تأثیر مدیریت چرای مراتع بر اشکال مختلف کربن آلی در دشت پنتی ایذه در استان خوزستان

نوع مقاله : مقاله کامل علمی پژوهشی

نویسندگان

1 دانشجوی دکتری گروه خاکشناسی، دانشکده کشاورزی، دانشگاه شهید چمران اهواز،

2 استاد گروه خاکشناسی دانشگاه شهید چمران اهواز

3 دانشیار گروه خاکشناسی دانشگاه شهید چمران اهواز

چکیده

سابقه و هدف: خاک، یک منبع کلیدی و به‏عنوان کنترل‏کننده چرخه‏های ژئوشیمیایی، آب و موجودات زنده و بزرگترین و اصلی‏ترین مخزن ماده‏ی آلی محسوب می‏شود. اطلاعات کمی در ارتباط با تأثیر مدیریت قرق بر اشکال مختلف کربن در خاک‏های مراتع استان خوزستان وجود دارد؛ لذا این مطالعه با هدف بررسی تأثیر مدیریت قرق بر میزان و اشکال مختلف کربن خاک در برخی خاک‏های مراتع دشت پنتی در استان خوزستان انجام شد.
مواد و روش‏ها: براین اساس، دو مرتع با مدیریت‏های مختلف (قرق شده و تحت چرا) در دشت پنتی ایذه انتخاب و سپس از 15 نقطه به صورت تصادفی و از دو عمق سطحی (0 تا 20 سانتی‏متری) و زیر سطحی (20 تا 40 سانتی‏متری) نمونه‏برداری صورت گرفت. پس از هواخشک کردن نمونه‌های خاک و عبور آن‌ها از الک دو میلی‌متری، خصوصیات فیزیکی، شیمیایی و اشکال مختلف کربن خاک شامل کربن آلی کل، کربن قابل اکسید شدن به‏وسیله پرمنگنات، کربن آلی ذره‏ای ریز و درشت، کربن محلول در آب و کربن زیتوده میکروبی خاک‏ها اندازه‌گیری شد.
یافته‏ها: نتایج نشان داد که مدیریت قرق درخاک‏های سطحی و زیرسطحی باعث افزایش میزان ماده آلی خاک شده است ولی در خاک‏های زیرسطحی علی‏رغم افزایش میزان مواد آلی، مقدار آن از لحاظ آماری معنی‏دار نبوده است. در لایه‏های سطحی مقدار آن معنی‏داری بوده است و باعث افزایش میزان کربن آلی کل (از 33/8 به 53/9 گرم بر کیلوگرم)، کربن آلی محلول (از 46/9 به 86/10 میلی‏گرم بر لیتر)، کربن زیتوده میکروبی (از1/418 به 2/456 میلی‏گرم بر کیلوگرم)، کربن قابل اکسید شدن توسط پرمنگنات (از 25/974 به 3/1035 میلی‏گرم بر کیلوگرم)، کربن آلی ذره‏ای ریز (از 6/430 به 7/450 میلی‏گرم بر کیلوگرم) و کربن آلی ذره‏ای درشت (از10/680 به 4/701 میلی‏گرم بر کیلوگرم) شده است. به نظر می‏رسد برای اینکه اثر تغییرات مدیریت به قسمت‏های پایین‏تر خاک تأثیرگذار شود نیازمند مدیریت با مدت زمان بیشتری هست. مقایسه بیومس در داخل (405 گرم بر متر مربع) و خارج قرق (117 گرم بر متر مربع) حاکی از وضعیت خوب پوشش گیاهی در داخل قرق و مؤثر بودن قرق در احیا مراتع منطقه می باشد.
نتیجه‏گیری: نتایج نشان داد که کربن زیتوده میکروبی، کربن محلول خاک و کربن قابل اکسید شدن توسط پرمنگنات حساسیت بیشتری به مدیریت قرق نسبت به اشکال دیگر کربن داشته و شاخص‏های مناسبتری برای بررسی تأثیر مدیریت قرق بر کیفیت کربن آلی اضافه شده به خاک می‏باشند. همچنین، بر اساس شاخص نسبت طبقه‏بندی کربن نسبت به اشکال مختلف کربن آلی در این مطالعه، مدیریت قرق یکی از اقدامات مدیریتی مناسب و کارآمد بوده و باعث بهبود کیفیت خاک گردیده است؛ از این رو ضروری به نظر می‏رسد که تیمار قرق به‏عنوان یکی از برنامه‏های اصلی در طرح‏های منابع طبیعی تجدید شونده مد نظر قرار گیرد. در کل نتایج این مطالعه حاکی از اثرات نامطلوب چرای مراتع بر کیفیت مواد آلی خاک است که می‏تواند در درازمدت پایداری تولید در اکوسیستم‏های مرتعی را به خطر بیندازد.

