نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهیدباهنر کرمان، ایران
2 استاد گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهیدباهنر کرمان، ایران
3 استاد گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان
4 استادیار مهندسی طبیعت، دانشکدهی منابع طبیعی، دانشگاه جیرفت، ایران
چکیده
این مطالعه با هدف مقایسه قابلیتها و برجسته کردن تفاوتها و شباهتهای بین دو سامانه ردهبندی آمریکایی و طبقهبندی جهانی در گروهبندی خاکرخهای مورد مطالعه در مناطق مختلف استان کرمان با شرایط اقلمیی متفاوت به انجام رسید. به این منظور تعداد یازده خاکرخ شاهد، انتخاب، تشریح و نمونهبرداری گردید و پس از انجام آزمایشهای فیزیکوشیمیایی معمول، ردهبندی آنها براساس سامانههای مزبور، نهایی شد. نتایج نشان داد که ردهبندی خاکها در مناطق کم ارتفاع بافت و رابر و منطقه رودبارجنوب و قلعهگنج با اقلیم خشک نسبتاً مشابه میباشد. اما در مناطق با ارتفاع بیشتر از 2000 متر بافت و رابر با اقلیم نیمهخشک تنوعی از خاکها مشاهده شد. بیشترین تفاوت این دو سامانه ردهبندی در خاکرخ سوم این منطقه بیانگر اهمیت افق کلسیک به آرجیک در سامانه طبقهبندی جهانی نسبت به سامانه ردهبندی آمریکایی بود. علاوه بر این، بیشترین تمایز این دو سامانه ردهبندی مربوط به منطقه جیرفت و عنبرآباد بود که طی سالهای نرمال، تغییر اقلیم باعث تفاوت در رژیم رطوبتی از یوستیک به اریدیک شده و این تغییر اقلیم باعث تفاوت در نامگذاری خاکها از آلفیسول و اینسپتیسول به اریدیسول شده است. در حالی که تغییر اقلیم در نامگذاری خاکها بر اساس سامانه طبقهبندی جهانی وارد نمی گردد، بنابراین تفاوتی در نامگذاری خاکها در این سامانه ایجاد نمیکند. نتایج ردهبندی خاکها بیانگر این بود که سامانه طبقهبندی جهانی در بیان وضعیت خاکهای مناطق مورد مطالعه از کارایی بیشتری برخوردار است.
کلیدواژهها
عنوان مقاله [English]
Soil Taxonomy and WRB comparison to classify soils with different climatic conditions in Kerman Province
نویسندگان [English]
- Saleh Sanjari 1
- Mohammad Hady Farpoor 2
- Majid Mahmoodabadi 3
- Saied Barkhori 4
1 Ph.D. Student, Department of Soil Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran
2 Professor, Department of Soil Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran
3 Professor, Department of Soil Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran
4 Assistant Professor, Nature Engineering Department, Faculty of Natural Resources, University of Jiroft, Iran
چکیده [English]
Introduction Soil classification is a process of showing basic differences among soil classes (5). Different soil classification systems are created for soil classification, but Soil Taxonomy and World Reference Base for Soil Resources (WRB) are among the most favoured systems in the world including Iran. This system (WRB) is accepted by soil scientists in the world and Soil Taxonomy has also been used in several countries (7). Each of the two mentioned systems has its own strong and/or weak points to show soil characteristics. However, comparing Soil Taxonomy and WRB for calcareous and gypsiferous soils of central Iran, Sarmast et al. (16) reported that according to specifiers used in WRB, this system could be more efficient than Soil Taxonomy. Various environmental conditions and its fluctuations in Kerman Province caused different soils to be formed in the province. Use of soil moisture and temperature regimes by Soil Taxonomy which is totally neglected by WRB system may emphasize that Soil Taxonomy could provide better results for these soils. That is why the present research was performed to compare Soil Taxonomy and WRB systems in the area of the present research with different climates and to show the efficiency of the two systems to describe selected soil characteristics in Kerman Province.
