Journal of Water and Soil
Year:2017 | Volume:31 | Issue:2 |Papers Count:30

Introduction: Nowadays, contamination of water is one of the problems that are more considered. Fecal Coliform (FC) is one of the most common indicator organisms for monitoring the quality of water. The problem that complicates the modeling of indicator organisms such as Fecal Coliform is determining the appropriate amount and an optimum rate of decay. It has been reported by many scientists that the decay coefficient or mortality rate is significantly affected by environmental elements. In this study, the effect of environmental parameters such as temperature, turbidity, radiation and suspended sediment concentration on the coliform decay coefficient hasbeen verified to have a dynamic and variable decay coefficient for better and reliable estimations of fecal coliform concentartion values. …

Introduction: The nitrogen cycle may be affected by chemical fertilization and industrial waste water.Nitrate can affect the human body through water and food, which can be transformed into nitrate and nitrosamine as a threat for humans and aquatic life. Therefore, detecting the influential elements and factors on this cycle, are essential from the environmental protection point of view. Many of scientists utilize mathematical models for these kind of problems. These models encompass linear and nonlinear differential equations that aresolved by numerical computer cods. The numerical codes are called “Deteministic computer models”, and running the model with different input values is called a computer experiment. One of the most famous models for the estimation of nitrogen river load is INCA-N (Integrated Nitrogen in Catchments). …

Introduction: The conflict between environmental protection and the economic development by different land uses within a watershed are challenges facing land use planners in many developing countries. Because of the growing demand for water, water resources optimization allocation management is at the forefront in formulating sustainable development policies for many countries. Conjunctive use of surface water and groundwater is being practiced in many regions of the world to bring more areas under irrigation, increase agricultural production and productivity, and also maintain overall system balance. …

Introduction: Soil physical quality isone of the most important factors affects plants water use efficiency in agricultural land uses. In the literature, some soil physical properties and indices such as S-index, Pore Size Distribution (PSD), porosity, Air Capacity (AC), Plant Available Water (PAW) content, Least Limiting Water Range (LLWR) and Integral Water Capacity (IWC) were mentioned as the soil physical quality indicators. It has been reported that the soils with the same PAW, LLWR and IWC may have different physical qualities. The index of Integral Energy (EI) of the soil moistureranges may differ between the soils with equal soilmoistureover a defined water content range. …

Introduction: It is important to understand the processes of diffusion and transporting solute in the furrow irrigation system, because of their role in diffusion of pollutants in the environment. Movement pattern of fertilizer from the source ofplants is usually under the effect of advection and turbulent diffusion processes.Maximum solute diffusion length (SDL) is the minimum distance which materials such as a fertilizer, could uniformly spread in the whole flow cross section. The SDL depends on hydraulic properties, condition of vegetation and channel specifications. Velocity profile of furrows as a result of parabolic shape of the crosssection is different thanthe rivers and rectangular channels. The main objectives of this study were to investigate SDL in a permeable parabolic channel and evaluate the effect of different discharges and bed roughness on diffusion length in a parabolic cross-section of a furrow. …

Introduction: Rice is one of the cereals that are widely used food in the world as staple.Rice is the largest consumer of water among agricultural products. At the field level, rice receives up to 2–3 times more water per hectare than other irrigated crop for producing of one kilogram of rice.Accordingto water resources limitation in Iran, According to water resources limitation in Iran, careful planning is essential to optimal use of water resources in agriculture as the largest consumer. One of the methods to reduce water consumption in rice cultivationis changing the traditional irrigation methods (flooding) to periodic irrigation. …

Introduction: Qazvin plain is one of the most important agricultural regions in the central part of Iran.Because of recent continuous droughts and the increases in the demands of different sectors such as agriculture, industry, environment and domestic, the plain is faced witha severe shortage of water resources. Due to the declining share of surface waters, farmers increased the using of groundwater. And the overusing of groundwater for irrigation has caused the severe drop in water level of the aquifer. …

Introduction: Due to the rapid rate of population growth, water resource topics wasmainly affected by the economic and social components, however, the importance of environmental issues in such projects has gained more attention. As pollution loads are increasing, it has become more essential to incorporate water quality in water resource management issues. Under this condition, optimal water allocation by considering multiple objectives of water quality and quantity issues can lead to sustainable and optimal benefit of stakeholders. This study was done in order to balance environmental and economic concerns in water resource allocation. …

