فصلنامه اقتصاد کشاورزی و توسعه
پیاپی 93 (بهار 1395)

In spite of large emphasis on agriculture and food security in the upstream documentation and national development plans, importation of agricultural and food products has had an upward trend mainly influenced by various variables within last three decades. Imports of these products have increased of nearly 5 million tons in 1981 to more than 21 million tons in 2012. Aims of present study is identifying and examining the effective factors on Iranian agricultural import demand for the period 1991-2012 using combination of exploratory data analysis methods (EDA) with Artificial Neural Network. For this purpose, information of eleven goods consist of Wheat, barley, rice, corn, Soybean meal, oil (soybean and sunflower), sugar, eggs, milk, poultry and beef meat have been used. The result of modeling shows that nonoil GDP (29.5%), oil incomes (27.7%), tariff rate (16.5%) and amount of domestic production (14.6%) have the greatest effect on import demand. Also the results revealed that relative price of agricultural products imports (6.6%) and lag of import demand (5.1%) have the lowest effect on import demand.

Today keep increasing the use of chemical fertilizer and water is an effort to improve yield, while overuse of fertilizer is making formerly arable land unusable but led to degrading the quality of water and serious problems for environmental. Hence, for accurate management, we require comprehensive and complete information on the economic and environmental impacts of different management methods. So, by using SWAT model were simulated the economic and environmental effects of each management strategies. Then, mathematical programming was used to determine the optimal cropping pattern subject to resources and environmental constraints in irrigation and Drainage Dorudzan. Based on the findings of this study, we can improve the economic and environmental benefits by moving from current status to economic or bio-economic pattern. Also, by moving from economic pattern to bio-economic pattern, 0.31 percent reduction of economic benefit is leading to improve nitrogen losses by 6.58 percent. In other words, we incur the cost equal to 64.5 thousand rials for reduction per kg nitrogen losses.

Due to importance of export and necessity of innovation in exported products and as a result, adaption to global markets, this study has been investigated the effects of innovation on total and agricultural export during 1976-2010, by using vector error correction model. For this purpose, the share of export in GDP, foreign direct investment, labor productivity, number of patents and trade mark has been used as indicators of innovation. Results indicate that labor productivity has positive effect on both agricultural and total export. Also foreign direct investment and patents have direct relationships with total export. Trade mark has direct relationship with agricultural export too. According to the results, it is recommended that the level of efficiency and productivity increase by training labors until with technology changes, improve skills of labors as well as develop society.

Agriculture sector in Iran and some other countries of the world has a vital role in national development. Scientific acquiring of the current situation of regions is an important and imitative step in improvement planning of this sector. The purpose of this descriptive-analytical study was to investigate agricultural developmental levels of sub – districts of Paveh township using Vikor method. Secondary data (published or on the web site of related organization) and field data (by filling checklist from related organization) for 91 indicators in sub-sectors of horticulture, animal husbandry, agronomy, sustainability, infrastructural, educational- human resources (extracted from reviewing literature review and interviewing with rural development, geography and agricultural economics experts) were used. By division by mean, their units omitted and for weighting indicators Mc Granahan method and for weighting sub sectors AHP method were used. The results revealed that there are differences regards agricultural development level among rural sub –counties in Paveh Township. Holy sub- district ranked as first and Sirvan, Makovan and Shamshir sub- districts were in second place and the Shivesar was in third place of agricultural developmental level. Based on the findings, some recommendations to improve agricultural development of sub- districts have been suggested.

The main purpose of this study was to measure technical, allocative and economic efficiency producers of colza in the Mazandaran province. For this purpose, 110 producers of colza in 2014 in the major areas of cultivation of colza in the province were selected with random sampling cluster classification technique. Cities were include Neka, Behshar, Sari and Joybar. The necessary information through interviews with farmers is obtained. For estimating the production function, Transcendental function is used. Among various estimates of the stochastic frontier approach has had the best results. The results showed, there is a significant relationship between dependent variable (yield in unit area) and the number of labor, hours of plowing, seed amount, the amount of urea, phosphate, potash fertilizer and herbicide and farm size also results showed that the mean technical, allocative and economic efficiency colza producers have respectively, 75%, 56% and 42%. Survey the effect of various economic and social factors on efficiency shows that, number of labor, hours of plowing, the amount of seed, urea, phosphate and potash fertilizers, herbicides, farm size, planting and harvest date, and employee to non-agricultural work have direct efficiency of colza growers.