کلیدواژه‌ها


عنوان مقاله [English]

Effects of Grazing on Different Forms of Organic Carbon in Peneti Plain of Izeh Area in Khuzestan Province

نویسندگان [English]

  • Alireza Owji 1
  • Ahmad Landi 2
  • Saeid Hojati 3
1 Phd student, Dept. of Soil Science, Shahid Chamran Univ. of Ahvaz, Iran
2 Shahid Chamran University of Ahvaz
چکیده [English]

Background and objectives: Soil is a key resource that control the cycles of water, biota and geochemicals and the greatest organic matter reservoir. Little information is available about the effects of grazing on different forms of soil organic carbon in Khuzestan Province pastures. Therefore, this study was conducted to evaluate the effects of grazing management on amount and forms of organic carbon in some pasture soils from Peneti Plain of Izeh Area in Khuzestan Province.

Materials and methods: Accordingly, two adjacent pastures with different management (grazing and grazing exclusion) around the Izeh city were selected and then, random soil samples were taken from the surface (0 to 20 cm) and subsurface (20 to 40 cm) in 15 points. After air drying the soil samples and passing them through a 2 mm sieve, physical, chemical properties and forms of organic carbon including total organic carbon (TOC), permanganate-oxidizable carbon (POXC), fine particulate organic carbon (FPOC) and coarse particulate organic carbon (CPOC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) of the soils were measured.

Results: The results showed that grazing management has increased soil organic matter of surface and subsurface soils the values were statistically significant in the surface layers, and increased the amounts of TOC (from 8.33 to 9.53 g kg-1), DOC (from 9.46 to 10.86 g L-1), MBC (from 418.1 to 456.2 mg kg-1), POXC (from 974.25 to 1035.3 mg kg-1), FPOC (from 430.6 to 450.7 mg kg-1) and CPOC (from 680.10 to 701.4 mg kg-1), but despite the increase in organic matter contents of subsurface soils the difference was not statistically significant. The effect of management practices, in order to have a significant effect to lower parts of the soil, it requires a longer period management. Comparing the biomass upon non-grazing (405 gm-2) and grazed (117 gm-2) areas, indicates a good condition of vegetation in the non-grazing and the effectiveness of enclosure in rehabilitation of pastures in the study area.

Conclusion: The results showed that MBC, DOC, and POXC are more sensitive than other forms of organic carbon to grazing management. They are more appropriate indicators for grazing management on organic carbon quality being added to the soil. Also, based on carbon stratification ratio index (CSRI), regarding different forms of organic carbon in the study area, non-grazing was one of the most proper and efficient management practices which improved soil quality. Accordingly, it seems that non-grazing practices should be considered as one of the major programs in renewable natural resources plans. On the other hand, the results indicate adverse effects of grazing on the quality of soil organic matter endangering the long-term sustainable production in pastures.

کلیدواژه‌ها [English]

