فصلنامه اقتصاد کشاورزی
سال پانزدهم شماره 4 (زمستان 1400)

Carbon dioxide (CO2) is a major component of the ecosystem, but its high concentration, along with the emission of other greenhouse gases, causes global warming, climate change, and environmental degradation. For this reason, the reduction of carbon dioxide emissions has been considered in recent decades. One of the factors that affect CO2 emissions is human capital, the effectiveness of human capital in reducing CO2 emissions depends on the level of development of countries.

This study has investigated the threshold effect of development on the impact of human capital on CO2 emissions in 18 Asian countries during the years 1995-2019 using panel threshold regression model.

The results show that two threshold levels for development should be considered. human capital at the level of development less than 27.48 has no significant effect on reducing CO2 emissions. If the level of development is between 27.48 and 29.32, human capital will reduce CO2 emissions. The greatest impact of human capital on reducing carbon dioxide emissions will be when the level of development exceeds 29.32.

Improper use of chemical fertilizers in recent decades has endangered the health of humans and other living organisms while creating adverse consequences for environmental pollution and upsetting the balance of nutrients in the soil. To this end, the promotion of the use of bio-fertilizers (EM) by the Ministry of Agriculture Jihad is on the agenda, but unfortunately it has not been well received. Obviously, the use of new inputs is important in the decision-making of farmers, the effects of income and economic benefit. This study, which was funded by the Agricultural Jihad Organization of Kohgiluyeh-va-Boyerahmad Provinces, seeks to answer the question of whether the use of biofertilizers, given their high cost, can increase profitability.

The implementation of this research in the cropping year of 2018-19 in the form of a research-extension project in a corn farm with an area of one hectare in the suburbs of Basht city was carried out under farmer conditions. For this purpose, a field experiment in a randomized complete block design (RCBD) with six fertilizer treatments and three replications in farmer conditions and the costs, gross margin and economic benefits of each treatment were compared. The accounting profit formula was used to calculate the profits of the mentioned farms. Since the calculation of initial investments and fixed costs for all six farms is fixed, in this study, the method of calculating the gross margin (GM), which is actually an estimate of farm profits, was used. The the gross margin is calculated from the difference between sales revenue and total current expenses for the same cropping year.

The results of analysis of variance of field experiment showed that fertilizer treatments had a significant effect on revenue and farm profit (gross margin) at the level of probability (P = 0.01). Based on the comparison of the average revenue and farm profit using Duncan's test, it was found that the lowest farm profit and revenue related to chemical fertilizer treatment only (or control treatment) (C) and the highest revenue related to integrated treatment of biofertilizer, chemical fertilizer and organic (BOC). Comparison of the averages of the effect of fertilizer treatments on gross income as well as farm profit was determined using Duncan's test at a probability level of 5%. The lowest farm profit, in the amount of 101.9 thousand tomans per hectare related to the chemical fertilizer treatment only (or control treatment) (C) and the highest farm profit, related to the chemical fertilizer treatment+bio fertilizer+organic fertilizer (BOC) in the amount of 382.8 thousand tomans. Other treatments with averages of 122.1, 200.9, 254.4 and 357.6 thousand tomans related to organic fertilizer (O), biofertilizer+chemical fertilizer (BC), biofertilizer (B) and biofertilizer+organic fertilizer (BO) treatments, respectively.

The Covid-19 virus pandemic has affected the entire world and all economic sectors. The agricultural sector has been affected by this crisis from various dimensions, too. The broiler industry is the largest industry in Kurdistan province, which has been affected by this pandemic in various ways, such as supply chain of inputs, changes in supply and demand structures. The broiler industry of Kurdistan province has directly and indirectly created employment for about 14,000 people. Kurdistan province has more than 750 active broiler farms, which use about 15 million broiler chicken pieces in each period and 60 million pieces per year. Kurdistan province produces about 4% of the country's chicken meat. This study aims to investigate and estimate the implications of the Corona pandemic on production, performance and economic efficiency of broiler farms in Sanandaj township, Kurdistan province, Iran.

Production and performance criteria were extracted from summarizing and comparing data in Excel software. To estimate the efficiency criteria by data envelopment analysis model, DEAP software was used; and in order to evaluate the difference between the means, the matched-pairs t-test was conducted in SPSS software. Necessary data were obtained through a simple random sampling method. The collected data were related to two breeding periods in autumn 2019 before the pandemic, and autumn 2020 after the pandemic. All production, performance and efficiency measures calculated and compared in pre-pandemic and post-pandemic periods.

