available capacities is one of the main goals of municipalities and water organizations.
Materials and Methods: This research was performed in a greenhouse with an area of 120 square meters located in the college of Agriculture of Shiraz university with longitude 52032’, latitude 29036’,1810 height above sea level, and in flower pots with dimensions of 30 * 30*30 in order to investigate the effect of water stress in the traditional irrigation method on morpho-physiological factors and water productivity in two variety long grass. The research was in the form of split plots based on a random full canton with three replication and three levels (%100 per) (w1), (%75 per) (w2), (%50 per)(w3) of water requirement. The grass used in this design is Festuca, arundinacea Schreb with two variety named Asterix and Talladega which are considered as cold grasses and has a root depth of 15-20 cm. The first 3 cm of sand (to create drain conditions) was placed in the bottom of the flower pot, and then 24 cm of soil was poured on it and compacted until it reached the required density. On April 10, two variety of grass seeds were poured manually on the pots (10 grams of seeds per pot). Then, 100 gr of rotten and screened animal dung was poured on the seeds in each flower pot and irrigated with a hose by a traditional (manual) system. Early cultivation was done manually due to the application of more water and the establishment of grass. In this way, every day for a week, two to three times irrigation and after the seeds germinate (10 days after cultivation), once-daily irrigation and until the seeds germinate completely (20 days after cultivation), the irrigation period was once between 7 until 15 days, and then water stress was imposed. The first grass mowing was done after the grass was completely established (30 days after cultivation). Also, in order to compensate for the shortage of nutrients in the soil after two months (July) 6 gr /m2 of urea fertilizer (0.54 gr/ m2 to each flower pot) was applied. The onset of stress was two months after cultivation (July 10), and the duration of stress was 45 days. To determine the water requirement a separate flowerpot among the other flowerpots was located, and provide the moisture to FC level. Every other day, the water lost by this flower pot compared to the initial weight (FC), the same amount of water was given to the flowerpots with 20% more as for the leaching requirement.
Results and Discussion: Analysis of experimental data was performed by SAS 9.4 statistical software, and Duncan’s multiple range experiments at 5% level were used to compare the means, at the level of 5% probability. Results and data analysis was investigated under water stress in two varieties.
Dryness stress and water use efficiency: Water productivity in both varieties of grass and in different irrigation treatments did not change significantly at 95%. So decline in the amount of irrigation water has not affected water productivity.
Interaction of dryness and grass quality: The results showed that water stress and the interaction of water stress and grass variety on the appearance quality of grass were not significantly different at 95% and in the second ten days of August, the appearance quality was more desirable than in the first half.
Interaction of dryness and relative leaf water content of leaf: The relative water content of the leaf was weekly measured during the stress period. The results of comparing the mean relative water content (RWC) of leaf under water stress in two types of Festuca grass showed that the effect of water stress interaction was significant in Asterix grass variety on the relative water content of leaf at 95% level. The relative water content of the leaves is a good index of the water situation of the leaves, and its reduction in the leaves causes wilting and reduces the freshness and appearance quality of the grass and reducing the relative water content of the leaf has not affected the appearance quality of the grass.
Interaction of dryness and leaf growth rate: The leaf growth rate was measured during the stress period (monthly) in three ten-day periods (August). The results of comparing the means showed that the effect of water stress interaction and two variety of grasses on leaf growth rate was not significant during the first ten days. In the second ten days, the effect of water stress was significant in both Asterix and Talladega grass and growth rate in irrigation treatments of 75 and 50% (percentage) of full irrigation was significantly different from full irrigation.
Conclusion: The results of this study showed that deficit irrigation could increase water use efficiency without reducing the quality of green cover. With less water consumption (half full irrigation), the appearance quality of the grass will be well maintained. The relative water content of the leaf decreased as dryness stress progresses and causing changes in the cell membrane and thus increasing electrolyte permeation from the cell. Considering that dryness stress has not reduced the appearance quality of the grass, reducing the relative water content of the leaf has not affected the appearance quality of the grass. Generally, the growth rate in all three decades was maximum in dryness stress 75% (percentage), which indicates the high photosynthesis of the plant in this stress.
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 ...
