تأثیر شوری آب آبیاری بر میزان رشد و زنده‌مانی کرم خاکی (E. fetida)

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشیار گروه علوم خاک، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران

2 دانش آموخته دکتری گروه علوم خاک، دانشکده کشاورزی، دانشگاه بوعلی سینا، همدان، ایران

چکیده

به منظور بررسی تأثیر شوری آب آبیاری بر میزان رشد و زنده‌مانی کرم خاکی گونه Eisenia fetida، آزمایشی در قالب طرح کاملاً تصادفی در 3 تکرار در آزمایشگاه شیمی علوم خاک دانشکده کشاورزی دانشگاه بوعلی سینا همدان اجرا شد. انواع مختلف آب بکار برده شده در این پژوهش شامل: آب مقطر و آب‌های شور تهیه شده با نمک NaCl با هدایت الکتریکی(EC)  6،4،2 و8 دسی­زیمنس بر متر بود. آزمایش در ظروف پلاستیکی با بستر کود دامی که در یک محفظه اقلیمی با 16 ساعت نور و 8 ساعت تاریکی در دمای 25 درجه سانتی­گراد بمدت 42 روز نگه داری شدند انجام شد. درصد زنده ماندن و تغییر وزن کرم­های خاکی در طی 3 و 15، 21، 33، 27، 39، 42 روز بعد از قرار دادن کرم­های خاکی در ظروف پلاستیکی تعیین شد. نتایج تجزیه واریانس نشان داد که سطوح مختلف شوری با گذشت زمان بر درصد زنده ماندن و تغییر وزن کرم­های خاکی، تأثیر معنی­داری در سطح احتمال یک درصد داشته است. با افزایش میزان شوری، درصد زنده ماندن کرم­های خاکی کاهش یافت، بطوری‌که بیشترین کاهش در طی 42 روز در تیمار EC8 (آبیاری با آبی با EC 8 دسی­زیمنس بر متر) به میزان 32/8 درصد مشاهده شد. همچنین، با گذشت زمان تغییرات وزن کرم­های خاکی با افزایش شوری آب آبیاری بیشتر مشهود بود، بطوری‌که کاربرد آب باEC  8 دسی­زیمنس بر متر در طی 15روز موجب کاهش وزن کرم­های خاکی به میزان 73/12 درصد گردید درحالی‌که همین میزان شوری در پایان 42 روز، موجب کاهش وزن کرم­های خاکی به میزان 67/67 درصد شده است. میزان LC50 برای مرگ و میر بعد از 27و 42 روز به ترتیب 5/7 و 31/4 دسی­زیمنس بر متر و میزان EC50 برای رشد به ترتیب 94/7 و 82/6 دسی­زیمنس بر متر  بدست آمد.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Salinity on Growth and Survival of Earthworm Eisenia fetida

نویسندگان [English]

  • Gh. Rahimi 1
  • F. Karimi 2
1 Associate Professor Department of Soil Sciences, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
2 Ph.D. Graduate of Soil Science, Department of Soil Sciences, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran
چکیده [English]

