Hosna Fayazi; Ebrahim Zeinali; Afshin Soltani; Benyamin Torabi
Abstract
Global climate change is among the most important agricultural and food security challenges. This study tries to investigate the effect of climate change on potential yield and water productivity of forage maize (Zea mays L.) in Iran. Two scenarios of RCP4.5 and RCP8.5 are used to predict the future ...
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Global climate change is among the most important agricultural and food security challenges. This study tries to investigate the effect of climate change on potential yield and water productivity of forage maize (Zea mays L.) in Iran. Two scenarios of RCP4.5 and RCP8.5 are used to predict the future climate (2050s) and climate data of 2001-2015 have been used as the base period. Potential yield is estimated using SSM-iCrop2 model according to the GYGA protocol and the climate changes for both scenarios are applied in the model. The results show that the climate change will not have a considerable effect on forage maize yield compared to the current conditions (85.6 ton ha-1) and will only lead to an increase of 0.9% and 1.6% in on both scenarios, respectively. This may be attributed to maize being a C4 plant and thus non-effectiveness of CO2 increase on its growth. Also, the temperature will remain in optimum range for maize in most of the main regions for forage maize cultivation areas in Iran. Water productivity in both scenarios will increase by 0.4% and 1.6%, compared to current conditions (10.4 kg m-3), respectively, which may be due to increased CO2 concentration and more closure of stomata. Also, improved water productivity in forage maize may be attributed to increase yield potential due to the fact that no considerable changes are observed in terms of the required water, evapotranspiration and irrigation times.
samaneh rahban; Benjamin Torabi; afshin soltani; Ebrahim Zeinali
Abstract
The present study tries to estimate the yield gap of irrigated canola in Iran as the first step for planning sustainable improvement of production. It has been performed in the modeling laboratory of Gorgan University of Agricultural Sciences and Natural Resources in 2017-2019. The protocol provided ...
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The present study tries to estimate the yield gap of irrigated canola in Iran as the first step for planning sustainable improvement of production. It has been performed in the modeling laboratory of Gorgan University of Agricultural Sciences and Natural Resources in 2017-2019. The protocol provided by the GYGA project is used for detection of climatic zones as well as major weather stations in canola production regions to estimate the yield gap. The actual yield of the irrigated canola in its major production regions is between 1184 to 2358 kg ha-1. The range of potential yield is estimated between and 3823 and 6520 kg ha-1. The highest potential yields belongs to Hamedan and Lorestan provinces and the lowest value to Khuzestan Plain. The range of the yield gap in its major production regions in the country is 2480 to 4365 kg ha-1, i.e. 53% to 77% of gap and with an average, 3276 kg ha-1 equal to 65% of the gap. With respect to the exploitable yield as the target yield, the exploitable yield is between 1544 and 3208 kg ha-1, with an average of 2261 kg ha-1. The magnitude of this gap indicates that the potentials of canola production in Iran are not exploited properly. Analyzing the reasons and methods of amendment the present yield gap and adoption of efficient management methods to achieve higher yields is crucial with regard to food security and economic.
Alireza Nehbandani; Mojtaba Saadati; Mahdi Goodarzi; Afshin Soltani
Abstract
Food security reduction due to climate change is one of the most important challenges in the 21st century. This study was carried out to predict the potential yield and production of the country’s strategic crops examining various climate change scenarios. In this study, the potential yield & ...
