JOURNAL OF AGROECOLOGY (کشاورزی بوم شناختی)
Year:2017 | Volume:7 | Issue:2 |Papers Count:10

Introduction: The timing with which weeds emerge is one of the most important factors in competition (Baghestani and Zand, 2004). Weeds that emerge at the same or approximate time as crops inflict the most damage (Eslami et al., 2006). Models can predict the emergence time (Leon et al., 2004, Dorado et al., 2009). The goal of the present study is to investigate the emergence model of weeds (blade and flag leaf) in two different regions, Saba-Shahr and Pakdasht, based on thermal models. Beyond that, if possible, another goal is to recommend the best weed emergence models for predicting the timing of weed emergence in these regions.Materials and methods: The experiment was carried out based on a complete randomized block design with four replications in two regions, Saba-Shahr and Pakdasht fields, in 2010-11. The weeds included blade leaves Sinapis arvensis L. (wild mustard), Raphanus raphanistrum L. (wild radish), Descurania Sophia L., and flag leaf (Phalaris minor). For the examination of weed emergence, different models were used such as sigmoidal, logistic, Gompertz, a three-parameter Weibull and a four-parameter Weibull based on growing degree days (GDD). Root mean square error (RMSE), coefficient of determination and the corrected AKAIKE information criterion (AICc) were used to find the appropriate model(s).Results and discussion: The result showed that the emergence model and weed growth in the two regions were different. The best models, based on the lowest RMSE, AICc and adj R2 were Gompertz and sigmoid for predicting weed emergence in Pakdasht and Saba-Shahr. The emergence rate of weeds in Saba-Shahr showed that wild radish was the first (40 GDD) to emerge among the weeds. After that, wild mustard needed 50 GDD and Phalaris minor needed 60 GDD to emerge. The emergence of Descurania Sophia needed 150 GDD, and for this reason had delayed growth. In Pakdasht, wild radish was also the first weed to emerge (110 GDD). Wild mustard and Phalaris minor both emerged with 115 GDD and Descurania Sophia (180 GDD) was seen after that.Conclusion: The results of this study showed that in the two regions, with the emergence of wild radish, wild mustard, Phalaris minor and Descurania Sophia, interference crops must be planted earlier for increasing interference capability. On the other hand, the control of wild radish, wild mustard and Phalaris minor was more important than the control of Descurania Sophia.

Introduction: Over the last decade, pressure on natural resources has increased due to population growth and the need for food security. This is especially true in developing countries. Excessive use of productive inputs increases the importance of sustainable agriculture to enhance performance and reduce environmental degradation. Sustainable agriculture is the ability to properly manage natural resources to ensure food security and environmental sustainability (Praneetvatakul et al., 2001).This study aims to assess the sustainability of the common agricultural systems in Ardabil Province.Materials and methods: For this purpose three criteria, each measure itself composed of several sub-criteria, for each city were considered. These included environmental, economic and social criteria. In total, 17 sub-criteria were under consideration for assessing agricultural sustainability. The study data required for standardization of an agricultural sustainability model were collected from sources as diverse as the Agricultural Organization, demographic yearbooks, the Regional Water Authority, and environmental organizations. The study also benefitted from views of technical experts in agriculture and the environment through questionnaires collected in 1395. In this study, to assess the sustainability of agriculture, combine quantitative and qualitative data, as well as achieve more effective decision-making, an approach with a combination of AHP and TOPSIS was used (Radulescu and Rahoveanu, 2010). Determination of Value-Weighted index was accomplished using the Analytic Hierarchy Process (AHP). The relative importance of each sub-option (agricultural areas) was also categorized using the TOPSIS technique (Dadashian et al., 2015).Results and discussion: Based on the results, environmental criteria, with 0.443 relative weights, had the highest impact. Social criteria, with 0.169 relative weights, had the lowest effect on agricultural sustainability. Among the environmental sub-criteria, the most important were fertilizer and pesticide usage with 0.158 relative weights, and efficient irrigation systems with 0.145 weights. Soil salinity, as one of the environmental sub-criteria, had the lowest importance in the assessment of sustainability. From the economic sub-criteria, risk with 0.148 relative weights was the least important and crop yield with 0.295 relative weights was the most important. Among social criteria, presence in promotion classes with 0.377 