جستجوی مقالات مرتبط با کلیدواژه « مدیریت پایدار » در نشریات گروه « کشاورزی »

In general, mining is associated with the destruction of natural resources and the environment, intentionally or unintentionally. This has gone so far that the supporters and advocates of natural resources and the environment consider mining and mining activities as one of the most important factors in the destruction of natural resources and the environment. On the other hand, the importance and role of mining and mining in the progress of the country and achieving sustainable development is not hidden from anyone. In other words, mining activities cannot be stopped, nor can the importance of natural resources and environment be ignored as one of the pillars of sustainable development. What is certain is the point of interaction and balance of these two categories of restoration and revitalization of mines. This means that after benefiting from small and large mines, it is necessary to restore and restore these mines with the aim of sustaining natural resources and the environment, and as far as possible, the destructive conditions and disturbances created should be returned to the previous state. Mining or close to the original state.

Analyzing changes in land use/cover and identifying their drivers is essential for developing sustainable land management approaches that restore ecosystem resources and services. This research analyzes land use/land cover changes in the Fandoghlo region in Ardabil province in the last two decades based on Landsat 8 (OLI/TIRS L1TP) satellite images and investigates governance and socio-economic drivers based on household surveys and key informants interviews. The results recorded a negative net change in forest (187.5 ha) and rangeland (662.5 ha) ecosystems and a positive net change in agriculture (587.1 ha) and man-made (267.6 ha). Analysis of the 20-year (2003-2023) change detection matrix showed that about 26% of the study area experienced a transition. Based on the results of the investigation of 11 governance and socio-economic drivers, the observed change in ecosystems caused by the expansion of agriculture (91%), poverty (71%), livestock pressure (68%), weak law enforcement (65%), wood smuggling (62%), increasing demand for firewood (60%), population growth (44%), fires (41%), incompatible forms of tourism (40%), distance to the road (36%), and mining (11%). These socio-economic drivers have a significant impact on the availability of ecosystem services, community welfare, biodiversity, and climate. Therefore, this study recommends coordinated efforts by stakeholders to develop participatory ecosystem management and public awareness on the coexistence of nature conservation and sustainable livelihoods. In order to protect ecosystems in this region, it is crucial to empower local communities, understand the dynamics of agricultural lands, and manage the causes and consequences of recent demographic changes.

Currently, the protection and sustainable management of forest ecosystems in the Zagros vegetation area has always been the main concern of activists and officials in this area. On the other hand, the agricultural Extension as an interdisciplinary science examines the phenomenon of decline of Zagros oak forests from a sociological and psychological perspective, as well as from an agricultural and rural perspective, and offers strategies that maintain the sustainability of natural resources while maintaining livelihoods. Also elevate. the present study aimed to Explain the Sustainable Management Extension Strategies of Zagros Oak Forest by using SWOT method. In this regard, internal and external factors were collected through in-depth interviews with 30 scientific and executive experts in the provinces of Zagros basin in the form of strengths, weaknesses, opportunities, and threats. Additionally, they were identified through line-by-line analysis in the form of common content and using MAXqda12 software analysis. In the next step, the internal and external factors questionnaire was adjusted and and the weight factor of each factor was calculated and the identified strategies were prioritized based on the Quantitative Strategic Planning Matrix.Considering the results in the internal and external factor evaluation matrix for the sustainable management of forests in the basin, as well as the dominance of weaknesses in the external factor evaluation matrix and threats in the internal, defensive pattern was more prioritized for managing the forests sustainably compared to the other strategic patterns.