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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.
hossein dehghani; Hamidreza Haji Agha Bozorgi; ali asghar ghaemi
Abstract
Introduction: The main problem of salinity, in addition to reducing agricultural and horticulture products is the gradual decline of their cultivation area. Several factors such as climate and irrigation (precipitation, fraction of leaching), soil type and soil salinity, salinity of irrigation water, ...
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Introduction: The main problem of salinity, in addition to reducing agricultural and horticulture products is the gradual decline of their cultivation area. Several factors such as climate and irrigation (precipitation, fraction of leaching), soil type and soil salinity, salinity of irrigation water, uniform distribution of the system and irrigation with saline water affects the soil salinity changes. Therefore, in irrigated agriculture, soil salinity should be reduced and controlled to an optimal level of the economic production. Leaching with proper irrigation management is one of the effective ways to reduce soil salinity.
Materials and Methods: The study was conducted during 2012-2013 in as pistachio garden located in the Safaeieh region of Semnan province. The garden was 100 ha and 2 ha of that was selected for this study with 10 years old pistachio trees equipped to subsurface drip irrigation system. The treatments of this study were three irrigation regimes; control (I1), Irrigation based on irrigation requirement (I2) and I2 plus leaching requirement (I3), three soil depth of 25, 50, and 75 cm from soil surface and time before and after irrigation. The drip line laterals include emitters with 2.26 lph flow rate was buried in 40 cm soil depth. Soil samples to evaluation salt concentration were collected from 25, 50, and 75 soil depth before and after irrigation. To study the impact of different irrigation regimes, soil depth and time (before and after irrigation) and also their bilateral impact a factorial design in randomize block was applied.
Results and Discussion: The results showed that ECe and SAR accumulation decreased after development, growth stage and continued to end growth stage. The results showed that I2 and I3 irrigation regimes were more effective in reducing the amount of sodium from the root zone and the I2 irrigation regime showed better performance in comparison to I3 irrigation regime. Regarding the amount of magnesium in the soil, the I2 irrigation regime was more successful than the I1 and I3 regimens. In I1 irrigation regime, the amount of magnesium at the end growth stage increased compared to the beginning growth stage. Significant decrease in ECe level at the end growth stage compared to the beginning growth stage belonged to the I2 irrigation regime, which suggests that I2 irrigation regime was more successful in ECe leaching during the period of pistachio growth, which attributed to the potential for leaching from the soil surface to the depths below the soil surface. The results showed that excessive water application under saline conditions for any reason, such as leaching not only does not have a beneficial effect on the removal of salts from the root zone, but also may lead to accumulation of salts and damage to the plant. The highest amount of calcium in the soil was recorded 98 days after the first irrigation under the I2 and I3 irrigation regimes which was 52.5 and 58.1 Meq/l, respectively. The lowest amount of this element The I1 and I2 regimens were 40.8 meq/l, respectively, which were recorded in 152 days after the first irrigation. In terms of SAR, the lowest value in the I2 regime was more noticeable than other irrigation regimes. The effects of soil depth of time after the first irrigation showed that there was no significant difference at the depth of 25 cm and 75 cm at the end growth stage compared with the valued recorded in beginning growth stage, but at a depth of 50 cm there was a significant reduction in ECe. The highest ECe value equaled to 14.5 dS/m was recorded at a depth of 75 cm in 98 days after first irrigation. In the I1 irrigation regime at all three depths of 25, 50 and in the I3 irrigation regime at a depth of 75 cm the amount of SAR at the end growth stage were not less than that in beginning growth stage, however, the reduction in SAR was recorded in the I2 irrigation regime at all three depths.
Conclusions: Irrigation regime I2 was successful to control the SAR in different soil depth compared to the other two irrigation regimes, which is very important for the next irrigation season to moderate the harmful effects on blossoms. Moreover, it is suggested that in a field, equipped with a subsurface drip irrigation system, leaching water at the end of the season by surface irrigation or heavy subsurface drip irrigation during the rainfall to leach out the accumulated salt to lower soil layers.
ali asghar ghaemi; B. Zamani
Abstract
Introduction: Barley is very important to feed humans, livestock, medical, industrial uses, especially in fermentation industries. In Iran, barley crop cultivation was nearly 1.4 million hectares withits production of 1.3 million tons in 2003 (2). Barelyis the oldest crops to environmental stresses such ...