weighted value and population density with 0.100 weighted value had a respectively high and low impact on sustainability. According to the results of regional ranking, Germi, Bilesavar and Meshginshahr, with weighted values of 0.624, 0.620 and 0.589, were the most favorable regions in terms of sustainability. Sarein, Nir and Parsabad, with weighted values of 0.395, 0.463 and 0.468, had the weakest sustainability. A one-by-one examination of the sustainability sub-criteria of the city of Germi reveals the main reasons for the optimal conditions for agricultural sustainability in this city compared to others. Germi has the maximum criteria of conservation tillage of about 6.10 and the aforementioned low criteria of soil salinity, fertilizer consumption and chemical pesticides. The results of this study showed that in more urban areas such as in Parsabad and the economic center, Maghan, the intended purpose is only maximum earnings and enhanced functioning, with no regard for sustainability or sustainable development issues.Conclusion: Overall, the data showed the agricultural sustainability for Ardabil Province and determined the strengths and weaknesses of each city in the province. These results enable us to identify the importance of various criteria affecting sustainability and compare regions with good accuracy to apply appropriate policies to improve agricultural sustainability.

Introduction: The IPCC states that the climate is changing. Since rainfed agricultural crop yield is influenced by climatic factors, climate variables and a changing climate can affect yield and yield risk. The aim of this study is to identify the impact of climate variables and change on crop yield and the yield risk of wheat and barley in West Azerbaijan Province.Materials and methods: To this end, the stochastic yield function of Just and Pope was used with panel data for the period of 1383-94 for five counties in West Azarbaijan. These counties are the largest producers of these two crops in the province. To estimate the econometric models of crop yield and yield risk functions, linear, quadratic, Cobb-Douglas, transcendental and translog functional forms were used.Results and discussion: Results show that precipitation and average temperature have a positive effect and wind speed has a negative impact on crop yield. Maximum and minimum temperature also have different effects. Minimum temperature has a negative effect on barley yield but a positive effect on wheat yield. Whereas the effect of maximum temperature is negative for wheat but positive for barley. Additionally, average temperature has a negative effect on the yield risk of both crops and is risk-decreasing. Precipitation and average maximum temperature have a negative effect and average minimum temperature has a positive effect on the yield risk of barley. Variables that have positive effects on the yield risk of wheat are average maximum temperature and wind speed and they are risk-increasing. Average humidity during the growth season has a negative effect on the yield risk of wheat. Elasticities of the variables with regard to crop yield and yield risk of the crops has been calculated. Results of the calculation of the elasticities of precipitation, average temperature, minimum temperature, maximum temperature and wind speed with regard to yield of wheat equal 0.23, 1.75, 0.16, -1.56, and -0.16, and with regard to barley 0.52, 0.82, -0.47, 1.04 and -2.15, respectively. Average temperature has the highest positive effect on wheat yield and wind speed has the lowest negative effect on barley yield. Also, results of the calculation of elasticities of average temperature, maximum temperature, humidity and wind speed with regard to yield risk of wheat are -53.27, 66.63, -10.30 and 6.32. With regard to barley, elasticities of precipitation, maximum temperature, average temperature and minimum temperature are -2.24, -4.89, -20.48 and 34.92. Increasing maximum and minimum temperature have the highest positive impact on yield risk of barley and average temperature has the lowest negative impact.Conclusion: As the results show, climate variables have an impact on crop yield and yield risk of rainfed wheat and barley in West Azarbaijan. Average temperature and precipitation have a positive impact and wind speed has a negative impact on the yield of rainfed wheat and barley. Average temperature also has a negative impact on the yield risk of both crops. The effect of precipitation on the yield risk of wheat is non-significant but has a negative impact on the yield risk of barley. Wind speed has a positive impact on the yield risk of wheat but its effect is nonsignificant on the yield risk of barley. In addition, results show that the impact of climate factors on crop yield and the yield risk of rainfed wheat and barley in West Azarbaijan are nonlinear and these factors do not affect crop yield and yield risk independently. The interaction of these factors, however, will affect crop yield and yield risk.

