Irrigation
M. Zokaee Khosroshahi; K. Parvizi
Abstract
IntroductionWater is a critical factor for the growth and fruiting of the grapevines. Considering the water scarcity crisis in Iran and most parts of the world in recent years, it is necessary to apply methods such as deficit irrigation for the optimal management of water use in agriculture. It has been ...
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IntroductionWater is a critical factor for the growth and fruiting of the grapevines. Considering the water scarcity crisis in Iran and most parts of the world in recent years, it is necessary to apply methods such as deficit irrigation for the optimal management of water use in agriculture. It has been determined that by deliberately reducing water consumption in vineyards, it is possible to preserve the existing water resources and improve the water use efficiency. Materials and MethodsA research was carried out in summer 2023 in a randomized complete block design with three replications on 8-year-old vines of the Turkmen-4 variety, to investigate the effect of deficit irrigation levels on the quantitative and qualitative traits and water use efficiency of grapevines. The vines were planted with 2 x 4 meter intervals, were trained as a vertical trellis on a bilateral cordon system, and the vineyard was irrigated by drip irrigation. The experimental treatments included full irrigation (providing 100% of vine water requirement; as control), 25% deficit irrigation (providing 75% of vine water requirement) and 50% deficit irrigation (providing 50% of vine water requirement). Irrigation of the vineyard started from May 22 and continued until November 6 at 7-day intervals, according to the conventional procedure. The water requirement of each vine in non-stressed condition was calculated by a class A evaporation pan based on reference crop evapotranspiration (ETo) and crop coefficient (Kc) throughout the season. Then, the amount of water for each treatment was determined according to the irrigation levels in the treatments and applied in volume form. Results and DiscussionThe amounts of water consumption of control, 25% and 50% deficit irrigation treatments were 5140, 3855 and 2570 m3 per hectare, respectively. The results showed that irrigation levels had a significant effect on the berries length, berries diameter, cluster length, cluster width, berries weight, cluster weight, sugar percentage, chlorophyll index, relative water content, midday leaf water potential, vegetative growth, vine yield, yield index and water use efficiency. The 25% and 50% deficit irrigation treatments caused a decrease of 7.2% and 14.2% of the berry length compared to full irrigation, respectively. Also, these treatments caused a reduction of 8.3% and 13.9% of the berry diameter, respectively. While the 25% deficit irrigation treatment had no significant effect on the berries sugar content (°Brix), the 50% deficit irrigation treatment caused a significant decrease (5%) in sugar content compared to the control. Both relative water content and midday water potential of the leaves decreased significantly with the reduction of irrigation levels. Reducing the level of irrigation led to a significant decrease in the SPAD index and vine vegetative growth. Increasing the intensity of deficit irrigation had a significant negative effect on yield components including berry weight, cluster weight, vine yield and yield index. The highest and lowest yields were obtained from full irrigation and 50% deficit irrigation, respectively but the effect of 25% deficit irrigation on yield reduction was not significant. Although the 25% and 50% deficit irrigation treatments caused a 5.8% and 27.5% decrease in vine yield, respectively but these treatments increased water use efficiency by 34% and 44.5%, respectively compared to the control. The lowest water use efficiency was related to the control (3.53 kg of fresh fruit per cubic meter of water used), while the water use efficiency of vines under 25% and 50% deficit irrigation was 4.73 and 5.10 kg of fruit per cubic meter of water, respectively. The 25% and 50% deficit irrigation treatments had a statistically significant difference with the control in terms of water use efficiency, but the difference between the two was not significant. ConclusionIn the present study, reducing the volume of irrigation water led to a decrease in vine yield, but what is important is the low yield reduction rate compared to the amount of water consumption. The decrease in vine yield was 5.8% and 27.5%, respectively with a 25% and 50% decrease in water consumption. Also, with 25% and 50% reduction in water consumption, the yield index decreased by 6.1% and 27.3%, respectively. Meanwhile, the water use efficiency of vines increased by 34% and 44.5% in response to 25% and 50% deficit irrigation treatments, respectively. It is recommended to apply 25% deficit irrigation to increase the water use efficiency of Turkmen-4 grapes in climatic conditions of Malayer, but 50% deficit irrigation leads to a decrease in quality of grapes.
