arash mohammadzadeh

Field pea (Pisum sativum spp . arvense L.), as a legume crop is a viable alternative crop that can be integrated into cropping rotations with cereals within dryland farming systems. However, crop production under rainfed conditions, which is highly dependent on climate, is associated with high risk due to weather fluctuations and uncertainty. Therefore, identifying the optimal levels of manageable factors is essential for effectively mitigating the risks associated with environmental factors, particularly those related to climatic conditions. In the present study, the effects of managerial factors, including sowing date, sowing depth, and plant nutrition, on the yield of forage pea were investigated through a split-plot factorial experiment conducted with three replications. This study was carried out over two growing seasons, 2022-23 and 2023-24, at the Dryland Agricultural Research Institute (DARI) located in Maragheh. The main plots consisted of two planting dates (Entezari or dormant seeding, and spring), while factorial combinations of fertilizer application at two levels (application and no application) and sowing depth in three levels (3, 6 and 9 cm) were assigned in sub-plots. Forage yield was significantly affected by planting date, sowing depth, and fertilizer application. The optimal sowing depth was determined to be 6 cm. Additionally, optimal plant nutrition significantly improved forage yield. In the first year, the forage yield associated with the Entezari sowing date was marginally superior to that of the spring sowing. However, in the second year, the yield from the spring sowing date was significantly higher than that from the Entezari sowing date. In general, while Entezari planting can extend the crop growth period and optimize the use of environmental resources, the simultaneous emergence of pests, such as cutworms (Agrotis spp.) and leaf beetles, during years when outbreaks are possible can cause significant damage and reduce crop yields compared to spring planting.

Nowadays sustainable production of agricultural products to ensure food security is among the goals and macro policies, Therefore, attention to energy flows, economic indicators and environmental issues is inevitable. Therefore, the present research was carried out in the years 2021 and 2022 with the aim of investigating energy indicators, greenhouse gas emissions and economic indicators on two plants, alfalfa (Medicago sativa L.) and corn silage (Zea mays L.), which play an important role in providing fodder for livestock in Alborz province cities. The desired data was obtained from interviews with farmers and completing questionnaires for each plant. Results showed that the highest energy input, output and net energy in alfalfa were 61964.1, 271760 and 209795.9 Mj.ha-1, respectively, Also, for corn, the highest input, output and net energy were 35330, 240120 and 204790 Mj.ha-1 respectively. The highest efficiency of energy consumption in alfalfa and corn was obtained 4.38 and 6.8 respectively. Among the different inputs, diesel, nitrogen chemical fertilizer and irrigation water had the largest share in the energy input. The comparison between alfalfa and corn in terms of global warming showed that alfalfa plants with the production of 3097.6 kg of CO2 per hectare had a greater role in global warming than corn plants with the production of 1879.7 kg of CO2 per hectare that three factors, diesel, chemical fertilizer and electricity have played the most important role on this.

Harvest loss is one of the main challenges in wheat production systems. More than 75% of harvest losses are related to the header loss which is influenced by various factors such as defective cutting blade and unsynchronized speed between the combine forward with reel speed and plant density. The low performance of wheat combine harvesters has always existed and yield losses during harvesting will result in less income for the farmers. Therefore, estimating the amount of harvest losses within different parts of the harvester and determining the factors affecting yield loss according to the actual situation of mechanized wheat harvesting is important for the effective reduction of harvest losses.

The Present study was performed at the research station of Dryland Agricultural Research Institute (DARI) located at Maragheh during the 2020-2021 cropping season and 18 dryland winter wheat fields were assessed for estimating harvest loss. The soil tillage system was carried out as minimum tillage and sowing rate was 380 plant m-2. Harvest losses were measured separately for head losses, cleaning losses, and beating losses. John Deere 1055 and 955 combine harvesters were evaluated in this study. Seasonal services of the harvesters were performed before the experiment and its technical health was ensured. Each plot area was 120 m2 that the head losses and yield estimation were evaluated in half of the plot (60 m2) and the other half of the plot was devoted to the estimation of cleaning and beating losses. Also, to determine the effective factors in the rate of losses of different units, forward speed, linear speed of the Reel, spike density, crop yield, and grain moisture were measured at the harvest time.