Introduction: Iron is one of the essential micronutrients for plant growth. The total amount of iron in soil is often more than plant iron requirement, but the low solubility of iron compounds in many of soils leads to low uptake of this element by plant and eventually, results in iron deficiency symptoms in plant. Iron is the structural component of cytochromes, leghemoglobines and ferredoxins. This element participates in many vital activities of plants, such as photosynthesis, respiration and fixation of molecular nitrogen. Some of micaceous minerals including muscovite and phlogopite which contain significant amounts of iron are plentiful in soils of arid and semiarid regions of Iran. The purpose of this study was to evaluate the ability of two plant species (alfalfa and barley) to uptake structural iron from muscovite and phlogopite. …

Introduction: Heavy metal contamination not only adversely affects the chemical properties, availability of nutrients and biological activity of the soils, but also causes serious risk to the human health from entering the food chain. Cadmium as an unnecessary heavy metal is highly toxic to plants. Cadmium toxicity inhibits plant growth and even death. Metabolic processes such as photosynthesis and cellular respiration are disturbed due to cadmium toxicity. Among the heavy metals, zinc is an important nutrient in many biological processes such as photosynthesis, activity of antioxidant enzymes, proteins, hormones and other activities. Because of the similar chemical behavior of cadmium and zinc, interaction between the two metals is of interest to many researchers. …

Introduction: Magnetic susceptibility measurements can serve a variety of applications including the determination of changes in soil-forming processes, the study of parent material effects, understanding sedimentation processes, soil drainage conditions, and even the separation and identification of soil delineations.The technique is especially attractive since it is relatively rapid, non-destructive, and can be applied to both intact and disturbed samples of soils. Magnetic susceptibility is defined as the ratio of the total magnetization induced in a sample relative to the intensity of the magnetic field that produces the magnetization. …

Introduction: Nitrogen is the main component of fertilizer programs necessary for production of high quantity dryland barley. This element is the second limiting factor, after water in dryland areas. So for economic production of barley, the proper nitrogen fertilizer application is essential to increase seed quantity and quality in Iran dryland areas. Many researchers have been confirmed that dryland barley yield increased by nitrogen application management. Nitrogen fertilization in dryland areas can increase the use of soil moisture, and improve barley yields to some extent. …

Introduction: Rhizosphere is commonly defined as the zone where root activity significantly influences the biological and chemical properties of the soil. Biological, physical and chemical characteristics of rhizosphere, especially metal availability and metal chemical forms are different than the bulk soil. Plant roots continuously release compounds such as sugars, amino acids, and carboxylic acids. Plant roots have the ability to transform metal fractions for easier uptake through root exudation in the rhizosphere. This study was conducted to investigate change in availability and fractions of Copper in the rhizosphere of sunflower (Helianthus annuus L.) in a sandy contaminated soil treated with chelators (EDTA, citric acid andpoultry manure extract (PME)) in greenhouse condition. …

Introduction: Land suitability evaluation (LSE) may be considered as a worldwide accepted procedure to achieve optimum utilization of the available land resources for sustainable agriculture. The common LSE procedures, like the widely accepted “A framework for land evaluation” presented by FAO, however, do not consider variability of soil quality parameters; whereas, the soil quality and its suitability for different uses are influenced by highly variable land management strategies. Therefore, assessing the spatial variability pattern of environmental variables and their accumulative effects on land suitability for specific crops, is the key for achieving to thoughtful land use planning for sustainable use. The present study was done aimed to evaluation of spatial variability of land suitability for irrigated wheat in Zanjan plain using accumulated limitation scores and geostatistics. …

Introduction: Aggregate, as the basic unit of soil structure, represents a collection of primary particles which their adherence to each other is more than their connection to environ soilparticles. Aggregate stability is a highly complex parameter influencing a wide range of soil properties, including carbon stabilization, soil porosity, water infiltration, aeration, compatibility, water retention, hydraulic conductivity andresistance to erosion by water and overland flows. Maintaining high stability of soil aggregate is essential for preserving soil productivity, minimizing soil erosion and degradation and thus minimizing environmental pollution as well.Nevertheless, aggregate stability is described as one of the soil properties that can serve as an indicator of soil quality. The main purpose of this study is to determine the most important component of soil aggregate (macro and/ormicro) in estimating the soil structural stability in the Rabor region, Kerman province, using geostatistical method. …