Materials and Methods According to climatic variations, four study sites were selected in Kerman Province. Sites 1 (elevation of < 2000 m asl) and 2 (elevation of >2000 m asl) in Baft and Rabor areas were located in the south west of the province. Moreover, sites 3 (around Jiroft and Anbarabad) and 4 (around Roodbar-e-Jonoob and Ghaleganj) were located at the center and south of the province, respectively (Fig. 1). Table 1 shows the soil moisture and temperature regimes of the areas under study (3). Twenty-five pedons on different geomorphic surfaces were described and one representative pedon on each geomorphic surface (total of 11 representative pedons) were selected (Fig 1). Soil description and sampling performed (18) and the collected samples transferred to the laboratory. It is to be noticed that soil moisture regime in site 3 has changed from ustic to aridic during normal years defined in Soil Taxonomy. Ustic/ hypertermic soil moisture/temperature regimes were reported for soils of Jiroft and Anbarabad according to the soil moisture and temperature map of soils of Iran (3). However, according to the latest climatic data (30 years' data and the concept of normal years as defind in Soil Taxonomy, 2014) used in the NSM Software, the soil moisture regime was estimated as weak aridic.
Results and Discussion Histic, mollic, argillic, natric, calcic, anhydritic, and cambic horizons were investigated after field work and laboratory analyses. Results of the study show that addition of new Calcixeralfs, Gypsiustalfs, and Gypsicalcids great groups together with newly added Calcic Natrargids, Calcic Natrustalfs, Gypsic Calciustalfs, Typic Petrogypsids, Anhydritic Haplogypsids, and Angydritic Petrogypsids subgroups to the Soil Taxonomy system from one hand, and addition of anhydrite and hypercalcic qualifiers to WRB from the other hand, cause a higher correlation between the two systems. Besides, climatic fluctuations of the recent years in Jiroft and Anbarabad areas caused a change in the soil moisture regime according to normal years defined in Soil Taxonomy. That is why soil name was changed in Soil Taxonomy system. However, WRB system shows no variation because this system is not related to climatic data. Since anhydritic horizon was added to Soil Taxonomy (2014) system, addition of this horizon is recommended to WRB for better correlation of the two systems as was also suggested by Sarmast et al. (16). Meanwhile, soil names in the WRB system provide more information about characteristics of young soil (including yermic qualifier to show desert pavement) compared to Soil Taxonomy.
Conclusion Soil classifications showed that WRB system could describe soil characteristics in the area more efficiently compared to Soil Taxonomy. Climate change caused a variation in soil moisture regime of Jiroft and Anbarabad areas according to normal years of Soil Taxonomy system, which in turn changed soil nomenclature in this system. WRB system is not related to climate that is why soil names were not changed in the above mentioned areas. Besides, WRB system is more efficient to classify gypsiferous soils because gypsum content which is an important factor for management of gypsiferous soils is better focused by WRB. However, lack of anhydritic horizon in the WRB system is a weak point, that is why addition of this horizon was suggested by the authors. It is recommended that soil moisture/temperature regimes of study sites be calculated by softwares using climatic data because the climatic variations of the recent years might have changed the soil moisture/temperature regimes reported in the map of 1998 due to the definition of normal years defind in Soil Taxonomy.
کلیدواژهها [English]
- Argillic horizon
- Soil moisture regime
- Central Iran
- climatic change
- Normal year
References
- Artieda, O., Herrero, J., and Drohan, P.J. 2006. Refinement of the differential water loss method for gypsum determination in soils. Soil Science Society American Journal, 70:1932–1935.
- Banaie, M.H. 1998. Soil Moisture and Temperature Regimes Map of Iran. Soil and Water Research Institute of Iran, Iran.
- Bower, C.A. and Hatcher, J.T. 1966. Simultaneous determination of surface area and cation exchange capacity. Soil Science Society American Journal, 30: 525–527.
- Cline, M.G. 1949. Basic principles of soil classification. Soil Science, 67: 81– 91.
- Esfandiarpour Boroujeni, I., Farpoor, M.H., and Kamali, A. 2011. Comparison between Soil Taxonomy and WRB for Classifying Saline Soils of Kerman Province. Journal of Water and Soil, 25(5): 1158-1171. (In Persian, Abstract in English).
- Esfandiarpour, I., Salehi, M.H., Karimi, A., Kamali, A., 2013. Correlation between Soil Taxonomy and world reference base for soil resources in classifying calcareous soils: (a case study of arid and semi-arid regions of Iran). Geoderma 197-198, 126–136.
- Eswaran, H., Rice, T., Ahrens, R., and Stewart, B.A. 2002. Soil Classification: A Global Desk Reference. CRC Press, Boca Raton.