The results showed that the loss of cutting unit had the largest share of harvest loss with 89%. By implementing the correct settings of the cleaning and beating units and choosing the right harvest time, as well as choosing reel speed (RS) in accordance with the forward speed (FS), the head loss was reduced by 0.45% and the total loss was reduced by 0.51%. Head losses increased with a decreasing ratio of RS/FS (V2/V1) and the lowest head loss was obtained at a relative speed (V2/V1) of 1.6-1.8. By reducing the FS to 2 km/h and increasing the relative speed (V2/V1) to values greater than 2, as well as by reducing the relative speed to 1.36, head losses increased sharply. In other words, by adjusting the FS according to the spike density and stabilizing the relative speed (V2/V1) in the allowed limit (1.6-1.8), as well as making the correct adjustments of the winnowing and threshing system, the losses of the combine were reduced to less than 1%. To reduce the losses of the cutting unit, it is necessary to design and install the relative speed (V2/V1) stabilization system for grain harvesters.

Conservation agriculture represents a sustainable strategy for the long-term preservation of natural resources through effective crop and soil management practices. Despite its numerous advantages, the global adoption of conservation agriculture remains relatively limited when compared to conventional agricultural systems. In Iran, efforts to promote conservation agriculture over several decades have not resulted in widespread adoption among farmers. This can be attributed to a variety of factors, including technical challenges (such as access to specialized machinery and equipment), social barriers (including farmer knowledge and awareness of conservation agriculture), and economic obstacles (such as the availability of financial support policies). Considering the importance of conservation agriculture in sustainable crop production especially in dryland condition, this research aimed to identify the challenges of applying conservation agriculture in dryland crop production systems from the perspective of farmers. 

The present study was performed in east Azerbaijan province of Iran during 2022-2023. The target population was the farmers engaged in rainfed crops in dryland condition of Maragheh, Hashtrood, Mianeh, Charuymaq and Ahar counties. The data used in this study was obtained through face-to-face interviews with 53 farmers who were available for interview identified by local Jihad agriculture experts. The questionnaire validity was evaluated by the faculty members and experts in dryland agriculture. Data analysis was done by using Excel 2016 software. Also, correlation analysis between variables was done by Origin Pro software version 22. 

Results showed that because the higher share of cereals (wheat and barley) in cropping pattern, there is no proper crop rotation in the study area. A large part of crop residue especially in cereals, is harvesting as forage because of feed higher prices in the area. The most of farmers prefer to use conventional tillage system for seedbed preparation. Lack of suitable machinery, lack of awareness and knowledge of farmers toward conservation agriculture, and yield reduction in the first years of adoption are the main barriers of rapid expansion of conservation agriculture. Facilitating farmers’ access to conservation agriculture machinery by providing the financial facilities; participatory research involving farmers, researchers and extension agents and creating agricultural extension model sites, and support policies such as economic incentives or subsidies are the main strategies for the adoption of conservation agriculture.

Biochar can reduce the plants vulnerability to diseases with different mechanisms such as improving soil fertility, increasing the population and activity of beneficial microorganisms, limiting the activity of pathogens, absorbing toxins produced by pathogens, stimulating the production of antibiotics, inducing plant systemic defense and changes in root exudates. The role of biochar in reducing plant diseases depends on the biochar properties, biochar dosages, soil properties, crop, and the type of pathogen. The biochar properties are affected by the type of biomass and production temperature. In addition, the mechanisms of biochar to protect the plant against each type of pathogens may be different. Therefore, considering the importance of biomass type and carbonization temperature in the efficiency of biochar, it is suggested to pay more attention to the ability of biochars produced from different biomasses and temperatures to reduce plant diseases.