The present research was conducted with the purpose of applying the theory of planned behavior in explaining the environmental behavior of the villagers in Ilam province about protection of the oak forests in South Zagros. The statistical population of the research consists of all the villagers of Ilam province settled in the South Zagros region (N=5512). Sample size using the table of Bartlett et al. (2001), 416 people were determined and stratified random method with proportional assignment (according to the city of activity) was used for sampling. In this research, the status of the environmental behavior pattern of the villagers of Ilam province in the protection of the oak forests of South Zagros region was analyzed using SPSS22 and SMART PLS3 statistical software. And according to the calculated indicators, the reliability and validity of the model was confirmed. The results of the structural equation modeling approach indicate that attitude variables (β=0.745), mental norms (β=0.638) and perceived behavioral control of the villagers of Ilam province (β=0.589), influence It has a positive and significant effect on their intention to carry out the environmental behavior of protecting the mentioned forests. Also, based on the results, perceived behavioral control (β=0.602), intention (β=0.711), time perspective (β=0.653) and spatial attachment of the villagers of Ilam province towards the protection of oak forests of South Zagros (β=0. 473), have a positive and significant effect on their environmental behavior in the protection of said forests. In general, based on the findings, it can be seen that the theory of planned behavior through the variable of the intention of the villagers of Ilam province to carry out the environmental behavior of protecting the oak forests can respectively account for 52 and 61% of the changes in the variables of the intention and behavior of the rural households towards the protection of To predict the oak forests of South Zagros basin.

Detailed water resource balance reports are very important in promoting sustainable watershed management programs. The main purpose of this study is to evaluate and use the SWAT+ model as a new version of the SWAT model in simulating hydrological processes and determining the role of effective factors in the changes of water balance components in Tashk Bakhtegan basin. In this regard, after preparing the required information and entering them into the SWAT+ model, the steps of calibration and validation of the model for river flow in 10 hydrometric stations, base flow in three upstream stations, as well as calibration of the underground water level, evapotranspiration and yield of major cultivated crops was done at the basin level during the period (1980-2014). The evaluation of the model calibration results in most of the stations shows the index values of (R2>0.5) and (NSE>0.2) that the results were favorable and acceptable. Comparing the results of the water balance obtained from SWAT+ with the results of other studies shows that the final values of the evaporation-transpiration parameter were higher and the surface currents were lower than the results of other researches, so that only compared to the results of the SWAT model, the three mentioned components increased by 17. 0, 1.13 and showed a decrease of 0.06 billion cubic meters per year. Examining the spatial and temporal changes of the balance components also showed that the changes in precipitation and evapotranspiration decrease from north to south of the basin, and in areas with high rainfall, their fluctuations are more proportionate and congruent. The most important factor in the decrease of water flow (74.7 percent) and the increase of evaporation-transpiration (80.3 percent) of the basin is related to non-climatic and human factors such as land use change, construction of dams, etc. and the effect of climatic factors on water flow changes and evaporation-transpiration is 25.3 percent and 19.7 percent respectively. Evaluation of SWAT+ model calibration results and comparison of its results with other studies conducted in the basin indicate the acceptable performance of this model in simulating and separating the contribution of different climatic and human factors in the hydrological conditions of the studied basin. Therefore, according to the new capabilities of this model and the improvement of the simulation processes of underground water and its exchange with the river compared to the SWAT model, it is recommended to use this model in order to estimate and verify the water balance components of basins.

After implementing a logging ban in the northern forests of Iran and increasing protection forces in recent years, the current performance needed to be evaluated. The purpose of the research was to compare two approaches - sustainable exploitation and exploitation cessation - from the perspective of local stakeholders and experts, considering the physical and technical challenges in forest protection. The validity and reliability of the questionnaire were confirmed using acceptable content validity (above 0.7) and incongruity rate (below 0.1) in pairwise comparisons based on AHP. Two groups, consisting of 20 local stakeholders and 21 forest experts in the Chafroud 10 and Malakroud 24 basins, conducted a hierarchical analysis to compare the physical and technical challenges in forest protection. The results indicated that physical protection challenges were three times more important than technical challenges. Among the technical challenges, the establishment of protection belts, fence weaknesses, and issues with silvicultural operations were prioritized. In terms of physical protection, trespassing, constructions, illegal wood cutting and smuggling, livestock grazing, traditional exploitations, and fires were ranked from first to fourth. Therefore, the sustainable exploitation approach was favored over exploitation cessation. The Mann-Whitney U test revealed no significant difference between the opinions of local stakeholders and forest experts in the study area. Thus, it can be concluded that simply halting wood exploitation and forest management plans is not the solution to the physical and technical protection challenges faced by the Hyrcanian forests. To address these challenges, it is recommended that past forestry plans be revised and implemented in accordance with the criteria and principles of sustainable management for all forest units.

