مقالات رزومه حجت قربانی واقعی

Currently, soil erosion is considered one of the important environmental problems in Iran's watersheds. Accurate estimation of sedimentation and soil erodibility is very important for the protection and management of natural resources. Soil erodibility indicates the potential ability of soil to erode, and its increase is considered a serious threat to the stability and production capacity of agricultural lands. Measuring soil erodibility by direct method is expensive and time-consuming, and nowadays indirect methods are used to determine it. One of the most common indirect methods for estimating this parameter is the use of the Wischmeier and Smith nomograph, which was developed for non-calcareous soils. However, the majority of the soils in Iran is calcareous and the use of the nomograph method does not provide a correct estimate of the amount of erodibility. Loess is one of the most important Quaternary sedimentary formations in northeastern Iran, which consists of a relatively high percentage of lime. Therefore, the main goal of current research is to determine the most suitable indirect model to determine soil erodibility in Loess lands with the origin of calcareous sediments.

In the current study, Arab-Qara-Haji watershed with an area of 2596 hectares located in the east of Golestan province was selected as a typical loess area. The average annual precipitation of this watershed is 489 mm and it has a moderate semi-arid climate. This area is one of the sedimentary basins of Kopeh-Dagh zone related to the Jurassic period and consists of limestone and loess sediments. Based on the field studies, three main types of soil including hills (67.1%), loess plateaus (20.6%) and river terraces (12.3%) were identified in this watershed and the land unit was selected as working units. For this purpose, 48 surface samples (0-10 cm depth) were collected from each part of the land unit. In this research, two series of samples were taken from each section. The first series of samples was used to determine the soil physicochemical properties and the second series was sampled by a special cylinder to determine the soil saturated hydraulic conductivity using the falling head method. In the laboratory, soil texture was determined by hydrometric method (D<0.075), soil granularity by sieve analysis (D>0.075), soil organic matter by wet burning method and neutral lime percentage by Nelson method. The experience of the soil expert of this research was used to determine the soil structure in field. Then, soil erodibility was estimated using four indirect methods, including Weishmeier and Smith nomograph, Torri, Shirazi, and Vaezi. In this study, the soil actual erodibility was measured using rain simulator in the field (in plots of 1 m2). Then the validation of the models was performed using three standard indices MAD, RMSE and MAPE and the most appropriate model was selected.

Soil texture assessment in this watershed revealed that around 90 percent of soil samples have silt loam texture and the rest of samples has loam one. Also, the average lime in study area was estimated about 29%. The high percentage of lime (29%) and silt (60%) in this watershed has greatly increased the tunnel erosion probability. The validation results of the used models revealed that the use of the Vaezi method to estimate the soil erodibility factor in the loess lands of the study area has the highest accuracy (RMSE=0.00225). However, it is less estimated than the actual values. These results were confirmed in all 3 soil types of Arab-Qara-Haji watershed. After Vaezi model, Shirazi model (RMSE=0.03600) is more suitable than other models to estimate the soil erodibility factor in the loess lands of the area. This model has overestimated in all three types of soil including hill, loess plateau, and alluvial terrace, which is 11.2 times higher than the actual data from the rain simulator in the Arab-Qara-Haji watershed. After the Vaezi and Shirazi models, Wischmeier nomograph and Torri models, respectively, have a weaker performance in determining the soil erodibility factor in the limestone lands of the study area. Like the Shirazi method, Wischmeier nomograph and Tori methods have overestimated the soil erodibility factor. In the study area, this increase has been18.6 and 21.9 times higher than the actual data for Wischmeier nomograph and Torri models, respectively.

The present research results revealed that the use of Vaezi model to estimate soil erodibility in loamy lands with a high percentage of neutral lime is more appropriate compared to other used models. Based on the Vaezi and colleagues model, if the amount of neutral lime in the soil is less than 13%, it has a controlling role on the soil erodibility factor. While, this model is not able to estimate the soil erodibility in areas with neutral lime more than 30%. Therefore, for a number of soil samples in which the neutral lime was above 30%, the Vaezi model was not able to calculate the soil erodibility factor. It seems that currently, for the areas where the percentage of neutral lime in the surface soil is less than 30%, the use of the Vaezi model is more suitable than other models. It is suggested to recalibrate and update the Vaezi model for areas where the percentage of lime is more than 30%. The present research results revealed that the use of Vaezi model to estimate soil erodibility in loamy lands with a high percentage of neutral lime is more appropriate compared to other used models. Based on the Vaezi and colleagues model, if the amount of neutral lime in the soil is less than 13%, it has a controlling role on the soil erodibility factor. While, this model is not able to estimate the soil erodibility in areas with neutral lime more than 30%. Therefore, for a number of soil samples in which the neutral lime was above 30%, the Vaezi model was not able to calculate the soil erodibility factor. It seems that currently, for the areas where the percentage of neutral lime in the surface soil is less than 30%, the use of the Vaezi model is more suitable than other models. It is suggested to recalibrate and update the Vaezi model for areas where the percentage of lime is more than 30%.