The aim of this study was to investigate the quantity of energy input, compare the energy flow and the quantity of greenhouse gas emissions between wheat and barley ecosystems, in the cities of Tehran province. The needed information was collected by questionnaire method from farmers in Tehran province cities. Then, energy indices, different forms of energy and global warming potential were calculated. The results showed that the highest input energy in the production process of wheat and barley belonged to Islamshahr city with 86159 and 76793.9 MJ ha- 1, respectively. In addition, the most direct energy, renewable energy and non-renewable energy belonged to wheat and barley farms in Islamshahr and Rabat Karim cities. Wheat and barley farms in Tehran had the most indirect energy. On the other hand, the lowest quantity of different forms of energy in the wheat and barley ecosystems belonged to the rainfed farms of Tehran province located in cold regions. In general, in wheat and barley ecosystems of Tehran province, the share of direct energy was more than indirect energy and the share of non-renewable energy was more than renewable energy. The quantity of greenhouse gas emissions in wheat and barley farms in the western cities of the province, including Islamshahr equivalent to 10474.5 and 10081 kg eq. CO2 per ha respectively. Therefore, by taking into account the climatic conditions of the region and managing the consumption of production inputs, it is possible to increase the efficiency of energy consumption and reduce the emission of greenhouse gases in Tehran province.

Climate change phenomenon is one of the most important global challenges for mankind in providing sufficient and healthy food for the ever-increasing world population. The leading factors of climate change, such as increasing temperature, changing precipitation patterns, and increasing the frequency and intensity of weather events, affect soil characteristics, especially in the ecosystems of arid and semi-arid regions. These changes can directly affect the growth and production of crops. The amount of soil organic matter is one of the most important indicators of soil quality and health, which affects many physical, chemical and biological characteristics of soil and is directly and indirectly affected by climatic factors such as temperature and rainfall. On the other hand, the balance of input and output of organic carbon to the soil is effective on the amount of carbon dioxide in the atmosphere and thus on global warming and the climate change phenomenon. The results of many forecasts show that in arid and semi-arid regions, climate change will lead to an increase in temperature and a decrease in rainfall. Therefore, considering that the amount of organic matter in the soil decreases with the increase in temperature and decrease in humidity, it seems that the phenomenon of climate change will have adverse effects on the amount of soil organic matter and biological activity, and then on the production of crops in arid and semi-arid regions. Therefore, it is very important to use the necessary solutions to mitigate these adverse effects and adapt to the upcoming conditions. Mitigation refers to methods that lead to the reduction of greenhouse gas emissions, especially carbon dioxide; But the goal of adaptation is to mitigate the inevitable effects of climate change. Based on the results of various publications, compliance with the principles of the conservation agriculture system is considered one of the most important mitigation and adaptation solutions in dealing with the consequences of climate change in arid and semi-arid regions. Due to the fact that the climate change phenomenon is an inevitable event and its adverse effects and consequences in human life are felt more and more intense day by day, it is necessary for the management of soil resources to have the necessary foresight regarding the results of this phenomenon on the quality of the soil and the potential of producing agricultural products, especially in Arid and semi-arid areas should be considered.

Biochar is a carbon-rich charcoal material resistant to decomposition, which is produced by heating biomasses in an oxygen-free environment or with limited oxygen. It is used with the aim of increasing organic carbon and improving the physical, chemical and biological characteristics of the soil. Thus its use in the low-fertile soils of hot and dry regions of Iran, which are often deficient in organic carbon, is important. Addition to its high stability in the soil, biochar can sequester atmospheric carbon dioxide in the soil for several hundred to several thousand years. In addition, it can improve soil fertility for a long time by affecting its physical, chemical, and biological properties. The stability of biochar is affected by several factors, such as the characteristics of biochar and soil, the interaction of biochar with soil components and environmental factors, which are examined in this article. Therefore, it is important to use biochar in the soils of arid and semi-arid regions of Iran, which are often deficient in organic carbon.

