Fatemeh Fattahi-Naghani; Mahdi Ghobadinia; abdolrahman mohammadkhani; Mohamad reza Nori Emamzadeie
Abstract
Introduction: Change and decrease in atmospheric precipitation in recent years as well as increase in population and further demand for agriculture in the arid and semi-arid regions (such as Naghan) has led to a significant decrease in surface and groundwater resources. Therefore, achieving optimal utilization ...
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Introduction: Change and decrease in atmospheric precipitation in recent years as well as increase in population and further demand for agriculture in the arid and semi-arid regions (such as Naghan) has led to a significant decrease in surface and groundwater resources. Therefore, achieving optimal utilization of water in agriculture, new irrigation systems has been considered to gain the most crop yield with less amount of water consumption. Also cultivated area can be expanded by these systems, containing lands with irregular topography, due to the high water distribution uniformity. Besides developing irrigation system, irrigation management is an important tool for increasing crop productivity. Researchers have shown that applying deficit irrigation (DI) under drip system, has led to improve the quality of grape yield, decrease water consumption and increase water efficiency. The aim of this study is to investigate the effect of irrigation system and water stress on water consumption, yield and physiological indices of grapes.
Materials and Methods: The study field was located in Naghan, Chaharmahal & Bakhtiari Province, Iran. Experiences were done during summer 2016, in a completely randomized block design, with four replications in a grapevine garden The treatments included: CTRL, Furrow irrigation as common method in the area (control), surface irrigation with 100% water requirement (SI100), surface irrigation with 60% water requirement(SI60), drip irrigation with 100% water requirement(DI100) and drip irrigation with 60% water requirement (DI100).At the beginning of the experiences, 20 vine trees were selected with average of 60 years old. The field was divided into blocks, and the treatments were applied, randomly. Then the blocks were set up for the surface and drip irrigation. As the next step, required water was collected in a reservoir to obtain constant and reliable amount of water. In the control treatment, irrigation schedule of the gardeners (custom of the region) were considered in which irrigation event was at the beginning of the season. Also, drip and surface irrigation treatments were according to the soil water deficit. At the end of the experiment, water use efficiency, product performance, RWC, number of cubes per cluster, the weight of the cube in the cluster, cluster length, the number of main branches of the cluster and also qualitative properties such as soluble solids (Brix), total acid and pH of grape juice were measured.
Results and Discussion: According to the results of qualitative traits, the amount of applied water significantly affected the grapes pH in the level of 5%. The lowest grapes pH was due to the control treatment and the highest to the surface irrigation 60%. Also, measuring total soluble solids (TSS) in grape indicated significant difference in 1% level which revealed that deficit and drip irrigation increased sugar in grapes and therefore quality of the crop. The results of quantitative traits showed the number of cubes in treatments had a significant difference at a probability level of 1%. Number of cubes in surface irrigation treatment 100% (SI100) had the highest value, while the quality of the crop was lower. The treatments differed significantly in weight of 100 cubes and the drip irrigation treatment 100% (DI100) did not have a significant difference with control treatment, while deficit irrigation resulted in reducing the crop weight. Relative water content of leaves (RWC) had the highest amount in the control treatment, while low water stress reduced this index. Wet and dry yields were highest in the control treatments (CTRL); while, the lowest amount was due to the low irrigation treatments of DI60 and SI60 with 19% and 34% reduction, respectively for the wet and dry yield. Drip irrigation with 100% water requirement (DI00) was not significantly different from the control treatment in most of the quality parameters, cluster and yield characteristics but had less water consumption and higher water use efficiency.
Conclusions: Regarding the conditions of the region and the reduction of water resources, an accurate and efficient plan for irrigation is needed. So, the common method of irrigating in the region was assessed, as well as new methods of applying drip system and deficit irrigation. The results of this study indicate that drip irrigation system with 100% water requirement has no significant difference with the conventional irrigation method in the region, on quality and quantity of the gape yield. However, applying the drip system reduced the water consumption by 40%, and increased efficiency. Hence, drip irrigation system is suggested to be replaced by the traditional system.