Soil hydraulic conductivity is one of the important parameters to estimate soil erodibility, soil water flow, estimate runoff, and design drainage systems. This study was carried out to determine the hydraulic saturation (Ks) of surface and subsurface loess soils of Aghemam watershed (2) that located in the northeast of Golestan province. For this purpose, three types of soils in this area including hill, loess plateau and alluvial terrace in two surface and subsurface layers were sampled. In this study, in addition to determining Ks using the falling head method, some physicochemical properties of soil samples such as salinity, neutral lime, organic matter and soil texture were measured in the laboratory and their relationship with Ks was investigated. Then, the spatial variations of surface and subsurface saturation hydraulic conductivity in the study area were plotted using GIS software and IDW method. The spatial variations of Ks in both layers indicated its direct relationship between the two layers. However, the value of this parameter in the surface layer is more than for the subsurface layer. Also, the amount of Ks is relatively high in the two types of loess plateau and hill (3.9 cm/h), except in the alluvial terrace type, which is generally low (0.9 cm/h). The statistical results of linear multiple regression and stepwise methods showed that among the variables studied, the organic matter and neutral lime parameters, respectively, have the most impact on determining the amount of surface Ks (R2 = 0.9556) and subsurface (R2=0.8607) in the study area.

Water is one of the main important environmental factors limiting rice cultivation, in arid and semiarid regions like Iran. In order to evaluate the effect of growth inducers on sub-irrigation technology performance in rice water requirement, this field experiment was conducted as a factorial plot, based on completely randomized design with 6 replications, with two irrigation treatments (flooding and sub-irrigation with porous clay capsules), and two inducers (Mycorrhiza and salicylic acid) in 2016 at the research farm of GKU. Salicylic acid was used as seed treatment along with leaf spray in the concentration of 2 mM, two times in vegetative and reproductive growth. Mycorrhiza was used as root inoculation and was also mixed (20 gr.m-3) with the top 40 cm of soil. In this study, some morphological traits including plant height, the main panicle length, the weight of filled seeds, 1000-grain weight, weight of main panicle, the weight of whole panicles, grain yield, biological yield, water consumption, water productivity, water use efficiency and harvest index were measured, calculated, and assessed after harvesting. Grain yield for flood irrigation method for salicylic acid, mycorrhiza and control treatments were 5170, 4710, and 4202 kg.ha-1, respectively. While these values were 4985, 4807 and 4063 kg.ha-1 for the subsurface irrigation method, respectively. The results showed that rice grain yield, biological yield and harvest index were not significant in the two irrigation methods. But the water use efficiency and water productivity index in the subsurface irrigation system were significantly higher than the flood irrigation. Finally, the near-saturated soil matric potential method was able to increase the subsurface irrigation efficiency compared to the flood irrigation method at rice culture.

Water is one of the main important environmental factors limiting plant culture, in arid and semiarid regions like Iran. Providing continuous soil moisture content in the range of field capacity and reducing water losses in near root zone can play a key role in the development of soil and water management programs. Subsurface irrigation system with porous clay capsules are able to release water in the soil at field capacity range. This method is one of the traditional methods to reduce water consumption and increase water use effficiency for providing water requirement of plants in small scale farms at the worlds. There are different types of porous pipes. Clay nozzles are a type of porous clay pipes that allow optimal use of irrigation water due to the moisture supply of field capacity at the roots of plants.

In this study, subsurface irrigation with porous clay capsule nuzzle was used to provide the water  requirement of two fruitful plant (Grapes and Oranges) and measure the volume of water consumption in comparison with drip irrigation method. Porous clay capsule is able to release water into soil about field capacity in low hydroustatic pressure. The soil water content in field capacity was measured by mini soil Tensiometer in 30 kPa soil suction. Soil moisture in field capacity content was 28% for clay soil texture in citrus orchard. In subsurface and surface irrigation methods, 4 porous clay capsules and 2 dripper (8 litr.h-1), were placed for each citrus plant respectively. The volume of water consumed after each irrigation in both methods was measured by a water meter counter with precision +/-1 liter. In citrus plants, to compare the effect of irrigation type the collar diameter and plant height were studied for three consecutive years, and were compared using t-test (P<0.05).

The volume of water used in subsurface irrigation method was less than the surface irrigation method. The results showed that the water supply using buried porous clay capsule irrigation method for citrus plant compared to surface drip irrigation method was associated 42% reduction in water consumption.. Comparison of collar diameter and plant height of citrus plants showed that there was no statistically significant difference (p<0.05) in two irrigation methods. Collar diameter and height growth of citrus trees in subsurface and surface irrigation methods in 2015 compared to 2012 was about 2.5 times.

According to the results of the present study, it can be concluded that the use of porous clay capsules will be one of the most effective traditional methods of optimization and management in water consumption of small scale orchards, especially at arid and semiarid region. An examination of the work done to date on clay nozzles shows that less attention has been paid to the economic aspects and competitiveness of these parts with other nozzles available in the market. It seems that the challenge of sedimentation of water-soluble materials inside the parts or attacking the roots on them has prevented the entry of large private sector investors into this completely economic and high-income environment.

