جستجوی مقالات مرتبط با کلیدواژه "physical" در نشریات گروه "آب و خاک"

Considering the lack of renewable water resources in the world and the high share of the agricultural sector in water consumption, makes increasing water productivity very important. Corn is an important type of fodder that is harvested for consumption as silage of the whole plant (Coors et al., 1997). Despite having one harvest stage, this plant has a high dry matter yield. Its silage is easily prepared and it is a tasty fodder with stable quality for livestock and has higher energy than other fodder (Curran and Posch, 2000). Research results in Hamedan province in two traditional and modern irrigation systems showed that the average physical water productivity for fodder corn in traditional and modern irrigation systems was 5.11 and 6.67 kg per cubic meter of water, respectively. The average economic water productivity for fodder corn in traditional and modern irrigation system was 7678 and 10068 rials per cubic meter of water, respectively (Seyedan and Mottaghi, 2019). The main purpose of this article was to measure the water received in the field of fodder corn fields in Behbahan city and to investigate their physical and economic water productivity. To do this, the applied irrigation water, physical and economic water productivity under different agricultural management and in irrigation networks and systems can be compared and evaluated.

This research was carried out in the field and in order to investigate the effects of independent variables on applied irrigation water, physical and economic water productivity in the cultivation of fodder corn in irrigation methods and networks under the management of farmers in the cropping season (2016-2017). It was implemented in Behbahan city. Thus, in 12 farms of the farmers, the applied fodder corn irrigation water was measured (without interfering in their irrigation program). The effective rainfall of the 2016-2017 crop year in Behbahan city was calculated using the United States Department of Agriculture (USDA) method. To determine the applied irrigation water, first, the inflow rate from the selected water source was measured with a suitable device (WSC flume, water meter and ultrasonic flow meter). The SPSS16 software was used for step-by-step linear multivariate regression analysis. Linear multivariate regression analysis was used to investigate the effects of independent variables on dependent parameters. One-way analysis of variance was performed with SPSS16 software. The purpose of using one-way analysis of variance was to statistically show a significant difference between the average of two or more "independent" groups. In order to compare the indicators of physical and economic water productivity , there was a need to resolve the difference. Therefore, to solve the scale difference, the common method of Z-Score standardization was used.

The results of the analysis of variance in the regression model showed that the growth period of the plant had the most significant positive effect on the amount of irrigation water with the t-statistic of 5.288. Performance with a t-statistic of 5.919 had the most significant positive effect on economic water productivity. Among the independent variables, yield and applied irrigation water had the most significant positive and negative effect on the physical productivity of water with the values of 6.419 and -6.381, respectively. The applied irrigation water varied from 4826 to 14733 cubic meters per hectare. The results of the analysis of variance and the descriptive results of the mean of the traits showed that the highest value of physical water productivity was equal to 10.128 kg/m3 in rain irrigation and the lowest value was 4.818 kg/m3 in surface irrigation in the traditional network. They had a significant difference. The calculated Z-Score values showed that 50 and 33% of the sprinkler and surface irrigation farms (modern network) had acceptable economic productivity, but 100% of the surface irrigation farms in the traditional network did not provide acceptable economic productivity.

The amount of irrigation water used in the fields with sprinkler irrigation method was 46 and 33% less than traditional and modern network fields that were irrigated by surface irrigation method. Also, the consumption of irrigation water in the surface irrigation method in the traditional network was 20% more than the surface irrigation in the modern irrigation network. This increase in water consumption was effective in reducing the irrigation efficiency of traditional networks compared to modern networks that irrigated with surface irrigation. The reason for the higher consumption of irrigation water in the surface irrigation method in the modern network compared to sprinkler irrigation can be attributed to the following factors: 1- The lack of irrigation management during the change of the irrigation shift of the fields, which sometimes happens due to the absence of the irrigation worker during the shift change. 2- lack of control of the incoming water of the fields due to the lack of meters or devices to measure the incoming flow. 3- Improper leveling of lands under the modern irrigation network, which increases the irrigation time of these fields. By covering the traditional irrigation canals with concrete or other coverings suitable for the climate of the region, water losses can be reduced. Also, the necessary training for the correct use and management of irrigation water according to the different stages of fodder corn growth will be effective in reducing water consumption. Water according to the stages of growth and development of the plant prevented the occurrence of under-irrigation stress in the stages of flowering and seed filling, which is the most important stage sensitive to water stress.