Introduction: Land degradation and soil losses are common and universal problems which is a pose threat to food security, ecosystem health and consequently sustainable development and human well-being. Meanwhile, improving the chemical and physical properties of biological soil crusts is an effective factor in soil loss controlling. Also, the chemical properties specially soil nitrogen are the important factors for soil quality determination. To this end, various strategies on techniques of amendments have been implemented to improve soil properties and quality. …

Introduction: Application of chemical fertilizer is one of the methods to supply nutrient elements for plants and it is an effective method to meet plants nutrients demands; but organic fertilizers such as biochar application can be used as a proper solution to decrease gases resulted from agricultural activities, increase soil's organic matters and to manage soil fertility. Biochar can increase soil fertility of some soils, increase agricultural productivity, and provide protection against some foliar and soil-borne diseases. Biochar is a high-carbon charcoal used as a soil amendment and it is made of plant biomass and produced during pyrolysis process in the absence of oxygen. The ability of biochar to store C and improve soil fertility will depend on its physical and chemical properties, which can be varied in the pyrolysis process (pyrolysis temperature) or through the choice of raw materials. …

Introduction: Citrus is an important fruit crop cultivated in tropical regions of the world with immense nutritional value and advised on daily basis in diet. In Iran, it is cultivated in high reaches of northern and southern regions. The low productivity has been ascribed mainly to the nutritional health of the plantations which is the most concern among farmers. To plan fertilization efficiently, it is necessary to know the desirable concentration of macro and micro nutrient in tissues that are representative of the plant’s nutritional status.Traditionally, to determine the optimum fertilizer doses the most appropriate method was to apply fertilizer on the basis of soil test and crop response studies (Regar and Singh, 2014) which defied the synergistic and antagonistic effects in relative availability of different essential nutrients from soil. …

Introduction: Dynamics of organic carbon and nitrogen are controlled by several factors, including physical, chemical and biological properties of soil. Heavy metals contaminate soils and change soil properties and affect organic carbon and nitrogen dynamics. Since toxicities of heavy metals are different and organic carbon and nitrogen dynamics are affected by available concentrations of these metals, the aims of this experiment were to assess the effects of different levels of soil cadmium on mineralization of organic carbon and nitrogen. …

Introduction: Phosphor (P) is the second nutrient element after nitrogen mostly required by plant. P is the main component of nucleic acid, phospholipid, ATP and some coenzymes. The effectiveness of phosphate fertilizer application is only about 15% - 20% and 10 – 25%, based on the different references. Rock phosphate (RP) as a source of P is not expensive, but its availability of P is low. Solubility of RP can be increased by phosphate solubilizing microorganisms. Increasing RP solubility by microorganisms is due to the lowering of pH and/or organic acid excretion. …

Introduction: Among wide variety of soil pollutants including heavy metals, acidic precipitation and other toxicants, the importance of heavy metals due to their pollution capacity has received growing attention in recent years. These metals enters into soil through municipal and industrial sewage as well as direct application of fertilizer and pesticides. High cadmium and lead concentration in soil lead to severe environmental pollution.Such pollution not only has a destructive effect on crop yield but also endangers human being and other creatures’ health after entering in their food chain. Several physical, chemical and biological methods used to reduce the adverse effect of high concentration of heavy metals in soil. …

Introduction: Arsenic (As) is the twentieth element in earth's crust and the contamination of soils and ground waters by it is common and disturbing. In addition to geological factors and soil parent material, human activities such as mining and smelting, coal combustion and the use of arsenic-containing compounds such as insecticides, pesticides, wood preservations and etc lead to the accumulation of high levels of this metal in the soils. Long-term exposure to As can lead to skin, bladder, lung, and prostate cancers. …

Introduction: Given the fact that Iran is located in the center of the dryland of earth and is significantly influenced by the deserts of Central Asia and hot dry deserts of Arabia and Africa, is one of the most arid and low rainfall land areas. So is the proper management of water resources is of critical importance. The first step in the proper management of water resources is studying the factors that affected these resources including climate change. In fact climate change is a dynamic process in terms of time and place. …

Introduction: Surface soil moisture is one of the most important variables in the hydrological cycle, and plays a key role in scientific and practical applications such as hydrological modelling, weather forecasting, climate change studies and water resources managements. Microwave radiometry at low frequencies (1.4GHz) is an established technique for estimating global surface soil moisture with a suitable accuracy. …