In light of the inefficiency of conventional and traditional forest conservation systems, the shift from government-centered to community-centered policies in forest management through social forestry becomes increasingly essential. Accordingly, the necessity for employing structural analyses with a futures-oriented approach is emphasized. Based on this premise, the present study aimed to identify and analyze the key drivers influencing the development of social forestry using a futures-oriented approach in the forests of Golestan Province. This research employed a mixed-method (qualitative and quantitative) design and was conducted through survey technique. The study population consisted of experts and forest protection personnel in Golestan Province. A total of 50 participants were purposefully selected as the sample. After data collection, 20 indicators derived from the Delphi method were analyzed using the MicMac software, incorporating cross-impact analysis. The results indicated that the social component has the highest impact, while the economic component has the least impact on the development of social forestry in Golestan Province's forests. Based on the obtained results, two factors, namely "Shifting from Centralized Government-Centered Policy to Integrated Community-Centered Management" and "Benefitting from Governmental Economic and Budgetary Support," from the policy-management component, "Conducting Facilitative Activities and Utilizing Village Promoters for Community-Centered Management" and "Identifying Rural Leaders and Involving Them in Community-Centered Forest Management" from the social component, and "Empowering Local Communities through New Job Opportunities and Strengthening Income Resources" from the economic component, were identified as the most influential key drivers for the development of social forestry in Golestan Province's forest management. In light of the findings, the development of a long-term vision document considering the three dimensions of forest protection, local communities, livelihood, and empowerment, with a future-oriented perspective, is recommended.

The main purpose of this descriptive-analytical study was to identify and explain the barriers to protection of water resources in the Urmia Lake Basin. Participants in this research were key experts and informants in UL Rehabilitation Headquarters, Urmia University, Agriculture-Jihad Organizations, Regional Water Companies, Departments of Environmental Protection and Agricultural and Natural Resources Research and Education Centers in three provinces of West Azerbaijan, East Azerbaijan and Kurdistan among which 19 people were selected through purposive sampling method for doing the research. Semi-structured interviews (in individual and group form) were used to collect data and the data were analyzed using MAXQDA software. The results of the study showed that barriers to water resources protection in the Urmia Lake Basin were in the form of 28 different signs among which not using the real participation of stakeholders in water resources management (among the signs related to social- cultural barriers), lack of promotion of sustainable and compatible livelihoods with water resources at the basin level (among the signs related to economic barriers), lack of sufficient coherence for decision-making between local, provincial and national levels (among the signs related to organizational- Institutional barriers), the lack of comprehensive water distribution law (among the signs related to legal-administrative barriers) and top-down management of water resources (among the signs related to management barriers) had the highest priorities compared to other signs. Finally, based on the research findings, some strategies were presented to eliminate barriers to the protection of water resources in the Urmia Lake Basin.

The need to decentralize government at the local level can guarantee the participation of rangeland beneficiaries. So the present study has analyzed the perceptions of rangeland beneficiaries of participatory governance in Incheh salt marshes in Golestan province. The research is descriptive-survey and statistical population consists of 120 beneficiaries, 92 of whom were selected as the sample size. The questionnaire was the main tool of data collection and participatory governance was evaluated with 32 items in the form of 9 components. The validity of the questionnaire was obtained by experts and its reliability was obtained by calculating the Cronbach's alpha coefficient. Statistical calculations based on SPSS25. The results showed that the "implementation" and "conflict resolution" with the highest and "planning" and "coordination" with the lowest were at the highest and lowest levels of governance index, respectively. On the other hand, according to the average obtained in the participatory governance index (3.58), the tendency of governance is toward community-oriented management. There was a positive and significant relationship between the variables of livestock history, number of livestock, age, annual income and the tendency to rule in the rangeland. According to the obtained results and also the importance of rangeland governance, the involvement of beneficiaries in the preparation of rangeland plans and projects and the use of their rich native knowledge, holding classes in line with the cooperative activities of beneficiaries with the Department of Natural Resources and Watershed Management as a representative of the government are the most important suggestions of this research.

