ارزیابی چرخه حیات در بوم‌نظام‌های تولید گندم (Triticum aestivum L.) ایران: 1- مقایسه سطوح مصرف نهاده

نوع مقاله : علمی - پژوهشی

نویسندگان

• مهدی نصیری محلاتی ¹
• علیرضا کوچکی ²

¹ فردوسی مشهد

² دانشگاه فردوسی مشهد

10.22067/jag.v9i4.45790

چکیده

در طی چند دهه گذشته تولید گندم (Triticum aestivum L.) در کشور با اتکاء به مصرف نهاده‌های شیمیایی افزایش قابل توجهی داشته است. با این حال پیامدهای محیطی مصرف این نهاده‌ها برای انسان و منابع طبیعی به درستی مشخص نمی‌باشد. در این پژوهش مجموعه‌ای از اثرات محیطی شامل تغییر کاربری اراضی، تخلیه منابع غیر‌قابل تجدید، پتاتسیل گرمایش جهانی، پتانسیل اسیدی شدن محیط، پتانسیل پر غذایی آب و خاک و سمیت اکولوژیکی برای انسان و محیط حاصل از بوم‌نظام‌های تولید گندم کشور با استفاده از روش استاندارد ارزیابی چرخه حیات از مبداء تولید مواد اولیه تا دروازه مزرعه مورد بررسی قرار گرفت. مطالعه بر روی 14 استان که روی هم 80 درصد از سطح زیر کشت و تولید گندم کشور را شامل می‌شوند، به اجرا در آمد. ابتدا بوم‌نظام‌های واقع در این استان‌ها بر اساس سطح مصرف نهاده‌ها به سه گروه کم، متوسط و پر نهاده طبقه‌بندی و سپس در مرحله ممیزی کلیه نهاده‌های ورودی و نیز مواد انتشار یافته در محدوده مرزهای تعریف شده برآورد شدند. نتایج حاصل از ممیزی بر حسب دو واحد کارکردی (هکتار و تن دانه گندم) برای هر گروه تأثیر بر اساس واحد مربوط به آن گروه معادل‌سازی شد و در نهایت، تأثیر سطح مصرف نهاده‌ها بر هر یک از اثرات محیطی مورد مقایسه قرار گرفت. نتایج نشان داد که در واحد کارکردی هکتار با افزایش میزان مصرف نهاده‌ها کلیه اثرات محیطی حاصل از بوم‌نظام‌های گندم به طور معنی‌داری افزایش یافت، ولی با محاسبه این اثرات بر حسب تن گندم به دلیل اختلاف عملکرد بین بوم‌نظام‌ها نتایج متفاوتی به‌دست آمد. شدت تخلیه منابع غیر قابل تجدید (سوخت‌های فسیلی و منابع P و K) در نظام‌های پر نهاده معادل GJ/ha 1/27 و تقریبا 8/1 برابر نظام‌های کم نهاده بود در حالی‌که براساس واحد عملکرد مقدار این انرژی در نظام‌های پر نهاده تنها 10 درصد بیشتر از نظام کم نهاده بود، زیرا برای تولید هر تن گندم در نظام کم نهاده به 3850 متر مربع زمین نیاز است در حالی‌که همین عملکرد در نظام پر نهاده از 2374 متر مربع به‌دست می‌آید. بر این اساس عملکرد بیشتر بوم‌نظام‌های پر نهاده باعث شد تا در آن‌ها پتانسیل اسیدی شدن، سمیت آبی و سمیت برای محیط‌های خشک بر حسب واحد عملکرد کمتر از نظام‌های کم و متوسط نهاده باشد. در حالی‌که پتانسیل گرمایش جهانی، پر غذایی و سمیت برای انسان در نظام‌های پر نهاده در هر دو واحد کارکردی وضعیت نامطلوبی در مقایسه با نظام کم نهاده داشت.