P. Daneshpazhoh; A. R. Ghasemi; Mohamad reza Nori Emamzadeie; R. Barzegar
Abstract
Introduction: Optimal water utilization is one of the most important challenges of the present century. Due to limited water resources and the existence of alternate droughts in the country, optimal use of it is necessary. The deficit irrigation technique is one of the most effective and practical ways ...
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Introduction: Optimal water utilization is one of the most important challenges of the present century. Due to limited water resources and the existence of alternate droughts in the country, optimal use of it is necessary. The deficit irrigation technique is one of the most effective and practical ways in which it can determine and justify the minimum water consumption with acceptable economic performance. Its use in reducing water consumption for biomass production and for irrigation of annual and perennial crops. To effectively apply water deficit management, an understanding of the effects of irrigation at different stages of vine growth is required. Partial Root-zone Drying (PRD) is also one of the new irrigation techniques over the past years. The results of many studies indicate that water use efficiency has increased and there is no significant reduction in the yield in this irrigation method. In this technique, only half of the roots are irrigated at each turn and the remaining half remains dry. On the other hand, in recent years, the use of natural minerals has improved in order to improve the physical and chemical composition of the soil, which leads to an increase in water holding capacity in the soil. One of the methods for 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. Zeolite is one of these minerals that increases the soil water holding capacity. So far, many studies have been carried out on the use of PRD, as well as the use of zeolite, but none has examined the effect of these two simultaneously. Therefore, in the present study, the efficiency of both above method and deficit irrigation on yield and water use efficiency of sweet pepper were investigated.
Materials and Methods: This research was carried out in a completely randomized design with 9 treatments and 4 replications in a greenhouse in Shahrekord University. This study was carried out at three levels of irrigation of 100%, 75% and 50% of the water requirement of the plant by Partial Root-zone Drying and zeolite in two levels of 2 and 4% by weight in the soil, in one and two sides of the pots with a height of 30 and diameter 28 cm. After preparing the culture medium, the F1 type Lummus seedlings were transferred to the pots. During the transfer of transplants into the pot, careful attention was paid to the fact that the roots were developed on both sides. Physiological parameters such as leaf area, total fresh and dry weight of the whole organ, total fresh weight of fruit, diameter and number of fruits and chemical indices including vitamin C, pH, total soluble solids and chlorophyll a, b and total chlorophyll with water use efficiency were measured and evaluated. In order to analyze the results, SAS software (version 1/9) was used. Mean comparison was also performed by LSD test.
Results and Discussion: The results of this study showed that there was a significant difference in the 1% level for fresh and dry weight, fresh weight of fruit and chemical indices of vitamin C, pH and soluble solids, and a significant difference at 5% for diameter fruit and chlorophyll. The results of comparing the meanings showed that fresh weight and fruit diameter were significantly decreased in all treatments than control. The number of fruits in severe irrigation (50%) and in both levels of zeolite showed a significant decrease compared to control. Vitamin C value as an important indicator of fruit quality in all treatments was significantly higher than control, in other words water stress causes an increase in the amount of vitamin C in the fruit, and the amount of pH in the most treatments has decreased significantly compared to the control treatment.
Conclusion: Given that all important processes such as photosynthesis, nutrition, opening and closing of stomatal and plant growth and development are under the influence of water, most of the studied traits in this research (except chlorophyll) in zeolite-containing treatments, showed a significant advantage over non-consumption of zeolite. The results also showed that application of PRD method with zeolite in deficit irrigation resulted in significant increase in water use efficiency in all treatments.
shekoofe najafabadi; mohammad reza Nori Emamzadeie; Mehdi Ghobadinia; Abdolrazagh Danesh shahraki
Abstract
Introduction: Water scarcity is the most important limiting factor in the production of crops in arid and semi-arid regions. Thus, actions for increasing the efficiency and productivity of farm water is inevitable. A large proportion of the water, used in irrigation, evaporates, so an effective solution ...