One of the important parameters for identifying the erosion-sensitive points is the use of soil erodibility factor, which is determined by two methods; direct and indirect methods. The direct method for calculating soil erodibility has good accuracy. However, it is economically expensive. Therefore, this method is not considered by experts. The indirect and conventional method for calculating the soil erodibility is the Wischmeier nomograph method, which was presented for non-calcareous and semi-wet soils of the United States. Since the majority of the soils in Iran are calcareous, hence in this research, the Vaezi method, which is designed for this type of soil, was used. Loess is one of the most important Quaternary sedimentary formations in northeastern Iran, which has variable sedimentation and erosion potential due to its physicochemical properties. This study was conducted to evaluate and compare the estimated values of soil erodibility (K) from two methods of Wischmeier nomograph and Vaezi method in calcareous-loess soils of Arab-Qareh-Haji watershed in the east of Golestan province.

The study watershed with an area of 2595 hectares is located in the northeast of Golestan province. To perform this research, after the initial studies, the components of the land unit in the study area (including river terrace, loess plateau, and hill) were selected as the working unit. For this purpose, 42 surface samples (0-10 cm depth) were collected from each part of the land unit. In this study, the standard laboratory methods were used to determine the soil physicochemical parameters. Soil physicochemical properties, including soil texture, neutral lime, organic matter, coarse sand, very fine sand+silt, and soil structure, were measured in the laboratory. The saturation hydraulic conductivity of soil in the laboratory was estimated using the falling head method. In this research, the actual soil erodibility was measured using a rain simulator in the field (in plots of 1 m2). Then, spatial changes of soil erodibility in the study area were plotted using GIS software and inverse distance weighting (IDW) method. F-test and Games-Howell at the probability level of 0.05 were used to compare and determine the statistical difference between the estimated erodibility values (the Wischmeier nomograph and Vaezi methods) with actual data. To estimate the most effective parameter in the soil erodibility using the Vaezi method, multiple linear regression and stepwise methods were used. Statistical tests were performed using Minitab software.

The average silt particles in the soil were measured about 60% in the Arab-Qareh-Haji watershed, which plays an important role in the soil erodibility. In this watershed, the ratio of fine sand to coarse sand was calculated about 18, and this can be one of the main causes of runoff in this area. Soil texture assessment in this watershed revealed that around 90 percent of soil samples have silt loam texture, and the rest of the samples has loam one. Also, the average lime in study area was estimated at about 29%. This amount is higher than the standard lime (15%) in the soil to create stable aggregates in the wet state. Then, soil erodibility values were determined by three methods Wischmeier nomograph, Vaezi method, and rain simulator (actual data). The results showed that the value of soil erodibility using Wischmeier nomograph was estimated at about 30.4 and 18.8 times higher than for the Vaezi method and actual data, respectively. The results of F-test and Games-Howell test with 95% probability showed that there was no significant difference between the soil erodibility from the Vaezi method and the actual data, while there was a significant difference between the Wischmeier method and the actual data. Results of multiple linear regression and stepwise methods showed that the most important variables in estimating the soil erodibility are silt, organic matter, neutral lime factors, and coarse sand, respectively (R2 = 0.9648, R2-adj = 0.9539). In this study, it was not possible to estimate the soil erodibility factor by Vaezi method due to the high percentage of neutral lime for a number of samples.

In this study, the average lime was estimated at about 29%. This amount is higher than the standard lime (15%) in the soil to create stable aggregates in the wet state. Therefore, it seems that excess lime in the wet soil can reduce the stability of aggregates. In this watershed, a large number of tunnels and gully were observed, which indicates that this soil is erodible. The statistical analysis results showed that the soil erodibility values from the Vaezi method in this watershed were relatively close to the actual data but were less estimates, while the Wischmeier nomograph method was significantly different from the actual data and was overestimated. However, for areas where the amount of neutral lime was over 30%, the Vaezi method was not able to calculate the soil erodibility factor. Hence, for the areas where the percentage of neutral lime is lower than 30%, the use of the Vaezi method is more suitable than the Wischmeier nomograph method, and for areas where the percentage of neutral lime is higher than 30%, the model needs to be calibrated and updated.

Rice is the second most important cereal in the world, and it has the highest water requirement among grain crops. Applying different irrigation methods is necessary in order to determine the best method to achieve maximum yield. Therefore, in this research, the effects of flooding and underneath conditions on chlorophyll fluorescence and agronomic traits of rice have been investigated.

This experiment was conducted in 2017 at the research farm of Gonbad-e-Kavos University. Two experiments were designed for agronomic and photosynthetic traits in flooding and underneath irrigation conditions in order to investigate two genotypes 87.110 (line selected from mass populations) and AE121 (an aerobic line). The first experiment was combined in two separate experiments (flooding and underneath) and 18 replicates. Given the uniformity of the ground, the base design was considered as CRD. The second experiment was conducted to compare the performance of irrigation methods and cultivars with the first experiment in a land with a greater area (100 m2) in three replications. The germinated seeds were transplanted to nursery on 12 May. During the stage, care was taken in the nursery, such as irrigation, fertilizer, aeration and weeding. In this design, the distance between the plots was one meter and the distance between the blocks was two meters, so that the adjacent plots had no effect on the moisture content. Transplantation was carried out after 3-4 leaves with the selection of healthy and uniform seedlings on June 20th by 20 × 20 cm spacing and three seedlings. In the method of flood irrigation, the land was prepared as usual. To prepare underneath irrigation treatments, each plot was removed to a depth of 40 cm and porous clay capsules were used. The irrigation system consisted of three main pipelines (the number of irrigation treatments), one valve head and one volume meter installed on each main pipe. The main tubes were spread along the floor and the water needed for each treatment was taken using 16 mm tubes at the beginning of each plot. By placing the pressure gauge at the beginning of the pipelines, the system pressure was modulated in the underwater irrigation system. At the end, the agronomic traits and chlorophyll fluorescence parameters were measured.