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Introduction: Barley is very important to feed humans, livestock, medical, industrial uses, especially in fermentation industries. In Iran, barley crop cultivation was nearly 1.4 million hectares withits production of 1.3 million tons in 2003 (2). Barelyis the oldest crops to environmental stresses such as drought and salinity resistance (3).The different barely growth stages with extreme water requirement can benoted in germination stage, stem elongation, heading the production stage, the stage of flowering and seed production. Typically, for spring and autumn barely respectively 3 and 4 to 5 times irrigation is done during the growing season. The barley water requirement over its life is between 4 and 7 thousand cubic meters and 518 liters of water is needed to produce one kilogram of dry matter. Due to limited water resources and low rainfall in Iran, efficient use of water is absolutely essential and the maximum water utilization must be achieved by applying a minimum amount of water in agriculture. One of the ways to increase productivity in agricultural water is deficit irrigation.Deficit irrigation is an optimization strategy for water use efficiency in irrigation.The purpose of this study was to evaluate the simultaneous effect of fertilizer treatments (150, 225 and 75 kg/ ha) and water at three different levels (100%, 75% and 50% of crop water requirement) at different growth stages on leaf area index, weight fresh and dried herb and plant nitrogen concentration and the effect of irrigation and nitrogen fertilizer on yield, yield components and productivity of water use.
Materials and Method: This research was conducted in Shiraz University in fall 2012 to study the effect of interaction of deficit irrigation and nitrogen fertilizer on yield, yield component and water use efficiency and nitrogen concentration in different stages of barley (Bahman species) growth. This experiment were evaluated using a randomized complete block design with s plit-plot layout with three deficit irrigation treatments ( consisted of irrigation with 100% ,75% and 50% of crop water consumption use) and three nitrogen fertilizer treatments (included 75 kg/ha, 150 kg/ha and 225 kg/ha) with three replication. A total of 27 experimental plots were carried out. In each plot, 11-row barley with 30 cm spacing apart and 5 cm depth were planted by hand. Barley seeding rates on the basis of 200 kg per hectare were planted in each experimental plots in the first half of November.Nitrogen requirement was applied in three stages of the growth: 30% before cultivation, 40% in shooting stage and 30% in barleyclusterstage.Irrigation treatments included 100% = W1, in this treatment 100% treatment crop water requirement was estimated by neutron meter (this was the control treatment which received muchwater as neededand no water stress in all growth stages),75% = W2: in this treatment 75% of the crop water requirement was applied, and 50% = W3: the 50% of the crop water requirement plant was applied. During differentgrowth stages plant required data were collected and the parametersinclude: grain yield, biological yield, straw yield, number of grains per spike, spike per unit area, grain protein, harvest index, 1000 grain weight, number of unfilled and filled grain per spike and efficiency of water use were determined . Tests to determine the percentage of leaf nitrogen and protein was measured by kjeldahldevice(6405UV / VIS). The software SAS (version.9.1) was used to analyze data and graphs were drawn in Excel.
Results and Discussion: results showed that the highest yield,yield component was obtained on 100% irrigation and 225 kg/ha fertilizer treatments. Also it was observed that at the certain level of irrigation treatment by increasing the amount of nitrogen fertilizer the amount of this parameters will be increased.Result also showed that at the certain level of nitrogen fertilizer by decreasing water, the maximum plant response to the nitrogen fertilizer consumption will be decreased gradually in most cases, 225 kg/ha nitrogen fertilizer treatment caused most of crop yield parametersbut the differences of crop yield at this treatment with 150kg/ha nitrogen fertilizer treatment wasnot significant. Water use efficiency for 50% deficit irrigation treatment was 0.77 and for 100% irrigation treatment was 0.55. Regarding the results obtained from this study andexisting water crisis problem in Iran, it can be noted that the irrigation ofbarley should not be exceeded more than the 100% of crop water consumption use but using 75% of water requirement is suggestive. Also using 150kg/ha nitrogen fertilizer treatment is more suitable for the area.
Conclusion: This study was conducted in order to determinethe yield performance of barley (Bahmanspecies)inBadjgah (Fars Provience)using three different irrigation treatments of 100, 75 and 50 percent of crop water requirement (based on the total available water plant) and three nitrogen treatments include 225, 150 and 75 kg/ ha in the spring and autumn cultivation. In terms of deficit irrigation, during the growing season crop will interface with different intensities and durations of water stress. This tension changes in response to nitrogen fertilizer by plant that creates unpredictable and in some cases is not always the same.Statistical analysis showed that there are significant differencesbetweenthe different treatments of irrigation, nitrogen fertilizer and their interaction.Applying 75% of barley water requirement is suggestive. Also using 150kg/ha nitrogen fertilizer treatment is more suitable for the study area.