The results showed that the total number of day-old chicks in pre-pandemic and post-pandemic periods was not significantly different. Total production of small and medium farms decreased slightly in the post-pandemic period; whilst total production in large farms, due to the increase in weight of chickens, not only did not decrease but also increased significantly. The grain-to-chicken conversion ratio increased on all farms, so that more grain was used to produce one kilogram of chicken, in the post-pandemic period. The reason for this could probably be the irregularity in the sales process and the increase in the number of storage days. The age of slaughter increased in all farms in the post-pandemic period, significantly. Due to the increase in slaughter age, the average weight of chickens at slaughter also increased significantly. Furthermore, the percentage of losses in all farms showed a significant increase. Regarding efficiency, no significant difference was found in the average technical efficiency of broiler farms before and after the corona outbreak. Nevertheless, the difference between the average allocation and economic efficiency of the farms in the  pre-pandemic and post-pandemic periods were significant; In all three capacity groups, there was a significant decrease in both allocation efficiency and economic efficiency in the post-pandemic period.

The spread of the phenomenon of globalization of the economy led to the relations and cooperation of countries in order to study the interests in the form of Regional cooperation should be on the agenda of many developing countries, especially Iran. Under such circumstances, it has encouraged Iran to create the necessary conditions for trade with tariffs and economic convergence.In this research, an attempt has been made to study trade (export and import) of Iran and five member countries of the Eurasian Economic Union with each other, compared to other countries and using an applied model called the Smart model, the effects of trade creation and trade diversion resulting from the interim agreement between Iran and the Eurasian Economic Union and Review and analyze member countries using period data 2016 to 2020. In this regard, the main question of this research is what has been the impact of the agreement on trade and the fulfillment of the commodity obligations of the parties since its implementation. So, the hypothesis has been tested that the development of Iran's trade with Eurasian Economic Union countries will lead to a reduction in Western sanctions pressure, providing the necessary grounds for Iran’s economic development and foreign trade and benefiting from the economic capacities of the Union.

In this paper, using a partial equilibrium model called Smart Simulation Model, the effects of tariff reduction on Iran's trade flow in agricultural trade with Eurasian Economic Union countries in the form of concepts of trade creation and trade deviation have been investigated. In the next step, the effects of tariffs on agricultural commodity groups at the classification level of coordinated system (HS) have been analyzed.The statistical population of this study includes Eurasian Economic Union and Iran. The total value of bilateral trade (exports and imports) between Iran and the Eurasian Economic Union Between 2016 to 2020 is derived from the Customs of the Islamic Republic of Iran and from 2016 to 2019, Trade map site using Excel software. Iran's tariff statistics are taken from the Export and Import Regulations Book (2016-2020).

Results of Research on this agreement shows, relatively, trade between Iran and the five countries of Eurasian Economic Union has improved in the year since its implementation, compared to the average of the past three years. The results of the Smart model show a 4.4% increase in imports from the agricultural sector from the union due to tariff reductions, part of which is due to trade creation and part due to trade diversion.

Changes in the global climate have become one of the most crucial challenges facing agriculture in the twenty-first century. Climatic change is mainly characterized by a rise in greenhouse gas emissions and global average temperature as well as changes in precipitation levels and patterns. Undoubtedly, these changes affect the growth and productivity of agricultural production, and thus food security in many parts of the world like Iran. At present, supplying sufficient food and meeting food security in Iran relies on the management of climatic variables that affect agricultural production. Therefore, it is necessary to study the effects of climate change on agricultural production and food security in arid and semi-arid regions of this country such as the Khorasan region. Given the importance of this issue, the objective of the current study is to investigate climate change and its impacts on the yield and yield risk of selected crops, as well as on food security in the Khorasan region.

The daily observed data for maximum temperature, minimum temperature, and precipitation is provided from the Meteorological Organization of Iran for 1961–2010. The daily reanalysis data for the period (1961–2005) are obtained from the National Centers for Environmental Prediction (NCEP). The large-scale daily predictors for the CanESM2 model were developed by the CCCma for selected station. These data are used to predict climate parameters under three climatic scenarios (RCP 2.6, RCP 4.5 and 8.5) for 2030. This study used SDSM to downscale GCM-CanESM2 outputs. SDSM model, one of the most widely used models in the world, is applied to downscale future climate projections using the 26 predictors derived from a large-scale climate model. In the current study, a production function technique developed by Just and Pope is applied to investigate the effects of climate variables on the mean and variance of crop yields. This technique consists of two parts: the first component is relating to the yield levels and the second part is related to the yield variance.