کلیدواژه‌ها

• اثرات محیطی
• بوم‌نظام پر نهاده
• پایداری
• مصرف انرژی

---

عنوان مقاله [English]

Life Cycle Assessment (LCA) for Wheat (Triticum aestivum L.) Production Systems of Iran: 1- Comparison of Inputs Level

نویسندگان [English]

• Mahdi Nassiri Mahallati ¹
• Alireza koocheki ²

¹ Ferodwsi University of Mashhad

² Ferodwsi University of Mashhad

چکیده [English]

Introduction
Agricultural intensification has serious environmental consequences such as depletion of non-renewable resources, emission of greenhouse gases, threatening of biodiversity and pollution of both surface and underground water resources. The life cycle assessment (LCA) provides a standard method for assessing environmental impacts from various economic activities, including agriculture, and covers a wide range of impact categories across the entire production chain. Over the past few decades, food production in Iran has been increased drastically due to heavier use of chemical inputs. Since the use of LCA method is overlooked for assesseing the effects of agricultural intensification in Iran and few researches are conducted at local level (such as province, cities), the purpose of this research is evaluation of wheat production systems throughout the country based on the level of intensification using LCA method.

Materials and Methods
Fourteen provinces covering 80 percent of total cultivated area of wheat production in the country were subjected to a cradle to gate LCA study using the standard method. The selected provinces were classified as low, medium and high input based on the level of intensification and all inputs and emissions were estimated within the system boundaries during inventory stage. Required data for yield, and level of applied inputs for 14 provinces were collected from the official databases of the Ministry of Jihad Agriculture. The various environmental impacts including, abiotic resource depletion, land use, global warming potential, acidification and eutrophication potential, human, aquatic and terrestrial ecotoxicity potential of wheat production systems over the country was studied based on emission coefficients and characterization factors provided by standard literatures. The integrated effects of emission of each impact category were calculated per functional units (hectare cultivated area as well as ton grain) and three production systems were compared for the intensity of environmental impacts of each category.

Results and Discussion
The results indicated that on per hectare basis all impact categories increased significantly with increasing inputs level. However, with grain yield ton as a unit of functional variable, results were obtained due to yield differences in wheat production systems. Depletion of non-renewable resources (fossil fuels and P+K resource) in high input systems was 27.1 GJ ha-1 which is almost 1.8 times higher than low input systems. However, energy consumption per unit of yield was exceeded in intensified system only by 10% because 1 ton of grain yield in high input systems was obtained from 2374 m2 area compared to 3850 m2 required for the same amount of yield in low input systems. Higher yield of intensified systems when calculated per ton grain was led to lower acidification potential, aquatic toxicity and terrestrial toxicity. However, global warming potential, eutrophication potential and human toxicity was not compensated by yield advantage and these impacts were higher in high input systems with both functional units. Global warming potential (GWP) in high input systems reached to 2911 kg CO2eq ha-1 but it was 45% lower (1600 kg CO2eq ha-1) in low input systems. When calculated with ton grain as functional unit, GWP of high input systems (1600 kg CO2eq t-1) was only 11% greater than that of low input systems.

Conclusion
Global warming potential, depletion of non-renewable resources, eutrophication potential, and human toxicity were identified as the most sensitive impact groups to intensification in wheat production systems of Iran, compared to other impact categories. In general environmental impacts of high input systems were greater than low input systems and the difference was very clear when the area was used as functional unit. It seems that increasing the use efficiency of inputs together with management practices based on the replacement of external inputs, is an appropriate approach to reduce environmental impacts while sustaining high yields. Further analysis at provience level is needed to compare the spatial variation of environmental impacts of wheat production systems in the country.

کلیدواژه‌ها [English]

• Energy use
• Environmental impacts
• High input system
• Sustainability
• wheat

مراجع

Andersson, K., and Ohlsson, T. 1999. Life Cycle Assessment of bread produced on different scales. International Journal of Life Cycle Assessment 4: 25-40.