Introduction: Oilseed rape (Brassica napus) is one of the most important oil plants. While a major portion of vegetable oil is needed from outside suppliers, oilseed rape, because of its high yield, can play a critical role in increasing oil and meal production to meet domestic demands. Golestan Province, especially the eastern part, is one of the most important oilseed rape production areas in Iran. The yield of oilseed rape in this region often averages less than 2 t ha-1. The estimation of yield gap and the determination of the responsible factors are a good approach to improve farmers’ average yield. The present study aims to use the Comparison of Performance Analysis (CPA) method to estimate oilseed rape yield gap in eastern Golestan and to quantify the contribution of each factor to this yield gap in order to reduce yield limitations and improve farmers’ yield. Materials and methods: To identify the limitations of production management, this study was carried out in the 2013-14 and 2014-15 growing seasons. The study was executed in Gonbad, Kalaleh and Galikash, the main oilseed rape production areas in eastern Golestan. In the two years studied, 332 farms were evaluated. The study focused on factors of management methods; soil factors were not considered. All data collected on farm management were analyzed for each city and then for the entire surveyed region with stepwise regression and the CPA method (Torabi,et al., 2011; Nekahi, et al., 2014). Thus, yield gap was obtained as the difference between potential yield and the actual average yield of local farmers (Van Ittersum and Cassman, 2013).Results and discussion: Whilst actual yield was 1,081 in Gonab, 1,456 in Kalaleh and 1,728 kg ha-1 in Galikash, the results showed the attainable yield could have been 3,032, 3,516 and 4,032 kg ha-1 in these areas. Thus, the yield gap was 1,951, 2,060 and 2,304 kg ha-1. The actual yield in the eastern part of the province was estimated at 1,417 kg ha-1, whereas attainable yield could have been 4,800 kg ha-1, resulting in a yield gap of 3382 kg ha-1. The application of nitrogenous fertilizer was one of the main reasons for yield gap in all the surveyed regions. It reduced yield by 25% in this part of the province. Sulfur fertilizer caused 16 percent of the yield gap. Weeds were the other reason. The lack of weeding was responsible for 16% of the yield gap and the failure to apply Lontrel for the management of weeds for 12%. Disease outbreak was another cause. The application of fungicides offsets 16% of the yield limitation. Seed rate, 6%, and sowing date, 4%, also contributed to the gap. Cultivar and seed treatment were each responsible for less than 2%.Conclusion: Weed management, disease, seeding rate, sowing date, cultivar, and seed treatment, were the main causes of yield gap. Therefore with better management and optimal use of nitrogen and sulfur applications, oilseed rape yield can be increased by as high as 3,382 kg ha-1.