Soil science
S. Mohammadi; A. Sepehry; M. Farzam; H. Barani
Abstract
IntroductionThe aim of the present study was to investigate the effect of soil conditioners on physiological responses (stomatal resistance, leaf temperature, chlorophyll, percentage of root colonization, carotenoids, proline) of Lycium depressum Stocks to drought stress. The experiments were performed ...
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IntroductionThe aim of the present study was to investigate the effect of soil conditioners on physiological responses (stomatal resistance, leaf temperature, chlorophyll, percentage of root colonization, carotenoids, proline) of Lycium depressum Stocks to drought stress. The experiments were performed in semi-controlled greenhouse conditions.Materials and MethodsThe experiment was conducted as a factorial experiment based on a completely randomized design including the main factor, irrigation at 4 levels (100, 75, 50 and 25% of field capacity) and the sub-factor of soil conditioners. In each combined treatment, 5 repetitions of irrigation and soil remediation and a total of 160 pots were used. Subsoil treatments including hydrogel and nitrobacter, mycorrhiza and zeolite were added to each pot. 500 cuttings of the target plant were planted in the greenhouse. The grown cuttings were transferred to the pots where the experiments were carried out. At each irrigation level, 40 pots containing 4 kg of vegetation soil of the target species were considered and the agricultural capacity (FC) of the target soil was determined in the soil laboratory. A total of 160 pots were placed in the greenhouse for testing. The main treatment of the experiment included irrigation levels (100, 75, 50 and 25% of the crop capacity) and sub-treatments of soil conditioners including Stacosorb hydrogel in the amount of 3 grams per kilogram of soil in each pot in the lower part of the plant roots. Zeolite with the industrial name of mineral zeolite (Mineral Zeolite) was added in the amount of 8 grams in each pot in the lower part of the root of the plant. Nitrobacter (a collection of strains of Azotobacter sp, Azospirillum sp and Bacillus sp with the brand name Nitrobacter Diane) was added to the amount of 3 cc in each pot in the upper region of the plant roots. Addition of mycorrhiza (the mycorrhiza used in this experiment was Glomus mosseae and was prepared as soil containing mosseae fungi) in the amount of 10 grams per pot in the lower part of the plant roots. After adding soil conditioners, irrigation was done according to the crop capacity in 4 irrigation levels, in the determined treatments.Results and DiscussionMeasurement of physiological characteristics showed different responses in each of the variables. Carotenoid changes in 50% irrigation showed the lowest value (p<0.05) and the control treatment without mycorrhiza showed the highest value in the measurement of chlorophyll and carotenoid at 100 and 75% irrigation levels. The results of measuring colonization percentage, stomatal resistance and leaf temperature showed the lowest value in 25% irrigation. In the control treatment, proline parameters and root colonization percentage increased under the influence of drought stress, and stomatal resistance parameters, leaf temperature and chlorophyll decreased under the influence of drought stress. With intensification of drought stress, chlorophyll and carotenoid contents of the plant increased and the amount of proline decreased in Nitrobacter treatment with mycorrhiza, which was significantly different from the control treatment. In the control treatment with mycorrhiza, with increasing drought stress, the leaf temperature increased and the amount of proline decreased, which was different from the control treatment. Aperture resistance decreased from 48 m2 / mol.s 100% irrigation level to 44 m2 / mol.s 25% irrigation, leaf temperature at 100% irrigation level in mycorrhizal-free hydrogel modifier from 26 ° C Decreased to 21.57 ° C in 25% irrigation, at 100% irrigation level in non-mycorrhizal zeolite modifier the amount of chlorophyll b + a from 0.6 mg / g to 1.20 mg / g in 25% irrigation increased. The amount of carotenoids at 100% irrigation level in zeolite modifier with mycorrhiza increased from 0.1 mg / g to 0.2 mg / g in 25% irrigation in control treatment with mycorrhiza at 100% irrigation level compared to the level Irrigation increased by 50% and root colonization by 1.5%. The amount of proline in mycorrhiza-free hydrogel treatment was measured at 100% 2.77 μmol / g irrigation and at 50% irrigation level 2.66 μmol / g. Reduction of proline at 50% irrigation level indicates that the hydrogel modifier has increased the resistance of Lycium depressum Stocks to drought stress.ConclusionThe results of this study showed that the increase in drought causes changes in the physiological performance of the plant and the use of soil conditioners under drought stress due to the improvement of the physiological parameters, will increase the resistance of the plant by 50%. Nitrobacter treatments without mycorrhiza, hydrogel and zeolite with mycorrhiza and without mycorrhiza, due to further improvement of physiological parameters, is recommended to plants in nature.