The aim of this study was to investigate some soil properties that were affected by management including logging, tourism and forest reserve in Guilan province, Iran. In each of the studied area, five transects with a length of 200 meters, perpendicular to the road, were selected and soil samples at 10, 50, 100, 150, and 200-meters distances from the road were gathered. In each transect, five samples of 25 m2 were selected. Measured soil properties were consisted of bulk density, porosity, pH, organic carbon, and microbial respiration. The results showed that with increasing distance from the road, the mean of bulk density in the area of logging, tourism and forest reserve decreased from 1.64 to 1.10, 1.33 to 1.07 and 1.11 to 1.08 gr/cm3, respectively, and mean of pH decreased from 6.96 to 5.48, 6.57 to 5.48 and 4.88 to 4.56, respectively. The highest and lowest levels of organic carbon and rate of microbial respiration were observed in the control and logging areas, respectively. The results of analysis of variance showed that there is a significant difference between all soil properties in the sampled areas and different road distances. Mean comparison also showed that there was a significant difference between the mean of soil properties in the control area with the logging and tourism areas. The results of this study showed that the type of management of natural areas may have different destructive effects on soil properties.

In this study, using the frequency ratio (FR) model, an attempt has been made to identify areas with high groundwater potential of the Sira catchment. Effective factors for preparing groundwater potential map including slope aspect, slope percentage, slope length (LS), Elevation, stream power index (SPI), topographic wetness index (TWI), plan curvature, distance to rivers, distance to roads, distance to faults, lithology, land use, soil hydrological groups and drainage density considered for groundwater potential zone mapping. In the GIS environment, the maps of factors were prepared and overlapped. There are 83 springs in the region, of which 58 were used for modeling and 25 for validation in the FR model. Finally, using the model output, the potential map of groundwater resources was created. The ‌ROC curve was used to validate and evaluate the groundwater potential maps. Validation results showed that the area under the curve (AUC) in the frequency ratio model is 81.21percent, which has a good performance in the potential of groundwater resources in the region. Based on the results of spring potential, 5.07, 13.59, 42.85, and 38.48 percent of the region were in low, medium, high, and very high classes, respectively.

Rangelands are considered as the most basic bed for sustainable development of the environment and ecological phenomena and in addition to a considerable role in production and sustainable rural development, play a key role in preventing soil degradation and erosion and groundwater storage. In recent years, rangelands of Iran have not proper condition due to destruction by climate change and drought, as well as grazing pressure. Therefore, providing effective strategies in rangeland management and sustainability seems necessary and will lead to stability and sustainability in rangeland areas, especially in the long time. In this study, using SWOT analysis, strategies and solutions for sustainable development of rangelands in Kalaleh city of Golestan province were investigated.

In this study, according to the practical objectives of the study, a survey and documentary method was used to collect data and information. The statistical population of this study was experts familiar with the rangeland management in Department of Natural Resources and Watershed Management of Golestan province and Kalaleh city. The sample size was determined by available and non-random sampling method and 26 experts participated in this study. After designing the questionnaire in the form of Likert scale and validation using the opinion of experts and specialists, Cronbach's alpha coefficient was used to determine the level of reliability that obtained 0.84 and showed the proper reliability of the questionnaire. In order to analyze the data and determine the most important strengths, weaknesses, threats and opportunities, the SWOT model was used. SWOT model is one of the most important and powerful tools for strategic management that is used in the process of external and internal analysis and the creation of proper strategies. In SWOT analysis, internal factors (strengths and weaknesses) and external factors (opportunities and threats) were examined and then strategies and solution for sustainable development of rangelands were designed.

According to the results of this research, the average age and work experience of experts participating in the study were 41.3 and 13.1 years, respectively and more than half of whom had a master's degree. According to the results, "large area of rangelands" with a weight coefficient of 0.0498 is the most important strength of rangelands from the viewpoint of the experts and then there are "indigenous knowledge to rehabilitate and protect rangelands" and "the willingness of stakeholders to participate in the implementation of projects and rangeland management", respectively. But the most important weakness of rangelands was "traditional livestock system depends on rangeland forage" with a coefficient weight of 0.0486. Also, "the presence of unauthorized stakeholders in the rangelands and reduction of ownership area for livestock grazing" and "reducing the percentage of class I plants and rangeland production" are the next priority weaknesses, respectively. According to the findings, "improving the perspective of multi-purpose use of rangelands" is the most important opportunity for sustainable development of rangelands from the viewpoint of the experts and the most important threat is "climate change and reduction of water resources in rangelands". The final score of internal and external factors was 2.569 and 2.102, respectively that shows the superiority of strengths over weaknesses and threats over opportunities. Thus, the strategy of sustainable development of rangelands was determined as competitive strategy (ST).