In this review article, while investigating the evidences of the high stability of biochar in the soils, the   most effective factors the fate of biochar in the soil, including the mechanisms of biochar removal from the soil, biochar stabilization in the soil, and interactions of biochar with soil components, and the gaps and required research areas are presented.

Biochar is higher resistant to degradation than the original carbon compounds in biomass. However, by interacting with soil components, biochar undergoes changes over time and is removed from the soil. The intensity of these changes and biochar residence time in the soil depends a lot on the type of biochar; So, biochars produced from grassy biomass and biochars produced at low temperatures are less stable. In addition, biochar interacts with all soil components, including organic matter, mineral particles, nutrients, living organisms, and soil water and atmosphere, and the result of these interactions determines the stability of biochar in soil. External factors such as the presence of plant and induced root changes, wind and water erosions, leaching, and fire also affect the fate of biochar in the soil. Among these, considering the interactions between microorganisms and biochar in soil, it seems that soil microorganisms play the most important role in the decomposition and destruction of biochar in soil. However, mechanisms such as the entrapment of biochar particles inside aggregates, binding of biochar with organic and inorganic components of soil, and inactivation of soil enzymes by biochar can increase the stability and durability of biochar in soil.

Considering the very high stability of biochar in soil and the necessity of increasing soil organic carbon as the main factor of soil fertility factor, the use of biochar in Iranian soils it can directly and indirectly improve the fertility of these soils while increasing soil organic carbon. However, after biochar is added to the soil, it interacts with the soil components and its characteristics change and evolve over time (aging). However, due to the novelty of biochar technology and the wide range of its application fields, our information on its interactions with various soil components, its long-term changes and developments in the soil and environment, and its long-term effects on the soil and the environment are not yet clearly defined and much research is needed in this field.

This research was done with the aim of checking energy and economic indicators and the amount of greenhouse gas emissions in the production system of two products, tomato and onion in 2021 and 2022 in Alborz province. The information required for this research was obtained through interviews with farmers and completing questionnaires. The results of this study showed that the highest energy input, energy output, and net energy in onion were obtained in Savojbolagh city at the rate of 21324.8, 105600, and 24275.3 Mj.ha-1, respectively. In tomato, the highest input energy, output energy, and net energy was 73799.8, 56000, and -13495.4 Mj.ha1, respectively (in tomato, net energy is negative due to the greater input energy than output energy). The highest energy efficiency consumption was obtained in onion and tomato, 1.4 and 1.32 respectively. In the comparison of energy efficiency, the highest value in onion and tomato were observed 0.82 and 0.99 Kg.mj-1. Among the various inputs in the onion and tomato production systems, diesel, nitrogen chemical fertilizer, animal manure, irrigation water, gasoline, and manpower had the largest share in input energy in the order of priority. Onion and tomato by producing 3065.8 and 3045.4 kg of CO2 per hectare, played a role in the emissions of greenhouse gases. The analysis of economic indicators also showed that onion with a net income of 9608.7 $.ha-1 compared to tomato with a net income of 4840.3 $.ha-1 has generated more income. According to the obtained results it can be possible that reduce the amount of energy input and greenhouse gas emissions and thus, provide the necessary conditions for the establishment of more sustainable agriculture by modifying production methods such as using modern irrigation methods and also replacing animal and biological fertilizers with chemical fertilizers.