Andersson, K., Ohlsson, T., and Olsson, P. 1998. Screening life cycle assessment (LCA) of tomato ketchup: a case study. Journal of Cleaner Production 6(3-4): 277-288.

Anton, A., Montero, J.I., Munoz, P., and Castells, F. 2005. LCA and tomato production in Mediterranean greenhouses. International Journal of Agricultural Resources Governance and Ecology 4(2): 102-112.

Audsley, E. 1997. Harmonisation of environmental life cycle assessment for agriculture. Final Report. Concerted Action MR3-CT94-2028. Silsoe Research Institute, Silsoe.

Banaeian, N., Omid, M., and Ahmadi, H. 2011. Energy and economic analysis of greenhouse strawberry production in Tehran province of Iran. Energy Conversion and Management 52: 1020-1025.

Bazrgar, A.B. 2011. Environmental assessment of Khoraszn sugar beet production systems using LCA. PhD Dissertation, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. (In Persian with English Summary)

Bennett, R., Phipps, R., Strange, A., and Grey, P. 2004. Environmental and human health impacts of growing genetically modified herbicide-tolerant sugar beet: a life cycle assessment. Plant Biotechnology Journal 2(4): 272-278.

Boer, D.I.J.M. 2002. Environmental impact assessment of conventional and organic milk production. Livestock Production Science 80(1-2): 69-77.

Braschkat, J., Patyk, A., Quirin, M., and Reinhardt, G.A. 2003. Life cycle assessment of bread production–a comparison of eight different scenarios. In: Proceedings of the Fourth International Conference on Life Cycle Assessment in the Agri-Food Sector, Bygholm, Denmark.

Brentrup, F., and Ku¨ Sters, J. 2000. Methods to estimate to potential N emissions related to crop production. In: Weidema B, and Meeusen M, editors. Agricultural data for life cycle assessments, vol. 1. The Hague, The Netherlands: Agricultural Economics Research Institute p. 133-151.

Brentrup, F., Kusters, J., Lammel, J., Barraclough, P., and Kuhlmann, H. 2004. Environmental impact assessment of agricultural production systems using the life cycle assessment (LCA) methodology–2, the application to N fertilizer use in winter wheat production systems. European Journal of Agronomy 20(3): 265-279.

Brentrup, F., Küsters, J., Kuhlmann, H., and Lammel, J. 2001. Application of the life cycle assessment methodology to agricultural production: an example of sugar beet production with different forms of nitrogen fertilisers. European Journal of Agronomy 14: 221-233.

Charles, R., Jolliet, O., Gaillard, G., and Pellet, D. 2006. Environmental analysis of intensity level in wheat crop production using life cycle assessment. Agriculture, Ecosystems and Environment 113: 216-225.

Crutzen, P.J., Mosier, A.R., Smith, K.A., and Winiwarter, W. 2008. N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels. Atmospheric Chemistry and Physics 8(2): 389-395.

Dalgaard, T., Halberg, N., and Porter, J.R. 2001. A model for fossil energy use in Danish agriculture used to compare organic and conventional farming. Agriculture Ecosystems and Environment 87(1): 51-65.

De Vries, W., Kros, J., Oenema, O., and de Klein, J. 2003. Uncertainties in the fate of nitrogen II: a quantitative assessment of the uncertainties in major nitrogen fluxes in the Netherlands. Nutrient Cycling in Agroecosysts 66: 71-102.

Del Grosso, S.J., Mosier, A.R., Parton, W.J., and Ojima, D.S. 2005. DAYCENT model analysis of past and contemporary soil N2O and net greenhouse gas flux for major crops in the USA. Soil and Tillage Research 83(1): 9-24.

ECETOC, 1994. European Chemical Industry Ecology and Toxicology Centre (ECETOC). Ammonia Emissions to Air in Western Europe. Technical Report No. 62. ECETOC, Brussels.

Ecoinvent, 2007. Ecoinvent Data V.2.01. Swiss Centre for Life Cycle Inventories.http://www.ecoinvent.ch./

EERE, 2000. Industrial technologies program: energy and environmental profile, the agricultural chemicals chain. US Dept of Energy, Energy Efficiency and Renewable Energy.