A. Firoozi; seyed majid mirlatifi; Hamed Ebrahimian
Abstract
Introduction: Agriculture consumes a large portion of groundwater resources. In order to understand the status of groundwater resources in a basin and to optimize its management, it is necessary to carry out an accurate examination of the fluctuations in the groundwater levels. Recharging groundwater ...
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Introduction: Agriculture consumes a large portion of groundwater resources. In order to understand the status of groundwater resources in a basin and to optimize its management, it is necessary to carry out an accurate examination of the fluctuations in the groundwater levels. Recharging groundwater aquifers is one of the main strategies for water resources management which its accurate estimation plays a crucial role in the proper management of ground water resources. That portion of the excess irrigation water which becomes in the form of deep percolation should not be considered as wasted water, if its quality is not adversely reduced and it enters and recharges groundwater aquifers. The question is whether deep percolations resulting from irrigating farms with low application efficiencies and poor irrigation management in the Urmia basin would finally recharge ground water aquifers or not. In order to provide a solution to the aforementioned question, after calibrating HYDRUS-1D model, it was used to estimate the fluctuations of the levels of the water tables as a results of irrigations or rainfalls in a number of wheat, barley and sugar beet fields located in Miandoab and Mahabad regions where all agricultural practices were managed and carried out by the local farmers.
Materials and Methods: In order to ascertain the effects of irrigation on the groundwater recharge, the required field data was collected from nine agricultural fields including one wheat farm, three barley farms, and three sugar beet farms, all located in the Miandoab region and two wheat fields located in the Mahabad region. All the water balance parameters for each one of the fields were measured in the studied fields, including the depth of irrigation at each irrigation event by using WSC flumes. The Surface runoff from the studied farms was considered as negligible, since all the fields were irrigated using closed end borders. The evapotranspiration of wheat, barley and sugar beet were calculated in the regions using the CROPWAT8.0 model.
The soil texture of each of the study fields were determined by hydrometric method in the laboratory and then soil hydraulic parameters were estimated by ROSETTA model. The soil moisture of all the fields during the growing season were measured using a PR2 moisture meter instrument measuring soil moisture at various depths up to 105 cm below the soil surface. The amount of deep percolation occurring during the growing season was simulated by the HYDRUS-1D model. The soil water content measured by PR2 (Delta-T Device) probe were used for HYDRUS-1D model calibration and validation using the inverse solution method. Because of the occurrence of rainfall, irrigation and evapotranspiration, the atmospheric boundary condition was selected as the upper boundary condition and free drainage was considered as the lower boundary condition in order to estimate the groundwater recharge, assuming that water passes through and below the root zone. In areas with shallow ground water depth, constant flow with zero flux was chosen as the lower boundary condition in order to determine the fluctuations of the ground water level. Since the groundwater level in this case study was shallow, zero flux was considered as the lower boundary condition. The soil moisture content before irrigation was selected as the modelling initial condition.