The results showed that in the first experiment, the maximum water use efficiency was related to underneath conditions. This result was also repeated in the second experiment. In terms of flooding, the amount of water consumed was 6540 units higher than underneath conditions. The amount of water consumed in flooding irrigation was 864.71 and 1267.34 units more than underneath irrigation in the first and second experiment, respectively. Differences between irrigation treatments and cultivars were significant in most agronomic traits except length, width and area of flag leaf, yield, total weight, number of infertile panicle and main panicle length. Also, the effect of cultivar and irrigation methods were significant on chlorophyll fluorescence traits except F' and Y (II).

The results indicated that most of the studied traits in the floodwater irrigation conditions were better than the underneath irrigation. The yield was also higher in underneath conditions than in the case of flooding conditions. The results of analysis of variance of both experiment in the studied traits showed that there is a significant difference between flooding conditions and underneath irrigation and also between genotypes under irrigation conditions. The mean comparison in underneath conditions also showed that the AE121 genotype has a higher potential under both conditions and can be recommended for high yielding.

Calf diarrhea diseases result from complex interactions of the infectious and non-infectious agents and is one of the most common diseases reported calves up to 3 months old. Among the bacterial causes of diarrhea Escherichia coli and Salmonella species are the most common. Concurrent with the development of new chemical drugs and antibiotics, their harmful effects are gradually emerged. Nowadays the research works results show that herbal medicines have not any harmful effects. The goal of this study is synergic effects of Bentonite Nano clay and essential oils of Cinnamomum zeylanicum on Escherichia coli and Salmonella in Vitro. For determination the minimum inhibition concentrations (MIC) of essential oils of Cinnamomum zeylanicum, and Bentonite nanoclay was investigated individual and combination with each other on two causal agents of bacterial diarrhea in BHI broth media by macro-dilution method. The result showed that the MIC of essential oils of Cinnamomum zeylanicum was 0.01% and 0.02% for Salmonella and Escherichia coli, respectively. Meanwhile the MIC of essential oils of Cinnamomum zeylanicum combinated with Bentonite nanoclay was 0.01% and 12.5 mg/mL for Salmonella and 0.02% and 25 mg/mL for Escherichia coli. In conclusion, essential oils of Cinnamomum zeylanicum individual and also combination with montmorillonite nanoclay have a good accurate to control on two major agents of bacterial diarrhea.

Different parts of forest roads and uphill are usually the main sources of surface runoff, sediment, water resources pollution in forest streams and soil loss. Today, soil erosion and its consequences is a global matter of concern. This study was conducted in Kohmiyan forest near-Azadshahr in order to assess the effect of forest road uphill gradient in controlling the runoff production and soil loss by a rainfall simulator. Treatments include four levels of gradients (>20%, 20-40%, 40-60% and 60-80%). Other parameters such as soil moisture content, resistance to penetration, vegetation cover and precipitation were considered constant. Then, the amount of runoff and soil loss in each level were collected at an intensity of 80 mm/h with 15 min duration and sampled at three minute intervals. The results indicated that the average amount of total runoff in level 1 (gradient >20) to level 4 (60-80%) were 5.97, 10.14, 14.27 and 18.60, respectively. Sediment concentration were 4.15, 5.87, 7.84 and 10.68 g/l-1; runoff coefficient were 12.01, 20.25, 28.51 and 37.20 percent and total soil loss were 21.65, 54.67, 108.13 and 191.51 gr, respectively for each one square meter. The results of ANOVA showed there is significant difference between the amount of runoff and soil loss due to road gradient. The results of Duncan test also indicated that with increasing uphill gradient, the amount of runoff and sediment increased significantly.

In order to evaluate the performance of sub-irrigation system using porous clay capsules, the experiment was conducted as factorial plot in base of randomized complete block design with three replications and two irrigation treatments on two different time, 21-MAY-2016 and 21-JUNE-2016 for rice culture. In this study some morphological traits including grain yield, number of empty seeds, number of filled seeds, number of whole seeds, weight of main panicle, main panicle length, 1000-grain weight, plant height, water consumption and water use efficiency were assessed. The results showed that flooding irrigation had no significant effect on the yield increasing compared to sub-irrigation at two sowing dates. Also, the water consumption decreased 30% and 39.5% using sub-irrigation in two sowing date (21-MAY-2016, and 21-JUNE-2016) respectively, comparision to flooding irrigation. Based on the result grain yield at two sowing date had significant effect. The grain yield decreased 28 percent in the second date of culture (4463 kg.ha-1) compared the first date of culture (3212 kg.ha-1) at two irrigation methods. Generally, using porous clay capsules technique, rice culture could be provided without yield loss at arid and semiarid reigons.