Climate change is one of the most significant global challenges threatening food security now, in the near and far future. This mainly occurs in the form of increasing temperature, change in rainfall pattern, and increase in extreme weather events. There are strong evidences demonstrating the vulnerability of agriculture sector in arid and semi-arid regions to climate change. This may directly impact on crops growth and production or indirectly impact on their environments. The ability of soil to produce a crop depends on its physical and chemical properties and these properties are directly and indirectly affected by climatic factors such as temperature and rainfall. Most predictions show that in arid and semi-arid regions, including many regions of Iran, climate change will lead to an increase in temperature and a decrease in rainfall. Therefore, considering the importance and role of temperature and humidity in physical and chemical quality indicators of soil and production stability, it seems that the phenomenon of climate change will have adverse effects on soil and then on crop production. Therefore, it is very important to use the necessary solutions to mitigate these adverse effects and adapt to the upcoming conditions. In this article, by reviewing and summarizing the research on the effects of climate change on the characteristics of arid and semi-arid soils, an attempt has been made to provide some kind of foresight of possible changes in the physical, chemical, and biological properties of soil due to climate change.

To study the effects of artificial seed ageing on germination indices in the laboratory condition and seedling establishment and yield of two red kidney bean genotypes in the field condition, an experiment was carried out at Research Field of Faculty of Agriculture, University of Tehran, Karaj, Iran in 2011. The two experiment design, were as factorial with four replications arranged in randomized complete blocks design (RCBD) and complete randomized design (CRD) for field and laboratory condition, respectively. The experimental treatments consisted of four levels of seed ageing – 0 (control), 2, 4 and 6 days seed ageing – and two red bean genotypes (Akhtar and Sayyad). Results showed that germination percentage, germination rate, normal seedling and seedling vigor index significantly decreased by seed ageing treatment in standard germination test. Also, seed ageing significantly decreased germination percentage, germination rate, seedling length and dry weight, normal seedling and seedling vigor index in accelerated ageing test. Studied genotypes was different in terms of germination percentage, germination rate, normal seedling, seedling length, seedling vigor index and electrical conductivity test. In the electrical conductivity test, seed leakage increased by increment of seed ageing level and is sever in Akhtar compared to Sayyad. In the field condition, seedling emergence and grain yield significantly affected by genotype and seed ageing. Seedling emergence index, seedling establishment percentage and grain yield decreased by seed ageing treatment that was severe in Akhtar than that of Sayyad genotype.

Agriculture development heavily relies on chemical inputs such as synthetic fertilizers, pesticides, fossil fuels and other energy-intensive inputs. This development is having a serious impact on public health and the environment. Therefore, efficient use of resources is a primary and most vital implications for sustainable agriculture development. Sustainability indices are quantitative values that can be used to evaluate the efficiency and quality of agroecosystems and are useful tools for making suitable decisions in its management. These including energy flow indices, global warming potential (GWP), economic indices, environmental impact quotient (EIQ) of pesticides, efficiency of land, water and fertilizers use and etc. Alfalfa and corn silage as the main source of feed for livestock, have a notable area in the cropping pattern of Maragheh-Bonab plain. Therefore, evaluation of sustainability for these crops will help the sustainable management of agroecosystems in the study area. The present study was conducted to: (a) determine energy efficiency and global warming potential; (b) determine the environmental impacts of pesticides; (c) assess input use efficiency and; (d) economic analysis of alfalfa and corn silage production systems in East Azerbaijan province of Iran. In the present study, the sustainability of alfalfa and corn silage production systems lies in the Maragheh-Bonab plain in southern East Azerbaijan province in northwestern Iran were evaluated using quantitative indices such as energy efficiency and productivity, greenhouse gas (GHG) emission; economic indicators; pesticide risk (field environmental impact—FEIQ); tillage impact (TI); fertilizer, labour, land and water use efficiency, and the eco-efficiency index. For this purpose, data was collected from 110 farmers by survey to determine crop production in the region. Secondary data including climate characteristics and products sale price was obtained from previous studies and organizations such as the Agricultural Ministry of Iran. The results showed that the values of input energy, output energy and net energy in alfalfa production system (48151, 432920 and 384768 Mj.ha-1, respectively) were higher than corn silage production system (35557, 217350 and 181792 Mj.ha-1, respectively). Also, it was observed that the values of energy use efficiency and specific energy of alfalfa (9 and 15.8 MJ.kg−1, respectively) were higher than that of corn silage (6.1 and 4.1 MJ.kg−1, respectively). In terms of economic indices, despite of lower total cost of production in corn silage (1089 $.ha-1), the highest values of gross production value (6447 $.ha-1) and net return (4193 $.ha-1) were related to alfalfa production system. In terms of GWP and EIQ, alfalfa production had the higher values with compared to corn silage production. However, eco-efficiency (ratio of economic value to the environmental impact) values based on of GWP and EIQ was significantly higher for alfalfa (1.75 $.kg -1 CO2eq-1 and 35.3 $.EIQ-1) than corn silage (1.5 $.kg-1 CO2eq-1 and 26 $.EIQ-1). Land production efficiency, economic land production efficiency, irrigation water productivity, economic irrigation water productivity, nitrogen use efficiency, phosphorous use efficiency and potassium use efficiency were 140 kg.ha-1.day-1, 21.5 $.ha-1.day-1, 4.1 kg.m-3, 0.63 $.m-3, 335 kg.kg-1, 1191 kg.kg-1 and 1826 kg.kg-1 in alfalfa production system and 583 kg.ha-1.day-1, 22.9 $.ha-1.day-1, 8 kg.m-3, 0.31 $.m-3, 656 kg.kg-1, 3553 kg.kg-1 and 65525 kg.kg-1 in corn silage production system, respectively. It can be concluded that environmental impacts of pesticides and global warming effect per area in alfalfa production system were higher than corn silage production system. However, in terms of economic indices and energy use efficiency, alfalfa production system was superior to corn silage production system.