According the results of this study, legal and incentives planning to attract private sector investment according to rangeland potentials (Ecotourism, medicinal plants, various livestock products), implementation multi-purpose use of rangelands, reforming rules and regulations, increasing the budget of Natural Resource Departments, and improving infrastructure, educational and medical facilities in rural areas were considered as competitive strategies. Based on the research results, it is suggested that in order to improve the participation of local communities in sustainable rangeland management, the necessary measures should be taken by holding workshops and training and extension classes. Also, by providing the necessary facilities, the conditions for the development of the region, private sector investment and diversification of the livelihood of the rural residents should be provided.

In recent decades, several factors such as population growth, limited surface water resources due to reduced rainfall, and over-withdrawal of aquifers have caused a sharp drop in groundwater levels (GWLs) in many plains of Iran, including Salmas plain located in the province of West Azerbaijan. In this study, the numerical model of the Salmas plain aquifer was prepared using MODFLOW model in GMS software in both states of steady flow (September 2015) and non-steady flow (from September 2016 to August 2017). The input parameters of the model were calibrated for the measured values of GWL at the location of observation wells and validated from August 2016 to July 2018. Finally, the GWL was investigated applying 6 scenarios including a 10% to 30% decrease in pumping wells and a 5% to 15% increase in rainfall. The results of studied scenarios showed that reducing the pumping rate of the wells significantly improves the condition of groundwater resources. By reducing the pumping rate of the wells up to 30%, the volume of groundwater will increase by 13.66 mcm and shortage of the aquifer reservoir will be compensated. However, 15% increase in annual rainfall will improve the condition of the aquifer by only 0.5 mcm. Results show that reducing the rate of withdrawal from wells reduced the amount of groundwater flow entering the aquifer from 41.98 mcm in the calibration state of the model to 38.7 mcm in terms of 30% reduction of discharge rate in the wells. However, the increase in rainfall did not cause significant changes in the amount of groundwater inflow and outflow. The results of this study indicate that management scenarios such as preventing over-withdrawal from authorized wells and blocking unauthorized wells have more significant effects on improving the GWL than possible climatic scenarios.

Many regions in Iran, are facing significant stagnation of natural resources, including access to sufficient and sustainable water, and its adverse consequences have appeared in many sustainability indicators of these regions. Good governance is commonly recognized as the most important initiative for addressing the agricultural water shortage in the country. Thus, it is crucially important to examine the priority area of interventions for the realization of water governance. With this in mind, this research is conducted to identify the key factors and driving forces of agriculture water governance in Tarom County in Iran. The required data were collected through semi-structured interviews with 29 managers and experts in agriculture, environmental protection, and rural water supply and sewerage departments and were coded and analyzed using MAXQDA software. Then, the interaction of identifies key factors was examined by pairwise comparison questionnaires filled by 12 experts and managers and analyzed with MICMAC Software. The findings revile that, the governance of agricultural water resources in Tarom city is unstable and the facilitation of stakeholder’s participation and, decentralization and delegation of authority to the local level are two main driving forces for the realization of water governance in the region. Furthermore, improving the irrigation water efficiency, formulation of appropriate regulatory policies in water supply and demand sections, as well as proper management of surface and groundwater are identified and recommendable as the key goals for improving agriculture water governance.

