بررسی ورودی های انرژی برای تولید هلو با استفاده از تجزیه و تحلیل حساسیت در ایران

The purpose of this research was to investigate the energy balance between the energy inputs and yield in peach production in Golestan province of Iran as a case study. The results showed that total energy consumption in peach production was 37536.96 MJ ha−1 where the diesel fuel with about (26.32%) was the major energy consumer. The direct energy shared about (50.98%) whereas the indirect energy did (49.02%). Energy use efficiency, energy productivity, specific energy and net energy were 0.55, 0.29 kg MJ−1, 3.41 MJ kg−1 and −16642.03 MJ ha−1, respectively. Econometric assessment results revealed that the energy inputs of human labor, machinery, diesel fuel, chemical fertilizers and farm yard manure had significant influence on the yield. The impact of human labor energy (1.36) was found as the highest among the other input parameters. Sensitivity analysis indicated that the MPP value of energy inputs was between −2.8 and 11.31. Also the MPP value of human labor was the highest, followed by diesel fuel and farm yard manure energy inputs, respectively.

Peach (Prunus persica) is a member of the Rosaceae family, the peach is thought to be originated in China and spread to the rest of the world by means of seeds. The botanical name of peach (Prunus persica) refers to the putative country of origin, Persia (Iran). Its species well adapted to temperate and subtropical regions, between latitudes of 30° and 45° north and south [1] and [2]. Iran is one of the main cultivation regions and it is the 6th largest producer of peach after China, Italy, United States of America, Spain and Greece, respectively. The production of peach and the other nectarines was about 574958 tons/year in Iran [3] and the cultivation land area was about 56562 ha in 2008 from which 6% was the share of Golestan Province [4]. Agriculture is considered as a supplier and consumer of energy. It uses large quantities of locally available non-commercial inputs, such as seed, manure and animate energy, and commercial inputs directly and indirectly in the form of fuel, electricity, fertilizer, plant protection, chemicals, irrigation water and machinery. They all can be converted and stated in the form of energy units. Efficient use of energies helps to achieve increased production and productivity and contributes to the economy, profitability and competitiveness of agriculture sustainability in rural living [5]. Energy use in agriculture has developed in response to growing populations, limited supply of arable land and desire for an increasing demand for standard of living. In all societies, these factors have encouraged an increase in energy inputs to maximize yields, minimize labor intensive practices or both [6]. Energy requirements in agriculture are divided into four groups: direct and indirect, non-renewable and renewable energies. Direct energy (DE) includes energy embodied in human labor, diesel fuel, water for irrigation and electricity while indirect energy (IE) refers to chemical fertilizers, farm yard manure, chemicals and machinery used in the agricultural production. Non-renewable energy (NRE) includes chemicals, machinery, diesel fuel, electricity and chemical fertilizers, and renewable energy (RE) consisted of human labor, farm yard manure and water for irrigation [7]. Energy input–output relation analysis is usually used to appraise the efficiency and environmental effects of the production systems. This analysis will determine how efficient the energy is used. Several studies have been conducted on energy analysis in agriculture such as apple, canola, soybean, barley, alfalfa, strawberry, potato, and kiwifruit in Iran [8], [9], [10], [11], [12], [13], [14] and [15], apricot, canola, field crops and vegetables, cotton, cherry, sweet cherry, tomato, pomegranate, sugar beet, citrus in turkey [16], [17], [18], [19], [20], [21], [22], [23], [24] and [25], wheat, maize and sorghum in United States [26] and [27], wheat, maize, sugar beet, sunflower, grape, olive, almond, barley, oat, rye, orange, lemon, apple, pear, peach, apricot and plum in Italy [28], apple, sunflower and cotton in Greece [29], [30] and [31], wheat and cotton in Punjab [32] and [33], rice in Malaysia [34], wheat in New Zealand [35], cereal, potato, sugar beet in Denmark [36], soybean in India [37]. But there is not an exhaustive publication analyzing energy input–output and sensitivity analysis in peach production. Therefore the main objectives of this study were to establish the energy use efficiency per hectare, to analyze the sensitivity of energy inputs and also to determine relationship between energy inputs and yield using mathematical models on the peach orchards in Golestan province, Iran.

Based on the present study the following conclusions are drawn: 1. The total energy input for peach production in this study was about 37536.96 MJ ha−1, which diesel fuel with the share of (26.32%) and water for irrigation with the share of (2.95%) had the biggest and lowest amount of energy inputs in the peach production, respectively. Energy output was computed as 20894.93 MJ ha−1. 2. On average, 50.98% of total energy input used in peach production was direct, while the contribution of indirect energy was 49.02%. Furthermore the shares of renewable and non-renewable energy inputs were 17.64% and 82.36%, respectively. Management of plant nutrients by renewable resources like farmyard manures would increase rate of renewable energy. 3. The impact of diesel fuel, chemical fertilizer, farmyard manure and human labor energy inputs was significantly positive on yield. 4. The MPP value of human labor was the highest, followed by diesel fuel and farm yard manure energy inputs, respectively. Likewise the appraised MPP for machinery, chemicals and water for irrigation energies were found negative and it shows that the farmers may use too many of these inputs or they did not use them in the approved manner. 5. Energy use in peach production is not efficient and damaging to the environment because of chiefly surplus input use. The most suitable consumptions of chemicals, fertilizers, diesel fuel and other major inputs would be useful in reducing negative effects to environment and human health. 6. The negative amount of net energy concluded a sustainable management of inputs usage. It is suggested that new policies, such as training the farmers to consume optimized inputs, using the modern methods of irrigation and utilize of machinery management for field preparing, harvest and post harvest processes. These recommendations can be executed to reduce the negative effects of energy inputs such as plant, soil and climate pollution.