تنوع زیستی حشرات در بوم‌نظام‌های زراعی ارگانیک و رایج گندم (Triticum aestivum L.) و سیب‌زمینی (Solanum tuberosum L.) در منطقه فریمان

نوع مقاله : علمی - پژوهشی

نویسندگان

1 گروه اگروتکنولوژی، دانشکده کشاورزی،دانشگاه فردوسی مشهد، مشهد، ایران.

2 گروه اقتصاد کشاورزی، دانشکده کشاورزی،دانشگاه فردوسی مشهد، مشهد، ایران.

چکیده

حفظ و افزایش تنوع زیستی حشرات در بوم­نظام­های ارگانیک به­عنوان یکی از مهمترین مؤلفه­های اصلی در کنترل آفات بدون کاربرد سموم شیمیایی مطرح بوده و نقش بسزایی در کاهش آلودگی­های زیست­محیطی و رسیدن به پایداری در کشاورزی دارد. هدف از انجام این مطالعه بررسی تنوع زیستی حشرات در دو بوم­نظام رایج و ارگانیک گندم (Triticum aestivum L.) و سیب­زمینی (Solanum tuberosum L.) در مزارع شهرستان فریمان بود. برای این منظور تحقیقی در سال زراعی91-1390 در مزارع گندم و سیب­زمینی رایج و ارگانیک این شهرستان انجام گرفت. نمونه­برداری از سطح مزارع رایج و ارگانیک در طول فصل رشد و در سه زمان مختلف (در سیب زمینی 45، 75 و 105 روز پس از کاشت و در گندم 200، 225 و 255 روز پس از کاشت) انجام گرفت. تعداد حشره در هر خانواده حشرات شناسایی شد. شاخص­های مورد بررسی در دو بوم­نظام رایج و ارگانیک شامل شاخص­های تنوع شانون- ویور، سیمپسون و مارگالف، ضرایب یکنواختی پیلو و سیمپسون، غنای گونه­ای و همچنین تنوع آلفا و بتا بودند. نتایج آزمایش نشان داد که مزرعه ارگانیک گندم نسبت به مزرعه رایج از غنای گونه­ای بیشتری برخوردار بود که در مجموع، 41 خانواده برای کشت ارگانیک و 34 خانواده در کشت رایج گندم جمع­آوری شد. تنوع آلفا در کشت رایج گندم بیشتر از کشت ارگانیک بود، در صورتی­که از لحاظ تنوع بتا کشت ارگانیک نسبت به رایج برتری داشت. در گیاه سیب­زمینی غنای گونه­ای در کشت رایج بیشتر از ارگانیک بود که برای دو بوم نظام رایج و ارگانیک به ترتیب 22 و 18 خانواده مختلف از حشرات به دام افتادند. میزان تنوع آلفا و بتا نیز در کشت رایج سیب­زمینی در مقایسه با کشت ارگانیک آن بالاتر بود. کمتر بودن تنوع گیاهی کمتر اطراف مزارع به عنوان زیستگاه حشرات را می­توان دلیل اصلی کاهش تنوع زیستی حشرات در بوم­نظام ارگانیک سیب­زمینی عنوان کرد. اختلاف معنی­داری نیز بین دو بوم­نظام رایج و ارگانیک گندم و سیب­زمینی از لحاظ شاخص­های تنوع و ضرایب یکنواختی مورد بررسی مشاهده نشد.

کلیدواژه‌ها


عنوان مقاله [English]

Insect’s Biodiversity in Conventional and Organic Agro-ecosystems for Wheat (Triticum aestivum L.) and Potato (Solanum tuberosum) in Fariman Region

نویسندگان [English]

  • Mansoreh Mahloji Rad 1
  • Parviz Rezvani Moghaddam 1
  • Mehdi Parsa 1
  • Ghorbanali Asadi 1
  • Naser Shahnoshi 2
1 Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad,Iran
2 Department of Agricultural Economy, Faculty of Agriculture, Ferdowsi University of Mashhad,Mashhad, Iran
چکیده [English]