In this study, the effects of salinity pollution and temperature of the effluent of the Norwegian ‎desalination plant on the physicochemical factors of sea water and ‎macrobenthic communities were investigated. Among the physical and chemical factors, the most changes ‎were related to salinity and temperature and were measured between stations 1 and 8 (P<0.05). ‎In the cold season, the salinity and temperature at station 1 (freshwater effluent outlet) were ‎‎38.67±0.32 ppt and 23±0.58 °C, respectively, and at station 8 (control point), 0.78 ppt. 35.67 ± ‎‎19.33 ± 0.21 degrees Celsius and in the hot season, the salinity and temperature in station 1 were ‎‎36.33 ± 0.60 ppt and 31.67 ± 0.17 degrees Celsius, respectively, and 40.67±0.23 ppt and ‎‎35.67±0.10 °C were measured at station 8. In this study, the predominance was with Amphipoda ‎in summer and Isopoda in winter. Pearson's correlation showed a negative and significant ‎relationship between the density of macrobenthos with salinity and temperature. The diversity ‎index in station 1 was the lowest compared to the reference station. The findings of this study ‎show the effect of desalination wastewater discharge on the physical and chemical characteristics ‎of water and the population of macrobenthos. Among the investigated parameters, salinity and ‎temperature were the most effective influencing parameters, which decreased with the distance ‎from the wastewater discharge site.‎

Rangeland ecosystems cover more than half of the earth's land surface, these ecosystems have high carbon sequestration and cause the formation of about 10% of the total biomass carbon reserves and 30% of soil carbon. Carbon sequestration potential differs according to plant species, habitats, and management methods. Each ecosystem has a certain potential which is determined by utilizing of natural vegetation, climatic conditions, and physical and chemical properties of the soil. Moreover, the amount of carbon in the soil and plants depends on the characteristics of topography, and any change in the elevation and slope of the habitat will affect the amount of organic carbon in the soil and plant cover and carbon sequestration. Therefore, it is important to determine the effects of elevation and slope characteristics, type of vegetation and canopy cover, and soil characteristics on the amount and changes of carbon sequestration. In this study, the carbon sequestration capacity and its relationship with some physical and chemical characteristics of soil, topography, and rangeland habitat have been investigated.

Sampling was conducted in six sites in elevation gradient (from 1400 to 3600 m above sea level; rainfall from 350 to 700 mm; the mean temperature varies from -0.24 to 10.1 °C) in the north of Sablan Mountain, Meshginshahr County, Iran, including three sites with the dominant physiognomy of grass-shrublands and three sites with grassland in three elevation levels of less than 2000, 2000-2500 and more than 2500 m above sea level. In each site, soil sampling was conducted at two depths of 0-15 and 15-30 cm. The random-systematic method was used to study vegetation variables. In this way, 10 plots of one m2 (based on the distribution pattern of plants) were established in each of the three transects with a length of 100 m along each transect. After determining the normality of the data and the homogeneity of the variance of the data,  two-way analysis of variance general linear model (GLM) was used for the overall comparison.

The results showed that with the increase in elevation in the two investigated habitats (grassland and grass-shrubland), the carbon sequestration in the soil increased. Moreover, the results indicate that the depth of the soil has a significant effect on the carbon sequestration capacity. Thus the highest amount of soil carbon deposition is in the soil depth of 0-15 cm in the grassland habitat with an elevation of more than 2500 m (70.53 gr cm-2), then the depth of 0-15 cm in the grass-shrub habitat. At an elevation of more than 2500 m (63.98) and a soil depth of 30-15 cm, the grassland habitat is at an elevation of 2000-2500 m (62.73), and its lowest amount belongs to a soil depth of 30-15 cm. The grass-shrub habitat is at an elevation of less than 2000 m. The results of the correlation analysis of carbon sequestration in habitats and different elevation classes indicate a negative relationship with the percentage of sand, acidity, and electrical conductivity of the soil, and a positive correlation with the percentage of clay and silt, the percentage of organic carbon and organic matter, the percentage of carbon, particulate organic matter, soil nitrogen, and total vegetation cover has shown.

The distribution of carbon stocks between biomass and soil varies among ecosystems and is influenced by elevation, so that the carbon sequestration potential is more significant in high elevation classes than in lower classes. Based on the estimated carbon values in the studied habitats, it can be concluded that the higher percentage of canopy cover and density preserves more moisture and prevents evaporation, which in turn can affect the amount of cover and density. Therefore, the effect of vegetation in different elevation classes on the amount of changes in soil carbon deposition is confirmed based on the results obtained in this research. Overall, the carbon sequestration potential is different according to habitat and elevation classes; therefore, by better understanding these factors and investigating the management factors that affect the sequestration process, we can take steps towards strengthening carbon sequestration and sustainable management of rangelands.