The irrigation of turf grass is the major factor to water consumption in advanced urban area. Therefore, reduce water consumption using subsurface irrigation system could be a new strategy for optimization of water requirement. The purpose of this study was to investigate the effect of subsurface irrigation system, sprinkler and superabsorbent polymers on quantitative and qualitative characteristics of turf grass. Experimental design was a split -plot with three replication in agriculture faculty of Tarbiat Modares university in 2014. During the experiment, some factors such as applied water volume, wet and dry weight of sprouts, sprouts length, color and length of roots were measured to express the differences between irrigation methods. The results showed that, without using superabsorbent polymer, subsurface irrigation could reduce 41% of water consumption compared to sprinkler irrigation. Meanwhile this reducing consumption was 51% using superabsorbent polymer treatment. Also, length of roots in buried porous clay capsules irrigation was significantly different at%5 level in comparison to sprinkler irrigation. The superabsorbent application had significant effect on increasing root growth but the other index, wet weight, length and color of Sprouts had no significant effect. According to the results of this research, application of buried using buried porous clay capsules is recommended in order to optimize water consumption for urban area located at arid and semi-arid regions.

Roads provide access to forest resources for properly management of timber production, transportation, forest protection and ecotourism. Also, forest roads are known as one of the main sources of sediment production in forest watersheds. Globally, soil erosion is one of the most important environmental problems which is threaten soil and water resources. Therefore, it is necessary to investigate on soil erosion of forest roads and determination of its quantity rate. The measurement of soil erosion rates under natural rainfall conditions is costly and time consuming. Data provided by rainfall simulation and static site measurements can be used to predict erosion rates under natural conditions, especially for erosion rates from forest roads. Various studies were investigated the factors affecting water erosion in forest roads and their results had shown a significant correlation among slope percentage, vegetation cover percentage, climate, Physical and chemical soil characteristics, road traffic with the amount of soil erosion. This study, specifically, aimed to assess the effect of vegetation cover on soil erosion, runoff production and sedimentation.
This study was done to investigate the effects of vegetation cover of cut-slope forest road on erosion variables such as runoff amount, sediment concentration, soil loss, time to runoff and runoff coefficient in Kohmiyan Forest of Azadshahr. It was conducted five treatments of vegetation cover including 0, The results indicated that the average amount of runoff in five levels of vegetation cover including bare ground, less than 25%, 25-50%, 50-75% and 75-100% were 24.7,17.82, 12.78, 5.23 and 2.64 l/m2, average amount of sediment concentration were 15.66, 9.41, 7.37, 5.07 and 2.39 g/l and average time of runoff were 12.00,75.00, 150.00, 238.75 and 365.75 and runoff coefficient were 47.8, 35.62, 25.71, 10.58 and 5.27 percent, respectively. The results statistically showed significant differences between amount of runoff and soil loss due to vegetation cover of road cut-slope. The results of Tukey test indicated significant differences among mean runoff and sediment of five level and decrease with increased road cut-slope of vegetation cover percentage.
The effect of vegetation cover on the cut-slope road is completely significant on the amount of runoff, sediment concentration, soil loss, time to runoff and runoff coefficient. In other words, the amount of runoff and soil loss has a reverse and significant relationship with vegetation cover percentage. Vegetation cover percentage has had a positive impact and role in the reduction of the amount of runoff and sediment in the forest roads.

IIn many semiarid regions of Iran, soil erosion has become a serious environmental problem affecting land productivity, nutrient loss, water quality, and freshwater ecosystems. Rates of soil loss differ according to erosion type and land degradation processes. Rill erosion is commonly observed when rainstorms occur on steep slopes and sediment transport in rill flows exhibits the characteristics of non-equilibrium transport. In this paper, sediment concentration of rill flow is estimated by adaptive neuro-fuzzy inference system (ANFIS). A series of mathematical equation and parameters effecting on` rill hydrodynamics and soil detachment were used for well-defined rill sediment concentration. A series of filed experiments were performed to evaluate the model. The stepwise method was used to selecting the most important and effective input variables from measured input parameters of soil properties, topographic and vegetation attributes affecting sediment concentration of rill flow. Based on the stepwise procedure the most significant parameters in the model predications were steep slope, vegetation percentage, clay percentage and shear stress parameters. The values of sediment concentration simulated by the model were in agreement with observed values with Coefficient of Correlation (R2), Root Mean Square Error (RMSE) and Mean Bias Error (MBE) of 0.697, 30.5 and 1.0, respectively. The results of the investigation show that the data-driven ANFIS modeling approach can be a powerful alternative technique for correctly estimating rill sediment concentration.