Due to the occurrence of droughts during recent decades and their direct impact on the agricultural sector, proper management of agricultural water resources is of particular importance. Therefore, the present study was conducted with the aim of identifying and prioritizing strategies for sustainable management of agricultural water resources in Lorestan province. In this study, quantitative-qualitative and exploratory approaches were employed as the main research method. The qualitative section of the study was based on Grounded Theorizing. In the first stage of Grounded Theorizing, 16 semi-structured interviews were conducted with water resources management experts. The major objective of this stage was to identify the solutions. The results of this stage revealed that there are 44 solutions for sustainable water resources management that can be categorized in four "educational-cultural", "supportive-institutional", "economic", and "technological" components. In the second stage, the Delphi-fuzzy technique was used in two stages to reach an agreement among the experts and to prioritize the identified steps. The most important solutions in each step were including, comprehensive support of innovative ideas about reducing water consumption in the agricultural sector, directing water to groundwater aquifers to conserve water from winter rainfall for use in low water seasons, strengthening farmers' perception towards water shortage by providing training courses on sustainable water resources management strategies and cultivation of low-water crops, and guaranteed purchase of these products from farmers to prevent the cultivation of irrigated crops. According to the results, research, the institutionalization of water conservation culture based on education, is the main implication of achieving sustainable agricultural water management in Lorestan province.

The main purpose of this research was to analyze the crisis situation of Lake Urmia (LU) catchment area and providing solutions for its sustainable management using DPSIR model. Participants in this research were key experts and informants in LU Rehabilitation Headquarters, Urmia University, Agriculture-Jihad Organizations, Regional Water Companies, Departments of Environmental Protection and Agricultural and Natural Resources Research and Education Centers in three provinces of West Azerbaijan, East Azerbaijan, and Kurdistan among which 14 cases were selected through purposive sampling method. Semi-structured interviews (individual and group) were used to collect the required data and data were analyzed in MAXQDA software using directional content analysis. The results of the research showed that the factors related to crisis situation of the LU catchment area were included 45 different indicators among which climate change (among the indicators related to the driving forces of the LU crisis), inappropriate policies and poor management of water resources (among the indicators related to pressure factors in the expansion of the crisis), reducing the water level of the lake (among the indicators related to the current situation), and increasing air pollution due to dust and stress on local communities (among the indicators related to the effects) had the highest priorities compared to the others. Moreover, according to the results of the study, it was found that the most important responses to resolving the crisis of LU and its sustainable management were included establishing the new organizations and institutions, carrying out projects related to groundwater balancing, increasing the capacity of NGOs, tightening enforcement of water protection laws, and increasing extension and training activities for farmers in the field water resources protection.

The Inter-basin water transfer is one of the ways to deal with water shortage. However, in some cases, this solution has more destructive effects than its benefits. Therefore, it is necessary to fully identify the potential damages of inter-basin water transfer projects, so that they can be prevented in future plans. Iran is one of the leading countries in inter-basin water transfer projects and so far, 10 projects are under operation and 19 more are on the agenda. The main purpose of this research study is to identify the damages of projects in operation in Iran. To achieve this aim, all information related to the in-operation projects were collected and extracted involving descriptive-analytical approach, from literature resources, news and interviews. A total of 20 damages were identified as a result of the investigations. Due to the different nature of these damages, after identification, they were classified into four areas including, environmental, economic, political and social. According to the results, there were only 10 damages in the research literature, which means that the literature is incomplete in relation to the damages of inter-basin water transfer projects. It is recommended that the results of this research be used in the study of future plans.

Human is under threat due to the shortage of fresh water, its deteriorating quality, and rising water stress around the world. Proper management of water resources is very important to ensure the sustainable social and economic development in any country in the world. In order to sustain freshwater resources, they must be used efficiently without compromising the needs of future generations. The present study was conducted to ensure the sustainable management of groundwater resources. For this purpose, four indicators of vulnerability, resilience, reliability, and combined stability, each of which includes aspects of sustainability, were used as the objective function of management issues. Using the combined simulation-optimization model of Namdan plain aquifer and the ant colony optimization algorithm, a decision model was created. The results indicate the effectiveness of four indicators of vulnerability, resilience, reliability and combined stability to increase groundwater level and positive changes of water storage. So that the aquifer storage change under each scenario was 11.7, 13, 12.3 and 12.4 million cubic meters, respectively. According to the results obtained from four management issues, analyzed in this study, the most important effect in improving the aquifer with a significant reduction in pumping from well while the such reduction should be measured at the aquifer level.