Result and Discussion: The HYDRUS-1D model was calibrated by comparing the model estimated soil moisture contents with the corresponding measured values which indicated the coefficient of determination (R2) and root mean square error (RMSE) values ranging from 0.6 to 0.85 and 0.17 to 0.033 (), respectively. Another set of measured soil moisture data which was collected by using PR2 instrument and was not used for calibrating the model, was applied to verify the model simulation of the soil moisture content. Comparing the measured and simulated soil moisture contents at this verification stage resulted in coefficient of determination (R2) and root mean square error (RMSE) values ranging from 0.62 to 0.88 and 0.002 to 0.023 (), respectively. There was no significant difference between the predicted and measured soil moisture data in all the fields (P-value> 0.05). The minimum and the maximum coefficient of determinations in the validation stage were obtained in the T5 field with a silty loam soil and in the H3 field having a sandy loam soil. The accuracy of the model performance after it was calibrated and verified using the collected field data, was appropriate for estimating the soil water content during the growing season. The model was used to simulate the soil water contents from the soil surface to the depth of the water table during the growing season to evaluate the degree of aquifer recharge if any happened. The soil moisture front advanced to a depth of 0.7 m below the soil surface in the M1 field and to 4.7 m in the T1field. The amount of groundwater recharge varied from field to field depending on each field’s soil type, cultivation and irrigation management including the depth and the time of the irrigations. The amount of groundwater recharge increased by decreasing crop evapotranspiration. The percentage of ground water recharge in N1, M1 and M2 fields due to limited availability of water resources which resulted in deficit irrigation was very low. The irrigation water requirements estimated by the CROPWAT model for the aforementioned fields were more than the depths of the irrigation water applied by the farmers. The CROPWAT model estimated the irrigation water requirements during the growing season for wheat, barley and sugar beet in the Miandoab region to be 308, 273 and 736 mm, respectively. However, the depths of irrigation applied to such farms ranged from 306 to 500 mm.
Conclusion: This research was conducted to ascertain the effects of local farmer’s irrigation management practices considered as poor management in some areas with plenty of water resources available and rainfall on the amount of the groundwater recharge occurring in the regions studied located in the Lake Urmia basin. The simulated groundwater recharge by the HYDRUS-1D model indicated that the amount of recharge varied from field to field depending on soil type, cultivation and irrigation management practices. In all the fields, the highest amount of groundwater recharge occurred when the crop evapotranspiration was low and therefore, enhancing deep percolation to take place. The highest percentage of groundwater recharge was 28% of the sum of the irrigation and rainfall depths which occurred in the barley field (H3).
tahereh raiesi; bijan moradi; Behruz Golein
Abstract
Introduction: Citrus is the main fruit group grown in tropical as well as sub-tropical climate of more than 150 countries in the world. In Iran, the total area under citrus crops is 0.284 M ha with a production of 4.345 M ton and a productivity of 17 ton per ha. Citrus is also one of the most important ...
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Introduction: Citrus is the main fruit group grown in tropical as well as sub-tropical climate of more than 150 countries in the world. In Iran, the total area under citrus crops is 0.284 M ha with a production of 4.345 M ton and a productivity of 17 ton per ha. Citrus is also one of the most important horticultural products in Mazandaran, with 112,000ha devoted to its cultivation. Drought stress is frequent in Iran and is common in the dry summer periods in Mazandaran. Therefore, irrigation is essential during mentioned periods in this province. Irrigation scheduling and water requirement of the citrus crops are one of the main concerns of the citrus fruit production. Irrigating based on soil water potential (tensiometer) is one of the irrigation scheduling methodologies. In addition, fertilization is used to promote quantity and quality of fruit production. Potassium has a key role in the osmotic adjustment of plants and alleviate the effects of drought stress. Until now, studies on citrus to evaluate the effects of potassium fertilization to mitigate the negative effects of drought stress have not been conducted. In the present study, we hypothesised that K applications via soil could contribute to osmotic adjustment of citrus and alleviate the effects of drought stress. Thus, the objective of the present study was to evaluate the effects of different soil water potential and rate of potassium (K) application on biochemical indices and growth responses of Thomson navel (Citrus, sinensis (L.) osbeck) orange seedlings on Citrumelo rootstock.