  • Pasture
  • Grazing management
  • Soil carbon
  • Soil quality
1.An, H., and Li, G.Q. 2015. Effects of grazing on carbon and nitrogen in plants and soils in a
semiarid desert grassland, China. J. Arid Land. 7: 3. 341-349.
2.Anonymous, 2015. Yearbook of meteorological status of Khuzestan province. Iranian
Meteorological Organization, Research Division of Khuzestan Province.
3.Banaii, M.H. 1998. Soil Moisture and Temperature Regimes Map. Soil and Water Research
Institute of Iran. Tehran. (In Persian)
4.Benbi, D.K., Brar, K., Toor, A.S., and Singh, P. 2015. Total and labile pools of soil organic
carbon in cultivated and undisturbed soils in northern India. Geoderma. 237: 149-158.
5.Blair, G.J., Lefroy, R.D.B., and Lisle, L. 1995. Soil carbon fractions based on their degree of
oxidation and the development of a carbon management index for agricultural systems.
Austr. J. Agric. Res. 46: 1459-1466.
6.Brevik, E.C., Cerda, A., Mataix-Solera, J., Pereg, L., Quinton, J.N., Six, J., and Van Oost, K.
2015. The interdisciplinary nature of soil. Soil J. 1: 117-129.
7.Cao, G.M., Tang, Y.H., Mo, W.H., Wang, Y.A., Li, Y.N., and Zhao, X.Q. 2004. Grazing
intensity alters soil respiration in an alpine meadow on the Tibetan Plateau. Soil Biology and
Biochemistry. 36: 237-243.
8.Cao, Y.Z., Wang, X.D., Lu, X.Y., Yan, Y., and Fan, J.H. 2013. Soil organic carbon and
nutrients along an alpine grassland transect across Northern Tibet. J. Moun. Sci. 10: 564-573.
9.Chapman, H.D. 1965. Cation-exchange capacity. P 891-901, In: C.A. Black (Ed.), Methods of
soil analysis - hemical and microbiological properties. Agronomy.
10.Chen, J., Zhou, X., Wang, J., Hruska, T., Shi, W., Cao, J., Zhang, B., Xu, G., Chen, Y., and Luo,
Y. 2016. Grazing exclusion reduced soil respiration but increased its temperature sensitivity in a
Meadow grassland on the Tibetan Plateau. Ecology and Evolution. 6: 3. 675-687.
11.Christensen, B.T. 1992. Physical fractionation of soil organic matter in primary particle size
and density separates. Advances in Soil Science. 20: 1-90.
12.Costa, C., Papatheodorou, E.M., Monokrousos, N., and Stamou, G.P. 2015. Spatial
variability of soil organic C, inorganic N and extractable P in a mediterranean grazed area.
Land Degradation and Development. 26: 103-109.
13.Culman, S.W., Snapp, S.S., Freeman, M.A., Schipanski, M.E., Beniston, J., Lal, R.,
Drinkwater, L.E., Franzluebbers, A.J., Glover, J.D., Grandy, A.S., Lee, J., Six, J., Maul, J.E.,
Mirksy, S.B., Spargo, J.T., and Wander, M.M. 2012. Permanganate oxidizable carbon
reflects a processed soil fraction that is sensitive to management. Soil Sci. Soc. Amer. J.
76: 494-504.
14.Dai, W., and Huang, Y. 2006. Relation of soil organic matter concentration to climate and
altitude in zonal soils of Chin. Catena. 65: 87-94.
15.Dai, E.F., Zhai, R.X., Ge, Q.S., and Wu, X. 2014. Detecting the storage and change on
topsoil organic carbon in grasslands of Inner Mongolia from 1980s to 2010s. Acta
Geographica Sinica. 24: 6. 1035-1046.
16.Eskandari, N., Alizadeh, A., and Mahdavi, F. 2008. Policies of range management in Iran
(Rangeland Technical Office). Pooneh Press.
17.Feng, W.T., Zou, X.M., and Schaefer, D.A. 2009. Above and belowground carbon inputs
affect seasonal variations of soil microbial biomass in a subtropical monsoon forest of
southwest China. Soil Biology and Biochemistry. 41: 978-983.
18.Ferreira, A.O., Amado, T.J.C., Nicoloso, R.S., Sa, J.C.M., Fiorin, J.E., Hansel, D.S.S., and
Menefee, D. 2013. Soil carbon stratification affected by long-term tillage and cropping
systems in southern Brazil. Soil and Tillage Research. 133: 65-74.
19.Franzluebbers, A.J. 2002. Soil organic matter stratification ratio as an indicator of soil
quality. Soil and Tillage Research. 66: 95-106.
20.Franzluebbers, A.J. 2013. Pursuing robust agroecosystem functioning through effective soil