Soil is the upper layer of earth in which plants grow and is consequently very important for organisms and human nutrition. The protection of the soil against degrading processes, such as soil salinization and alkalization, is one of the main challenges in sustainable land management. Soil salinization and alkalization are two major environmental concerns leading to soil degradation especially in arid and semi-arid regions across the world. The balance of organic carbon in the soil is important for soil sustainability. Intensive cultivation enhance soil organic carbon (SOC) depletion. In order to alleviate the detrimental effects of SOC depletion, carbon-rich organic amendments such as biochar or compost are often applied to the soil. Therefore application of organic amendments to soil is an effective strategy to improve soil properties and to mitigate the negative impacts of inappropriate management strategies. Biochar is a carbon-rich compound produced by the pyrolysis of biomass in oxygen-limited conditions. Its use as an organic amendment to soil with specific inherent characteristics has been recognized. In this regard recent studies have shown that application of biochar to soil as an organic amendment can improve soil physical properties and help to keep the carbon balance in the soil. Moreover, compost as an organic amendment is capable to improve soil properties and increase the soil productivity.

The soil sampling was carried out near Kabutar Khan in Rafsanjan, Iran (56°22′N, 30°18′E), on a saline-sodic soil with Silty Clay soil texture (42% silt, 50% clay and 8% sand). The biochar was obtained from three different feedstocks consist of Conocarpus erectus, bagasse of Sugarcane and hard shell of Pistacia Vera. The obtained feedstocks were pyrolyzed at 400°C for 2 h with increasing rate of 7 °C/min in a sealed reactor to prevent O2 input (Muffle Furnace, SEF-101 Model). Afterwards the produced biochar was cooled slowly to the room temperature, then the EC, pH, specific surface area and CHNS of biochars were measured using the standard methods. The required amounts of soils and biochars were weighed by a total 5000 g dry weight of sample and mixed in the dry state. The soil samples were received three doses of biochar (0, 2, 4 % biochar, w/w). The mixtures of soil and biochar were packed into pots and controlled a bulk density of about 1.5 g cm-3 by artificial compaction. Treatments were replicated three times. The soil without any biochar was used as the control. The mixtures were wetted at three soil moisture contents (25, 50 and 75% field capacity) during incubation time (120 days). The treatments were kept at a temperature-controlled glasshouse. After 120 days of incubation, the untreated soils and biochar-amended soils were taken for physical and chemical analyses.Particle size distribution was measured by hydrometer method and soil organic carbon by oxidation method with potassium dichromate. The consistency limits (liquid limit and plastic limit) of soils were determined according to the ASTMD4318 procedure. The field capacity was measured using the pressure plates with the standard rings in the lab. Mechanical strength is a sensitive indicator of the soil physical condition and has been commonly used to evaluate soil water erosion, structural stability, tillage performance, and root penetration. Higher strength found in saline-sodic soil often impedes seedling emergence and root penetration.

Our results revealed that application of organic matter in the form of biochars and compost was effective on soil aggregation. The formation and stability of the soil aggregates play an important role in the crop production and soil degradation prevention. Moreover, the biochar application showed two main effects including direct and indirect effects. Our results confirm the addition of biochar to soil can cause a substantial and significant change in the soil physical characteristics of the strongly acidic Ultisol, namely a significant increase in LL and PI, higher water-holding capacity, and reduction in mechanical strength. These changes are undoubtedly associated with the particular properties of biochar and in particular with its high porosity and low bulk density. The beneficial effect of biochars on soil physical properties is mainly due to the dilution effect of biochar with higher porosity and lower density. When the biomass is heated, volatile matters may release out of the biomass to create micropores on the surface, and meanwhile those trapped inside the biomass are evaporated to expand the microstructure. Thus, the resulting biochar has much higher surface area and porosity. These properties are particularly useful for soil application of biochar especially for enhancing soil water-holding capacity, reducing mechanical strength, and increasing soil aggregation. The dilution effect can be attributed to the increased volume of pores as well as the decreased particle density in soil amended with biochar. The effectiveness of different biochars in improving the soil physical properties can be explained by their porosity and bulk density.