Introduction: Salinization of soil has been reported as a problem in many parts of the world. Salinization could occur either as a result of natural processes e.g. high concentrations of salt in parent materials or groundwater and/or anthropogenic actions such as over-irrigation. The salinization probably affects the chemical and physical properties of soil, soil microbiological processes, plant growth, and soil fauna. Both quantity and quality of water, however, are the most important eco-factors needed for earthworm survival and development, and also biodegradation processes.
Materials and Methods: In order to investigate the effect of irrigation water salinity on the survival and growth of earthworm Eisenia Fetida, an experiment was conducted in a completely randomized design with three replications under environmental conditions of the laboratory of Soil Sciences Department of Bu-Ali Sina University in Hamedan. The different types of water used in this study were: distilled water and saline water made with NaCl salt with electrical conductivity (EC) of 2, 4, 6, and 8 dS m-1. The experiment was carried out using completely randomized design in plastic containers of size 19 × 13 × 8 cm. Ten earthworms per container used in each exposure regime were introduced into the relevant test salinity by placing them on the surface and allowing them to burrow in. The test containers were covered with perforated lids to limit water loss due to evaporation and kept in 16 hours light, 8 hours dark at 25°C in a climate chamber for 42 days. Sampling was done at 3, 15, 21, 27, 33, 39, and 42 days after earthworms were introduced to the substrates to investigate mortality and weight changes of earthworms. The LC50 (concentration at which 50% of the earthworms are killed) and the EC50 (effect concentration at which a 50% reduction in a measured parameter) values for the salts expressed as conductivity (dS m-1) were calculated on day 27 and 42 by using the Probit Analysis.
Results and Discussion: On day 3, no significant effect of salinity on percentages of survival was found.  The survival rate of Eisenia fetida was significantly affected in the EC range used during 42 days (Table 2). The irrigation with distilled water (EC0) had the highest survival rate while the irrigation water with EC 8 dS m-1 had the lowest value. During the 39 days of exposure, no significant difference was found in survival rate of earthworms between EC 2, EC 4 and EC 6 dS m-1, but at the end of day 42, the salinity levels with EC 8 dS m-1 had a significant effect on percentage of earthworm survival in which 91.68% mortality occurred. The mean weight change of earthworms exposed to water with EC 2 dS m-1 was not significantly different (p < /em> < 0.01) from those exposed to the distilled water during 39 days, but there was a decrease in earthworm weight on day 42. The calculated LC50 for mortality after 27 and 42 days was 7.5 and 4.31 dS m-1, respectively, and EC50 for growth was 7.94 and 6.82 dS m-1, respectively.
Conclusion: Our results showed that increased salinity had harmful effects on the growth and mortality of the earthworms (Eisenia fetida). Salinity can have detrimental effects on earthworms at concentrations considered safe for many plant species. We determined 42 day LC50 for mortality 4.31 dS m-1 (2521 mg lit-1). The EC50 for growth was 6.82 dS dS m-1 (3989 mg lit-1). The weight of earthworms was significantly affected by NaCl and dispersion analysis showed that NaCl concentration had a statistically significant influence on the weight of earthworms. The argument for using NaCl is that it is the predominant salt in most saline environments particularly in wastewaters. Since the salt type is dependent on the source of the contamination, it is, therefore, possible that other salts apart from NaCl could be the main compounds in saline toxicity in a specific area. The results of the current study suggest that the effects of salinity depend on the salt composition. Therefore, it would be important to assess the type of salt ions in soil in risk assessment, as this affects the extent of toxicity to soil organisms.

کلیدواژه‌ها [English]