Introduction: Organic fertilizer, such as vermicompost and spent mushroom compost (SMC) have a large nutrient value, mainly as nitrogen (N), phosphorous (P) and potassium (K) (Elliot and Dempsey, 1991). These compounds could therefore be used in the production of vegetables and medicinal plants to reduce the harmful effects of chemical fertilizers and increase soil fertility (Benton and Wester, 1998). Summer savory has many biological active ingredients in its essential oil, which are widely used today in the pharmaceutical and food industries (Hadian, 2008). The main objective of this research was to study the effect of vermicompost and SMC on the growth indices, micronutrient content and essential oil in savory shoots (Satureja hortensis L.).Materials and methods: A pot experiment was conducted on savory (Satureja hortensis L.) in a completely randomized design in the research field of Mohaghegh Ardabili University. Treatments included volume ratios of zero (control), 10%, 20%, 30%, 40% and 50% of vermicompost and SMC in washed and unwashed conditions. At the end of the growth season, the growth traits measured included plant height, shoot and root fresh and dry weight, number of leaves, number of main stems, number of lateral branches, leaf area and chlorophyll. Essential oil of savory was extracted using Clevenger's hydro-distillation apparatus. In order to measure essential oils and their constituents, a gas chromatograph (GC) and a gas chromatography-mass spectrometry instrument (GC/MS) were used. Quantities of copper, iron, manganese and zinc were measured through an atomic absorption spectrometer, GBC Avanta P (Emami, 1996).Results and discussion: The results showed that an application of vermicompost in the substrate had a significant effect on the growth characteristics of savory (p < 0.01). The maximums in plant height, plant dry weight, plant fresh weight, number of leaves, root length, leaf dry weight and chlorophyll index were achieved with an application of 10% vermicompost to the basic substrate. Most of the measured traits such as plant height, plant fresh weight, number of leaves, root fresh weight, number of main stem and chlorophyll, significantly decreased when a higher percentage of vermicompost was added to the substrate. This may be due to the high electrical conductivity, the production of phenolic compounds and the accumulation of heavy metals and their toxicity in high proportions of vermicompost. The control treatment, however, obtained the lowest plant height, plant fresh weight, leaf area, leaf number, root dry weight, number of main stems and leaf dry weight to plant weight. This indicates the positive effect of vermicompost and SMC on savory growth. The highest essential oil content (2.45%) was observed in 30% vermicompost treatment. Treatment of 40% unwashed SMC showed the lowest percentage of essential oil (1.8 %), significantly different from other treatments (p < 0.01). Results of the effect of different treatments on the content of micronutrients in plant shoots illustrated that the highest Fe content in shoot was revealed in 40% unwashed SMC, although the most Zn content was found in 50% unwashed and washed SMC. Furthermore, the plants grown in 20% and 30% of vermicompost and washed SMC had the highest Cu in the shoot of savory. The application of organic fertilizers did not significantly the increase of Mn content, and even decreased it in some cases.Conclusion: In general, this study showed that the use of proper proportions of vermicompost and SMC in the soil can have a positive impact on the growth index, essential oil percentage and the content of the micronutrients of savory. The use of high ratios of organic fertilizer to the soil, however, could reduce most of the traits in savory.

Introduction: Increasing our knowledge of environmental hazards and resistance to herbicides while avoiding high costs has led to the use of applied approaches that pose minimal danger to the agroecosystem and reduce herbicidal pollution. Living mulches are plants from the Fabaceae family that are used as cover crops. Since cover crops uptake water and nutrients from the soil, they require appropriate management to reduce their competition with the main crop and prevent lost yield. Thus the growth rate, density and other effective growth factors of living mulch is important. The objectives of the experiment were to investigate the impact of using berseem clover (Trifolium alexanderinum) and trigonella (Trigonella foenum-graecam) as cover crops on the yield and yield components of wheat as well as weed reduction.Material and methods: In order to investigate the effect of using berseem clover (Trifolium