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Introduction: Water scarcity is the most important limiting factor in the production of crops in arid and semi-arid regions. Thus, actions for increasing the efficiency and productivity of farm water is inevitable. A large proportion of the water, used in irrigation, evaporates, so an effective solution for conserving water is to control the evaporation on arable lands. Nowadays using mulch or plastic mulch is common and it makes efficient use of water in furrow irrigation possible by conserving and storing soil moisture. Mulch does not let dry air contact topsoil and it also prevents topsoil from solar irradiance and reduces evaporation and maintain soil moisture. Recent research in order to economize on water use and irrigation efficiency and water use efficiency has led. Thus, regarding the problem of water scarcity, the objective of this research is to investigate the effects of evaporation suppressing monolayers on the efficiency of water consumption and growth indices of seed corn single cross SC 704 in an arid and semi-arid region.
Materials and Methods: This research was conducted in Shahrekord University during 2015. The experimental design was randomized complete block design with 6 treatments and 3 replications. The treatments include control treatment (uncovering) and transparent plastic wrap, black plastic, cotton gunny and white and blue pp woven fabric. Planting and growing operations were conducted due to agronomic principles. Changes in soil moisture within the root-zone during the season were measured by using thetaprobe and all operations by measuring the amount of irrigation water used in all experimental plots of each treatment were applied separately using flow measurement and the amount and time of each irrigation was determined and applied based on MAD=50 by supplying required water.
Results and Discussion: The measurement results showed that variance analysis of relative water content (RWC) and water efficiency under the impact of different coverings had a significance difference with p-value of 0.01. Also the amount of the dry matter and harvest index of corn showed significance with p-value of 0.05. Results showed that mulch at all stages of measuring the impact of increasing the leaf relative water content it could originate from growing trend of air temperature during the period. Under these treatments the plants are expected to experience more desirable conditions regarding maintaining and distributing of soil moisture in comparison with other treatments and the indicator. The highest amount of dry matter calculated is for the blue pp woven fabric treatment that shows the ideal growth conditions and appropriate performance of the plant under the impact of this covering and the lowest amount is for the cotton gunny treatment. Leaf area index (LAI) is one of the important growth indices. In flowering (anthesis) stage, the maximum amount of LAI is 5.08 for the blue pp woven fabric treatment. The minimum amount of LAI is 2.5 for the cotton gunny treatment and it is because of There macroporous coating that weed growth has been hindering plant growth. On the basis of the hundred seed weight, the heaviest weight is 18.18 for the white plastic treatment and the lowest weight is 13.46 for the indicator treatment. The highest amount of harvesting index (HI) is 53.97 for the transparent plastic treatment and the lowest amount is 41.12 for the black plastic treatment.The corresponding amount is an increase of 32 percent compared to control treatment. The reason of reduction of HI is the reduction of seed performance than biological performance in water scarcity. One of the indices for evaluating irrigation management is water efficiency. The highest amount of water efficiency is 2.6 and 2.7 kg/m3for the blue pp woven fabric and white pp woven fabric covering and it reduces water wastage in form of evaporation and causes water conservation. And it protects the top soil from solar irradiance.
Conclusion: This research was conducted at Shahrekord University to investigate the effects of various coverings on water efficiency and corn seed performance. Using covering causes temperature growth in the soil under the covering and it also causes further and fast plant growth. It reduces evaporation from topsoil. As a result, it causes soil moisture to be invariable and because of lack of light under the coverings, photosynthesis is impossible, thus, weeds could not grow. Blue pp woven fabric of mulch to mulch increased 42% dry matter was cotton sack. Mulches effect of the corn harvest index showed a clear plastic mulch to increase 32 percent harvest index compared to the control. Mulches blue pp woven fabric, white pp woven fabric, cotton gunny, black plastic and transparent plastic, respectively, increases of 92, 85, 28, 14 and 78 percent of water use efficiency were compared to control.Therefore, plants under the impact of blue pp woven fabric and white pp woven fabric coverings access more water and nutrients than the indicator treatment, so water efficiency increases. Using coverings has conserved moisture more in the top layers of soil by reducing evaporation form topsoil.
