Sajjad Rahimi-Moghaddam; Khosro Azizi; Hamed Eyni-Nargeseh; Seyed Ahmad Kalantar Ahmadi
Abstract
Introduction: Canola is one of the most important oilseed crops in overall the world. This oilseed crop is mainly utilized for its high oil content (with about 40–45% oil). However, in recent years, the area under cultivation of canola has got decreased due to water scarcity. Applying drought tolerant ...
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Introduction: Canola is one of the most important oilseed crops in overall the world. This oilseed crop is mainly utilized for its high oil content (with about 40–45% oil). However, in recent years, the area under cultivation of canola has got decreased due to water scarcity. Applying drought tolerant cultivars (Shirani Rad et al., 2013) with high water use efficiency can help to develop the area under cultivation of canola and increase canola production. Therefore, the current study was conducted to assess the water use efficiency of spring canola cultivars in warm and temperate climates.Material and methods: This study investigated the different cultivars as a strategy for increasing canola production and improving its water use efficiency under different climate types in Khuzestan and Lorestan provinces. For this purpose, four locations including Khoramabad and Kuhdasht in Lorestan province as temperate semi-arid climate regions and Dezful, and Shushtar in Khuzestan province as hot and arid climate regions were selected. Daily long-term climatic data (included minimum and maximum temperatures, rainfall, and global radiation) were collected for these locations from Iran Meteorological Organization. In this study, Hyola308 (early-maturity), Hyola401 (mid-maturity), and RGS003 (late-maturity) cultivars were used. In order to simulate the growth and yield of canola in different locations APSIM-Canola model (Robertson and Lilley, 2016) was employed. OriginPro 9.1 software (Seifert, 2014) was considered for all statistical analyses and drawing of figures.Results and discussion: The results showed that grain yield, biomass, water use efficiency, grain weight, actual evapotranspiration, the average temperature during canola growth period, and the length of the canola growth period were substantially affected by cultivar and region (climate type). According to results, the highest grain yield and water use efficiency (3037 kg ha-1 and 6.9 kg mm-1 ha-1, respectively) were achieved for mid-maturity cultivar (Hyola401). Furthermore, simulation results revealed that temperate and semi-arid regions compared to hot and arid regions increased grain yield, biomass and water use efficiency by 2507 kg ha-1, 10100 kg ha-1, and 2.7 kg mm-1 ha-1, respectively. Khorramabad × Hyola401 treatment had the highest water use efficiency, grain yield, and biomass (9 kg mm-1 ha-1, 4954, and 17943 kg ha-1, respectively) due to lower the average temperature during canola growth period (10.9 ° C) and higher the length of the canola growth period (2424.9 day) while the lowest amount of these traits was recorded in Dezful × Hyola308 treatment (5 kg mm-1 ha-1, 1369, and 5514 kg ha-1, respectively).Conclusion: The results indicated that expanding of canola cultivation in temperate regions can be used to boost the canola production in Iran and to improve the sustainability of canola cultivation agroecosystems. Also, using a mid-maturity cultivar such as Hyola401 in both temperate and hot climate conditions can increase water use efficiency and sustainability of canola production agroecosystems through higher production per water consumption.
Fateme Aghamir; Saeid Soufizadeh; Ahmad Soheili
Abstract
Introduction: Climate change is one of the most important human challenges in food security in the agricultural sector, especially in arid and semi-arid regions. The most important climatic variables affecting crop yield, rainfall and temperature, carbon dioxide, especially in rainfed areas are of great ...
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Introduction: Climate change is one of the most important human challenges in food security in the agricultural sector, especially in arid and semi-arid regions. The most important climatic variables affecting crop yield, rainfall and temperature, carbon dioxide, especially in rainfed areas are of great importance. The results of researchers in Iran indicate the effect of obvious and undeniable climate change on crop yields in Iran. By using modeling knowledge in selecting the appropriate plant and cultivar for a region, determining the optimal plant characteristics, determining the best crop management, predicting the effect of diversity and climate change on crop growth and yield, and estimating potential yield in a low cost, fast and accurate way can be Adverse climate change on agriculture with negative mitigation options. Material and methods: In the present study, the effect of temperature increase, increase and decrease of 20% in precipitation and increase of carbon dioxide concentration on phenology and yield of dryland wheat in four cities of Dehgolan, Divandere, Saqez and Sanandaj in Kurdistan province with long-term climatic data of Kurdistan province in it was studied from 1370 to 1393. In this study, in order to simulate the daily growth and development of wheat in the conditions of climate change and to evaluate the potential effects of the simulation under the APSIM wheat model, 24 climate change scenarios and 1 baseline scenario, based on the product of temperature increase multiplied by +1, +2 , +3 and +4 ° C, change in precipitation of 2020% and three concentrations of carbon dioxide were considered 462.5, 527.5 and 725 ppm, respectively. Model inputs include climate (temperature, rainfall and radiation), soil (soil water and soil nitrogen), genetic coefficients and crop management information and its outputs including flowering date, physiological maturity date, maximum leaf area index date, leaf area index, Grain yield and biological yield were analyzed in future and past climatic conditions. Results and discussion: In scenarios with increasing rainfall compared to the base period, flowering uniformity, physiological maturity will increase in all cities but will decrease in Dehgolan. The uniformity of the maximum range of the leaf area index will increase in all cities and in Dehgolan the percentage of increase in uniformity is the lowest. Also, the uniformity of the leaf area index of Dehgolan and Sanandaj will increase, and Saqez and Divan Darreh will decrease. With decreasing rainfall, flowering uniformity, physiological maturity, the maximum range of leaf area index decreases in all cities and the percentage of uniformity reduction in Dehgolan is the lowest. With increasing rainfall, biological and grain yield fluctuations were highest in Dehgolan and lowest in Sanandaj, and with decreasing rainfall, all cities had biological fluctuations, Sanandaj had the least fluctuations and Divan Darreh had the most fluctuations. Conclusion: The effect of climate change factors including temperature, precipitation and carbon dioxide on different regions of Kurdistan province is different; In rainfed cultivation, in the basic period, wheat phenology and yield are affected by the initial water moisture in the soil, while by changing the climate, wheat phenology can be justified by increasing the temperature with the optimal crop temperature and by increasing rainfall with the wheat leaf area index.
