JOURNAL OF WATER AND SOIL (AGRICULTURAL SCIENCES AND TECHNOLOGY)
Year:2017 | Volume:31 | Issue:3

Introduction: Due to the increase in water consumption resulting from climate change and rapid population growth, overexploitation of groundwater resources take place particularly in arid regions. This increased consumption and reduced groundwater quality is a major problem especially in arid areas of concern among water resources managers and planners. The use of modern simulation tools to evaluate the performance of an aquifer could help the managers and planners to decide. In this research, finite difference method was used to simulate the behavior of the quality and quantity of groundwater. …

Introduction: Solute transport modeling in water bodies and especially rives, provides a useful tools for decision-makers and consumers, to take a timely decisions in order to prevent or avoid any catastrophic consequences. Many factors such as velocity, cross-section area, bedform and etc. affect the transport of any solute particle in the media. The aforementioned factors vary both in width and depth, which cause some of the particles to deviate from the main channel to areas in which the particle stays for a longer time. …

Introduction: Rainfed agriculture plays an important role in food production. In Iran, 6 million hectares of cultivated landsare rainfed. Moreover, about 10% of raw agricultural products are being produced by rainfed agriculture. Yields of rainfed fields are decreased due to drought in recent years in Iran. Supplementary irrigation is a suitable management to improve and enhance the yield of rainfed agriculture. …

Introduction: In recent decades, the most important issue for agricultural activities is maximizing the productions. Today, wheat is grown on more lands than any other commercial crops and continues to be the most important food grain source for humans. Sustainable agriculture is a scientific activity based on ecological principles with focus on achieving sustainable production. It requires a full understanding of the relationships between crop production with soil and land characteristics. …

Introduction: Water scarcity is the most important limiting factor in the production of crops in arid and semi-arid regions. Thus, actions for increasing the efficiency and productivity of farm water is inevitable. A large proportion of the water, used in irrigation, evaporates, so an effective solution for conserving water is to control the evaporation on arable lands. Nowadays using mulch or plastic mulch is common and it makes efficient use of water in furrow irrigation possible by conserving and storing soil moisture. …

Introduction: Aqua Crop model was developed to simulate crop response to water consumption and irrigation management. The model is easy to use, works with limited input, and has acceptable accuracy. In this study, the data of an alfalfa field (as a perennial fodder plant) in the Iranian city of Ardestan was used to calibarate and validate the performance of Aqua Crop model to simulate the crop productivity in relation to water supply and irrigation management. …

Introduction: The proper management of water resources in a watershed requires precise understanding and modelling of the hydrological processes. HSPF model uses an infiltration excess mechanism to simulate streamflow and requires the hourly precipitation data as input. Despite the high accuracy of the HSPF model, the lack of rainfall data at short time scales (hour and less than hour) restricts implementation of the model especially for long time simulations. …

Introduction: The heavy metal concentration in agricultural lands, due to the toxicity, persistence and their accumulation in the environment has become a major concern. Ophiolitic formations extend in southern part of central Iran and parallel to folds of the Zagros Mountains, is located in the north of Neyriz town and in the west of Bakhtegan Lake. Rock weathering of these complexes forms sediments and soils with a large amount of Mn, Ni, Cr, Co, Mg and Fe. …

Introduction: Water scarcity is an important challenge worldwide, especially in arid and semi-arid regions.Water-scarce countries will have to rely more on the use of non-conventional water resources to partly alleviate water scarcity. The reuse of wastewater for irrigation is considered to be beneficial for crop production, and due to its nitrogen and phosphorus content, it can help to reduce the requirements for commercial fertilizers. …

Introduction: Soil erodibility (K factor) is generally considered as soil sensitivity to erosion and is highly affected by different climatic, physical, hydrological, chemical, mineralogical and biological properties. This factor can be directly determined as the mean rate of soil loss from standard plots divided by erosivity factor.Since measuring the erodibility factor in the field especially watershed scale is time-consuming and costly, this factor is commonly estimated by pedotransfer functions (PTFs) using readily available soil properties.Wischmeier and Smith (1978) developed an equation using multiple linear regressions (MLR) to estimate erodibility factor of the USA using some readily available soil properties. …

Introduction: Cadmium is one of the toxic heavy metals which is highly problematic in today's industrial world. It is essential to study the techniques for removing or reducing its availability, toxicity and consequently its hazardous effects in environment. Biochar is an amendment reported to be efficient in fixing heavy metals.Pyrolysis temperature is among the most important factors affecting biochar's characteristics, such as pH, CEC and specific surface area and generally it's potential to sorb heavy metals. On the other hand, soil moisture regime could affect pH and EC and consequently the Cd availability. …

Introduction: Atmospheric dust is an important source of heavy metals, particularly in urban environments.Heavy metals can easily attach to dust particles and be distributed in large areas. Therefore, assessing the extent of heavy metals pollution present in nuisance dust is important for establishing pollution control strategies and evaluating the results of previous measurements. Heavy metals contamination in atmospheric dust of Kermanshah provinehas not been previously investigated. …

Introduction: Evaluation of the nutrient status in soil is important from the nutritional, environmental, and economical aspects. Potassium is an essential element for plant growth and is a dynamic ion in the soil system.Soil testing is a useful tool that can help to ensure the efficient use of applied plant nutrients. Soil tests measure the quantity of a nutrient element that is extracted from a soil by a particular chemical extracting solution. The measured quantity of extractable nutrient in soil is then used to predict the crop yield response to application of the nutrient as fertilizer, manure, or other amendments. …