Introduction
One of the main objectives of organic agriculture is low negative effect on the environment and according to this issue, maintaining biodiversity is one of the key responsibilities of this agriculture system. Disuse of chemical fertilizers and using mechanization with less intensity caused significant increase in biodiversity in organic agriculture. Insect's diversity can help in biological control of pests, pollination and biological control of weeds and diseases. This study was performed based on the key role of insects in ecosystem function, especially in organic agro-ecosystems and effective factors for biodiversity of them and also with respect to the high potential for progressing of organic agriculture in Iran. The purpose of the study was to identify different families of insects in conventional and organic fields for wheat and potato crops in Fariman city.
Material and Methods
The study was carried out in wheat and potato fields at Fariman city in 2012. In order to collect insects, we used a sweet net with a diameter of 50 cm in 10 different regions of the fields. Sampling was performed after 45, 75 and 105 days after planting. Sampling was conducted which it covers total farm area. Shannon-weaver index, Simpsons reciprocal and Margalef indexes were used to calculate the insect’s biodiversity and Pielou and Simpson were used to calculate the species evenness. Relative frequency (pi) was used to determination of dominant species in each agro-ecosystem and the species with the highest relative frequency was considered as dominant species. In order to compare the alpha and beta diversity between two organic and conventional systems, we fitted the power function for species richness as a dependent variable and sampling number as an independent variable.
Results and Discussion
The results of the wheat farm showed that the total number of collected insects’ families during the growing season in the organic farm was higher than the conventional farm (2047 number of insects from 41 families vs. 1928 from 34 families, respectively). From total families, 32 families were the same in both organic and conventional wheat systems and 9 families were collected from the only organic farm. Two families were observed only on the conventional farm. Species richness was the same in both organic and conventional at first stage of sampling, but in the organic system, it was higher at the second and third stage of sampling. Insects’ diversity in the conventional farm was higher than organic based on obtained values for alpha diversity. Calculated beta diversity in the organic system was higher than conventional. In fact, beta diversity is the increasing rate of the species richness per increasing of sampling number and the high value of beta diversity in the organic system indicates that species richness and biodiversity of the organic system were higher than conventional at total farm area. In potato organic and conventional farms, 435 insects (from 18 families) and 787 insects (from 22 families) were collected, respectively. From total trapped families, 15 families were the same in both organic and conventional systems, 7 families only were in conventional farm and three families observed only in the organic farm. Therefore, species diversity in conventional system was higher in comparison with the organic system in the potato crop. Two families were introduced as dominant species in the organic farm with a relative frequency of 17% and 15.6%, respectively and Miridae family was dominant species in the conventional farm as 27.8% of relative frequency. Alpha diversity in conventional system was higher than organic. Beta diversity in conventional system was higher in 45 and 75 days after planting, but it was lower in 105 days after planting than organic. In total, the results showed that alpha and beta diversity were higher in conventional than organic. It seems that the reason for higher biodiversity in conventional compared to organic was related to failure to comply with the organic principles in potato farm.
Conclusion
It can be concluded that the move towards organic agriculture, in addition to preserving and enhancing biodiversity in agricultural ecosystems, has led to a reduction in using chemical pesticides and, as a result, the reduction of environmental pollution will be followed by the sustainability of agricultural production.

کلیدواژه‌ها [English]