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Food security reduction due to climate change is one of the most important challenges in the 21st century. This study was carried out to predict the potential yield and production of the country’s strategic crops examining various climate change scenarios. In this study, the potential yield & production of 17 crops (Wheat, barley, rice, common bean, rapeseed, chickpea, grain maize, cotton, lentil, potato, sesame, soybean, sugar beet, sugarcane, sunflower, alfalfa and Silage maize) were estimated under current conditions (period 2005-2014) & two climatic scenarios (optimistic:1.5 ° C increase in temperature with 14% increase in precipitation period 2005-2014; pessimistic: 1.5 ° C increase in temperature & 14% decrease in precipitation period 2005-2014) applying SSM-iCrop2 model. The results showed that the pessimistic scenario reduced the potential production of wheat & legumes (about 1%) & the optimistic scenario increased the potential production of these crops (4 & 2%, respectively). Both climate change scenarios reduced the potential production of rice, potato, oilseeds & sugar crops (4, 10, 5 & 7%, respectively). Furthermore, the potential production of Silage maize increased in both climate change scenarios (2% & 3%, respectively). The results showed that the major factors which alter crop yield could be the growing season duration, radiation use efficiency and transpiration efficiency. In general, wheat, barley, potato, and sugarcane were more affected by climate change than other crops.
raheleh arabameri; afshin soltani; Ebrahim Zeinali; benyanen torabi
Abstract
Yield gap analysis is a quantitative estimate of possible increase of the capacity to provide food for a specified area. It is an important component for designing strategies to supply food on a scale of regional, national, and global level. In this regard a study has been conducted to determine the ...
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Yield gap analysis is a quantitative estimate of possible increase of the capacity to provide food for a specified area. It is an important component for designing strategies to supply food on a scale of regional, national, and global level. In this regard a study has been conducted to determine the extent and function of chickpea and lentil crop vacancy distribution at Gorgan University of Agricultural Sciences and Natural Resources during 2016-2018. Using SSM-iCrop2 model, the study simulates potential yield in chickpea and lentil producing regions in Iran. For this purpose, it employs the protocol of Atlas Gap Project, called GYGA protocol, to identify climatic zones and identify important meteorological stations, located in chickpea and lentil production areas in the country. After identifying the important stations, the performance potential for the station range is simulated and then the regional results are generalized to the whole country, based on the GYGA protocol. For dryland chickpeas in the country, the values of actual and potential yield as well as yield gap have been 0.43, 1.04, and 0.61 tons per hectare, respectively. In case of rainfed lentils in the country, the values of actual yield and potential along with yield gap have been 0.43, 1.10, and 0.67 tons per hectare, respectively. The present study can be used for better management in low-yield and high-yield areas of the country for these two products.
Fatemeh salmani; afshin soltani; Ebrahim Zeinali; Hossein Shahkoomahali
Abstract
In order to simulate transplantation, the parameters related to cotton seedling growth are firstly measured in a factorial experiment in a randomized complete block design at Gorgan University of agricultural sciences and natural resources within 2018. The parameters are then utilized in SSM-iCrop2 Model. ...
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In order to simulate transplantation, the parameters related to cotton seedling growth are firstly measured in a factorial experiment in a randomized complete block design at Gorgan University of agricultural sciences and natural resources within 2018. The parameters are then utilized in SSM-iCrop2 Model. In the simulation section, four seedling size based on the leaf area (namely 17, 22, 27, and 37 cm-2 per plant) are evaluated in 4 planting dates (15 June, 1 July, 15 July, and 30 July). Results show that in early planting date, seedling transplantation rushes the process of crop maturation for 43 to 49 days. However, this has had no significant effect on yield values (from 453 to 461 g/m2) and net water requirement (312 to 316 mm). The usual sowing date causes the crop to mature between 27 and 38 days (earlier vacant land), whereas seed sowing at this planting date impairs the subsequent crop cultivation. At this planting date, as in early planting, transplanting has no strong effect on the yield (from 444 to 452 g/m2) and water requirement (299 to 308 mm). In a late planting date, seedling transplanting with four seedling sizes between 1 and 5 days results in premature seed germination, even though seed cultivation impairs subsequent planting. At this planting date, transplanting has a noticeable effect on the yield (361 to 441 g/m2), but the amount of pure irrigation (271 to 300 mm) remains unaffected by transplanting.
Benjamin Torabi; Najebullah Ebrahimi; Afshin Soltani; Ebrahim Zeinali
Abstract
The present study was conducted to parameterize the SSM_iCrop model and evaluate the prediction of growth and development of faba bean in Gorgan climate condition. This study was carried out on faba bean cv."Barkat" as split-plot in randomized complete block design with four replications at Gorgan University ...
