نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار، بخش تحقیقات حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان کرمانشاه، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرمانشاه، ایران
2 دانشیار، پژوهشکده حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
چکیده
تغییر کاربری جنگلها دارای پیامدهای متعددی از جمله تشدید وقوع سیل، فرسایش، رسوب و گرد و غبار است. بههمین منظور، پژوهش حاضر با هدف بررسی تاثیرات تغییر کاربری جنگلهای زاگرس بر فرسایشپذیری و رسوبزایی از طریق کاهش کیفیت خاک در بخشی از جنگلهای استان کرمانشاه انجام شد. در این راستا، ابتدا دو محدوده جنگلی و دیمزار مجاور آن که طی 10 سال اخیر بر اثر تغییر کاربری جنگل حاصل شده بود، انتخاب و 35 نمونه خاک از لایه سطحی (صفر تا 20 سانتیمتر) از هر دو کاربری برداشت شد. سپس، آزمایشهای فیزیکی و شیمیایی روی نمونههای خاک انجام گرفت. در مرحله بعدی، میزان فرسایشپذیری خاک محاسبه و میزان تولید رسوب هر دو کاربری با استفاده از بارانساز قابل حمل در صحرا اندازهگیری شد. نتایج این بررسی نشان داد که شش ویژگی مهم و کلیدی خاک، شامل پایداری خاکدانهها، وزن مخصوص ظاهری، کربن آلی، ازت کل، پتاسیم و ظرفیت تبادل کاتیونی از نوع کاربری زمین، تاثیر معنیداری پذیرفتهاند. البته در همه نمونههای مورد آزمایش مجموع رس و سیلت حدود 80 درصد بود که موجب تشکیل خاک با بافت سنگین شده است. متعاقبا عامل فرسایشپذیری خاک (K) و نیز شدت تولید رسوب در دیمزار نسبت به عرصه جنگلی به لحاظ معنیداری بیشتر بهدست آمد. با توجه به نتایج این بررسی و نقش اکوسیستم جنگلی زاگرس در استحصال آب باران، تغذیه آبهای زیرزمینی و مهار سیل و گرد و غبار، تداوم روند فعلی تغییر کاربری این جنگلها بههمراه شخم نامناسب، سوزاندن بقایای محصول و تردد ماشینآلات در دیمزارهای حاشیه آنها، موجب تشدید گرمایش زمین، افزایش ضریب رواناب و تبخیر، بحران کمآبی نسبت به شرایط کنونی خواهد شد.
کلیدواژهها
عنوان مقاله [English]
The effect of land use change from forest to rain-fed farms on soil physico-chemical characteristics, erodibility and sediment yield
نویسندگان [English]
- Mosayeb Heshmati 1
- Mohammad Ghaietury 1
- Mahmood Arabkhedri 2
- Yahya Parvizi 1
1 Associate Professor, Soil Conservation and Watershed Management Research Department, Kermanshah Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Kermanshah, Iran
2 Associate Professor, Soil Conservation and Watershed Management Research Institute (SCWMRI), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
چکیده [English]
Forest and land use change has many negative consequences including increased flooding, erosion, sedimentation and dust storms. The aim of the research was thus to investigate the effects of land use change in Zagros forests on erodibility and sedimentation via soil quality reduction in some forests of Kermanshah Province, Iran. In order to achieve this aim, in the first step, afforest area and its adjacent rain-fed farm (which is developed during recent 10 years a result of forest land change), were selected and 35 soil samples were collected from the surface layer (0-20 cm). Then, the physico-chemical analyses were done on the soil samples. In the next step, soil erodibility factor was calculated and sediment yield was assessed using portable rainfall simulator. The results showed that six key properties of soil including soil aggregate stability, bulk density, organic carbon, total nitrogen, total absorbable potassium and cation exchange capacity were significantly (p<0.05) influenced by land use type. Additionally, in all tested samples, the total clay and silt content was about 80%, which resulted in the formation of soil with heavy texture. Subsequently soil erodibility factor (K) and sediment yield intensity in rain-fed farm was found significantly (P<0.05) higher than those of forest. According to the results and the role of Zagros forest ecosystem on water harvesting, aquifer recharge, flood and dust control, the current trend of changing forest landuse to arable lands accompanying improper tillage practice, crops residue burning and heavy machinery traffic in nearby rain-fed farms, cause accelerating global warming, increasing runoff coefficient and evaporation as well as water scarcity in future.
