جستجوی مقالات مرتبط با کلیدواژه « تابع واکنش عملکرد » در نشریات گروه « کشاورزی »

The agriculture section as a subsection of our economy receives the most impact under the climate fluctuations. Climate change is an unsustainable factor affecting the yield of agricultural crops. Therefore, agricultural production, especially rainfed cultivation, has a high correlation with climatic factors. Climate change, in addition to affecting the production of agricultural crops, affects the sustainability and performance of agricultural products by influencing water resources. Agricultural product performance forecasting is one of the management tools in agricultural sector planning and policy making. The purpose of the current study was to evaluate the yield and production rate of three summer crops including cucumber, tomato and watermelon due to climate change in Khuzestan province and their prediction for the years 2025 to 2100.

In order to evaluate the reaction function of summer crops yield in Khuzestan province, meteorological data including precipitation, minimum temperature, maximum temperature and relative humidity of 13 meteorological stations including Ahvaz, Izeh, Andimeshk, Mahshahr, Behbahan, Dezful, Azadegan, Ramhormoz, Shushtar, Masjed Soleiman, Omidieh, Shadegan and Shoush was collected during the years 1991 to 2020. Excel and SPSS software were used to calculate and analyze the indicators. The climatic indices of Khuzestan province were divided into two climatic regions. Region (1) included Ahvaz, Mahshahr, Behbahan, Shoushtar, Omidie, Shadegan and Shoush, and region (2) included Dezful, Azadegan, Ramhormoz, Masjed Soliman and Andimeshk. The yield function of three products including cucumber, tomato and watermelon at two regions was estimated using panel data and Eviews software. Then, the yield and production rate of crops were predicted using the climate forecasting scenarios for the years 2025 to 2100.

The results showed that temperature had a negative and significant effect on the yield of tomato in region (1) and region (3), but it had a positive and significant effect on the yield of region (2). Rainfall had a negative and significant effect on the yield of tomato in region (1). But rainfall had a positive and significant effect on the yield of crops in region (2) and (3). Humidity had a positive and significant effect on tomato in region (1) and (2), but it had a negative effect on region (3). Temperature had a positive and significant effect on cucumber yield in region (1) and region (3). But it had a negative effect on the yield of cucumber in region (2). Rainfall had a positive and significant effect on cucumber yield in region (1) and (3). But it had a negative effect on the performance of region (2). Humidity also had a positive effect on the performance of cucumber in region (1), but it had a negative effect on the performance of region (2) and (3). Temperature had a negative and significant effect on watermelon yield in region (1) and (3), but it had a positive effect on watermelon yield in region (2). Rainfall had a negative and significant effect on the yield of watermelon in region (1), but it did not have a significant effect on the yield of region (2) and (3). Humidity had a negative and significant effect on the yield of watermelon in region (1) and (3), but it had a positive and significant effect on the yield of region (2). Also, the results showed that the highest percentage of yield changes in climate scenarios were related to cucumber in region (3) and watermelon and tomato in region (2). The results of forecasting the production rate of selected crops during the years 2100-2025 showed that the highest production rate was related to tomato in region (2), watermelon in region (2) and watermelon in region (1). Based on the results, during the years 2100-2025, the cultivated area of tomato crop in region (1) showed a more downward trend, but the cultivated area of cucumber crop in region (1) showed a more upward trend.

The results of yield forecasting until year 2100 showed that cucumber crop in region (3) and watermelon and tomato crops in region (2) have respectively higher increase rate of yield. Also, results demonstrated that in region (2), tomato and watermelon have higher production rate, respectively. Given to adverse effects of climate change on the production of studied crops and in order to prevent considerable reduction of production rate, solutions should be provided to adapt more to climate conditions, such as changing the cultivation pattern, optimal management of resources and production of varieties resistant to climate change. Therefore, according to the obtained results, it could be stated that region (2) has a relative advantage in the production of watermelon and tomato crops.

The research aim is to study the yield including irrigated and dry-farmed wheat, barley, and corn in the climate and sub-climates of the country. So, the average yield of the studied products, average rainfall, and average temperature data have been used for the climatic change from the period 1982-2015. Due to the fact that cereal products over 56% and 77% of the cultivated area in arid and semi-arid regions, respectively. Therefore, in this study, only cereal are studied and among all of the crops, they have been selected, the five crops that have the highest area under cultivation. Finally, the function of various crops’ demands was used to investigate the effects of climate change on crops.The results show that the highest yield coefficients of rainfall are to precipitation in cold and sub-climates semi-arid cold, semi-arid hot, semi-arid temperate, cold dry, hot dry and temperate dry are related to dryland wheat, irrigated wheat, dryland wheat, dryland barley, dryland barley, dryland wheat, respectively. In addition, the highest coefficients of function of demands to temperature in cold and sub-climates of semi-arid cold, semi-arid warm, semi-arid temperate, cold dry, hot dry and temperate dry are related to dryland wheat, dryland barley, irrigated wheat and dryland barley, dryland wheat, respectively. According to the results of the research and in order to efficiently manage production and better performance, agricultural products in climates and sub-climates in the country are recommended. Compilation of a comprehensive cultivation model and allocation of the type of crop cultivation in the climate and sub-climate should be done by considering the reaction rate of the yield of the products and the exploitation of most of the mentioned products.

The agriculture section as a subsection of our economy receives the most impact under the climate fluctuations. Climate change is an unsustainable factor affecting the yield of agricultural crops. Therefore, recognition of climate parameters and their effect on crops is one of the most important factors in increasing yield. Vegetable production globally, as a wage-earning profession, is very effective in improving the general public's economy. The inadequate use of potential climatic facilities causes the destruction of natural resources and the wasting of the national capital. The purpose of this study was to evaluate the yield and production of onion and tomato products due to climate change and its prediction for 2025-2100 in Hormozgan province.

In order to more accurately estimate the function of the reaction of the yield of horticultural products to the climatic components, the climatic indices of Hormozgan province were divided into two climatic regions. Region (1) includes Minab, Hajiabad, Rudan and region (2) includes Bandarlenghe, Band-Abbas, Qeshm and Jask. The yield function of two products, onion and tomato, in the two regions under study was estimated using panel data and Eviews software. Then, using the weather forecasting scenarios, the yield and production of vegetables (onion and tomato) for the years 2025 to 2100 were predicted. Agricultural and climatic data were collected during the years 2003- 2017.

Results showed that the temperature has an opposite effect and rainfall and humidity has a direct effect on the yield of onion and tomato. The most important factor affecting onion production in both regions is the temperature. On the tomato production, the humidity factor in the region (1) and the factor of temperature and humidity in the region (2) are almost the same in terms of effect level. The difference is that the temperature has a negative effect and the humidity has a positive effect on the performance. The negative effect of temperature on the onion yield was higher than that of tomato. The negative effect of temperature on onion production in the region (2) has a higher intensity than the region (1). Performance prediction up to 2100 showed that yield of onion reduce more than yield of tomato. the yield reduction in the region (2) is higher than the region (1). In contrast, the tomato production in the region (1) is higher than the region (2). According to the decline in the yield of two products, the production cuts for both products has been predicted in both regions until the year 2100.

According to the negative effects of climate change on the products under study, we should provide solutions to avoid the harmful effects and to adapt to the climatic conditions. This includes changing the region's cultivation pattern, managing optimal resources and producing climate change resistant seeds. Therefore, it can be stated that the region (1) has a comparative advantage in the production of onion and the region (2) in the production of tomato.