organic carbon management. Carbon. Management. 4: 43-56.
21.Gass, T.M., and Binkley, D. 2011. Soil nutrient losses in an altered ecosystem are associated
with native ungulate grazing. J. Appl. Ecol. 48: 952-960.
22.Gee, G.W., and Bauder, J.W. 1986. Particle size analysis. P 383-411, In: A. Klute (Ed.),
Methods of soil analysis, Part 1. American Society of Agronomy. Inc. Madison, WI, USA.
23.Ghani, A., Dexter, M., and Perrott, K.W. 2003. Hot-water extractable carbon in soils: a
sensitive measurement for determining impacts of fertilization, grazing and cultivation.
Soil Biology and Biochemistry. 35: 1231-1243.
24.Graham, M.H., Haynes, R.J., and Meyer, J.H. 2002. Changes in soil chemistry and aggregate
stability induced by fertilizer applications, burning and trash retention on a long-term
sugarcane experiment in South Africa. Europ. J. Soil Sci. 53: 4. 589-598.
25.Gregorich, E.G., Beare, M.H., McKim, U.F., and Skjemstad, J.O. 2006. Chemical and
biological characteristics of physically uncomplexed organic matter. Soil Sci. Soc. Amer. J.
70: 975-985.
26.Haynes, R.J. 2005. Labile organic matter fractions as central components of the quality of
agricultural soils: An overview. Advances in Agronomy. 85: 221-268.
27.He, N., Wu, L., Wang, Y., and Han, X. 2009. Changes in carbon and nitrogen in soil particlesize fractions along a grassland restoration chrono sequence in northern China. Geoderma.
150: 302-308.
28.Heidarian Aghakhani, M., Naghipour Borj, A.A., and Nasri, M. 2010. The effect of grazing
on vegetation and soil chemical properties Sisab rangelands, Bojnord, Iran. Quarterly
Renewable Natural Resources Research. First year, Second Issue. Pp: 14-27. (In Persian)
29.Kalambukattu, J.G., Singh, R., Patra, A.K., and Arunkumar, K. 2013. Soil carbon pools and
carbon management index under different land use systems in the central Himalayan region.
Acta Agriculturae Scandinavica, Section B, Soil and Plant Science. 63: 3. 200-205.
30.Landi, L., Renella, G., Moreno, J.L., Falchini, L., and Nannipieri, P. 2000. Influence of
cadmium on the metabolic quotient, L:D-glutamic acid respiration ratio and enzyme activity:
microbial biomass ratio under laboratory conditions. Biology and Fertility of Soils. 32: 1. 8-16.
31.Li, X., Zhang, C., Fu, Z., Guo, D., Song, X., Wan, C., and Ren, J. 2013. Grazing exclusion
alters soil microbial respiration, root respiration and the soil carbon balance in grasslands of
the Loess Plateau, northern China. Soil Science and Plant Nutrition. 59: 877-887.
32.Lorenz, K., Lal, R., and Shipitalo, M.J. 2008. Chemical stabilization of organic carbon
pools in particle size fractions in no-till and meadow soils. Biology and Fertility of Soils.
44: 1043-1051.
33.Marschner, B., and Kalbitz, K. 2003. Controls on bioavailability and biodegradability of
dissolved organic matter in soils. Geoderma. 113: 211-235.
34.Mctiernan, K.B., Jarvis, S.C., Scholefield, D., and Hayes, M.H.B. 2001. Dissolved organic
carbon losses from grazed grasslands under different management regimes. Water Research.
35: 10. 2565-2569.
35.Mirsky, S.B., Lanyon, L.E., and Needelman, B.A. 2008. Evaluating soil management
using particulate and chemically labile soil organic matter fractions. Soil Sci. Soc. Amer. J.
72: 1. 180-185.
36.Mofidi, M., Jafari, M., Tavili, A., Rashtbari, M., and Alijanpour, A. 2013. Grazing exclusion
effect on soil and vegetation properties in Imam Kandi Rangelands, Iran. Arid Land
Research and Management. 27: 32-40.
37.Mohammadi, H., and Tahmasebi, H. 2000. Range management plan in Penty area of Ize city.
Department of Natural Resources Khuzestan Province. (In Persian)
38.Neff, J.C., Reynolds, R.L., Belnap, J., and Lamothe, P. 2005. Multi-decadal impacts of
grazing on soil physical and biogeochemical properties in southeast Utah. Ecological
Applications. 15: 87-95.