Introduction: Elemental sulfur is byproduct of natural gas refining which during this process, H2S is removed from sour gas and after changes to solid sulfur, it is stored in large block forms. Continuous precipitation of sulfur and its oxidation causes soil acidification and as a result, nutrient cations such as Ca2+, Mg2+, Na+ and K+ will leach from the soil profile. Also, sulfate accumulation led to soil acidification and accelerates the silicates weathering in upper layer of the soil profile. …

Introduction: Peat is an organic soil which is formed by the accumulation of decayed vegetative matter that have formed in areas of poor water drainage. The mineral components of peat are derived from inorganic matter contained in sediments and by adsorption from groundwater. The inorganic (mineral) fraction of peat usually includes only 2–10 Percent of its dry weight, but for highly decomposed peats can increase to about 60 percent of dry weight. Thin sections of peat reveal detailed information of composition, structure, fabric and particularly pore properties which influence water retention and movement. …

Introduction: All living organisms, such as plants, animals and humans depends on the water and life may exist in a place where water is available. Groundwater is the main source of drinking water for more than 5.1 billion people around the world, especially in arid and semi- arid regions such as Iran. Currently, groundwater provided about 60 percent of the worlds drinking water and 77.8 percent of the Iran's drinking water. In recent years, it has been found that groundwater quality is also important as much as its quantity. …

Introduction: Potato production has fourth rank in the world after rice, wheat, and maize with the production of 321 million tons from 19.6 million hectares. In Iran this important crop has third rank after wheat and tomatoes with the production of 4.6 million tons. Potato is a temperate crop, growing and yielding well in cool and humid climates or seasons, but it is also cultivated in tropical to sub-polar climatic regions, and represents a major food crop in many countries. Potato is sensitive to nutrients deficiency especially phosphorus and zinc. At least one-third of the cultivated soils globally are estimated to contain too low amounts of bioavailable zinc for optimal crop production. In Iran more than 70 percent of irrigated soils suffer from zinc deficiency. Many reasons have role in mentioned deficiency such as calcareous and alkaline soils, lower organic carbon and higher application of phosphorus fertilizer. So, evaluation of zinc fertilizers efficiency is essential under different soil phosphorus conditions. …

Introduction: Potassium (K) is one of the major essential macronutrients for biological growth and development. The ability of some bacteria to release potassium from unavailable forms is an important feature for increasing plant yields of high-K-demand crops. Application of soil microorganisms is one approach to enhance crop growth. Some bacteria are efficient in releasing K from mineral sources and in recent years in order to produce and make of potassium biofertilizers, attention to the potassium releasing bacteria has been increased. Production of organic acids and acidic polysaccharides by the microorganisms are the main mechanisms by which K is released. …

Introduction: Salinity is one of the problems of arid and semi-arid soils. Identification and classification of saline/alkaline soils is necessity for dealing with difficult situations and correct management. Considering the nature of salinity data and selection of befitting methods to process data before use artificial neural network, can result in better simulations. The aim of this study was to investigate the optimal method for data processing to enhance the accuracy of surface soil salinity simulation and improve the efficiency of decision tree algorithm. …

Introduction: Soil salinization is increasing across developing world countries and agricultural production is decreasing as a result of this stress. Climate change could adversely affect soil salinization trend through the decrease in rainfall and increased evapotranspiration in arid regions. Policy and decision makers require continuous and quantitative monitoring of soil salinity to adapt with the adverse effects of climate change and increasing need for food. Indices derived from near surface or satellite based sensors are increasingly applied for monitoring of soil salinity so a considerable number of these indices are introduced already for soil salinity monitoring. …

Introduction: Human activities such as intensive cultivation and land use changes alter nutrients fluxes (mainly iron) and mineralogy in soil and terrestrial ecosystems. Iron is an essential element for plants and microorganisms and its solubility is controlled by stable hydroxides, oxyhydroxides, and oxides. In general, parent material, climate, and landscape position are the major factors that accelerate the weathering of the minerals and rocks containing Fe in the regional scale. …

Introduction: Gravel, cobbles and boulders as erodible parameters play significant role to control wind erosion. Therefore, our understandings of gravel, cobbles and boulders percentage variations help to analyze events in the landscape. Close-range photogrammetry as an accurate measurement tool based on photos analysis has been extraordinary improved in recent years and its usage is rapidly growing in environmental analyses. …

Introduction: Southeast watersheds of Iran including Great Karoon, Karkheh, Jarrahi and Zohreh have the most significant contribution in the water supply of the agriculture, industry, drinking water and hydroelectric power plants over Iran.25 percent of the country’s electricity is produced from hydroelectric power plants located in this region. The existence of a monthly relatively high resolution gridded precipitation dataset is of the most important needs of water resources management for such as deciding on the suitable time of dewatering and discharge of dams, calibration of dynamical monthly forecasting models and drought early warning. …

Introduction: Climate change in the current century is an important environmental challenge facing the world. Increase in atmospheric concentration of greenhouse gases such as CO2 as a result of human activities has caused a change in a number of hydroclimatic parameters. Climate change and global warming are the most important issues that have attracted many attentions in recent years. Climatic changes have interpreted as significant changes in average weather over a long period (Salari and ghandomkar, 2012). …