A. Atefi; ali asghar ghaemi
Abstract
The aim of the present research is to study the effect of both different irrigation water quality (treated wastewater and urban water) and N. P. K fertilizer via Tape subsurface micro irrigation on the soil chemical properties in the test area was investigated in Fras Bajgah Region in 2010. In this study, ...
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The aim of the present research is to study the effect of both different irrigation water quality (treated wastewater and urban water) and N. P. K fertilizer via Tape subsurface micro irrigation on the soil chemical properties in the test area was investigated in Fras Bajgah Region in 2010. In this study, the impact of treated Shiraz urban wastewater under micro irrigation in broccoli cultivation on the soil chemical properties was evaluated. According to the results of this research, Electrical Conductivity to a depth of 30 cm of soil was increased significantly due to irrigation with wastewater and irrigation fertilizer comparing to urban water. Also, using wastewater increased pH in surface layer of soil. Although, considering the buffer wastewater and soil environment and its resistance to ph variations, there was little increase. Moreover, the treatment containing the wastewater was led to increase Sodium Absorption Ratio (SAR) in the surface layer of soil. However, this effect was more in treatments which that have benefited the fertilizer and wastewater. Also, variations of Bicarbonate , Sulfate and accumulation B , sodium;Na, ferro;Fe, zinc;Zn, copper;Cu, potassium;K and magnesium;Mg, to a depth of 30 cm of soil and also the accumulation of nitrogen, calcium, phosphorus in the depth of soil in an area under studying was increased significantly due to irrigation with wastewater and irrigation fertilizer comparing to urban water. As expected, using the wastewater increases the concentration of heavy metals of nickel, lead and cadmium in under studying soil area.
A.A. Ghaemi; Z. Mahdi Hossein abadi; A.R. Sepaskhah
Abstract
Abstract
Microirrigation has the potential to minimize water droplet evaporation and wind drift losses associated with sprinkler irrigation, improving the irrigation control by frequent applications, providing the needed nutrients for crops through the system, minimizing deep percolation and improving ...
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Abstract
Microirrigation has the potential to minimize water droplet evaporation and wind drift losses associated with sprinkler irrigation, improving the irrigation control by frequent applications, providing the needed nutrients for crops through the system, minimizing deep percolation and improving crop yield. This study was conducted to evaluate sugar beet yield under conventional and alternate tape and furrow irrigation. The sugar beet pp22 was cultivated with 0.3 m row spacing. There were four treatments of tape irrigation (tapes from Iranian and foreign manufacturers) and two treatments of furrow irrigation. In each treatment four rows of sugar beet were grown. Alternate and every row irrigation was applied for both tape and furrow irrigation treatments. The amount of water used, irrigation application efficiency (Ea), water use efficiency (WUE), coefficient of uniformity (CU) of applied water and fertilizer in tape irrigation, white sugar percentage, gross sugar percentage, root yield, white sugar yield, gross sugar yield, the WUE of root yield, and the WUE of white sugar and gross sugar were assessed in a field experiment near the College of Agriculture of Shiraz University. The results showed that the amount of water used in tape irrigation treatments was 50 percent less than furrow irrigation treatments. The average Ea of tape and furrow irrigation was 90.7% and 52%, respectively. The CU of Iranian and foreign tape was 97% and 98%, while the CU of applied fertilizer was 97.5% and 94.5%, respectively. The highest white sugar percentage was found in alternate tape irrigation; however, the highest gross sugar percentage belonged to alternate furrow irrigation treatment. The highest root yield was obtained from Iranian tape irrigation treatment of all rows. The highest gross sugar yield was found in furrow irrigation; however, there was no significant difference among all treatments for white sugar yield. The amount of water used in tape irrigation was 58% of furrow irrigation, while the highest WUE of root yield, white sugar yield and gross sugar yield was found in the alternate tape irrigation. These values were the least for conventional furrow irrigation.
Key words: Tape irrigation, yield, furrow irrigation, sugar beet,Uniformity coefficient