Soil quality is one of the most crucial factors determining crop productivity and production stability. The soil's physical, chemical, biological, and ecological characteristics affect its quality. Numerous researchers have concentrated the evaluation on a small number of soil quality indicators because measuring all soil quality indicators would be time-consuming and expensive. This study looked at the spatial autocorrelation of soil quality in the southwest areas of the Urmia Plain to establish the minimal data set for quantitative assessment. To accomplish this, 120 composite soil samples were collected from a depth of 0 to 60 cm, and the soil quality index was then calculated using the IQI method in 4 modes: Total-Linear (IQIwL-TDS), Total-Nonlinear (IQIwNL-TDS), Minimum-Linear (IQIwL-MDS), and Minimum nonlinearity (IQIwNL-MDS). 22 physical and chemical characteristics were used to choose the data set. The characteristics of sand percentage, sodium absorption ratio, cation exchange capacity, Available phosphorus, active calcium carbonate, and nickel concentration were chosen as the minimum data set (MDS) using the decomposition method into principal components. The linear IQIMDS mode produced the greatest soil quality index result, whereas the non-linear IQIMDS mode produced the lowest. The non-linear mode of the IQI index has a greater correlation coefficient (R2=0.85) than the linear mode of the IQI index (R2=0.73), according to an analysis of the linear and non-linear correlation coefficient between the soil quality index with the total category and minimum data. The findings of computing the global Moran's index for study sets of IQI soil quality index data revealed that the soil quality data are not independent of each other and are spatially autocorrelated, distributed in clusters, and have spatial autocorrelation. Getis-ord GI statistics indicated that the eastern and southeastern parts of the research region comprise clusters with poor soil quality, salt marshes produced by Lake Urmia's drying up, and surrounding arid plains.

This research was carried out to investigate the physical and chemical properties of the soils obtained from dredging of the drainage drains in Abbas Irrigation channels in Ilam province. The area encompasses 16 thousand hectares. In this study sampling was carried out from two major branches. The drainage No. 1 with 21 km length, is flooded to the Rafahyeh river and drainage No. 2 with 5 km length is flooded to the Chikhab River. Sampling was done from drainage soil, dredged soil and the arable land around drainage. A comparison was performed between the three regions of drainage floor area, drainage agricultural land and dredged soil. Soil physico-chemical properties such as particle and bulk density, potassium, magnesium, sodium, calcium and phosphorus, carbonate and bicarbonate, sodium absorption ratio, exchangeable sodium percentage, organic matter, organic carbon, cation exchange capacity, sulfate, base saturation percentage and nitrogen. The results showed that the amount of potassium in dredged soil is more than recommended for soil. Phosphorus concentration was also higher than recommended for soil. Sodium, magnesium and calcium was lower than soil recommended levels. Due to the presence of calcareousmaterial,the amount of limein soils washigh and the amount of gypsum was high as well, due to the warm and dry climate and low rainfall. Soil pH of the region was mostly higher than 7 so they are categorized as alkaline and semi-alkaline soil. The studied soil is classified as saline soil due to high electrical conductivity.Soil texture was sandy clay loam.

The physical properties of soil are essential because of their role in supporting plant growth. These characteristics determine how the plant interacts with the soil, absorption of water and nutrients, root penetration, soil temperature, and the activity of microorganisms. Among the physical properties of soil, soil texture has a significant impact. On the other hand, with the increase in the population and the pharmaceutical industry's need for medicinal plants as the primary raw material for drug production, attention and research on the Lippia citriodora plant are essential. L. citriodora is effective in treating colds, asthma, colic, fever, diarrhea, dyspepsia, insomnia, and anxiety. L. citriodora tea is relaxing and soothing to the nerves. Its analgesic, anti-inflammatory, and antioxidant effects have been proven. Plants containing essential oil, such as L. citriodora may differ in yield and quality of oil according to the type of soil texture, so in order to achieve the highest yield of essential oil and the best quality, the soil should be adapted to the type and needs of the plant for better growth and development be provided. Therefore, the purpose of this research is to investigate the effects of different soil textures on the growth and development and the amount of essential oil of L. citriodora in greenhouse conditions.

This research has been carried out in pots in the research greenhouse of Yazd University in the crop year of 2017-2018. The experiment was conducted as a randomized complete block design in three replications for five months. Plastic pots with drains of 18 heights, opening diameter of 17 cm, and drain diameter of one cm were used for growing seedlings. The pots with different soil textures (loamy, sandy loam, sand, and silty clay loam) based on the calculation of the weight percent of soil moisture at the field capacity (FC) were irrigated. The length of the stem and roots were measured with a ruler with mm accuracy. A caliper was used to measure the thickness of the stem. The samples of shoots and roots were kept in an oven at 70 °C for 48 hr. A digital scale with an accuracy of 0.001 gr was used to measure the dry weight of the shoots and roots of the plants. In order to measure the root volume after separating and washing the roots, the roots of each replicate were placed inside a graded cylinder with a certain amount of water, and the volume of the root was measured in mm based on the change in the water volume inside the cylinder. To measure the plant leaf surface, five leaves of different sizes were randomly separated from each repetition and different parts of the plant, and using the ADC Bioscienticltd model (AM200) device, the total surface size of each of five leaves was measured in each repetition. The essential oil of L. citriodora was extracted by distillation method with water from a Cloninger machine. In this way, in order to increase the contact surface of the water with the plant in the process of extracting essential oils, first the dry leaves of the L. citriodora, were turned into powder by an electric mill and immediately transferred into a 2000 ml flask, then 500 ml of water was added to it. After boiling in water for three hr, the heat source was cut off and the resulting essential oil was poured into opaque glass containers and stored in a refrigerator at 4 °C. To check the statistical effects of each treatment on the study variables, the normality of the data was checked using the Kolmogorov-Smirnov test at the 95% confidence level. One-way analysis of variance (ANOVA) was also used and Duncan's test was applied to compare means. Pearson's correlation method was performed to check the correlation between soil texture and measured traits.