Sajjad Rahimi Moghaddam; Jafar Kambouzia; Reza Deihimfard
Volume 14, Issue 3 , October 2016, , Pages 27-40
Abstract
Introduction: Iran is located in an arid and semiarid region that is vulnerable to environmental changes. So, it would appear that the occurrence of climate change in this region would have a significant impact on agricultural production systems (Eyshi Rezaie and Bannayan, 2012). Climate change might ...
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Introduction: Iran is located in an arid and semiarid region that is vulnerable to environmental changes. So, it would appear that the occurrence of climate change in this region would have a significant impact on agricultural production systems (Eyshi Rezaie and Bannayan, 2012). Climate change might affect the water available for agriculture and, consequently, lead to drought occurring in semiarid areas (Koocheki et al., 2006). Evaluating adaptation strategies, such as changing the planting of dates, can help to increase maize water use efficiency under climate change conditions (Ramprasad et al., 2016). One of the cheapest ways to measure the effects of climate change on agricultural production is through a modelling approach and application of simulation models (Manschadi et al., 2010). Materials and methods: This study aims at investigating the sowing date as a strategy for maize adaptation and improving its water use efficiency under climate change conditions in Khuzestan Province. For this purpose, six locations in Khuzestan Province were selected (Ahwaz, Behbahan, Dezful, Izeh, Ramhormoz and Shushtar). Daily long-term climatic data including minimum and maximum temperatures, rainfall and global radiation in a baseline period (1980-2010) were collected for these locations from their meteorological stations. Then, daily long-term climatic data were generated for the future period of 2040-2069 in these locations by using a method proposed by AgMIP under two climate scenarios (RCP4.5 and RCP8.5). In this study, the SC704 cultivar was used. Taking into account three sowing dates (4 February, 19 February [a common sowing date] and 5h March), six locations, and two climate scenarios over 30 years, a total of 1620 simulation experiments were carried out in this study. In order to simulate the growth and yield of maize under different sowing dates, the APSIM model was applied.Results and discussion: Results indicated that early sowing date (4 February) with 10117.1 kg ha-1 had a higher economical grain yield compared to 19 February (10061.3 kg ha-1 ) and 5 March (7194.6 kg ha-1 ). Also, in the future period, the reduction percentage in economical grain yield at the different sowing dates compared to the baseline common planting date (19 February) showed that the early sowing date of 4 February recorded less reduction (-3.3 and -4.5 percent under RCP4.5 and RCP8.5, respectively) than 19 February (-6.5 and -6.7 percent under RCP4.5 and RCP8.5, respectively) and 5st March (-31.1 and -23.2 percent under RCP4.5 and RCP8.5, respectively). On average in Khuzestan Province, an early sowing date indicated higher water use efficiency (WUE) )11.8 kg ha-1 mm-1 ) compared to 19 February (10.7 kg ha-1 mm-1 ) and 5 March (7.6 kg ha-1 mm-1 ) in the baseline period. However, under climate change conditions, reduction of WUE in different planting dates compared to the baseline common sowing date (19 February) revealed that 4 February (2.8 and 3.3 percent under RCP4.5 and RCP8.5, respectively) was superior compared with 19 February (-12 and -11 percent under RCP4.5 and RCP8.5, respectively) and 5 March (- 40.1 and -32.5 percent under RCP4.5 and RCP8.5, respectively) in term of WUE in Khuzestan Province. Conclusion: In general, according to the results found the common sowing date of maize in Khuzestan is not optimal for maize in terms of water use efficiency and economical grain yield. Accordingly, to increase economical grain yield and water use efficiency in both the future and baseline periods at Khuzestan Province, farmers should choose the early sowing date (4 February) compared to the common and late ones.