39.Nelson, D.W., and Sommers, L.E. 1982. Total carbon, organic carbon and organic matter.
P 539-579, In: A.L. Page (Ed.), Methods of Soil Analysis, SSSA, Madison, WI, USA.
40.Rasse, D.P., Rumpel, C., and Dignac, M.F. 2005. Is soil carbon mostly root carbon?
Mechanisms for a specific stabilization. Plant and Soil. 269: 341-356.
41.Rhoades, J.D. 1996. Salinity: Electrical conductivity and total dissolved soils. P 417-435,
In: D.L. Sparks (Ed.), Methods of Soil Analysis, Part 3: Chemical Methods, SSSA Book
Series Number 5. Soil Science Society of America. Madison, WI.
42.Raiesi, F., and Asadi, E. 2006. Soil microbial activity and litter turnover in native grazed and
ungrazed rangelands in a semiarid ecosystem. Biology and Fertility of Soils. 43: 76-82.
43.Raiesi, F., and Riahi, M. 2014. The influence of grazing exclosure on soil C stocks and
dynamics and ecological indicators in upland arid and semi-arid rangelands. Ecological
Indicators. 41: 145-154.
44.Rui, X., and Xiuqin, W. 2016. Effects of grazing intensity on soil organic carbon of rangelands
in Xilin Gol League, Inner Mongolia, China. J. Geograph. Sci. 26: 11. 1550-1560.
45.Shahriari Geraei, D., Hojati, S., Landi, A., and Faz Cano, A. 2016. Total and labile forms of
soil organic carbon as affected by land use change in southwestern Iran. Geoderma. Reg.
7: 29-37.
46.Silva, F.D., Carneiro Amado, T.J., Ferreira, A.O., Assmann, J.M., Anghinoni, I., and Faccio
Carvalho, P.C. 2014. Soil carbon indices as affected by 10 years of integrated crop-livestock
production with different pasture grazing intensities in Southern Brazil. Agriculture,
Ecosystems and Environment. 190: 60-69.
47.Su, Y.Z., Zhao, H.L., Zhang, T.H., and Zhao, X.Y. 2004. Soil properties following
cultivation and non-greazing of semi-arid sandy grassland in northern china. Soil and Tillage
Research. 75: 27-36.
48.Steffens, M., Kolbl, A., and Knabner, I.K. 2009. Alteration of soil organic matter pools and
aggregation in semi-arid steppe topsoils as driven by organic matter input. Europ. J. Soil Sci.
60: 198-212.
49.Stevenson, F.J. 1994. Humus Chemistry-Genesis, Composition, Reactions. 2nd ed., Wiley,
New York.
50.Tarhouni, M., Ben Hmida, W., and Neffati, M. 2015. Long-term changes in plant life forms
as a consequence of grazing exclusion under arid climatic conditions. Land Degradation and
Development. 20: 214-216.
51.Thomas, G.W. 1996. Soil pH and soil acidity. P 475-490, In: D.L. Sparks (Ed.), Methods of
Soil Analysis, Part 3: Chemical Methods., SSSA Book Series Number 5, Soil Science
Society of America. Madison, WI.
52.Thompson, T.L., Zaady, E., Huancheng, P., Wilson, T.B., and Martens, D.A. 2006.
Soil C and N pools in patchy shrublands of the Negev and Chihuahuan Deserts. Soil Biology
and Biochemistry. 38: 1943-1955.
53.Vance, E.D., Brookes, P.C., and Jenkinson, D.S. 1987. An extraction method for measuring
soil microbial biomass C. Soil Biology and Biochemistry. 19: 703-707.
54.Vig, K., Megharaj, M., Sthunathan, N., and Naidu, R. 2003. Bioavailability and toxicity of
cadmium to microorganisms and their activities in soil: a review. Advances in
Environmental Research. 8: 121-135.
55.Walkley, A., and Black, I.A. 1934. An examination of the Degtjareff method for determining
soil organic matter and a proposed modification of the chromic acid titration method.
Soil Science. 63: 251-263.
56.Wei, J.B., Xiao, D.N., Zeng, H., and Fu, Y.K. 2008. Spatial variability of soil properties in
relation to land use and topography in a typical small watershed of the black soil region,
northeastern China. Environmental Geology. 53: 1663-1672.
57.Xu, M., Lou, Y., Sun, X., Wang, W., Baniyamuddin, M., and Zhao, K. 2011. Soil organic
carbon active fractions as early indicators for total carbon change under straw incorporation.
Biology and Fertility of Soils. 47: 745-752.