تحلیل میزان مصرف آب و انرژی و اثرات محیط زیستی تولید محصولات کشاورزی در دشت میاندربند استان کرمانشاه

این پژوهش، به‌منظور تحلیل میزان مصرف آب و انرژی و اثرات محیط زیستی تولید محصولات کشاورزی در دشت میاندربند استان کرمانشاه، با استفاده از رویکرد کمّی و برای محصولات گندم، جو آبی، ذرت دانه ای، کلزا، گوجه فرنگی و سیب زمینی انجام گرفت. جامعه آماری، 1676 کشاورز بود که طبق جدول کرجسی و مورگان، 315 کشاورز با استفاده از نمونه گیری تصادفی طبقه ای انتخاب شدند. جهت جمع آوری اطلاعات از پرسش‌نامه محقق ساخته و داده های ثانویه سازمان هواشناسی ایران استفاده شد. طبق نتایج پژوهش، تولید محصولات غالب در منطقه،m^3.ha^-1 50827 آب مصرف می کنند؛ سیب زمینی (m3.ha^-1 11440) و ذرت دانه ای (m^3.ha^-1 10492) بیشترین میزان آب را مصرف می کنند. کل مصرف انرژیmj.ha^-1 975608/50 بود که بیشترین میزان مصرف انرژی ورودی مربوط به سیب زمینی (25 درصد)، ذرت دانه ای (22 درصد) و گوجه فرنگی (15 درصد) می باشد. همچنین کودهای شیمیایی، سوخت دیزل و آب برای آبیاری بیشترین میزان انرژی را در بخش کشاورزی مصرف کردند. انتشار 2co، o2n و 4ch به‌ترتیب 3729/79، 152/05 و 0/293 کیلوگرم در هکتار و پتانسیل گرمایش جهانی،eq.ha^-1 2kg co 50872/52 بود که گوجه فرنگی با انتشار 15592/48 و جو با انتشار 3279/88 کیلوگرم معادل 2co، بیشترین و کمترین سهم را دارا بودند. می توان گفت کارایی پایین آبیاری، وجود تعداد زیاد چاه های غیرمجاز، اختصاص یارانه های کشاورزی و عدم محاسبه هزینه آب و انرژی موجب ناکارآمدی سیستم کشاورزی دشت میاندربند شده است؛ لذا افزایش کارایی آبیاری با استفاده از سامانه آبیاری نواری و همچنین افزایش قیمت آب و انرژی در بخش کشاورزی همراه با حفظ منافع کشاورزان می تواند در استفاده بهینه از آب و انرژی و کاهش مصرف آن ها موثر باشد.

analysis of water and energy consumption and environment impacts of agricultural production in miandarband plain of kermanshah province

introductionthe agricultural sector accounts for 70% of fresh water and about 30% of the world’s total energy consumption through food production and supply chain. water, energy and food are three basic interrelated sources of human health, as water and energy are vital to food production. in recent centuries, increasing pressure due to scarcity of resources and increasing demand for food and ultimately environmental pollution necessitates the need for optimal management of water, energy and food. in this regard, this study was conducted analysis of water and energy consumption and environment impacts of agricultural production in miandarband plain. materials and methodsthe present study was conducted using a quantitative approach for wheat, barley, maize-grain, canola, tomato and potato crops. the statistical population was 1676 farmers that according to krejcie and morgan table, 315 farmers were selected using stratified random sampling. a researcher-made questionnaire and secondary data of the meteorological organization of iran were used to collect information. in order to calculate the amount of energy consumed by the studied products, first the input and output energies of the products were measured and then converted to their equivalent energy. input energy in food production systems is both direct and indirect. to calculate the water consumption by each product, two elements of green and blue water of the products were calculated. the amount of greenhouse gas emissions for the inputs of the studied products was calculated using co2, n2o and ch4 emission coefficients for different inputs. results and discussionthe research results showed the dominant crops production in the region consumes 50,827 m3 ha-1 of water; potato (11440 m3 ha-1) and maize-grain (10492 m3 ha-1) consume the most water. the total energy consumption was 975608.50 mj ha-1; the highest input energy consumption is related to potato (25%), maize-grain (22%) and tomato (15%). chemical fertilizers, diesel fuel and water for irrigation used the most energy in the agricultural sector. total co2, n2o and ch4 emissions were 3729.79, 152.05 and 0.293 kg ha-1, respectively and total global warming potential, 50872. 52 kg co2= that tomato with emissions of 15592.48 and barley with emissions of 3279.88 kg co2eq, had the highest and lowest share. according to the results, the amount of water consumption by the studied products, except for tomatoes, is more than the recommended amount of water required during the growth period of the desired products by experts; in this regard, it can be said that low irrigation efficiency, poor supervision by relevant agencies, the existence of a large number of illegal wells, mismanagement, uncoordinated management, lack of long-term attitude and inefficient water consumption of irrigation and especially the land use system has caused high water consumption in the studied crops. according to the results, the smaller the farm area, the higher the water and energy consumption and the higher the gwp. in such farms the farmer has lost the advantage of scale and by applying pressure on the ground by increasing the irrigation cycle, the use of fertilizers and pesticides seeks to gain more efficiency. on the other hand, due to the small size of farms, they use less up-to-date technologies, thus indirectly increasing water and energy waste. the results showed that crops that are mainly grown in agriculture in the region with the lease system have the highest input consumption and have a negative impact on the environment of the region. in this regard, it can be said that land tenants in the region try to get the most economic benefit from the land in a shorter period of time, and this increases the pressure on resources. conclusionin general, it can be said that low irrigation efficiency, existence of a large number of illegal wells, allocation of agricultural subsidies and the lack of calculation of water and energy costs has caused the inefficiency of the agricultural system of miandarband plain. therefore, increasing irrigation efficiency using strip irrigation system and increasing water and energy prices in the agricultural sector can be effective in the optimal use of water and energy.