The results showed the significant effects of soil type on the amount of L. citriodora essential oil (P≤0.001). It has shown significant effects on plant height and root volume (P≤0.01) and on the thickness of the stem, the number of leaves per plant and the dry weight of the leaves (P≤0.05). While on some other traits, such as the number of plant branches, fresh weight of aerial parts, fresh weight of leaves, leaf area, root length fresh and dry weight of roots, no significant difference was observed. The results of Pearson's correlation coefficients showed that there is a positive and significant relationship between different soil textures and measured traits. The highest correlation for root length and leaf area was observed with coefficient of 0.89 and 0.80, respectively (P≤0.01). The results of the mean comparison showed that the highest length of the plant was in loamy texture and the lowest was related to silty clay loam texture, the highest number of leaves and dry matter in the aerial part was reported as well as root volume related to loamy texture. To investigate the effect of soil texture on the percentage of essential oil of L. citriodora showed that the highest percentage of essential oil is in silty clay loam texture and, the lowest percentage is related to sandy soil texture.

The results of investigating the effect of different soil textures on the morphological characteristics of L. citriodora medicinal plant showed that the maximum amount of stem thickness, number of leaves per plant, dry leaf weight, plant height, shoot dry weight, and root volume in L. citriodora was in sandy loam soil texture. Moreover, the highest percentage of essential oil is in silty clay loam texture and the lowest percentage is related to sandy soil texture. According to the obtained results, the L. citriodora plant needs a medium amount of nutrients for growth and development. Since the number of leaves produced by the L. citriodora plant in loam and sandy loam soil texture was more than in other textures. Therefore, it can be concluded that the performance of L. citriodora medicinal plant for producing essential oil in each plant is higher in loamy and sandy loam soils.

The main purpose of this study was to determine the return and physical and economical water productivity in the production of horticultural products using drip irrigation system under research conditions in Horticultural Sciences Research Institute (HSRI) in Alborz province during 2016-2019. In this study, the return criteria including; gross income, the percentage of sale return and the percentage of investment return, and also physical and economical productivity analysis were used to measure water productivity. According to the results, during 2017-2019, the average physical productivity of irrigation water in apple and pear genotypes was determined to be 2.75 and 1.7 kg/m3, respectively. The average economic productivity of water resulting from the gross profit of horticultural products in apple and pear genotypes was determined to be 39990.5 and 211486.7 Rials/m3 respectively, in Kamalshahr station. Results also showed that in 2016-2019, the average physical productivity of irrigation water in production of sour cherry, cherry, peach and apple genotypes was 1.08, 0.99, 1.69 and 1.61 kg/m3, respectively, and the average economic productivity of water based on gross profit of horticultural products in the genotypes of sour cherry, cherry, peach and apple were determined to be 106174.8, 95127.8, 25236.3 and 23011.2 Rials/m3, respectively, in Meshkindasht. The results of this study indicated the favorable state of the average economic productivity of water resulted from the profit of the production of apples and pears in Kamal Shahr station compared to the results of studies conducted in some parts of the country. However, in these stations the physical and economic productivity of water in the production of apple, pear and peach, have been generally much lower compared to the average ones resulted in some studied countries. So, investigation of their reasons using comparative studies and identifying strategies to increase water productivity in the production of these products at these research stations is recommended.

Increasing water productivity in agricultural sector is necessary, since this sector is the largest consumer of water in Iran. Because of higher irrigation efficiency, in particular, the reduction of losses of deep percolation and evaporation from the soil surface, drip-tape system is a good option for irrigation. Additionally, using varieties of a crop having high yield is another way to increase water productivity. The objective of this study is to investigate the crop yield and irrigation water volume and to estimate the physical and economical water productivity for different hybrids of maize by drip-tape irrigation. Field experiments were conducted at the research farm of the Agricultural and Natural Resources College of the University of Tehran, in Karaj in 2017. The treatments were nine hybrids of maize (BK42, KSC400, KSC260, BK65, KSC600, BK50, BK74, Barekat3 and KSC704). The results of this study showed that the type of hybrid had a significant effect on crop yield and water productivity. Generally, among the examined varieties, the BK65 hybrid had the highest biomass production (19.54 ton/ha) and biomass water productivity (3.43 kg/m3), and the lowest yield (10.55 ton/ha) and grain water productivity (1.62 kg/m3). Additionally, the KSC600 hybrid had the highest grain yield (13.86 ton/ha) and grain water productivity (2.12 kg/m3) compared to other hybrids. The reason for the high biological performance of BK65 hybrid compared to other hybrids was the higher growth of vegetative part related to reproductive part. The BK42 and KSC260 hybrids had the lowest yield and productivity.