alexanderinum) and trigonella (Trigonella foenum-graecam) as cover crops on the yield and yield components of wheat and weed control, an experiment was carried out in a randomized complete block design with eight treatments and three replicates in the autumn of 2011, in Behshahr, Iran. Treatments included a wheat planting distance of 20 cm and 30 cm with and without the presence of berseem clover and trigonella as cover crops. These were planted both in areas with weeds and without. The weed flora of the field included wild oat (Avena fatua L.), Milk thistle (Silybium marianum) and hairy vetch (Vicia villosa Roth). A sampling was carried out in order to evaluate wheat dry matter and density, the biomass of weeds, and the dry matter of cover crop. Variations in wheat and cover crop height were investigated by using the Gompertz sigmoidal model (Draper and Smith, 1981). Data were subjected to analysis of variance and means were compared with Duncan's test.Results and discussion: The results of the experiment showed that wheat in the presence of trigonella had a higher level of dry matter (419.39 g m-2), and higher economical (5,390 kg ha-1) and biological yield (16,256.70 kg ha-1). The wheat yield from the 20-cm plantings in all treatments was more than in the 30-cm plantings. The root of Fabaceae plants, by penetrating the soil deeply, improve and enhance the microorganism population and by biological nitrogen fixation that supply the nitrogen requirements of the main crop (Naghizadeh and Ghalavi, 2012). Moreover, cover crops through the uptake of nitrogen and nutrients prevent their leaching (Ranells and Wagger, 1984). The dry matter and height of trigonella both in the 20-cm and 30-cm plantings was higher than berseem clover. The reduction of weed biomass in the treatment with trigonella was higher than the treatments with berseem clover used as a cover crop. This result shows that trigonella is better able to adapt to the environmental growth conditions in wheat canopy compared to berseem clover and could be a suitable cover crop for wheat (Sabahi et al., 2006). Weed biomass in the 20-cm wheat planting was lower than in the 30-cm planting.Conclusion: Generally, both cover crops were successful in weed control and enhancement of wheat yield compared to a wheat monoculture. Trigonella, however, was more efficient than berseem clover in reducing weed Trifolium alexandrium L. growth and enhancing wheat yield. The results obtained from the research could be used in sustainable management practices to reduce weed growth and herbicide application in wheat fields.

Introduction: Climate change is considered one of the most critical socio-ecological challenges of the 21st century (Kittipongvises and Mino, 2015). Current scientific evidence proves that it has been induced by humans (Cismaru et al., 2011). Adaptation is necessary for addressing climate change (Lam, 2015). Climate change has considerable negative effects on growers' adaptive behavior to deal with this phenomenon and the effects will be felt most by vulnerable populations. The purpose of this study is to investigate wheat growers facing climate change in Kermanshah County and their adaptive behavior based on protection motivation theory to the survey method.Materials and methods: The study population included all wheat growers in Kermanshah County. The statistical sample was 232 wheat growers selected through a multi-stage cluster sampling. The face validity of the questionnaire was confirmed by experts. The reliability of the main scales of the questionnaire was examined by Cronbach Alpha coefficients, which were all at an acceptable level Results indicated a significant positive correlation between response efficacy, self-efficacy response, response costs, perceived severity, and perceived vulnerability with variable growers' adaptive behavior.Results and discussion: The results showed that the variables of self-efficacy response, perceived vulnerability and response costs have a direct effect on the variable positive growers' adaptive behavior. Collectively, these variables are capable of predicting 34 % of the variability of growers' adaptive behavior. The most effective variable in predicting adaptive behavior of farmers in the face of climate change was self-efficacy of the response, which has a direct and significant effect on farmers' adaptive behavior.Conclusion: This suggests that to identify the adaptive methods of farmers and especially the ease of carrying out adaptive measures for climate change, Agricultural Jihad and its affiliated centers should host training classes on adaptive behaviors in order to facilitate activities and effective strategies for change.