This paper evaluates the environmental impacts and economic aspects of saffron and canola production systems using energy and greenhouse gas (GHG) emission indices; economic indicators; pesticide risk (field environmental impact—FEIQ); tillage impact (TI); fertilizer, labour, land and water use efficiency, and the eco-efficiency index. Data used in this study were obtained from all growers of saffron and canola (35 for saffron and 60 for canola) in the Maragheh—Bonab plain using a face to face survey. The results showed that canola production was more energy-intensive than saffron. The global warming potential (GWP) and carbon footprint (CF) obtained for canola was higher than saffron. Moreover, FEIQ and TI for canola were higher than saffron. Although canola recorded more economic labour productivity, the saffron was superior to canola in terms of energy and economic indices, environmental aspects (GHG emission, TI, FEIQ), and water, land and nutrients use efficiency.

One serious challenge in agriculture during the 21st century is meeting the food demands of the growing population from restricted and decreasing per capita natural resources such as land, water, and minerals with minimum environmental degradation. But, developments in agriculture that heavily rely on chemical inputs such as synthetic fertilizers, pesticides, fossil fuels and other energy-intensive inputs, is having a serious impact on public health and the environment. Therefore, efficient use of resources and inputs is a primary and most vital implications for sustainable development of agriculture. Sustainability indices are quantitative values that can be used to evaluate the efficiency and quality of agroecosystems and are useful tools for making suitable decisions in its management (Mahdavi Damghani et al., 2006). These including energy flow indices, global warming potential (GWP), economic indices, environmental impact quotient (EIQ) of pesticides, efficiency of land, water and fertilizers use and etc.
In the present study, the sustainability of wheat and barley production systems lies in the Maragheh-Bonab plain in southern East Azerbaijan province in northwestern Iran were evaluated using the aforesaid indices. For this purpose, data was collected from 110 farmers by survey to determine crop production in the region. Secondary data was obtained from previous studies and statistics from organizations such as the Agricultural Ministry of Iran.
The results showed that the values of input energy, output energy and net energy in wheat production system (34412, 161462 and 127050 Mj ha-1, respectively) were higher than barley production system (29596, 126077 and 96480 Mj ha-1, respectively). Also, it was observed that the values of energy use efficiency and energy productivity of wheat (4.7 and 0.17 kg MJ−1, respectively) were significantly higher than that of barley (2.1 and 0.15 kg MJ−1, respectively). In terms of economic indices, despite of lower total cost of production in barley, the highest values of gross production value, net return, benefit to cost ratio and economic productivity were related to wheat production system. Our results are in agreement with the results of Sahabi et al. (2013). In terms of GWP and EIQ, wheat production had the higher values with compared to barley production. However, eco-efficiency (ratio of economic value to the environmental impact) values based on of GWP and EIQ was significantly higher for wheat (1.26 $ kg -1 CO2eq-1 and 37 $ EIQ-1) than barley (1.03 $ kg-1 CO2eq-1 and 31.4 $ EIQ-1). Also, land, water and fertilizer use indices for wheat were higher than barley. The land use efficiency, land production efficiency, economic land production efficiency, irrigation water productivity, economic irrigation water productivity, nitrogen use efficiency, phosphorous use efficiency and potassium use efficiency were 65.7%, 24.5 kg ha-1 day-1, 6.2 $ ha- 1 day-1, 1.6 kg m-3, 0.43 $ m-3, 56.7 kg kg-1, 136.4 kg kg-1 and 2401 kg kg-1 in wheat production system and 61.6%, 19.2 kg ha-1 day-1, 3.2 $ ha-1 day-1, 1.5 kg m-3, 0.26 $ m-3, 34.8 kg kg-1, 102.3 kg kg-1 and 376 kg kg-1 in barley production system, respectively.
It can be concluded that environmental impacts of pesticides and global warming effect per area in barley production system were lower than wheat production system. However, in terms of economic indices, inputs and energy use efficiency, wheat production system was superior to barley production system.

Decision making on budgeting is one of the most important issues for executing managers. Budgeting is a major tool for planning and control of projects. In public and non-profit organizations and institutions, estimating the costs and revenues plays an important role in receiving credit and budgeting. In this regard, in the present paper the case of Isfahan municipality is considered. One of the main expenditures of the 14 districts of Isfahan is the costs related to water. Predicting the total cost of water helps the municipality of Isfahan to optimize the water use in its 14 urban zones. Thus, in this study the total cost of water in the districts of Isfahan is estimated using regression analysis and neural network models. Then the results of the methods are compared with each other to minimize the deviations from the approved budget. Finally, the neural network method is selected as the main simulation method for forecasting the total cost of water in the districts of Isfahan.

To study the effects of different levels of water stress and nitrogen fertilizer on seed yield and yield components of two common bean genotypes (Phaseolus vulgaris), an experiment in a split plot factorial based on CRBD with four replications was conducted at the research farm of University of Tehran (Karaj-Iran) in 2010. Water stress treatments as the main factor included normal irrigation (60 mm evaporation from open pan), mild and sever water stress (90 and 120 mm evaporation from open pan, respectively) at fourth leaf stage. Nitrogen fertilizer at four levels comprised of zero, 50, 100 and 150 kg N/ha and two red kidney bean genotypes (namely, Akhtar and D81083) were allocated as sub plots in a factorial arrangement. The results indicated that water stress decreased pods/plant, seeds/pod, 100 seed weight, seed yield, total dry matter, harvest index and plant height, significantly (p ≤ 0.05), but increased seed protein. Nitrogen fertilizer application also increased plant traits, significantly, except for the seeds/pod and harvest index. The two bean genotypes were different in their characteristics excluding the seeds/pod and seed protein content, however, the seed yield was comparatively higher in D81083 than Akhtar genotype. The interaction effects of water stress × genptype on bean seed yield under normal irrigation and severe drought stress was recorded for D81083 and Akhtar genotypes, respectively. Similarly, the interaction effects of water stress × nitrogen on bean seed yield under normal irrigation with 150 kg N/ha and under severe drought stress without nitrogen was higher and lower, respectively