Materials and Methods: This study site was located at the Citrus and Subtropical Fruit Research Center of Horticultural Science Research Institute (36°54′11″N, 50°39′30″E), with a mean annual rainfall of 1200 mm. Thomson navel trees (Citrus, sinensis (L.) were planted at 7 × 6m distances. Soil had a pH (soil-to-water suspension ratio of 1:2) of 6.2 and contained 14.3 g kg−1 organic C and CaCO3<1%. The texture of soil was clay loam. A two-year field study was conducted in a factorial experiment based on randomized complete block design with four selected ranges of soil water potential, two levels of K application, and four replicates. Irrigations were scheduled using soil moisture tensiometers. The irrigation treatments were scheduled when soil water tensions reached 20, 40, and 60 kilopascal (kPa) on the tensiometers per treatment and results were compared with control (none irrigation) treatment. Soil water tensions of 20, 40, and 60 kPa correspond to soil water depletions of 17, 35, and 52%, respectively, of the available soil water for the studied soil. Levels of K fertilizer were 50 (k1) and 100 (K2) g K × age of tree. Potassium fertilizer was broadcast below the tree canopy in March. At the end of each year, yield, available K and some growth indices were measured. In addition, in the last year, proline, ionic leakage and electrical conductivity were also measured. All data were represented as mean of four replicates. Differences in yield, canopy diameter and available K among fertilizer and irrigation treatments and sampling years were analyzed using general linear model two-way analysis of variance (ANOVA) in SAS 9.1. Since the mentioned attributes were measured during two years to take into account annual variation, we used ANOVA procedure for a combined analysis of data. The significance of differences between the mean of treatments were determined by using Duncan test. All the statistical analyzes were performed by SAS 9.2.
Results and Discussion: The results showed that irrigation increased the canopy diameter (P<0.05). Under K1 application, the tree yield was not significantly different (P≥0.05) between irrigation at different water potentials (I1, I2 and I3). However, the K effects on tree yield depended on soil water potential and the positive effects of K2 application were evident only in the I2 and I3 treatments. However, K2 application reduced the yield in irrigation treatments including I0 and I1 significantly (P<0.05) compared with K1 application. In addition, the results of the last year showed that proline and ionic leakage were increased (P<0.05) by reduce of water potential in irrigation time. However, double application of K (K2) increased (P<0.05) proline and decreased ionic leakage as compared with normal application of K (K1). Moreover, available K and electrical conductivity were increased (P<0.05) by excessive application of K and reduce of soil water potential.
Conclusion: In summary, regarding this experiment, irrigation at 60 kPa (depletion coefficient =52%) and potassium application rate of 50 g K × age of tree was the best treatment.
fateme fathi; Mohammad reza Nori Emamzadeie; ahmad reza ghasemi; Masoud Ghasemi Ghahsareh
Abstract
Introduction: One of the methods of increasing the water use efficiency is the application of water absorbent materials in Soil. Super absorbent polymer increases the water saving in soil and decreases the amount of water used for irrigation. By developing paths in public places creating green wall is ...
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Introduction: One of the methods of increasing the water use efficiency is the application of water absorbent materials in Soil. Super absorbent polymer increases the water saving in soil and decreases the amount of water used for irrigation. By developing paths in public places creating green wall is very common. Green wall may have an efficient role in reducing cooling and heating energy of building and improving the thermal performance also it leads to biodiversity, reducing noise pollution and air pollution by absorbing CO2, dust and heavy metals. Irrigation requirement in green wall depends on the type of system, plant and climate condition. The plant used in this research was Osteospermum. The benefits of irrigation of capsule clay can be attributed to increase irrigation efficiency, yield and quality indices of products, the abundance of raw materials to make it and the lack of dependence on the currency for the pottery production Also simple and native technology doesn’t need power, reduced energy consumption and pests, diseases and weeds, thereby reducing the consumption of chemical pesticides insecticides, fungicides and herbicides, and the possibility of producing a healthier product, especially in cultivation. The other advantages of the greenhouse products are maintaining soil, preventing traps and the possibility of deploying in arid and semi-arid areas.