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.
Sayyedeh Maryam Mirabolghasemi; Mahdi Ghobadi Nia; ahmad reza ghasemi; mohammad reza Nori Emamzadeie
Abstract
Introduction: Rice is one of the cereals that are widely used food in the world as staple.Rice is the largest consumer of water among agricultural products.At the field level, rice receives up to 2–3 times more water per hectare than other irrigated crop for producing of one kilogram of rice.Accordingto ...
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Introduction: Rice is one of the cereals that are widely used food in the world as staple.Rice is the largest consumer of water among agricultural products.At the field level, rice receives up to 2–3 times more water per hectare than other irrigated crop for producing of one kilogram of rice.Accordingto water resources limitation in Iran, According to water resources limitation in Iran, careful planning is essential to optimal use of water resources in agriculture as the largest consumer. One of the methods to reduce water consumption in rice cultivationis changing the traditional irrigation methods (flooding) to periodic irrigation. Change of management from traditional water-logging irrigation to unsaturated improves the irrigation water use efficiency. Due to water scarcity problems, the aim of this study was to evaluate controlled drainage and the impact of irrigation management on growth characteristics and yield components of rice in the arid and semi-arid.
Materials and Methods:To Considering the effect of water table level on water productivity in rice cultivation, the study was done in Shahrekord university. The experiments conducted in pots with 40 cm diameter and 45 cm hight. The experiment was arranged following a completely randomized design with four treatments (water table level) and five repetitions. The water table managements including: control water table 2 cm on the top of the soil (FI),the control water table 20 cm below the soil surface (CD20), control water table 36 cm below the soil surface (CD36) and Intermittent irrigation(AI). Tocontroll the water level, two tanks were used, one as stabilizer water table and another to measure the amount of water used. The Treatmentsares are completely water logging for a week, in second week treatments were applied. Sampled four times during the growing season was performed to determine the dry matter content of leaf, stem and leaf relative swelling and at the end of the growing season, the volume of water consumed, harvest index, the amount of grain produced and thousand grain weight was measured and recorded. The data obtained were analyzed using SAS software and LSD test was performed for comparison of means.
Results and Discussion:The results showed reduced yield treatments for CD20, CD36 and AI for each unit reduction in water consumption respectively as much 0.36, 0.46 and 0.38 units. Also results showed irrigation management caused significantly decrease in swelling relative only in the first and Second measuring stages respectively at the 5 percent level and in the fourth measuring stages at 1 percent level. Dry matter productive also was reduced under irrigation management in the Second and fourth measuring stages respectively in 1st and 3rd measuring stages at the 5 percent level. The impacts of irrigation management are no statistically significant on the rice harvest index and thousand grain weights but water consumption was reduced in CD20, CD36 and AI. Resulted to increment 5 percent water use efficiency based on performance and a significant increase 1 percent in the efficiency of water use was based on biomass. The highest and lowest harvses index belongs to FI (39.1) and CD36 (35.4) respectly. The highest and lowest thousand grain weights belong to FI (1247 kg/ha) and CD36 (1101 kg/ha) respectly.
Conclusions:High water Stress causes roots gone to sleep and their growth will slow after re-watering. Water scarcity is not only the hinder root growth but causes the root fuzzy and reduce its ability to absorb substances. The results showed that water reduction, a significant decrease in grain yield not occurred, Lack significant differences in grain yield mean that the water supply was adequate at all levels and in none of irrigation regimes, the plant was not affected by water stress and plant roots grown have enough at critical stages that needs greater water and has access to available water at greater depths. Results showed that T2 (control water table level at 20 cm below surface of soil) for each unit reduction in water consumption, 0.36 units reduces seed productionand 16% reduction in the amount of dry matter, That these lowest values are in the between treatments. With this irrigation management and reduce water consumption by 23% compared to control treatment area under cultivation can increased by as much as 30% and the grain production increase from 3424 to 4210 Kg per hectare.