Our results depicted that application of biochars and compost as an organic amendments improved mechanical quality of the saline and sodic studied soil. Indeed all organic treatments decreased bulk density and enhanced soil aggregate stability while the biochar of Conocarpus illustrated the greatest effectiveness on soil physical and mechanical properties. Therefore it is a possibility to apply this biochar to the soil in the field scale but regarding the accessibility of biochar of Pistachio skin in the study area therefor we have another alternative to utilize in the soil. This research was conducted in the small scale and in a short time. Therefore, it is suggested that supplementary studies are carry out on farm scale for a longer periods.

Differences in climatic conditions, rainfall, transpiration of plant and evaporation from soil surface cause changes in yield production and crop water requirement. Due to the limitations of field assessment of plant growth, use of growth models can be a suitable tool for the study of plant behavior under different management conditions. Depending on different purposes over time, different models, including AquaCrop have implemented. Growth simulation methods are used to develop a sustainable strategy of water distribution, during the growing season, for achieving the best performance in reducing water consumption. Colza as a strategic product with high economic value is one of the main priorities in the cultivation pattern of the plains with different weather conditions. Therefore, this study was conducted to simulate a colza growth model and find the sustainable irrigation plans and groundwater allocation strategy, using crop growth simulation in four different climatic regions of Iran. This study aims to collect farm information and develop the colza crop growth pattern in four climatic regions of Iran. The experimental farms were located in Birjand, Bushehr, Shahrekord and Gorgan with arid, semi-arid, semi-wet and wet conditions, respectively. Simulation was performed to measure the level of canopy cover with the aim of achieving the final yield of the crop by AquaCrop software in the 2018-19 crop season. The information required to calibrate the AquaCrop model (including cultivation parameters, plant characteristics, growth schedule and soil texture) was entered into the model and calibrated to achieve actual crop yield. One of the main components of modeling is the daily estimation of soil moisture, which affects the water requirement, root growth rate and canopy cover of the plant, and thus the final yield production. Understanding the relationship between water, soil and plants has expanded widely since the presentation of the relationship between Doorenbos and Kassam (1979). The need to increase water productivity as a tool for water scarcity has led the Food and Agriculture Organization of the United Nations (FAO) to develop the AquaCrop model to simulate the response of crops to the amount of water consumed. Water productivity (kg/m3) is expressed as the ratio of final crop yield (kg/ha) and irrigation water (m 3/ha). Moreover, different scenarios of groundwater allocation were considered to supply crop water requirement, using soil water balance model in the root zone. The results showed that the highest amount of plant transpiration was obtained in Bushehr, Birjand, Shahrekord and Gorgan farms with a total of 900, 790, 717 and 407 mm, respectively. The highest yield was estimated in Shahrekord with more than 1800 kg/ha and the highest irrigation water productivity in Gorgan with 0.26 kg/m3. The results also showed that cultivation of colza at the beginning of the autumn planting period in each region increases the use of precipitation for canopy growth and thus reduces irrigation water consumption at the end of the season and increases productivity. Among the studied areas, the best range was related to Shahrekord colza cultivation with long growth period, acceptable yield, adaptive climatic conditions and suitable rainfall distribution for rainfed cultivation. The planting date is one of the effective management parameters in increasing water use productivity and effective use of rainfall. Therefore, the modeling results estimated an average decrease of about 10% in plant water requirements and a 1% increase in water productivity due to a ten-day reduction in planting date compared with the experiments performed. Notably, this crop is planted alternately with crops such as rice and cereals and the spring crop which generally has a higher economic value; also there is a limitation after harvest to prepare the field regarding the planting date. Therefore, attention to crop rotation and the possibility of changing and managing the time of planting and harvesting the first crop should also be studied. Effective use of rainwater, especially in areas such as Birjand and Bushehr, where water constraints are the main cause of reduced performance can be considered by relying on planning based on daily information. Differences in plant transpiration rate in daily, weekly and monthly scales indicate that irrigation intervals in Bushehr should be done with irrigation intervals of less than seven days at the end of the growing season to complete the flowers and fill the seeds with increased yield. In addition to rainfed cultivation for Golestan area, rainfed cultivation with supplementary irrigation at the end of the growing season is recommended for climatic conditions near Shahrekord and sprinkler irrigation for arid areas.