FAOSTAT. 2012. FAOSTAT Statistics Database. Rome, Italy: FAO.

Garrigues, E., Corsona, M.S., Angers, D.A., Van der Werfa, H.M.G., and Walter, C. 2011. Soil quality in life cycle assessment: towards development of an indicator. Ecological Indicators 18: 434-442.

Guinee, J. 2002. Handbook on Life Cycle Assessment. Operational Guide to the ISO Standards. (Ed.). Kluwer Academic Publishers, Dordrecht, The Netherlands.

Guinee, J.B., Heijungs, R., and Huppes, G. 2004. Economic allocation: examples and derived decision tree. International Journal of Life Cycle Assessment 9: 23-33.

Haas, G., Wetterich, F., and Kِpke, U. 2001. Comparing intensive, extensified and organic grassland farming in southern Germany by process life cycle assessment. Agriculture, Ecosystems and Environment 83(1-2): 43-53.

Hauschild, M. 2000. Estimating Pesticide Emissions for LCA of Agricultural Products. In: Weidema B, and Meeusen M, editors. Agricultural Data for Life Cycle Assessments, Vol. 2. The Hague, The Netherlands: LCANet Food p. 64-79 (Chapter 22).

Heijungs, R., Guinee, J.B., Huppes, G., Langreijer, R.M., De Haes, U., and Sleeswijk, A.W. 1992. Environmental Life Cycle Assessment of Products – Backgrounds 9267. CML, Leiden. 130 p.

Hulsbergen, K.J., and Kalk, W.D. 2001. Energy balances in different agricultural systems–can they be improved? In: Proceedings of the International Fertiliser Symposium, Lisbon, Portugal.

IPCC, 2006. IPCC Guidelines for National Greenhouse Gas Inventories. Intergovernmental Panel on Climate Change. Greenhouse Gas Inventory Reference Manual, Vol. 4.

ISO (International Organization for Standardization), 2006. ISO 14040: 2006(E) Environmental Management–Life Cycle Assessment–Principles and Framework.

Khoshnevisan, A., Rafiee, S., Omid, M., Keihani, A., and Movahedi, M. 2013. Evaluation of energy and environmental indices of potato crop using life: A case study on fereidon shahr county, Esfehan province, Iran. Biosystem Engineering 44(1): 57-66.

Koocheki, A., Nassiri Mahallati, M., Bakhshaee, S., Davari, A., and Zare Zadeh, M. 2013. A meta analysis on nitrogen fertilizer experiments on cereal crops in Iran. Journal of Agroecology (In Press). (In Persian with English Summary)

Lal, R. 2004. Soil carbon sequestration impacts on global climate change and food security. Science 304(5677): 1623-1627.

Mattsson, B., and Wallen, E. 2003. Environmental LCA of organic potatoes. In: Proceedings of the 26th International Horticultural Congress, ISHS, Acta Horticulturae 691.

Meisterling, K., Samaras, C., and Schweizer, V. 2009. Decisions to reduce greenhouse gases from agriculture and product transport: LCA case study of organic and conventional wheat. Journal of Cleaner Production 17: 222-230.

Mila` i Canals, L., Romanya, J., and Cowell, S.J. 2007. Method for assessing impacts on life support functions (LSF) related to the use of ‘fertile land’ in Life cycle assessment (LCA). Journal of Cleaner Production 15: 1426-1440.

MAJ, 2011. Ministry of Jehad-e-Keshavarzi of Iran, Statistical Database. Crop Production Statistics 2010-2011. www.maj.ir/portal/Home/Default.aspx (In Persian)

Narain, M., and Singh, B.P.N. 1998. Energy profile of a seed-processing plant. Applied Energy 30: 227-234.