So far, many researches about application of superabsorbent polymer have been done increasing the water use efficiency, irrigation interval and production yield but there has been no research conducted on drip and capsule irrigation in green wall. Two methods of drip and capsule irrigation compared with current irrigation methods in the green wall and polymer to reduce the number of irrigation steps was used due to lack and importance of water and introduction of capsule irrigation method as a new method of irrigation in the green wall in order to facilitate the implementation of irrigation system.
This study was conducted in order to compare capsule and drip irrigation along with different levels of polymer on Osteospermum plant.
Materials and Methods: This research was done in Shahrekord University. The experiment region has a semi-arid climate. The study was carried out as a factorial experiment in the form of completely randomized design with 8 treatments and 4 replications. Treatments were consisting of two types of drip and capsule irrigation and four levels of super absorbent polymer consist of zero, 0.3%, 0.6%, 0.9%. The experiment was done in pots. In order to simulate planting conditions circumstance with green wall, a shelf with four floors and 8 pot capacity in each floor was made from iron. The shelves were embedded so that the plant had a proper and identical condition in terms of growths, receiving light and irrigation. In this study the analysis of obtained data was accomplished with SAS software and for average comparison the LSD test at 5 percent level was used.
Results and Discussion: The results of analysis of variance showed that clay capsule and drip irrigation with different levels of superabsorbent polymer have a positive and significant effect on water use efficiency, relative water content, total chlorophyll and growth indices of Osteospermum. The results also showed that fresh and dry shoot weight, leaf area, mean shoot length and relative water content are related to the treatment of 0.6% polymer in drip irrigation and maximum flowering therewith water use efficiency is related to 0.6% polymer in capsule irrigation. The treatment of 0.9% polymer in capsule irrigation had the highest root length and chlorophyll content. Water use efficiency in capsule irrigation (2 kg/m3) was higher than drip irrigation (1.8 kg/m3).
Conclusions: The results showed that using capsule irrigation in green wall is applicable, despite its limitations and it can be used an irrigation method in green wall. Water use efficiency and number of flowers in this method were more than the drip irrigation method which enhanced the importance of this method. Accompanying this method with super absorbent polymer, improve the growth and water use efficiency by increasing the air conditioning, porosity and maintaining nutrients in soil. In compare with conducted researches, drip irrigation which is considered as one of the green wall irrigation methods has acceptable water use efficiency; also the existence of polymer had a positive effect on the growth of Osteospermum plant. The results showed the application of 0.6% polymer along with capsule irrigation could be a proper method for Osteospermum in green wall.
Marjan Nekokhoo; Seyfollah Fallah; Rahim Barzegar
Abstract
Introduction: Water resources are very limited for agricultural production. Therefore, optimal use of available water resources and increased water use efficiency in agriculture are necessary. Application of poly ethylene mulch is one of the approaches that can be effective in increasing water use efficiency. ...
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Introduction: Water resources are very limited for agricultural production. Therefore, optimal use of available water resources and increased water use efficiency in agriculture are necessary. Application of poly ethylene mulch is one of the approaches that can be effective in increasing water use efficiency. The water deficient trend is increasing in agricultural lands of the Iran and, on the other hand, the yield components of hull-less seed pumpkin are sensitive to drought stress. Therefore, the aim of this study was to determine the effect of transparent polyethylene mulch on the performance and water use efficiency of hull-less seed pumpkin under different irrigation rates.