S.S. Nurbakhsh; M. Ghobadinia; A. Danesh-Shahraki; mohammad reza Nori Emamzadeie; R. Fatahi
Abstract
Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling ...
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Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling is one of the most important factors in crop’s quality and quantity. The main objective of irrigation scheduling is to control crop’s water conditions in order to achieve its optimum yield level. So irrigation timing is the vital factor on which crop water stress and eventually yield's level are dependent upon. Moreover, irrigation timing is used in irrigation scheduling. The aim of this study was to evaluate the effect of irrigation time on water consumption, water use efficiency and yield of beans.
Materials and Methods: In order to observe the effect of the amount and the time of the irrigation on water consumption, yields rate and water use efficiency, the current research was carried out at the University of Shahrekord during the summer of 2012. The experiment was done as a completely randomized design with 4 repetitions consisting of irrigation time and the amount of irrigation in 4 and 2 levels (at 6, 8, 14 and 18) and (deficit irrigation, full irrigation), respectively. Beans seeds were planted in 32 similar vases with a diameter of 45 cm and height of 60 cm, in each experiment. Treatments were begun after 37 days from planting. Treatments were irrigated when the average moisture in the root zone was equal to the lower border of readily available water of full irrigation. At the end of the experiments, plants were completely harvested. Then the plant’s height, number of branches, numbers of pods per plant, pod and seed weight were measured.
Results and Discussion: Results showed that irrigating at different times during the day influenced water use efficiency, water consumption, seeds yield and number of pods in the bush. The water consumption was affected by irrigation time. Among full irrigation treatments, irrigation at 2 p.m. and 6 a.m. had the highest and lowest water consumption, respectively. The total amount of water used in irrigation at 8 a.m., 2:00 p.m. and 6 p.m. compared to 6:00 a.m. was increased by1.6, 9.5 and 4.1 percent, respectively. The results showed that irrigation at 2:00 p.m., caused a significant reduction in yield. Moreover, water use efficiency in 6 a.m. treatments had increased 18.5 percent more than that of the 2:00 p.m. irrigation treatment. The time of irrigation did not have a meaningful effect on bush height, the number of minor branches, the pod's length. The effect of the amount of irrigation water was meaningful on bush height, number of minor branches, seeds yield, the number of pods in the bush, pods length and seed weight. Seed yield at 8:00 a.m., 2:00 p.m. and 6:00 p.m. treatments has shown 0.29, 17.1 and 7.6 percent decrease in comparison with 6:00 a.m. irrigation treatment, respectively. Moreover, 100-seed weights were significantly affected by the irrigation time. The maximum and minimum weights of 100-seed weights were obtained at 6:00 a.m. and 6:00 p.m. irrigation, respectively. Analysis of variance showed that the number of pods per plant was affected by irrigation time. The maximum number of pods per plant was 101 which belong to the 6:00 a.m. treatment. In this experiment in the case of irrigation at 2:00 p.m., the number of pods per plant was significantly decreased in full and deficit irrigation. The results showed that although the irrigation frequency was the same, irrigation at maximum evapo-transpiration caused the plant to be under stress and the yield was reduced. In other word, it can be said that time of irrigation had no meaningful effect on the appearance and shape of the plant while it was effective in terms of the yield. Overall assessments showed that maximum of the measured features were obtained in the case of 6:00 a.m. treatment.
Conclusion: The results showed that irrigation at different times of the day and the applied water stress, reduced water use efficiency. These caused traits such as plant height; number of branches; number of pods per plant; pod and seed weight to be affected by the irrigation depth. Based on the results of this experiment it can be stated that, when there is no limit of water supply, it is recommended to irrigate in the early morning, before the steep slope of the temperature rise. However, in the situations with water shortage problems, is better to manage the water and the product.