Introduction The majority of the world's dry lands are still farmed by small scale. In these farms, low cost simple irrigation methods are paid attention by farmers and also international development programs. Efficient traditional methods of irrigation such as buried clay pot irrigation is one of the most important methods that could be of great use on small and medium sized farms and gardens that have not been well studied in Iran. Also, the information on shape of wetted zone of soil under buried clay pot plays the great significance in design and management of this type of irrigation system for many land farms at arid and semi-arid regions on small and medium sized farms and gardens. Clay pot or porous clay capsules irrigation is able to release water in near root zone with self- regulative. Several parameters such as saturated soil hydraulic conductivity, soil porosity, water supply, pressure head and irrigation time may affect on discharging and soil wetting shape under sub-irrigation with porous clay capsule.
Materials and Methods Present research was carried out in 2014 carried out on the field of agriculture of faculty of Tarbiat Modares University, to study simulated soil wetting shape under two different type of buried porous clay capsule (GBN and GN) in calcareous soil with clay loam texture. The soil are generally deep to moderately deep with clay loam texture, ~ 17% CaCO3 (lime) , 0.44% organic matter and a moderately soil permeability. The slope in this study area is 0.5 -1.5%. The GBN and GB have different size and discharge. In this paper, wetted radius and depth of GBN (3.5 cm diameter and 12 cm height) and GN (3.5 cm diameter and 3.5 cm height) porous clay capsules as a subsurface point source were measured at 10, 25, 50, 80, 100 kPa of hydrostatic pressure by discharge-pressure automation instrument which was designed for this purpose. The soil weting shapes measured after 24 hr of irrigation with GBN and GB of buried porous clay capsule under clay loam soil texture. In order to predict the water distribution of clay capsules, several parameters such as saturated soil hydraulic conductivity, soil porosity, water supply, pressure head and irrigation time were modeled by with Buckingham theorem in dimensional analysis technique. Residual errors analysis was used to validate the simulation model.
Results Discussion According to the experimental results, the soil water distribution shape in GN and GBN clay capsules types followed a spherical trend, which is due to the low discharge of clay capsules. The analysis results of residual errors showed that the average of ME, RRMSE and R2 were 9.82, 23.78, 89.48 and 10.92, 57.97, 90.4 for GB and GBN respectively. Therefore, dimensional analysis models have good accuracy in determining the wetted radius and depth of two clay capsule types. Tese shows that developed model can be used to simulate wetting pattern under porous clay capsule irrigation system with point source of water application. Also, the results showed that wetted radius and depth of GN at 100 kPa pressure head was similar to GBN up to 50 kPa. In other hand, irrigation engineers can selected and used GN insted of GBN for places with high pressure ability. Because, the run of smaller nozzle (clay capsule of GN) is earier in related to the GBN at fileds.
Conclusion Water distribution in soil is important for the design, operation, and management of irrigation system for arid and semi-arid regions. In order to, the four equation was developed to simulate soil wetted depth and width with Buckingham theorem in dimensional analysis technique under two types of buried porous clay capsule (GBN and GN) at point source of water application. It is important to know that, The discharge of clay capsules increased with increasing pressure head and the relationship between discharge and hydrostatic pressures trend to non-linear in GB and GBN.Based on our experiment results, these equations can be used as a reliable method to predict the wetted soil shape in clay loam soil and had good accuracy for practical project to provide aids for deciding depth and intervals of porous clay capsules and designing a subsurface irrigation scheme. In othe hands, the models simulated values were following distribution not different than observed ones in two porous clay capsule types. The main conclusion drawn from the two porous clay capsule size’s is that the soil wetted shape in GN type was similar to GBN type at high pressure head. This point is important to principles of irrigation engineering and managment.

Rill erosion is considered to be the most important process affecting soils created by the concentrated flow of water. In this research to quantify sediment transport and runoff in natural rills, two rill experiments under dry and wet conditions were accomplished in November 2013 in the Golestan Dam. Filed experiments lead to a closer understanding of the dynamics and power of different soil erosion processes in a rill channel. Water is introduced with an intensity of 12 L min−1 into a rill within 10 min. Rill cross sections, slope values, flow velocities and sediment concentrations were measured for each rill at three points every 5, 10 and 16 m from the origin along a rill. The flow velocity within the rill was measured by recording the travel times of the waterfront and of two applied colour tracers .The results showed that the flow velocity in the under wet condition is higher than dry condition. Under dry condition, the highest sediment concentrations are recorded at the initial runoff flow despite lowest flow velocity. The initial high sediment concentration may be attributed to the existence of a thin loose surface layer. Flow velocity increases along the length of the channel towards an increase with flow duration. However suspended sediment concentration measured tend to decline with decreasing the sediment-transport capacity. Temporal variations in the sediment concentrations indicated that changes Sediment concentration at the time of the creation of the nought erosion process with inflow water in the experiments and sediment transport mostly attributed to the bulldozer effect. Also showed that hydrological response and sediment production were significantly different in two rill channels which only ground cover were significantly different

