ارزیابی پایداری دو نظام تولید پسته تحت آبیاری بارانی و غرقابی با استفاده از روش تحلیل امرژی در استان قم

استفاده از رهیافت امرژی در ارزیابی پایداری نظام‌های کشاورزی، منجر به اعمال مدیریت صحیح در راستای افزایش پایداریِ تولید در این نظام‌ها است. در تحقیق حاضر، دو نظام تولید پسته در استان قم تحت آبیاری غرقابی و آبیاری بارانی با استفاده از روش امرژی بررسی شدند. نتایج نشان داد که ورودی امرژی کل برای نظام آبیاری غرقابی و بارانی به‌‌ترتیب 1016 × 4/05 و 1016 × 2/72 ام‎‌ژول خورشیدی در هکتار در سال بود. بر خلاف نظام آبیاری غرقابی، در نظام آبیاری بارانی وابستگی به جریان‎های خریداری شده امرژی بیشتر از جریان‎های محیطی امرژی بود. بیشترین سهم از ورودی امرژی کل در نظام آبیاری غرقابی مربوط به مصرف آب زیرزمینی با سهم 27/0 درصدی و در نظام آبیاری بارانی مربوط به کودهای آلی با سهم 26/14 درصدی بود. در نظام آبیاری غرقابی و بارانی به‌ترتیب، ضریب تبدیل 105 × 9/05 و 105 × 5/46 ام‎ژول خورشیدی بر ژول، تجدیدپذیری امرژی 2/43 و 3/45 درصد، نسبت عملکرد امرژی 2/157 و 1/571، نسبت سرمایه‌گذاری امرژی 0/86 و 1/75، نسبت بارگذاری محیطی 62/67 و 41/74 و شاخص پایداری امرژی 0/034 و 0/038 بود. علی‎رغم سهم بالاتر جریان‎های محیطی نسبت به بازاری در نظام آبیاری غرقابی، مصرف زیاد آب زیرزمینی به عنوان یک جریان تجدیدناپذیر موجب تشدید فشار محیطی این نظام گردید. استفاده از روش آبیاری بارانی موجب مصرف بهینه آب و در نتیجه کاهش فشار نظام روی محیط خواهد شد. در تحقیق حاضر، نظام آبیاری بارانی از نظر عملکرد، بهره‌وری از منابع، تجدیدپذیری نهاده‌ها و پایداری محیطی مطلوب‎تر از نظام آبیاری غرقابی بود.

evaluation of sustainability of two pistachio production systems under drip and flood irrigation using energy analysis technique in qom province

introduction: agricultural ecosystems depend on free environmental flows such as water, wind, sunlight, soil and soil organic matter and non-free flows such as fertilizers, pesticides, electricity, fuel, mechanical equipment and other industrial products. in this context, it is useful to use biophysical methods based on thermodynamic laws such as energy analysis, exergy analysis, exergy evaluation and life cycle evaluation with regard to the contribution of environmental services and inputs in the production system based on equivalent unit.by applying the emergy approach to analyzing the sustainability of agricultural systems, we can ensure that adequate management is implemented in order to increase the sustainability of production in these systems. in this regard, by evaluating and comparing two flood and drip irrigation systems in pistachio production using the integration of emergy and economic indicators, it is possible to provide an accurate picture of the sustainability of the two pistachio irrigation systems in qom city, so that based on the results, solutions for the development of cultivation and stabilization of pistachio production and the optimal presence of this plant in the cultivation pattern of the region should be provided.  materials and methods: in the current study, two irrigation systems for pistachio fields in qom province, iran, were analyzed using emergy analysis. for this study, we measured free renewable and non-renewable environmental flows, as well as non-free flows, in 2019 for two pistachio production systems that were irrigated by flood and rain.free renewable environmental flows including sunlight, rain, wind, evaporation and transpiration and river water; non-renewable environmental free flows including erosion and losses of soil organic matter; non-free flows include chemical fertilizers, pesticides, herbicides, machinery, fuel, organic fertilizers, labor and electricity that originate from outside the system.the output of the system was pistachio product.results and discussion: the largest free environmental input in both systems was the chemical energy of rain with 5.90e+14 sej ha-1 year-1. renewable environmental flows for both systems in this study were 6.36e+14 sej ha-1 year-1.this category of input sources for flood and drip irrigation systems constituted 1.57% and 2.34% of the total inputs to each system, respectively.consumption of underground water resources, evaporation and transpiration, loss of soil organic matter and soil erosion formed the main components of non-renewable environmental flows, whose share of the total input energy for flood and drip irrigation systems was 52.06% and 33.99%, respectively.most of the flow of non-renewable environmental inputs in both systems was related to underground water. in general, the amount of underground water consumption, evaporation and transpiration and soil erosion was higher in flood irrigation system than drip irrigation system. the total emergy inputs for the flood and drip irrigation systems were calculated to be 4.05e+16 and 2.72e+16 sej ha-1 year-1, respectively, according to the findings. in contrast to the flood irrigation system, the drip irrigation system was more reliant on purchased supplies than on environmental inputs. groundwater consumption accounted for 27.00% of total energy input in the flood irrigation system, while livestock manure accounted for 26.14% of total energy input in the drip irrigation system. transformities in the flood and drip irrigation systems were 9.05e+05 and 5.46e+05 sej j-1, respectively; emergy renewabilities were 2.43% and 3.45%; emergy yield ratios were 2.157 and 1.571; emergy investment ratios were 0.86 and 1.75; standard environmental loading ratios were 62.76 and 41.74; and standard emergy sustainability indices were 0.034 and 0.038, respectively.conclusion:despite the flood irrigation system’s larger contribution of environmental resources, the high use of groundwater as a non-renewable input resulted in an increase in environmental burden. the adoption of drip irrigation will lessen environmental burden on ecosystems while also improving water use. in the current study, the drip irrigation system outperformed the flood irrigation system in terms of yield, resource efficiency, renewability, and environmental sustainability.