کلیدواژهها [English]
- Soil aggregates stability
- Zagros forests
- Small-revenue rain-fed farms
- Organic carbon
- Azarbar, S.M., H. Ahmadi, N. Khorasani and M. 2006. Investigation relationship between wind erosion and value of animal habitats in desert area. Journal of Desert Research, l2: 4-13.
- Bahrami, A., I. Emadodin, M. Ranjbar-Atashi and H. Rudolf-Bork. 2010. Land use change and soil degradation: a case study, north of Iran. Agriculture and Biology Journal of North America, 1(4): 600-605.
- Bechmann, M., P. Stalnacke, S. Kværno and L. Oygarden. 2009. Integrated tool for risk assessment in agricultural management of soil erosion and losses of phosphorus and nitrogen. Science of the Total Environment, 407(2): 749-759.
- Blanco, H. and R. Lal. 2008. Principles of soil conservation and management. Springer Publisher, 617 pages.
- Busari, M.A., S.S. Kukal, A. Kaur, A., Bahtt and A.A. Dulazi. 2015. Conservation tillage impacts on soil, crop and the environment. International Soil and Water Conservation Research, 3: 119–129.
- Crittenden, N.P., M. Heinen, D.J.M. Balen and M.M. Pulleman. 2015. Soil physical quality in contrasting tillage systems in organic and conventional farming. Soil and Tillage Research, 154: 136–144.
- Fallahzade, J., M.A. Hajabbasi and B. Khalili. A study of the effects of deforestation on soil organic matter properties in a semi-arid ecosystem (central Iran). Proceedings of the 3rd International CEMEPE and SECOTOX Conference, Skiathos, June 19-24.
- Hajabbasi, M.A., A. Besalatpour and A.R. Melali. 2008. Impacts of converting rangelands to cultivated land on physical and chemical properties of soils in west and southwest of Isfahan. Journal of Science and Technology of Agriculture and Natural Resources, 11(42): 525-534.
- Hamza, M.A. and W.K. Anerson. 2005. Soil compaction in cropping systems: a review of the nature, causes and possible solutions. Soil and Tillage Research, 82(2): 121–145.
- Hazeltn, P. and B. Murphy. 2007. Interpreting soil test results. CSIRO Publisher, 169 pages.
- Heshmati, M., G. Ghaituri and K. Shahbazi. 2017. The food; consequence of landuse change. Agricultur-Jahad Organization of Kermanshah Province, Taghbostan Press, 68 pages (in Persian).
- Heshmati, M., N.M. Majid, J. Shamshuddin, M. Ghaituri and A. Arifin. 2013. Effects of soil and rock mineralogy on soil erosion features in the Merek Watershed, Iran. Journal of Geographic Information System, 2013(5): 248-257.
- Heshmati, M., A. Arifin, J. Shamshuddin, N.M. Majid and M. Ghaituri. 2011. Factors affecting landslides occurrence in agro-ecological zones in the Merek Catchment, Iran. Journal of Arid Environments, 75: 1072-1082.
- Jamshidi, M. 2017. The last page of natural history of Zagros. Journal of Sciences and Technology Knowledge, 8: 30-37 (in Persian).
- Jabro, J.D., B. Stevens, R.G. Evans and W.M. Iversen. 2010. Spatial variability and correlation of selected soil properties in the Ap horizon of a CRP grassland. American Society of Agricultural and Biological Engineers, 26(3): 419-428.
- Kamphorst, A. 1987. A small rainfall simulator for the determination of soil erodibility, Netherlands. Journal of Agricultural Science, 35: 12-26.