Soil organic carbon (SOC) has great impacts on soil properties, soil productivity, food security, land degradation and global warming. Similar to other soil properties, SOC has a strong spatial heterogeneity as a result of dynamic interactions between parent material, climate and geological history, at both regional and continental scales. However, landscape attributes including slope, aspect, altitude, and land use types are dominant factors influencing on SOC in areas with the same parent materials and climate regime. Understanding and identifying the spatial and temporal distribution of SOC is essential to evaluate soil quality, agricultural management, watershed modeling and soil carbon sequestration budgets. Therefore, the objectives of this study was to estimate soil organic carbon content in the Aligodarz watershed, and to investigate the effects of altitude, slope, and land use type on SOC.
The research was carried out in the Aligodraz watershed in Lorestan province of Iran. The study area is located between latitudes N 33° 10' 51.72"to N 33° 34' 28.22" and longitudes E 49° 27' 17.99"to E 49° 58' 40.84" 14 that covers an area of 1078.9 km2. It has an altitude between 1866.3 and 3200 m above sea-level. The primary land uses within the watershed include pasture, dryland and irrigated farming. In this study, soil samples were randomly collected from 206 sites at depth of 0– 15 cm during June and August 2003. The mean distance between samples was about 5 km. Soil samples were air-dried in the shade for about 7 days and then passed through a 0.25 mm prior to determination of SOC. Soil organic carbon content was determined in triplicate for each sample using the Walkey-Black method. Basic statistical analyses for frequency distribution, normality tests, Pearson's correlation and analysis of variance were conducted using SPSS (version 18.0). Calculation of experimental variograms and modeling of spatial distribution of SOC were carried out with the geostatistical software GS (version 5. 1). Maps were generated by using ILWIS (version 3.3) GIS software.
The results revealed that the raw SOC data have a long tail towards higher concentrations, whereas that squareroot transformed data can be satisfactorily modelled by a normal distribution. The probability distribution of SOC appeared to be positively skewed and have a positive kurtosis. The square root transformed data showed small skewness and kurtosis, and passed the K–S normality test at a significance level of higher than 0.05. Therefore, the square root transformed data of SOC was used for analyses. The SOC concentration varied from 0.08 to 2.39%, with an arithmetic mean of 0.81% and geometric mean of 0.73%. The coefficient of variation (CV), as an index of overall variability of SOC, was 44.49%. According to the classification system presented by Nielson and Bouma (1985), a variable is moderately varying if the CV is between 10% and 100%. Therefore, the content of SOC in the Aligodarz watershed can be considered to be in moderate variability. The experimental variogram of SOC was fitted by an exponential model. The values of the range, nugget, sill, and nugget/sill ratio of the best-fitted model were 6.80 km, 0.058, 0.133, and 43.6%, respectively. The positive nugget value can be explained by sampling error, short range variability, and unexplained and inherent variability. The nugget/sill ratio of 43.6% showed a moderate spatial dependence of SOC in the study area. The parameters of the exponential smivariogram model were used for kriging method to produce a spatial distribution map of SOC in the study area. The interpolated values ranged between 0.30 and 1.40%. Southern and central parts of this study area have the highest SOC concentrations, while the northern parts have the lowest concentrations of SOC. Kriging results also showed that the major parts of the Aligodarz watershed (about 87%) have statistically SOC content less than 1%. Lower SOC concentrations were associated with high altitude (r = −0.265**). The results of Pearson correlation analysis showed that soil organic carbon content has a significantly negative correlatiton with slope gradient (r = −0.217**). The results also indicated that the SOC content was variable for the different land use types. The irrigated lands had the highest SOC concentrations, while the pasture lands had the lowest SOC values.
The square-root transformed data of SOC in Aligodarz watershed of Lorestan province, Iran, followed a normal distribution, with an arithmetic mean of 0.81%, and geometric mean of 0.73%. The coefficient of variation and nugget/sill ratio revealed a moderate spatial dependence of SOC in the study area. The results indicated that the major parts of the Aligodarz watershed have SOC content less than 1%. The land use type had a significant effect on the spatial variability of SOC and that lower SOC concentrations were associated with higher altitude and slope gradients. The irrigated and pasture lands had the highest and lowest SOC concentrations, respectively.