Agricultural activities, especially rainfed wheat, is one of the main reason of the destruction of natural rangeland in the west of Iran. This study aimed to investigate the effect of changing natural rangeland to rainfed wheat for 40 years on some soil properties at the Saral Agricultural Research Station in Kurdistan province. Soil samples were collected from 0–25 cm depth randomly. Some soil properties such as soil texture, bulk density, mean weight diameter, cation exchange capacity, electrical conductivity, pH, calcium carbonate equivalent, total nitrogen, total organic carbon and available amount of Mg, Ca, K, P, NO3 and NH4 were measured. The results showed that land use change from rangeland to rainfed wheat significantly reduces soil quality with regard to all investigated properties except bulk density, calcium carbonate equivalent, P, K, NO3 and NH4. Determination of soil quality index (SQI) using Principal Component Analysis (PCA) showed that total organic carbon, total nitrogen, clay and silt almost justify more than 90% of the variance, which were selected as the minimum data set in the SQI calculation. The results of SQI showed that the index was significantly higher in rangeland (1.58) than in cropland (0.72), indicating degradation of soil quality by cultivating operations.

Investigation of water quality variations in rivers is one of the important criteria for determining the health of watershed. Quantitative and qualitative monitoring plays an important role in sustainable management of river ecosystems. In this regard, the present study was carried out to evaluate the water quality of Ziarat River in Golestan Province, after water sampling from six stations along the river from December 2016 to July 2017 using NSFWQI index. Correlation analysis and cluster analysis were also used to find out the relationships between physical and chemical parameters of water. The results were compared with the standard values of the World Health Organization (WHO) and US Environmental Protection Agency (EPA). The results of this study shows higher values of BOD, Na, Ca and PO4 at the downstream station, as compared to the ones in the upstream stations due to reciving wastewater from different sources. Statistical analysis indicates that there is a significant and strong relationship between some physical and chemical parameters of the river. The results showed that the mean concentration of DO, TDS, Cl, Na, Po4 and NO3 are 5.4, 627.5, 110.02, 48.5 and 9.25 mg/l respectively, and the mean value of Electrical Conductivity was 1028 μs/cm. The comparison of NSFWQI values at the six stations of Ziarat River in different seasons indicated that the first station (Tolboneh, Upstream) had the highest value (55) in May, and the sixth station (Downstream) had the lowest value (35) in July. According to this index, the river water quality is medium in the upstream station and bad in the midstream and downstream stations. The results interpretation showed from upstream toward downstream stations, the pollution load increases and the water quality decreases. Therefore, in order to manage the river water quality, the focus should be done on emission control of point source and nonpoint sourec pollusions. The results of this study provide the opportunity for decision on monitoring and controlling pollutant sources and the proper measures for restoration of river ecosystem for effective use in various applications. Finally, according to the results obtained from NSFWQI index, it can be said that the NSFWQI index describes the quality of water resources easily and reliably and its application is usefull for water resources management of other rivers.

Due to the importance of water that is one of the first needs of human life and according to the problem that Iran has an average annual rainfall of 240 mm and its population of 80 million, It is a dry and semi-arid country, and it faces a lot of water stress, It is essential to prevent water loss as much as possible. One of these methods is the control of evaporation from water storage tanks, which is possible in different ways. Climate change on earth has also contributed to the cause, and the rate of evaporation has been increasing in recent decades. This can sometimes reduce more than 40% of the volume of water stored in the dam. This study introduces different methods and products of chemical and physical of evaporation control from the water surface and disadvantages and benefits of each. Finally, the methods were compared and prioritized using Analytical Hierarchy Process(AHP) in economic, executive, and environmental terms.

Soils pollution with heavy metals is due to the presence of various metals such as copper, nickel, cadmium, zinc, chromium and lead. Heavy metals have a negative effect on the biological parameters of soil, including size, activity and diversity of soil microbial population, as well as the enzymes involved in the deformation of such elements as P, N, C, and S. Thus, the activity of soil enzymes as a bioavailable agent is reflected as a cheap and fast method for the natural and anthropogenic distribution of heavy metals contamination. The purpose of this study was to investigate the effect of lead, humidity and their interaction on urease and phosphatase enzyme activity during a 10 week incubation period. Different levels of acetate lead (50,100, 150 and 200 mg/kg soil) were added to the plots containing two different moisture regimes (field capacity and flooding). The activity of urease and phosphatase (alkaline and acidity) was measured after 2,4,6,8 and 10 weeks of incubation. The results indicated different levels of lead had no significant effect on the activity of urease and acidity phosphatase. In contrast, high levels of lead significantly reduced the activity of alkaline phosphatase. Moreover, moisture served a different role in the activity of these enzymes, and it was related to the lead concentration and incubation time. Additionally, the function and interaction of lead, moisture and time were very influential on urease and phosphatase activity. Therefore, the above three characteristics are very important to study soil contamination for the polluted soils.