- Gee, G.W., and Bauder, J.W. 1986. Particle size analysis. In: Klute, A. (Ed.), Methods of Soil Analysis. Agron. Monger, No Vol. 9. ASA and SSSA, Madison, WI, pp. 388–409.
- IUSS Working Group WRB. 2015. World reference base for soil resources 2014, update 2015. International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports No. 106. FAO, Rome.
- Moazallahi, M. and Farpoor, M.H. 2012. Soil genesis and clay mineralogy along the xeric aridic climotoposequence, South central Iran. Journal of Agricultural Science and Technology, 14: 683-696.
- Muir, J.W. 1962. The general principles of classification with reference to soils. Journal Soil Science.13(1): 22–30.
- Nelson, R.E. 1982. Carbonate and Gypsum. P. 181-196. In: A. L. Page et al. (ed), Methods of Soil Analysis. Part II. 2nd ed., Agron. Monogar. No: 9. ASA and SSSA. Madison, WI.
- Nelson, D.W. and Sommers, L.E. 1982. Total Carbon, Organic Carbon and Organic Matter. p. 539-577. In: A. L. Page et al (Ed), Methods of Soil Analisis. Part II. 2nd ed., Agron. Monogar. No: 9. ASA and SSSA. Madison, WI.
- Nooraee, K. 2010. Soil Genesis and Classification in Sirch-Kaleshoor Toposequence, Loot Watershed, Kerman. MSc thesis. Shahid Bahonar University of Kerman, Iran (in Persian, Abstract in English).
- Roca, P.N., and Pazos, M.S. 2002. The WRB applied to Argentinian soils: two case studies. European Soil Bureau, Research Report NO. 7. Latvia University of Agriculture, Jelgava, Latvia, pp: 191-197.
- Rossiter, D.G. 2001. Principles of Soil Classification. Lecture Notes. International Institute for Aerospace Survey and Earth Sciences (ITC), Enschede, the Netherlands (10 pp.).
- Rossiter, D.G. 2007. Classification of urban and industrial soils in the world reference base for soil resources. J. Soils Sediments 7 (2): 96–100.
- Sarmast, M., Farpoor, M.H. and Esfandiarpour Boroujeni, I. 2016. Comparing Soil Taxonomy (2014) and updated WRB (2015) for describing calcareous and gypsiferous soils, Central Iran. Catena, 145: 83–91.
- Sarshogh, M. 2010. The effect of aspect and slope position on soil morphological, physicochemical and mineralogical properties in Chelgerd region. MSc thesis, Shahrekord University, Iran (in Persian, Abstract in English).
- Schoeneberger, P.J., Wysocki, D.A., Benham, E.C., and Soil Survey Staff. 2012. Field book for describing and sampling soils. Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE.
- Soil Survey Staff. 1975. Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Soil Conservation Service. U.S. Department of Agriculture Handbook 436.
- Soil Survey Staff. 1998. Keys to Soil Taxonomy. 8th. ed. USDA-Natural Resources Conservation Service, Washington, DC.
- Soil Survey Staff. 2010. Keys to Soil Taxonomy. 8th. ed. USDA-Natural Resources Conservation Service, Washington, DC.
- Soil Survey Staff. 2014. Keys to Soil Taxonomy. 12th. ed. USDA-Natural Resources Conservation Service, Washington, DC.
- Toomanian, N., Jalalian, A., and Eghbal, M.K. 2003. Application of the WRB (FAO) and US taxonomy systems to gypsiferous soils in Northwest Isfahan. Iran Journal Agricalcure Science Technalogy, 5: 51–66.
- USDA-NRCS. 2012. JNSM: java Newhall Simulation Model. Version 1.6.0. user guide-part 1. National Soil Survey Center.
- Wilson, M.A., Shahid, S.A., Abdelfattah, M.A., Kelley, J.A., and Thomas, J.E. 2013. Anhydrite formation on the Coastal Sabkha of Abu Dhabi, United Arab Emirates. In: Shahid, S.A., Taha, F.K., Abdelfattah, M.A. (Eds.), Developments in Soil Classification, Land Use Planning and Policy Implications: Innovative Thinking of Soil Inventory for Land Use Planning and Management of Land Resources. Springer SBM Publishing, Netherlands, pp: 175–201.