Maintaining soil moisture content at about field capacity and reducing water loss in near root zone plays a key role for developing soil and water management programs. Clay pot or porous pipe is a traditional sub-irrigation method and is ideal for many farms in the world’s dry land with small and medium sized farms and gardens and is still used limitedly in dry lands of India, Iran, Pakistan, the Middle East, and Latin-America. Clay capsule is one of porous pipes in sub irrigation that is able to release water in near root zone with self- regulative capacity. Watering occurs only in amounts that the plants actually need (this amount is equal to field capacity) and released water in near root zone without electricity or use of an automatic dispenser. A study was carried out in 2013 on the experimental field of agriculture faculty of Tarbiat Modares University, to study the effect of two irrigation types on qualitative and quantitative characters in grape production (Vitis vinifera L.). In order to provide the water requirement of grape plant were used porous clay capsules for sub irrigation with height and diameter of 12 cm and 3.5 cm and dripper with Neta film type for drip irrigation, respectively. Porous clay capsules provided from soil science group at Tarbiat Modares University. In this research, the volume of water delivered to grape plants during entire growth period in two different irrigation methods was measured separately with water-meters installed at all laterals. The water consumption, yield production and water use efficiency were evaluated and compared in two drip and porous clay irrigation systems at veraison phonological stages. In the veraison stages, cluster weight, cluster length, solid solution and pH content were measured in grape fruits. Leaf chlorophyll content and leaf water content were also measured in two irrigation systems. The results of fruit quality characteristics showed that cluster weight, cluster length, solid solution and pH content has not significant different at 5% level in two system irrigation. Also, the foliar analysis showed that chlorophyll content and relative humidity of leaf has not been affected in two irrigation systems. Meanwhile, irrigation types were significantly effect on water consumption and water use efficiency. The average water consumption and yield production with buried clay capsules and drip irrigation methods on grapevine plant were 4050 and 6668 M3.ha-1 and 14.2 and 14.8 Ton.ha-1 respectively. The reducing water consumption with buried clay capsules irrigation method in related to drip irrigation was 39% on grapevine plants. Meanwhile, the average yield production with buried clay capsules and drip irrigation methods on grapevine plant was 14.2 and 14.8 Ton.ha-1 respectively. Also, the statistics analysis show that the yield and component yield have not significant different at 5% level in the surface and subsurface irrigation. According to the water consumption and yield production, using buried porous clay capsules created a better water use efficiency than drip irrigation method. In other words, Iran has been localized at arid and semi arid and have huge water consumption in agriculture, and therefore it is necessary to optimize water consumption especially in agriculture using new technology. According to the results of this research, using buried porous clay capsules is recommended in order to optimize water consumption for grape plants in different place in arid and semi-arid regions of Iran. The purpose of an efficient irrigation system is to apply the water in such a way that the largest fraction thereof is available for beneficial use by the plant. According to the experimental results reported here, it could be concluded that the reducing water consumption with buried clay capsules irrigation method in related to drip irrigation was 39% on grapevine plants. Meanwhile, the average yield production with buried clay capsules and drip irrigation methods on grapevine plant was 14.2 and 14.8 Ton.ha-1 respectively. Also, the statistics analysis show that the yield and component yield have not significant different at 5% level in the surface and subsurface irrigation. The final result, it could be concluded that the porous clay capsules have a good ability to providing water requirement of grape plant. The grape irrigation in huge area of Iran is doing with a traditional method and the authors of this work believe that porous clay capsules have a high water saving potential and good capability for irrigation of various types of crops.

Maintaining soil moisture content at about field capacity and reducing water loss in near root zone using sub-irrigation methods plays a key role in developing soil and water management programs. Providing soil moisture can be an efficient method of subirrigation systems for many orchards at arid and semi-arid regions. In this research, in order to provide the water requirement of grape plant were used porous clay capsules with height and diameter of 12 cm and 3.5 cm, respectively. The water consumption, yield production and water use efficiency were evaluated and compared in both drip and porous clay irrigation systems. The results showed that the irrigation types significantly affect water consumption and water use efficiency. The average water consumption and yield production with buried clay capsules and drip irrigation methods on grapevine plant were 4050 and 6668 M3.ha-1 and 14.2 and 14.8 Ton.ha-1, respectively. According to the results of this study, it can be concluded that using buried porous clay capsules leads to higher water use efficiency compared to drip irrigation in growing grapevine plant in arid and semiarid regions.

Buried porous clay capsule irrigation is one of the most important traditional methods that could be of great use on small and medium sized farms and gardens. Hydraulic characteristics of porous clay capsules are affected by clay type, clay percent, sand percent, T.N.V. %, wall thickness, soaking time, firing temperature and hydrostatic pressure. The present paper has attempted to evaluate the hydraulic characteristics of porous clay capsules based on firing temperature, soaking time, and hydrostatic pressure. Raw materials used for making porous clay capsules were obtained from calcareous soil of Nasr-Abad village of Gorgan city. The amount of sand added for improving hydraulic properties was 0, 200, 400, 600, and 800g into 1000g of Nasr Abad of Gorgan soils respectively. These produced clay capsules were named Gorgan-0, Gorgan-200, Gorgan-400, Gorgan-600, and Gorgan-800 respectively. Results showed that with increasing firing temperature, the soaking time of porous clay capsules decreased. Also the discharge of porous clay capsules, with increasing firing temperature increased. The relationship between discharge of Gorgan-0 and Gorgan-200 with hydrostatic pressures is linear and with increasing fine sand in Gorgan-400, Gorgan-600 and Gorgan-800, the relationship became non-linear. Meanwhile soil wetting shape with clay capsules followed a spherical trend, which is due to the low discharge of clay capsules.

A recognition of appropriate soil erosion control methods along with the use of convenient alternatives in erosion control are necessary for a proper management of natural resources. Run off control through polymers is one of the new methods employed in reducing soil erosion. This research was conducted to evaluate the effects of a polymer, called anionic polyacrylamide, on soil infiltarion rate. A factorial experiment based on a compelelty randomised design including the treatments of polymer at 0, 5, 10, and 15 mg/kg, and the final soil infilatration rates (in field and in the laboratory) in five replications was adopted. Data were analysed for an evaluation of the main and interaction effects in homogenous agricultural soils, using SPSS. The resutls indicated that using polyacrylamide at a concetration of 10 mg/kg has an optimal effect on increasing the final infiltartion rate in both field and laboratory conditions. In addition, in an evaluation of the initial infiltration rate, while employing the double ring method in the field along with polyacrylamide containing water, indicated that the polymer at a 10 mg/kg concentration has an optimal effect on enahncing the initial infiltration rate.