The aim of this study was to investigate the effect of different levels of modified biochar sugarcane bagasse and potassium zeolite as natural and environmentally friendly fertilizers on some physical and chemical properties of soil in a completely randomized design with four replications for three months per year 2018 was conducted at the Faculty of Water Engineering, Shahid Chamran University of Ahwaz. The levels of biochar and zeolite use included three levels of 0, 2 and 5 grams per kg of soil (0, 0.2 and 0.5 wt%).The results showed that the 2 and 5 grams biochar per kg of soil increased the total porosity by 3.7% and 9.2% respectively, 9.6% and 19% moisture content of crop capacity, 1 and 1.5% moisture content of wilting point, 9.8% and 21.3% organic carbon, 9% and 18% of absorbable phosphorus, 8% and 22% of nitrogen, 6.5% and 27.9% of electrical conductivity , 3.3% and 8% respectively of bulk density and 0.26% 0.92 percent soil acidity. The levels of 2 and 5 grams of zeolite per kilogram of soil also increased 2 and 6 percent bulk density, 2.33% and 3.89% specific gravity, 10.1% and 26.5 percent moisture content, 1.1% And 6.3% moisture content of wilting point, 0.65 and 1.05% of acidity, 9.1% and 33.5% of electrical conductivity, 0.09% and 3.4% of total porosity, 0.26% and 0.92% respectively Soil acidity was not significant and did not have a significant effect on specific gravity, organic carbon, absorbable phosphorus and soil nitrogen.

Resently, with regard to the excessive use of chemical fertilizers in agricultural land and the degradation of soil and the environment, the use of these fertilizers highlights the importance of using organic fertilizers and polymer materials such as hydrochloric and superabsorbent. The purpose of this study was to investigate the effect of different levels of modified hydrochar, cane sugar and superabsorbent type A200 as environmentally Compatible materials on some soil characteristics using a factorial design and a completely randomized block design with four replications for four Month was conducted at Shahid Chamran University, Ahvaz, Iran. The levels of hydrchar and superabsorbent use included three levels of 0, 2 and 5 grams per kg of soil (0, 0.2 and 0.5 wt%). The results showed that two and five gram hydrochar per kg of soil increased 5.9% and 9.4%, respectively, total porosity, 9 and 17.9% moisture field capacity, 0.43% and 1.2% moisture content of wilting point , 9.8% and 18% organic carbon, 4% and 15% of absorbable phosphorus, 6% and 18% nitrogen, 5.5% and 16% of electrical conductivity, and 7.7% and 7.7% reduction of bulk density, 0% and 0.77% of the specific gravity, 0.39% and 1% of soil acidity compared to the control. The Level of two and five grams of super absorbent per kilogram of soil also increased 10 and 18.6 percent moisture content of filed capacity, 8 and 11 percent moisture content of wilting point, 0.52 and 0.92 percent, acidity, 4.26 and 13 The percentage of electrical conductivity was 2.7 and 9.9%, respectively, and total porosity decreased by 2 and 5.7%, respectively, and had no significant effect on the amount of organic carbon, absorbed phosphorus, nitrogen and specific mass of soil. In general, the results indicate that hydrochar treatment is superior to superabsorbent treatment on Improvement soil physical and chemical properties of soil with loam texture.

  Soil Water Repellency (SWR) is one of the dynamic soil characteristics that either reduce water penetration in the soil or prevent it. In the northern forest areas of Iran, fire is one of the most important environmental concerns and one of the main factors of the change in soil water repellency phenomenon. Therefore, this study aims to investigate prescribed fire effect on the soil of forest areas of Toshen's watershed, temporal variability and its interaction with physical and chemical properties of soil in Golestan Province. Soil of forest areas in the slope class of 15-30% and depth of 0-5 cm of soil surface was studied in 30 replications in laboratory. Physical and chemical properties of soil, including percent of clay, silt and sand, soil organic matter, pH, EC and aggregate stability (MWD) were investigated before and after fire. In order to study the effects of fire on soil water repellency in laboratory conditions, prescribed fire was applied. SWR was determined with Water Drop Penetration Time and Molarity of an Ethanol Droplet tests, before and after fire. According to the WDPT test, before the fire, 100% of plots were wettable (class 1), but one day after the fire, 100% of the plots were showed slightly water repellent (class 2 and 3). The MED test showed that all plots were wettable (class 0) before the fire. One day after the fire, the intensity of SWR increased, so that 30, 50 and 20 % of the plots were slightly water repellent (class 1), moderately water repellent (class 2) and less strongly water repellent (class 3), respectively. Investigating the process of temporal variability of both SWR indices showed that the SWR class after the fire is temporary and up to one month after that, the SWR classes is greatly reduced. The results showed that there are good correlations between two post-fire hydrophobic tests. (R2=0.85). There was a moderate correlation between two WDPT and MED SWR tests with pH, EC, MWD and soil organic matter, but as for soil texture components, there was poor correlation. Relatively poor SWR correlations with soil physical and chemical characteristics indicate that these changes are not likely to be the main cause of SWR changes. Some of these changes can be explained by the variability of aggregate stability after the fire. These changes in the mechanical stability of the soil structure can be caused by two main mechanisms: (1) Changes in the composition of the solid components in the soil that increase the cohesion forces between the particles in the aggregates. Consequently, the stability of the soil structure against the physically destructive forces increases. (2) Changes in the physicochemical properties of the soil solution (an increase in the EC) that prevent clay dispersion and microaggregate destruction (physicochemical mechanism). Finally, the results of this study showed that despite the high wettability in loess soils, fire can be an external factor that causes a weak and immediate increase in SWR. The slightly soil water repellent may be due to the following: (i) SWR often occur in coarse soils with high organic matter. (ii) The samples were taken from the soil surface layer (0-5 cm), while the fire can cause some organic matter to accumulate in the subsurface layers and cause SWR on lower horizons.