Keywords: Bean, Deficit irrigation, Irrigation time, Water use efficiency
M.R. Nori Emamzadeie; A. Rahmati; B. Ghorbani; A.R. Mohammadkhani
Abstract
Abstract
Aeration is conducted on the perennial grasses such as lawns to reduce soil compaction and enhances the growth as well as improves soil infiltration. In order to evaluate the effects of aeration and topdressing on water infiltration phenomenon in a perennial lawn a factorial experiment in a ...
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Abstract
Aeration is conducted on the perennial grasses such as lawns to reduce soil compaction and enhances the growth as well as improves soil infiltration. In order to evaluate the effects of aeration and topdressing on water infiltration phenomenon in a perennial lawn a factorial experiment in a completely randomized design was conducted in the city of Isfahan in June 2009. Aeration, as the main experimental factor, consists of three levels, A0 (without aeration), A1 and A2 (with punching 1 cm diameter holes on the surface in a regular grid pattern and dimensions of 5×5 and 10×5 cm, respectively) and mulching, as the second experiment factor, consists of two levels, T0 and T1 (with and without any cover), were used for this purpose. To find the effects of the treatments on infiltration phenomena, infiltration was measured using Double Ring Method at three periodic times, i.e., 10, 70 and 130 days and data were analyzed ultimately using SAS software. The drawn results showed that applying A2T1 treatment, compared with A0T0 treatment as a control, increased cumulative infiltration by 286 percent and improved the final infiltration rate from 0.4 to 1 cm/h. On the other hand, A1T1 and A2T1 treatments application had no significant effect on the infiltration, but the effects of both treatments were significantly different from control, A0T0. On this basis, applying A2T1 treatment compared with A1T1 is technically and economically preferred, because of low Ip index. On overall, aeration improves soil permeability and its effects last by topdressing materials. By the way, aeration without topdressing is recommended for the lawn in flood prone areas.
Keywords: Aeration, Basic Infiltration Rate, Cumulative Infiltration, Loliumgrass, Topdressing
F. Fahalian; R. Moazenzadeh; M.R. Nori Emamzadeie
Abstract
A precise estimation of water consumption throughout a crop's growth season and of the amount of water consumed in each growth stage may play an important role in water resources management, integrated water and soil management, and proper irrigation scheduling. In a greenhouse, this faces with the conditions ...
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A precise estimation of water consumption throughout a crop's growth season and of the amount of water consumed in each growth stage may play an important role in water resources management, integrated water and soil management, and proper irrigation scheduling. In a greenhouse, this faces with the conditions specific to this environment. This study was conducted to propose a model to make an appropriate and accurate prediction of evapotranspiration (ET) for greenhouse cucumber. Two same microlysimeters with 28 cm diameter and 30 cm height were deployed simultaneously in the greenhouse for the cucumber culture. Amount of ET was measured daily by the weighing method in both mycrolysimeters. The data from the first microlysimeter were used to derive, and those from the second to validate the proposed models. The developed models were evaluated by root mean square error (RMSE), drawing measured versus predicted ET values, and t-statistics. The proposed model was initially developed in the form of a single regression equation with independent variables such as vapor pressure curve slope and relative humidity for the whole growth season; further however, a separate equation was developed for each of the four growth stages, as the initial model did not perform well (RMSE= 46.61%). The results showed that the proposed models made appropriate predictions of greenhouse cucumber ET. Average amount of cucumber ET were obtained with proposed models 0.398, 1.79, 3.428 and 2.061 mm for four growth stages. RMSE values also were obtained 15.78, 11.48, 9.11 and 7.08 percentage for four growth stages. Correlation coefficient from measured and predicted values of cucumber ET varied from 0.4 (using single equation) to 0.95 (using variable equations for different growth stages). All of the proposed models were significant (p