  • Earthworm
  • Electrical conductivity
  • Survival
1- Boyer J., Micellon R., Chabanne A., Reversat G., and Tiber R. 1991. Effect of terfoli cover crop and earthworm inoculation on maize crop and soil organisms in Reunion Island. Biology and Fertility of Soils 2: 364–370.
2- Carley W.W., Caracciolo E.A., and Mason R.T. 1983. Cell and coelomic fluid volume regulation in the earthworm Lumbricus terrestris. Comparative Biochemistry and Physiology 74: 569-575.
3- Chaudhari P.S., Pal T.K., Battacharjee G., and Dey S.K. 2001. Suitability of rubber leaf liter as substrate for epigiec earthworms,  Perionyx excavatus,  Eudrilus eugeniaeand Eiseniafetia. In: Proc. VII Nation. Symp. Soil Biology and Ecology, Bangalore. November pp. 7-9.
4- Dayananda K., Giraddi R.S., and Gali S.K. 2008. Effect of Salt and Sewage Wateron the Survival and Reproduction of Three Earthworm Species used in Vermicomposting. Karnataka Journal of Agricultural Sciences 21(1): 52-54.
5- Ficher E., and Molnar L. 1997. Growth and reproduction of Eisenia fetida (Oligochaeta, Lumbricidae) in seminatural soil containing various metal chlorides. Soil Biology and Biochemistry 29: 667-670.
6- Finney D.J. 1952. Probit Analysis. Cambridge, England, Cambridge University Press.
7- Ghabbour S.I. 1966. Earthworms in agriculture: a modern evaluation. Rev. Ecol. Biol. Soc 3(2): 259-271.
8- Guzyte G., Sujetoiene G., and Zaltauskaite J. 2011. Effects of salinity on earthworm (Eisenia fetida), The 8th International Conference May 19 –20, Vilnius, Lithuania.
9- Hartenstein R., Neuhauser E., and Collier J. 1980. Accumulation of Heavy Metals in the Earthworm Eisenia foetida. Journal of Environmental Quality 9(1): 23-26.
10- Helling B., Reinecke S.A., and Reinecke A.J. 2000. Effects of the fungicide copper oxychloride on the growth and reproduction of Eisenia fetida (Oligochaeta). Ecotoxicology and Environmental. Safety 46: 108-116.
11- Kadukova J., and Kalogerakis N. 2007. Lead accumulation from non-saline and saline environment by Tamarix smyrnensis Bunge. European Journal of Soil Biology 43: 216–223.
12- Lippi D., De Paolis M.R., Di Mattia E., Grego S., Pietrosanti T., and Cacciari I. 2000. Effect of salinity on growth and starvation-survival of a tropical Rhizobium strain. Biology and Fertility of Soils 30: 276–283.
13- Miller J.J., Beasley B.W., Larney F.J., and Olson B.M. 2005. Soil salinity and sodicity after application of fresh and composted manure with straw or wood-chips. Canadian Joutnal of Soil Science. 85: 427–438.
14- McLean M.A., Migge-Kleian E.S., and Parkinson E.D. 2006. Earthworm invasions of ecosystems devoid of earthworms effects on soil microbes. Biology Invasions 8: 1257–1273.
15- OECD/OCDE, (1984)ʽOECD guideline for the testing of chemicalsʼ, Earthworm Acute Toxicity Tests".
16- Olson B.M., McKenzie R.H., Bennett D.R., Ormann T., and Atkins R.P. 2003. Manure application effects on soil and groundwater quality under irrigation in southern Alberta. Alberta Agriculture, Food and Rural Development, Lethbridge, AB. 377.
17- Owojori O.J., Reinecke A.J., and Rozanov A.B. 2008. Effects of salinity on partitioning, uptake and toxicity of zinc in the earthworm Eisenia fetida. Soil Biology and Biochemistry 40: 2385–2393.
18- Owojori O.J., Reinecke A.J., Voua-Otomo P., and Reinecke S.A. 2009. Comparative study of the effects of salinity on life-cycle parameters of four soil-dwelling species (Folsomia candida, Enchytraeus doerjesi, Eisenia fetida and Aporrectodea caliginosa). Pedobiologia 52: 351-360.
19- Owojori O.J., and Reinecke A.J. 2014. Differences in ionic properties of salts affect saline toxicity to the earthworm Eisenia fetida. Applied Soil Ecology 83: 247–252.
20- Pawar R.B. 1996. Dynamics of earthworm-soil-relationship in semiarid tropics. Ph.D. Thesis, University of Agricultural Sciences, Dharwad (India).
21- Peinemann N., Guggenberger G., and Zech W. 2005. Soil organic matter and its lignin component in surface horizons of salt-affected soils of the Argentinean Pampa. Catena 60: 113-128.
22- Pereira C.S., Lopes L., Sousa J.P., and Chelinho S. 2015. Effects of NaCl and seawater induced salinity on survival and reproduction of three soil invertebrate species, Chemosphere 135: 116–122.
23- Ramoliya P.J., Patel H.M., and Pandey A.N. 2004. Effect of salinisation of soil on growth and macro- and micro-nutrient accumulation in seedlings of Acacia catechu (Mimosaceae). Annals of Applied Biology 144: 321–332.
24- Rietz D.N., and Haynes R.J. 2003. Effects of irrigation-induced salinity and sodicity on soil microbial activity. Soil Biology and Biochemistry 35: 845–854.
25- Sardinha M., Mullers T., Schmeisky H., and Joergensen R.G 2003. Microbial performance in soils along a salinity gradient under acidic conditions. Applied Soil Ecology 23: 237-244.
26- Schaefer M. 2005. The landfile of TBT contaminated harbour sludge on rinsing fildes– A hazard for the soil fauna Risk assessment with earthworms. Water, Air, and Soil Pollutoin 165: 265-278.
27- Scott-fordsmand J.J., Stevens D.P., and Mclaughlin M.J. 2002. The combined stress of soil salinity and zinc on Eisenia fetida. SETAC Europe 12th Annual meeting, 226.
28- Shirani H., Abolhasani Zrraatkar M., Lakzian A., and Akhgar A. 2011. Decomposition rate of municipal wastes compost, vermi compost, manure and Pistaco compost in different soil texture and salinity in laboratory condition. Journal Water and Soil 25(1): 84-93. (In Persian with English abstract)
29-Sumner M.E. 1995. Sodic soils: new perspectives. In: Naidu, R., Sumner, M.E., Rengasamy, P. (Eds.), Australian Sodic Soils: Distribution Properties and Management. CSIRO, Melbourne, 1–34.
30- Suthar S., Singh S., and Dhawan S. 2008. Earthworms as bioindicator of metals (Zn, Fe, Mn, Cu, Pb and Cd) in soils: is metal bioaccumulation affected by their ecological category. Ecological Engineering 32(2): 99-107.
31-Yuan B., Li Z., Liu H., Gao M., and Zhang Y. 2007. Microbial biomass and activity in salt affected soils under arid conditions. Applied Soil Ecology 35: 319–332.
32- Zhang S.J., Chao Y., Zhang C.L., Cheng J., Li J., and Ma N. 2010. Earthworms enhanced winter oilseed rape (Brassica napus L.) growth and nitrogen uptake. Agriculture, Ecosystems and Environment 139(4): 463-468.