In recent decades, increase in greenhouse gases, especially carbon dioxide (CO2), has caused the global warming as an undesirable phenomenon. On the other, increase carbon dioxide can change and improve yield of agricultural crops through facilitation in photosynthesis and transpiration. So assess the final effect of increasing this gas in the environment of agricultural crops production has been a controversial subject among agriculture and environment researchers. With this explanation of the study, the level of carbon dioxide emissions on the crops of Hamedan-Bahar plain predicted in the coming decades than 2012-2013 year. For this purpose, initially, the sensitivity of crop yields in Hamedan-Bahar plain than carbon dioxide emissions were estimated by using non-parametric approach based the nearest neighbor method (KNN). In the next step, the conditions of crop pattern were simulated by using of mathematical programming approach and PMP model, and then the effects of CO2 emissions on crop pattern were investigated in the several scenarios. The results indicated that increase in CO2 emissions has positive effects on crop pattern in the short run horizon 2020, but this trend will change in the long run. However, a balanced use of fossil and non-fossil fuels and the use of global approaches, achieves the highest gross margin will be in the coming years.

The present study was done with the aim of water resource management in the agricultural sector. In this regard, agricultural water policies using positive mathematical programming in the eight scenarios on cropping pattern of strategic products of Khorramabad county was applied in 2012-2013. Scenarios consist of an increase the 200, 300, 400 and 500 percent in price of water, reducing 20 and 30 percent in the amount of available water and apply combination policy of increasing 100 percent in price with decreasing 10 and 20 percent the amount of water. According to the results, in the policy of increasing the price of water until 500 percent, the acreage of irrigated crops was reduced and in opposite, the acreage of rain-fed crops was increased. The most reduction is related to the colza and bean with 0.31 and 0.2 percent that showed high sensitivity to raise price of water. Totally, change in the cropping pattern of irrigated crops to rain-fed crops was done and saving water was very low about 0.03 percent. In the policy of reducing the amount of available water, the pattern has been allocated to crops with high efficiency and low water consumption, and saving the amount of water is significant up to 35.84 percent.

Over pumping of ground water, especially in arid and semiarid areas, has had negative effects on environment. Recognition of productivity of water and soil resources is the first step toward planning and managing for increasing optimum operation of these resources. In this study, using a sample of 110 farmers, the condition of efficiency and farmer's desperation and migration due to over using of groundwater in Rafsanjan plain was investigated in 2012. Analysis and regression methods were used in this regard. Marginal product of water was estimated 0.04 kg per cubic meter that 33 present has decreased with compare to past tense (15 year ago). Also negative counteraction between decreasing efficiency of water resources and not hope to the condition of future of water resources was specified. This case was effective on farmer's migration. For elimination or reduction of ground water degradation and its effects, this paper recommended that in economic evaluation is attended to the social costs and benefits. Finally, for preventing the negative effect of farmer's desperation for future, it is better to give information to pistachio producers with introducing efficient methods for solving the problem.

Since agricultural sector is considered as the biggest user of freshwater resources in Iran, one of the major factors of Urmia lake drying might be attributed to unsustainable development of agricultural activities. Therefore, it would be of interest to focus the lake restoration measures on water usage management in agricultural sector. It seems that a program to change cropping pattern based on the use of species with lower water requirements instead of higher water need ones is an effective policy. In this study, we attempted firstly, to propose to farmers change in cropping pattern by replacing the sugar beet, alfalfa, corn and tomato with wheat and barley as a solution. Then, results of the survey have been assessed in economic terms. Area in which the survey has been undertaken is Simineh Rud basin. To collect data, a combined techniques of interview and questionnaires have been used. The results of this study showed that this program has sufficient acceptability to the farmers (in 2014) and in case of having financial support by government, it will have successful implementation. Meanwhile, from technical and economic point of view, implementation of such a program has benefit-cost ratio of 2.12 for wheat and 2.06 for barley. Therefore, based on feasibility of such proposal, allocating required budgets, implementing the proposed plan in all other sub-basins of Urmia lake and paying income deficit caused by change in cropping pattern to farmers may be suggested.

One of important producer supporting policy is input subsidy supporting and one of important economic variable is progressing in productivity. Hence, in this article, in addition of producer supporting policy and input subsidy supporting evaluating (by using of BP, MPS and PSE indices), effect of input subsidy supporting on agricultural TFP are assist (by using OLS regression model) for years of 1989-2009 (1st - 4th developing program). Results indicate that input subsidy supporting effect on TFP is negative and equal to -0.059 in short run and is positive and equal to 0.023 in long run. Research, education and promotion variable effect in short run and log run is 0.015 and 0.205, respectively. So, it seems that input subsidy supporting on TFP in addition to research, education and promotion policy could have positive effect on agricultural TFP progress.