Nassiri Mahallati, M., and Koocheki, A. 2014. Trend analysis of nitrogen use and productivity in wheat production systems of Iran. Journal of Agroecology (In Press). (In Persian with English Summary)

Nemecek, T. 2003. Life Cycle Inventories of Agricultural Production System, Dubendorf, Switzerland.

Nemecek, T., and Erzinger, S. 2005. Modeling representative life cycle inventories for Swiss arable crops. International Journal of Life Cycle Assessment 10(1): 68-76.

Nemecek, T., Heil, A., Gaillard, G., and Garcia, J. 2001. SALCA, Swiss Agricultural Life Cycle Assessment Database: Umweltinventare fur die Landwirtschaft. Unpublished Internal Document, Version 012, December 2001. Agroscope FAL Reckenholz, Zurich, Switzerland.

Nemecek, T., Dubois, D., Huguenin-Elie, O., and Gaillard, G. 2010. Life cycle assessment of Swiss farming systems: I. Integerated and organic farming. Agriculture Systems 104: 217-232.

Nemecek, T., and Kägi, T. 2007. Life Cycle Inventories of Swiss and European Agricultural Production Systems. Final Report Ecoinvent v2.0 No.15a. Agrospace Reckenholz-Taenikon Research Station ART, Swiss Center of Life Cycle Inventories, Zurich and Dubendorf, CH.

NRMRL. 2003. National risk management research laboratory, tools for the reduction and assessment of chemical and other environmental impacts (TRACI): user’s guide and system documentation. EPA/600/R-02/052. Ohio: United States Environmental Protection Agency.

Parr, J.F., Papendick, R.I., Youngberg, I.G., and Meyer, R.E. 1990. Sustainable Agriculture in the United States. In: Edwards, C. et al. (Eds.), Sustainable Agricultural Systems. St. Lucie Press, p. 50-67.

Pimentel, D. 2003. Food Production and the Energy Crisis. In: Frischknecht, R., Jungbluth, N., (Eds.). Implementation of Life Cycle Assessment Methods, Ecoinvent Report No. 3. Swiss Centre for Life Cycle Inventories, Dubendorf, Switzerland p. 22-28.

Piringer, G., and Steinberg, L.J. 2006. Reevaluation of energy use in wheat production in the United States. Journal of Industrial Ecology 10(1-2): 149-167.

Roy, P., Nei, D., Orikasa, T., Xu, Q., Okadome, H., Nakamura, N., and Shiina, T. 2009. A review oflife cycle assessment (LCA) on some food products. Journal of Food Engineering 90: 1–10.

Roy, P., Shimizu, N., and Kimura, T. 2005. Life cycle inventory analysis of rice produced by local processes. Journal of the Japanese Society of Agricultural Machinery 67(1): 61–67.

Soltani, A., Rajabi, M.H., Zeinali, E., and Soltani, E. 2010. Evaluation of environmental impacts of crop production using LCA: wheat in Gorgan. Electronic Journal of Crop production 3(3): 201-218. (In Persian with English Summary)

Tzilivakis, J., Jaggard, K., Lewis, K.A., May, M., and Warner, D.J. 2005. Environmental impact and economic assessment for UK sugar beet production systems. Agriculture, Ecosystems and Environment 107: 341-358.

Van der Hoek, K.W., and Van Schijndel, M.W. 2006. Methane and nitrous oxide emissions from animal manure management 1990-2003. Background document on the calculation method for the Dutch National Inventory Report. RIVM and MNP (Netherlands Environmental Assessment Agency), Bilthoven, The Netherlands pp. 1-50.

Wackernagel, M., Monfreda, C., Moran, D., Wermer, P., Goldfinger, S., Deumling, D., and Murray, M. 2005. National Footprint and Biocapacity Accounts 2005: the Underlying Calculation Method. Global Footprint Network, Oakland.

Zangeneh, M., Omid, M., and Akram, A. 2010. A comparative study on energy use and cost analysis of potato production under different farming technology in Hamadan province of Iran. Energy Conversion and Management 35: 2927-2933.