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The present study was conducted to parameterize the SSM_iCrop model and evaluate the prediction of growth and development of faba bean in Gorgan climate condition. This study was carried out on faba bean cv."Barkat" as split-plot in randomized complete block design with four replications at Gorgan University of Agricultural Sciences and Natural Resources in 2015-2016. The experimental factors consisted of planting date (27 November, 25 December and 31 January) and plant density (5, 15, 25 and 35 plants/m2). The parameters of phonological stages, leaf expansion and senescence, production and distribution of dry matter and water balance were estimated using the present data experiment and other data. The results of model evaluation showed that, it can well predict, days to flowering (RMSE = 3.8 and CV =4.1), days to maturity (RMSE = 11.9 and CV= 8.1), node number on main stem (RMSE = 1.7 and CV = 10.0), leaf area index (RMSE =0.8 CV =28.8), biological yield (RMSE = 158.5 and CV =21.6) and seed yield (RMSE = 118.6 and CV = 24.7). Therefore, the SSM_iCrop model can be used to evaluate the agronomic management and analyze the growth and yield of faba bean in Gorgan conditions.
Reyhane Rabbani; Farshid Ghaderi-Far; Ebrahim Zeinali; afshin soltani
Abstract
In order to investigate the effect of row spacing on yield and growth of cotton cultivars uncer two conditions of fertilizer application and non-fertilization, a study was conducted in Gorgan as a split-factorial experiment based on randomized complete blocks design with three replicates in 2017. Experimental ...
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In order to investigate the effect of row spacing on yield and growth of cotton cultivars uncer two conditions of fertilizer application and non-fertilization, a study was conducted in Gorgan as a split-factorial experiment based on randomized complete blocks design with three replicates in 2017. Experimental factors included three cotton cultivars (Sajedi, Kashmar and Golestan), row spacing at two levels (20 and 80 cm) and nitrogen, phosphorus and potassium fertilizers application at 350, 300 and 225 kg ha-1 and control treatment (No fertilizer), respectively. According to the results of analysis of variance, the effect of cultivar on number of reproductive branches and bolls as well as the height of first boll from ground was significant, whereas row spacing significantly affected number of vegetative branches and bolls, the height of first boll from ground, boll weight and lint yield. In all three cultivars studied, decrease in row spacing led to decreased plant height and increased leaf area index, dry matter and lint yield. Fertilization led to significant increase in plant height, leaf area index, number of reproductive branches and bolls, boll weight and yield. Among interactions, only the interaction of cultivar× row spacing on number of reproductive branches and interaction of row spacing× fertilizer on boll number, boll weight and lint yield were significant. Therefore, there is a significant interaction between row spacing and nutrient consumption in terms of growth characteristics and yield of cotton cultivars, and decreased row spacing in cotton can significantly increase lint yield.
Hamid Ahmadi Alipour; afshin soltani; hossein kazemi; Alireza Nehbandani
Abstract
Wheat (Triticum aestivum L.) as one of the most important agronomic crops has a special status in Iran. Reducing the yield gap is one of the ways to raise the production. In order to, the production rate and the wheat yield gap in Golestan province were analyzed by using a simple simulation model SSM– ...