- Karlen, D.L., M.D. Tomer, J. Neppe and C.A. Cambardella. 2008. A preliminary watershed scale soil quality assessment in north central Iowa, USA. Soil and Tillage Research, 99: 291-299.
- Miralles, I., Ortega, G. Almendros, M.S. Maranon and M. Soriano. 2009. Soil quality and organic carbon ratios in mountain agro-ecosystems of south-east Spain. Geoderma, 150: 120-128.
- Miller, R.H., D.R. Keeney and A.L. Page. 1983. Methods of soil analysis, part 2: chemical and microbiological properties. American Society of Agronomy, Madison, Wisconsin, 1159 pages.
- Morgan, R.P.C. 2005. Soil erosion and conservation. Blackwell Publisher, 316 pages.
- Nael, M., H.M.A. Khademi and M. Hajabbasi. 2004. Response of soil quality indicators and their spatial variability to land degradation in central Iran. Applied Soil Ecology, 27(3): 221–232.
- Navidi, M.N., Sarmadian and S.H. Mahmoodi. 2009. Studying the effects of land use change on soil physical and chemical quality indicators of surface horizons in rangelands of eastern Qazvin Province. Journal of Range and Watershed Management, 62(2): 299-310 (in Persian).
- Negassa, W., R. Price, A. Basir, S. Snapp and A. Kravchenko. 2015. Cover crop and tillage systems effect on soil CO2 and N2O fluxes in contrasting topographic positions. Soil and Tillage Research, 154: 64–74.
- Nosrati, K. 2009. Iran has highest rate of soil erosion in world. Tehran Times. www.tehrantimes.com, Tehran, Iran.
- Rosa, D.L., M.A. Romero, E.D. Pereira, N. Heredia and F. Shahbazi. 2009. Soil specific agro-ecological strategies for sustainable land use, a case study by using MicroLEIS DSS in Sevilla Province (Spain). Land Use Policy, 26: 1055-1065.
- Ryan, J., Estefan and A. Rashid. 2001. Soil and plant analysis laboratory manual. 2nd ed., International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, 254 pages.
- Senthikumar, S., B. Basso, A.N. Kravachenko and G.P. Roberton. 2009. Cotemporary evidence of soil carbon loss in the U.S corn-belt. Soil Science Society of America Journal, 73(6): 278-2085.
- Siadat, H., M. Bybordi andJ. Malakouti. 1997. Salt affected soils of Iran. A country report International symposium on Sustainable Management of Salt Affected Soils in the Arid Ecosystem, Cairo (Egypt).
- Taghimollaei, Y. and A. 2017. Sudden oak death in Iran forests. International Journal of Forest, Soil and Erosion (IJFSE), (1): 6-10.
- Teh, C.B.S. and J. 2006. Soil physics analyses. University Putra Malaysia Press, 212 pages.
- Torahi, A.A. and S. Chand Rai. Land cover classification and forest change analysis, using satellite imagery, a case study in Dehdez area of Zagros Mountain in Iran. Journal of Geographic Information System, 3: 1-11.
- Van-Reeuwijke, L.P. and J. Vente. Procedure for soil analysis. International Soil Reference and Information Center, Amsterdam, 142 pages.
- Wang, H., Q. Zhao, Q. Zeng, D.H. Hu, Y.L. and Z.Y. Yu. 2015. Remediation of a magnesium-contaminated soil by chemical amendments and leaching. Land Degradation and Development, 26(6): 613-619.
- Yusefi, A., A. Farrokhian Firouzi and B. Khalili Moghaddam. 2013. Evaluation of temporal variation of splash erosion in different slopes and agricultural and forest land uses. Journal of Soil and Water Conservation, 3(3): 11-20 (in Persian).
- Yousefifard, M., H. Khademi and A. Jalalian. 2007. Decline in soil quality as a result of landuse change in Chechmeh Ali region, Chaharmahal and Bakhtiari Province. Journal of Agriculture and Natural Resources, 14(1): 16-27 (in Persian).