The results showed that maximum temperature, minimum temperature, and precipitation have a significant impact on the yield of the studied crops, so these factors will lead to a decrease in the production of irrigated wheat, irrigated barley, and dryland barley in 2030 compared to the base year. Findings indicate that per capita availability of wheat will decrease from 148.22 to 104.44, 107.51,109.83 and for barley will decrease from 74.28 to 47.94, 54.19, 62.79, and for potato will change from 26.44 to 25.37, 25.53, and 27.24 (kg per person) under climate scenarios RCP2.6, RCP4.5 and RCP8.5, respectively. In addition, the results show that climate change in 2030 will reduce the production of irrigated wheat, barley, and rain-fed barley, while these changes will improve the production of potatoes and rain-fed wheat. Furthermore, the findings of the study reveal that the improvement of technology will be able to reduce the negative effects of climate change on the production of vulnerable products. Also, due to population growth in this region as well as climate change, the per capita availability of crops in 2030 will decrease, which will increase the dependence of this region on other regions of the country and imports to meet food needs.

Agricultural tourism refers to the aspects of agriculture and tourism. This method of tourism encourages tourists to visit fields and gardens and rural areas for recreation, education or active participation in agricultural production activities and living in the field. One of the first effects that agricultural tourism will have on the region's economy is its impact on the agricultural sector. In other words, the fundamental question for the development of agricultural tourism is whether it can develop the agricultural sector or become an alternative to agricultural activities. And eventually it will cause a recession in the agricultural production of the region. According to theoretical foundations, the relationship between agricultural tourism and the activities of the agricultural sector is very complex. Because this relationship on the one hand can lead to the development of the agricultural sector and on the other hand, if not properly managed, can lead to a recession in the agricultural sector. In other words, in this case, agricultural tourism becomes the main activity of farmers. It should be noted that one of the effective factors in the conflict between the relationship between the agricultural sector and tourism is due to the low capacity of the agricultural sector in terms of employment and income generation for the local community compared to tourism.

in this section, to identify how the impact of agricultural tourism development on agricultural sector development, a conceptual research model was designed and a questionnaire was developed based on this conceptual model. At the beginning, the most important components and existing capacities for the development of agricultural tourism in Golestan were evaluated. The first category of characteristics is related to the institutional, legal and natural components, which include three general categories of institutional conditions and laws, natural conditions and capacities in the region, as well as support and facilitation provided by the government and related organizations. The second category of components is related to individual characteristics. This section will include two sets of indicators related to the tendency and acceptance of agricultural tourism by farmers and the level of knowledge and awareness of people about agricultural tourism. In the next step, the consequences of the impact of agricultural tourism on the agricultural sector will be examined. In this section, components such as income and employment of farmers, environmental damage to tourists entering agricultural lands, etc. will be evaluated; But the relationship between agricultural tourism and agricultural sector development will be closely related to the functional components of the agricultural sector, so these components will be evaluated in the form of two categories of capacity and experience of farmers in agricultural work and a sense of satisfaction with agricultural activities.

A comparative study of farmers' beliefs about the impact of agricultural tourism development on agricultural sub-sectors in the three villages of Nouchman, Yelmeh Khandan and Alazman shows that: in horticulture, agriculture, animal husbandry, horse and camel breeding, fish farming, handicrafts and activities Homeowners The residents of Yalmeh Khandan expected a higher increase in their income compared to the other two villages. In beekeeping, greenhouses and ornamental plants and direct sales of agricultural products, the highest expected positive effect will occur in AlAzman. According to the comparative results in these three villages, it can be seen that the highest optimism about the positive impact of agricultural tourism on farmers' incomes is in Yalmeh Khandan village and the lowest optimism in this field is in Nouchman. The study of the impact of agricultural tourism development on agricultural sub-sectors in all surveyed villages shows that farmers believe that agricultural tourism can increase farmers' incomes. The highest level of increase is related to the agricultural sector and livestock and livestock activists. The least increase in farmers' incomes for fish farming will also occur.It can be seen that the variables of knowledge and awareness and capacities of agricultural tourism in rural areas have a positive effect on the tendency and acceptance of villagers for the development of agricultural tourism. On the other hand, government laws and protections on agricultural tourism have had a negative effect on tendency and acceptance. In a way that people's dissatisfaction with the conditions governing the laws of starting an agricultural business and the lack of government support has caused the tendency of people to start a business and work in this field. In the section on evaluating the attitudes of villagers and experts, we also came to the conclusion that the rules of this section are not very favorable. The results obtained from the study of variables affecting the welfare of farmers due to the development of agricultural tourism show that increasing the tendency and acceptance of people for the development of agricultural tourism, higher agricultural capacity and agricultural tourism capacity in the region can have a positive effect on farmers' welfare.