Introduction: Investigating whether agricultural ecosystems are performing as carbon source or sink due to either natural influences or management approaches plays a critical role in studies aimed at mitigating and adaptating to climatic variation. A sustained study of the application of agricultural ecosystems is the only achievable way to develop an accurate vision on gas exchange between the atmosphere and terrestrial ecosystems (Beziat et al., 2009). Estimating carbon budget in agricultural ecosystems is an effective way to find out whether a given ecosystem is a source or a sink of carbon dioxide (Twine and Kucharik, 2009). The goal of this investigation was to study the effects of maintaining crop residues on CO2 flux and carbon balance in an agricultural system.Materials and methods: This study was conducted to investigate the effects of increased residue rate on the CO2 emission rate and determine the soil carbon budget in the presence or absence of residue in the soil surface. A randomized block design experiment including five treatments and three replications was carried out on a research farm of the University of Ferdowsi in 2011-12. Treatments include 0, 2, 4, 8 and 16 t ha-1 of wheat (Triticum aestivum L.) straw. The carbon budget was estimated in both years using a static closed chamber method according to analysis by gas chromatography (Shimizu et al., 2009).Results and discussion: Results showed that in spring and summer, soil temperature was higher than air temperature. In winter and autumn, air temperature was usually higher than bare soil temperature. In both the experimental years, the temperature of residue-containing soil was lower than that of the air in spring. The treatment with the highest residue rate (16 ton ha-1) had the lowest temperature in all measurements, however, the difference between various residue treatments was slight and the difference between 8 and 16 tons ha-1 was not significant in any measurement. Duiker and Lal (2000) showed that soil temperature under application of residue was 14oc lower than bare soil. The daily CO2 emission rate ranged from 0.1 to 4.3 megagrams C ha-1year-1. The CO2 emission rate increased in line with increases in residue kept at the soil surface. The highest annual CO2 flux rate was obtained for 16 ton ha-1 residue as 3.7 in 2011 and 3.6 in 2012 and the lowest annual CO2 flux rate was gained in bare soil in the two experimental years as 0.7 and 0.9 tons ha-1. Based on this equation, annual CO2 flux was calculated. An exponential relationship between soil temperature and respiration has been also reported by other authors (Brar et al., 2013).Conclusion: Residue application had a significant impact on soil temperature. The difference was large between unmulched and mulched treatments. Our results indicated a high correlation (> 85%) between soil temperature and CO2 flux which was positive and exponential. Although the total calculated CO2 flux from the bare soil treatment was lower than the other treatments, this treatment had a carbon budget more negative than the other treatments, which is an ecologically negative factor.

Introduction: Sustainable agriculture is a kind of agriculture to human interests, uses resources more efficiently, and is in balance with the environment. One of the key strategies in sustainable agriculture is diversity restoration to agricultural environments and its effective management. Intercropping is an effective way to achieve sustainable agriculture. In comparison to a sole crop, intercropping better utilizes nutrients, water, and land (Fuente et al., 2014; Zhang et al., 2011). Conservation tillage also helps retain water and soil, and increases crop yield. This experiment was done to evaluate the effect of conservation and conventional tillage on biodiversity and water and nitrogen use efficiency in sole and additive intercropping of soybean (Glycine max (L.) Merr.) with sunflower (Helianthus annuus L.).Materials and methods: The experiment was conducted at the Bu-Ali Sina University, during the growing seasons of 2013-14. Tillage (conventional tillage and conservation tillage by chisel) and different planting patterns (sunflower and soybean sole cropping with weeding; sunflower and soybean sole cropping without weeding; and additive intercropping of 30%, 60% and 90% soybean with sunflower) were considered as main plots and subplots, respectively. Grain yield was determined for sunflower and soybean. Land equivalent ratio (LER) was calculated to measure efficiency of intercropping compared to pure cropping (Banik et al., 2006). Weed species, density and biomass were determined for weed infested treatments. Indices of Shannon-Wiener and Margalef for weed species were also used for studying biodiversity. SAS ver. 9.1 procedures and programs were used for analysis of variance (ANOVA) calculations.Results and discussion: The highest total weed density (50.50 plant m-2) and biomass (312.50 g m-2) were obtained from sunflower sole cropping without weeding at chisel tillage. Intercropping significantly changed weed density compared to sole cropping, as weed density and weed biomass were decreased in the intercropping systems. Indices of Shannon-Wiener and Margalef for intercrops were also lower than those for sole crops. The lowest Shannon-Wiener (1.22) and Margalef (1.12) indices for weeds were obtained with the treatment of 90% soybean + sunflower under conservation tillage. The highest grain yield of sunflower (363.00 g m-2) was achieved with a sole cropping treatment with weeding, but the intercropping system decreased this. Soybean grain yield also decreased with intercropping. Intercropping systems could increase water and nitrogen use efficiency in comparison with sunflower sole cropping without weeding. The highest land equivalent ratio (1.28) and relative value total (1.68) belonged to additive intercropping of 60% soybean + sunflower. One of the important benefits of intercropping is the higher productivity and profitability per unit area (Zhang et al., 2011). When the value of LER is less than 1, the intercropping negatively affects the growth and yield of crops grown in mixtures. When the value of LER is greater than 1 (LER>1), however, the intercropping favors the growth and yield of the crops. (Zhang et al., 2011). Moreover, the total land use efficiency was higher in the intercropping system compared to the sole cropping system, indicating the advantage of intercropping over sole cropping in utilizing environmental resources for crop growth (Fuente et al., 2014; Zhang et al., 2011).Conclusion: Generally, weed density and weed biomass were lower in intercropping systems than in pure cropping. Intercropping systems also increased water and nitrogen use efficiency in comparison with sunflower sole cropping. Therefore, additive intercropping of soybean with sunflower was more useful than sole cropping in terms of weed control and land use efficiency.