Materials and Methods: This experiment was carried out in the central part of Isfahan, Northern Baraan (320 and 32/N, 510 and 52/ E, and 1534 m above sea level) in a randomized complete block design with three replications, during 2016. Treatments consisted of full irrigation+ poly ethylene mulch (M+FW), 0.75% full irrigation+ poly ethylene mulch (M+0.75FW), 0.50% full irrigation+ poly ethylene mulch (M+0.5 FW), and full irrigation without mulch (FW). In April, the cultivation operations include mechanical planting, mulch were done. The spacing of the rows was 150 cm and the spacing between plants was 70 cm. The irrigation was applied until the plant was fully established and then drought stress was begun based on above irrigation treatments. The studied traits were number of fruits per plant, average fruit weight (kg), fruit yield (ton ha-1), number of seeds per fruit, fruit diameter (cm), 1000 grains weight (g), grain yield (kg ha-1), water use efficiency (kg m-3), oil content (%) and oil yield (kg ha-1). Statistical analysis was performed using SAS software and comparisons of the means were made using the least significant difference (LSD) test at the 5% probability level.
Results and Discussion: The highest number of fruits per plant belonged to M+FW treatment (with an average of 3.22) and the lowest was recorded in M+0.5FW treatment (with an average of 2.44). This difference between treatment FW and M+0.75FW can be due to the high moisture under the poly ethylene mulch. The highest fruit weight (3.60 kg) was obtained in M+FW treatments, which had a significant difference with other treatments. The difference weight of fruit in M + FW treatment was 14% compared to FW irrigation treatments. The highest fruit yield (95.72 ton ha-1) belonged to M+FW treatment and the lowest one (79.78) belonged to M+0.5FW treatment. The difference in fruit yield in M+0.75FW compared to FW treatment was 6%, but it was not significant. The number of seeds per fruit in M+0.75FW compared to FW and M+0.5FW treatments showed a difference of 13% and 17%, respectively which they were significant only with M+0.5FW treatment. With increasing drought stress, the amount of photosynthetic assimilate decreased, which reduced the number of seeds per fruit. The highest 1000 grains weight (173.13 g) belonged to M+FW treatment and the lowest one belonged to M+0.5FW (156.18 g). 1000 seeds weight in FW treatment was not significant compared to M+0.75FW treatment. Drought stress during plant development decreased the leaf area index in the plant. Application of plastic mulch reduces the effect of drought stress on leaf growth and its photosynthesis by decreasing water loss by evapotranspiration and transpiration. The difference grain yield between two treatments M+0.75FW with FW was 7% and this difference was not significant. Only significant difference was observed among M+0.5FW treatment with other treatments. The effect of different levels of moisture on water use efficiency was significant at 1% probability level. The highest water use efficiency was recorded in M+0.5FW treatment and the lowest was recorded in FW treatment. The difference in water use efficiency between M+0.75FW with full irrigation (FW) was 0.99 kg m-3, which was significant. Difference in water use efficiency between M+FW and FW was not significant for water use efficiency. The use of plastic mulch reduced water loss throughout the plant growth period and significantly increased water use efficiency. There was a significant difference among M+FW, M+0.75FW and FW for oil content. The highest and lowest oil contents belonged to M+FW and M+0.5FW, respectively. The maximum oil yield (558 kg ha-1) belonged to M+FW and the lowest one (412 kg ha-1) was obtained in M+0.5FW.
Conclusion: Transparent plastic mulch under water stress conditions can reduce the effect of drought stress on hull-less seed pumpkin by preserving water and other beneficial effects, including weeds reduction. Therefore, the use of this type of mulch is recommended for the cultivation of hull-less seed pumpkin in the central areas of the country facing the water crisis.
A. Hassanoghli
Abstract
Produced sludge from wastewater treatment plants is a source of macro and micro nutrients and organic matters which is needed for agriculture. On the other hand, application of sludge with no criterion may cause some health risks and also, soil and surface water and ground water resources pollution may ...