The aims of this study are evaluation of water use management and water use efficiency of Yamchi pressurized irrigation and Ghoorichay low pressurized (hydroflume) canals, with total area 3885 ha and located in Ardabil plain. Annual relative irrigation supply, Annaual relative water supply, relative rainfall supply, water productivity and irrigation water productivity, as physical water use efficiency and parameters pure and impure benefit of water use efficiency and pure and impure benefit of irrigation water use efficiency as economic parameters were calculated. Results showed that, for four years of 2011-12, 2012-13, 2013-14 and 2014-15 mean of irrigation deficit of Yamchi and Ghoorichay canals were calculated 28 and 43 percentage, respectively. For three years of 2012-13, 2013-14 and 2014-15 mean of water productivity in Yamchi and Ghoorichay canals was calculated 1.52 and 2.15 kg/m3 and mean of irrigation water productivity was calculated 2.16 and 4.08kg/m3, respectively. Mean of water pure and impure benefit for Yamchi canal were estimated 987.67 and 884.67 toman/m3 and for Ghoorichay canal were estimated 4028 and 9100 toman/m3 , respectively. Mean of irrigation water pure and impure benefit for Yamchi canal were estimated 12669, 1515.33 toman/m3 and for Ghoorichay were estimated 23988.33 and 6523.33 toman/m3, respectively.

Presently, floodwater spreading schemes are used as aquifer management projects in the country. In these projects, spreading a large volume of floods containing salts and suspended loads over the spreading network, may lead to differences in soil salinity and alkalinity. Therefore, it is necessary to study the amount and the trend of these differences over time in order to produce a suitable method to increase the utility of such designs. In this research, the results of 40 studies on the effects of spreading floodwater on the soil properties were evaluated. In general, studies show the improvement of the quality of some of the soil physical and chemical properties due to the floodwater spreading. These effects include: more balanced soil texture and soil moisture conditions, improved soil physical and chemical conditions, increase in some of the soil elements and consequently an increase in soil fertility compared to pre-construction floodwater spreading system, reduced infiltration, and providing suitable conditions for the growth of pasture plants and planted seedlings and consequently changing the ecological landscape of these areas.

Dust deposition phenomenon is an important climatic and environmental issue in arid and semi-arid regions. The objective of this study was to examine important characteristics of atmospheric dust in Kerman as one of the major cities in arid areas of our country with high potential of dust production. Dust samples were collected monthly using glass traps installed on the roof of 35 one-story buildings in Kerman for 7 months from April 20 to Nov. 20, 2012. To compare the results of atmospheric dust with those of soil, 60 surface soil samples (0-10 cm) from outside Kerman and 35 soil samples from urban areas were also collected. Some physical and chemical characteristics such as pH, electrical conductivity, organic matter, calcium carbonate equivalent, and particle size distribution were determined in dust and soil samples. The results of chemical analyses indicated that the amount of these properties is much higher than that in soils. Atmosphere dust particles appear to mainly originate from alkaline and saline soils surrounding the city of Kerman. Dust particle size distribution analysis further confirmed that dust particles have been transferred to Kerman city from medium to long distance areas. Temporal variability in dust chemical properties indicates that the contribution of anthropogenic and natural sources to urban dust in Kerman has seasonal changes. Based on the results obtained, it is necessary to control dust production outside and inside the city and its distribution in populated areas employing proper management practices.