Introduction: Golestan Province is one of the main areas of wheat production in Iran. In 2015, it ranked third among all the provinces of the country in term of acreage and yield (Anonymous, 2016). Given the strategic importance of wheat, it is necessary to identify suitable areas for its rainfed cultivation based on meteorology, agronomy, soil and land properties. This process is known as agroecological zoning. In addition to analyzing ecological factors affecting rainfed wheat production based on the consolidation of scientific references, this study will also identify suitable zones in Golestan for rainfed wheat cultivation.Materials and methods: Firstly, six factors were determined in 30 weather stations in the concurrent period 1991-2015 including: planting date, dates of each phenological stage of wheat based on growing degree-days (Ahmadi et al., 2016), precipitation, air temperature and the ratio of effective precipitation to crop evapotranspiration in each stage, and total growing season of wheat. These parameters were then estimated by the occurrence probability level of 75% (Sys et al., 1991). The possibility levels of higher and lower temperatures than the tolerable threshold of wheat in various stages of growth were also calculated. Next, a zoning map of the parameters and characteristics of elevation, slope, soil type and salinity were prepared in five classes. Finally, by overlaying these data layer (layer 26), the agroecological zoning of agricultural land of Golestan for the cultivation of wheat was performed. Results and discussion: Average air temperature during germination, flowering and seed filling stages of wheat in Golestan with occurrence probability of 75% were 8 (moderately suitable), 10.9 (moderately suitable) and 22.7oC (suitable), respectively. Also, the occurrence probability of temperature less than the tolerance threshold in the germination stage of wheat (10oC) was considerable in the province, but the occurrence probabilities of higher and lower temperatures than the tolerance thresholds of wheat in other growth stages were low in the dominant area of the province. The results showed that in terms of the ratio of effective rainfall to potential evapotranspiration during the total growth period, 92 percent of the province area was located relatively equally in moderately suitable (29%), suitable (9%), and very suitable (20%) classes for rainfed wheat cultivation. Also, soil salinity in 72 percent of the agricultural land was less than the tolerance threshold of wheat (6 dS.m-1). According to the results, total area of very suitable, suitable and moderately suitable zones for rainfed wheat cultivation in the agricultural zones of the province was 602,000 hectares, that is 51% and 117% more than the current acreage of total wheat and rainfed wheat, respectively. Furthermore, the sum of moderately to very suitable zones for rainfed wheat cultivation was calculated at 64.8 of the province and 85 percent of total agricultural land. In the entire country, the highest percentage of very suitable areas were located in Gonbad (24.7%) and Kalaleh (20.9%), suitable areas in Maravehtapeh (18.2%) and Gorgan (16.4%), and moderately suitable areas in Gonbad (22.8%), Aghghalla (19.7%) and Gomishan (17.7%).Conclusion: Suitable areas for rainfed wheat cultivation in Golestan Province are generally located in the middle strip of east-west. The extents of these zones in the occurrence probability level of 75% are over the current wheat acreage of the province. This result is consistent with the Bidadi et al. (2015) findings.