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Wheat (Triticum aestivum L.) as one of the most important agronomic crops has a special status in Iran. Reducing the yield gap is one of the ways to raise the production. In order to, the production rate and the wheat yield gap in Golestan province were analyzed by using a simple simulation model SSM– Wheat and GIS software. For this purpose, the managerial information of wheat farming and cultivation were collected based on the provincial level and with regards to the information of 25 weather station and the region soil information, the potential yield was simulated in the irrigated and rainfed conditions at the provincial level and then the potential yield zoning was performed in the GIS and then with regards to the farmer's production rate and real yield at the provincial level, the yield gap and the production one were also calculated in the irrigated and rainfed conditions. Results indicated that the yield average of irrigated and rainfed potential with regards to the figures and current agricultural methods are respectively 8.140 and 4.930 kg per hectare. Also, the potential production in the irrigated and rainfed conditions was obtained equal to 1.357 and 1.112 million tons (total 2.469 million tons). Results showed that in case of studying and removing the factors which may cause the yield gap in the said province, the wheat production can be increased from the current 926 thousand tons to 1.975 million tons. Based on the results of Golestan province, the most important factors causing wheat yield vacuum with current cultivars and agronomic management, improper irrigation management, improper cultivation of cultivars and inappropriate use of basic fertilizers, road and low fertilizer, and for eliminating yield vacuum, use of 165 to 215 kg of seed per hectare, using certified seeds of suitable cultivars for water and dry farming, consuming at least 50 kg of phosphorus fertilizer (equivalent to P2O5) during cultivation, consuming at least 95 kg of pure nitrogen per hectare and integrating farms are suggested.
Najebullah Ebrahimi; Benjamin Torabi; Afshin Soltani; Ebrahim Zenali
Abstract
To analyze the growth, it is necessary to access to accurate and well-arranged data obtained from measuring leaf area and dry matter accumulation. The purpose of this study was to evaluate different nonlinear regression models to study the trend of changes in leaf area index and dry matter production ...
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To analyze the growth, it is necessary to access to accurate and well-arranged data obtained from measuring leaf area and dry matter accumulation. The purpose of this study was to evaluate different nonlinear regression models to study the trend of changes in leaf area index and dry matter production and to estimate the parameters related to the growth analysis. The experiment was conducted on faba bean "cv. Barkat" in a split-plot experiment based on randomized complete block design with three planting dates and four densities in four replications. In this study, the beta and logistic models were fitted to the leaf surface data and the beta, Gompertz and logistic models to dry matter production. AICc benchmark showed that the beta model was fitted to the leaf surface data the better than the logistic model. LAImax in different densities varied between 2.3 to 5.3, tm between 131.9 and 144.2, and te between 158.7 and 163.5 days after planting. AICc benchmark showed that the beta model was fitted to the dry matter accumulation data the better than the Gompertz and logistic models. Wmax in different densities varied between 725.1 and 1484.3 g/m2, tm between 138.3 and 146.4 and te between 162.60 and 179.0 days after planting. Grain yield varied from 231 to 2744 g/m2, and with increasing density in each planting date, grain yield showed the increased trend. The results showed that yield changes were directly affected by maximum leaf area index, maximum dry matter accumulation and crop growth rate.
Amir Hajjarpoor; Habibolah Kashiri
Abstract
In this study, collecting of management information from about 700 wheat farms in Golestan province was conducted during two growing seasons of 2013-2014 and 2014-2015. In each of region, potential yields, the optimum crop management and simultaneously the percentage of wheat farms out of the optimal ...
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In this study, collecting of management information from about 700 wheat farms in Golestan province was conducted during two growing seasons of 2013-2014 and 2014-2015. In each of region, potential yields, the optimum crop management and simultaneously the percentage of wheat farms out of the optimal ranges were identified in both irrigated and rainfed conditions using boundary line analysis. To do this, the information was analyzed in three parts of irrigated, high- and low-yield rainfed conditions. By plotting farm’s yield data scatter, against management factors, highest yields in different levels of input or management factors were selected and a boundary function was fitted to the upper boundary of data points. According to the results, potential yield for irrigated, high- and low-yield rainfed wheat were estimated equal to 6816, 5791 and 3932 kg ha-1 with a yield gap of 42, 31 and 50 percent, respectively. The optimum ranges of sowing date, seeding rate, plant density, frequency and the amount of nitrogen fertilizer applied, the amount of nitrogen applied after sowing, the amount of phosphorus (P2O5) and potassium fertilizers (K2O) applied and irrigation frequency were determined according to the results. Consider the optimum managements, farmers in each region can shrink the yield gap and reach potential yield result in increasing the amount of wheat production in Golestan province.