Soil erosion by water is one of the most important processes of land degradation, especially in semi-arid areas. Among different types of the soil erosion, gully erosion accounts as one of the most critical processes which can cause soil destruction, changes in landscape and water resources filling of reservoir of dams,decrease in water transport capacity of rivers and agricultural lands destruction in the lowland areas. Based on the Posen definition, gully is a river with high slope walls and an erosive high slope and active head which occurs by erosion resulted from the surface flow (usually during or after high density rainfalls). Different factors play role in occurrence and development of gullies and sediment production resulted of this kind of erosion which includes slope, amount and distribution of rainfall intensity, construction operations, vegetable cover destruction, land-use change, unsuitable utilization, and susceptibility of bed materials to the erosion and flood. Considering the importance of gully erosion and the way of its occurrence and development and its control, more comprehensive studies are needed to be done. Although, some studies have done in this subject that some of them are depicted below: Rinkez et al showed that gully erosion is further occurred in soils with high exchangeable sodium percentage and sodium absorption ratio and they depicted that these two factors are important indices for soil diffusion amount in gullies. Buma and imson investigated factors such as electricity conductivity, calcium carbonate percentage, and the type of clay mineral in white, brown, and gray samples of marl in the Peter area, Spain. According to their results, factors such as electrical conductivity and sodium absorption ratio had high correlation with erosivity of the Bad Lands.
Material and Agh Emam(2) watershed is located between 55º 42´ 53˝ to 55º 45´ 43˝ eastern longitudes and 37º 41´ 01˝ to 37º 46´ 19˝ northern latitudes in the east parts of the Golestan province with an area of 2,595 hectares. Arab gharehaji rural is considered as the most important area which is located at the outlet of the basin. In current study, at first, frame work and total surface of the area were investigated by field observations and 9 digitated gullies were observed during field observations. Then, spatial position of each gully was determined by using global positioning system and map of gully distribution was obtained for the study area. Then, by overlaying this map on lithology, slope degree and altitude maps of the study area, the mentioned characteristics were determined for the gullies. After sampling from the soil, they were carried to the lab and clay percentage, silt percentage, sand percentage, saturation humid percentage, electrical conductivity, acidity, organic matter percentage, exchangeable sodium percentage, sodium absorption ratio, percentage of neutrophil materials for two considered depths were measured. Then, two statistical tests were applied in order to determine the significance and or non- significance of different physical and chemical characteristics of the soil which are compare means of two statistical populations and t-Student tests. Also, a non- parametric (chi-square) test was used in order to determine the statistical analysis of the effect of non-soil factors of occurrence of digitated gullies including slope classes, altitude classes, lithology and land use.
Initial investigations of the field observations, aerial photos and satellite images showed that different factors play role in the occurrence of digitated gully in the study area. So, physical and chemical characteristics of the soil, slope classes, altitude classes, lithology and land use were investigated in current study.
A: Results of the effective physical and chemical characteristics of the surface and sub- surface soil on the occurrence of digitated gully erosion
Results showed that, there wasn’t statistically significant difference between the percentages of sand, electrical conductivity, organic matter and lime, out of the digitated gully erosion (upland of the gully and beholder area) and their amounts in surface soils in the digitated gully, but, there was significant difference for silt, clay, saturated humidity percentage, cation- exchange capacity (CEC), exchangeable sodium percentage and sodium absorption ratio. Also, the results showed that there wasn’t statistically significant difference between the sand percentage, silt percentage, clay percentage, acidity, organic material and lime in sub- surface soils out of the digitated gully erosion (upland of the gully and beholder area) and their amounts in sub- surface soils in the digitated gully, but, there was significant difference for saturated humidity percentage, electrical conductivity, cation- exchange capacity, sodium absorption ratio and exchangeable sodium percentage.
B: Results of the role of non- soil effective factors on the occurrence of the digitated gully erosion The results of the non- parametric Chi- Square test of the effect of slope classes, altitude classes, lithology and landuse on the occurrence of digitated gullies showed that only lithology affected the occurrence of the digitated gullies. The results of current study are compatible with the results of Ghoddusi and Davoodirad, ZareMehrjerdi et al, Servati et al, Shadfar et al, Khuje et al, Rahi et al, Bayati Khatibi et al, Sayadi and Tashakkori.
Totally, it can be said that saturated humidity percentage, cation- exchange capacity, sodium absorption ratio and exchangeable sodium percentage as soil factors had effective role on gully erosion occurrence in the study area, while, lithology was effective among the non- soil factors. Therefore, considering these factors is necessary in order to control the erosion.

Tree plantations not only alter aboveground vegetation but also lead to significant changes in the physical and chemical properties of soils. Foresters have always relied on a knowledge of chemical and physical properties of soils to evaluate capacity of sites to support productive forests. The purpose of the present study was to investigate flora and plant species diversity in a tree plantation. To achieve this purpose, 20-year old soft and hardwood plantations (Pinus brutia Ten,Cupressus arizonica Green. and Amygdalus scoparia Spach.) were selected in Reymaleh region, Lorestan province. In each site, 10 plots of 100 m2 (10 ×10 m), totally 30 plots, were randomly selected and then 5 subplots (2.5 ×2.5 m) were located in the center and 4 corners of each (n=150). Composite soil samplings were made at 0-30 cm depth in each plot. The results indicated that there was significant difference among stands regarding organic carbon (%) and potassium (p=0.01) as well as total nitrogen (p=0.05). The highest organic carbon (%), potassium, and total nitrogen content were observed in Amygdalus scoparia and Cupressus arizonica stands, respectively. There was no significant difference among these stands with regard to pH, bulk density, and phosphorous content.