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Produced sludge from wastewater treatment plants is a source of macro and micro nutrients and organic matters which is needed for agriculture. On the other hand, application of sludge with no criterion may cause some health risks and also, soil and surface water and ground water resources pollution may be followed. In this regards, the effect of different amounts of sewage sludge used as organic fertilizer in compare with chemical fertilizers on transport of minerals below the root zone and yield and yield components in soybean cultivation were studied. Therefore, 15 cylindrical plastic soil culomns with a height of 100 cm and 60 cm diameter were constructed and drainage PVC pipes with geotextile filter were installed for all of them. The sludge of Ekbatan housing complex wastewater treatment plant after processing and digestion was taken place and used. The culomns were filled by a Clay Loam textured soil and Soybean (Williams variety) was planted. Treatments include three levels of wastewater sludge fertilizer (10, 25 and 50 ton/ha), chemical fertilizers (150 kg/ha ammonium phosphate and 50 kg/ha urea) and control without using fertilizer in three replications. According to the results, the highest mean amount of nitrate in drainage water of culomns (base on split plot through time as statistical completely randomized design) was 57.17 mg/lit in the early season and treatment related to the use of sludge was 50 ton/ha. The lowest mean value of nitrate obtained from the control in the end of cultivation season and was 3.51 mg/lit. The most yield of Soybean was 277.85 gr grains per culomn which obtained from use of 50 ton/ha of manure sludge. The greatest weight of 1000 grains and the number of pods with values of 127.42 gr and 856 in number, measured in this treatment too. Application of 25 ton/ha sludge, chemical fertilizers and 10 ton/ha sludge were after it, respectively. So, the highest use of sewage sludge on soybean cultivation (at the rate of 50 ton/ha), transfer the highest amount of nitrate below the root zone and led to the best yield indicators
M. Karimzadeh; A. Alizadeh; M. Mohammady Arya
Abstract
One of the important factors that limits the maintenance and expansion of agriculture in irrigated lands of arid areas is the water shortage. Reuse of the municipal waste water effluent as one of the uncommon water resources especially around the big cities has received a lot of attention. One of the ...
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One of the important factors that limits the maintenance and expansion of agriculture in irrigated lands of arid areas is the water shortage. Reuse of the municipal waste water effluent as one of the uncommon water resources especially around the big cities has received a lot of attention. One of the most important physical properties of the soil affected by using wastewater is the saturated soil hydraulic conductivity (Ks). In order to investigate the effect of wastewater on Ks, the farms with sand, silty loam and clay were selected from the area around Parkand Abad (2) refinery in Mashhad that has been irrigated during the past 5 years with wastewater. Undistirbed sample was selected and saturated with water , wastewater and mixture of them was used to determine the amount of ks (with constant head method) and the of soil in laboratory. The results showed that the farms with wastewater with total suspended solids of 60 mg per litere floating in water limits the ks in different textures. The reduction in soil with clay texture as about 9 Percent and in silty loam and sand was about 4.5 and 2 Percent respectively. Using water as the liquid of experiment didn’t have any effect on increasing the amount Ks so that leaching the soil under the irrigation with wastewater increased the soil saturation up to 3 percent That shows no effect of leaching in improving the water direction. The most change of pb was observed in clay soil about 11 percent and the least in sand texture soil about 0.6 percent that with respect to the amount of floating materials in wastewater (60 mg) per liter the use of wastewater has been effective in blocking the soil openings. It seems that the floating material in waste water soil aggregation and the duration of continuous use of wastewater are effective factors in changing the physical properties of soil such as Conductivity of water saturated soil.
S. Fallah; Fayez Raiesi
Abstract
The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main ...
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The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main plots consisted of two irrigation treatments (i.e., optimum irrigation and cut-off irrigation at silking stage for two weeks), and subplots comprised N fertilizers (cattle manure: 40.8 Mg ha-1, poultry manure: 13.3 Mg ha-1, urea fertilizer: 435 kg ha-1, cattle manure + urea fertilizer: 20.4 Mg ha-1and 20.4 Mg ha-1, respectively) and control (without fertilizer). Results indicated that the imposition of water deficit and fertilizer type had a significant effect on N uptake while P uptake was significantly affected only by fertilizer type. The highest N and P uptake were obtained with poultry manure. Similarly, significant differences in N and P use efficiency and N physiological efficiency were observed between the water deficit and fertilizer type (P