  • Species richness
  • Alpha diversity
  • Beta diversity
  • Diversity index
Alichi, M., and Minaei, K. 2002. Study on distribution of the beetles belonging to the family Carabidae in Shiraz region. 15th Iranian Plant Protection Congress, Razi University of Kermanshah. Iran7-11 September 2002, p. 175. (In Persian with English Summary)
Altieri, M.A. 1999. The ecological role of biodiversity in agroecosystems. Agriculture, Ecosystems and Environment 74: 19–31.
Armstrong, G. 1995. Carabid beetle (Coleoptera: Carabidae) diversity and abundance in organic potatoes and conventionally grown seed potatoes in the north of Scotland. Pedobiologia 39: 231-237.
Borrer, D.J., Teriplehorn, C.A., and Johnson N.F. 1998. An Introduction to the Study of Insects.7ed. Peter Marshal, Philadelphia.
Clark, M.S. 1999. Ground beetle abundance and community composition in conventional and organic tomato systems of California's Central Valley. Applied Soil Ecology 11: 199-206.
Clark, M.S. 1999. Ground beetles abundance and community composition in conventional and organic tomato systems of California’s central valley. Applied Soil Ecology 11: 199-206.
Clough, Y., Holzschuh, A., Gabriel, D., Purtauf, T., Kleijn, D., Kruess, A., Steffan-Dewenter, I., and Tscharntke T. 2007. Alpha and beta diversity of arthropods and plants in organically and conventionally managed wheat fields. Journal of Applied Ecology 44: 804-812.
Gabrie, D., Roschewitz, I., Tscharntke, T., and Thies, C. 2006. Beta diversity at different spatial scales: plant communities in organic and conventional agriculture. Ecological Applications 16(5): 2011–2021.
Gonnarsson, C., and Hansson, P.A. 2004. Optimization of field machinery for an arable farm converting to organic farming. Agricultural Systems 80: 85-103.
Kevan, P.G.1999. Crabid beetles in sustainable agriculture: A review on the pest control efficacy, cultivation impacts and enhancement. Agriculture, Ecosystem and Environment 74: 187-228.
Khodashenas, A.R. 2008. Investigation of structural biodiversity in winter wheat fields of Khorasan province. PhD dissertation, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. (In Persian with English Summary).
Mahmoudi, H., Mahdavi Damghani, A., and Liaghati, H. 2008. An Introduction to Organic Agriculture. Jihad Daneshgahi Publication Limited, Mashhad, Iran. (In Persian)
May, R.M. 1975. Patterns of species abundance and diversity. PP. 81–120. In: Cody, M.L. and J.M. Diamond (Eds). Ecology and Evolution of Communities. The Belknap Press of Harvard University Press, Cambridge, UK.
Menalled, F., Liebman, M., and Renner, K. 2006. The ecology of weed seed predation in herbaceous crop systems. In: Batish, D. (Ed.), Handbook of Sustainable Weed Management. The Haworth Press, Inc., Binghamton, NY.
Menalled, F.,Smith, R.G., Dauer, J.T., and Fox, T.B. 2007. Impact of agricultural management on carabid communities and weed seed predation. Agriculture, Ecosystems and Environment 118: 49–54.
Pfiffner, L., and Niggli, U. 1996. Effects of bio-dynamic, organic and conventional farming on ground beetles (Col. Carabidae) and other epigaeic arthropods in winter wheat. Biological Agriculture and Horticulture 12: 353-364.
Pielou, E.C. 1969. An Introduction to Mathematical Ecology. Wiley/ Inter science, New York, NY, USA.
Price, P.W. 1997. Insect ecology. 3th ed. 888 pp. John Wiley Publication, New York.
Rezaye- Nodeh, M., Afshari, A., Yazdanian, M., and Assadeh, G.H. 2011. Biodiversity of carabidae beetles (Cloeoptera: Carabidae) in agroecosystems of Azad shahr region, Golestan province, Northern Iran. Journal of Agroecology 3(3): 347-357. (In Persian with English Summary)
Sandhu, H.S., Wratten, S., and Cullen, R. 2010. The role of supporting ecosystem services in conventional and organic arable farmland. Ecological Complexity 7: 302-310.
Scialabba, N. 2000. Opportunities and constraints of organic agriculture, A Sociological analysis. Rome: FAO. Available at http:// www.fao.org/ organicag (May 20, 2008).
Shah, P.A., Brooks, D.R., Ashby, J.E., Perry, J.N., and Woiwod, I.P. 2003. Diversity and abundance of the coleopteran fauna from organic and conventional management systems in southern England. Agriculture and Forest Entomology 5(1): 51-60.
Sullivan, C.M., and Gormally, M.J. 2002. A Comparison of Ground Beetle (Carabidae: Coleoptera) Communities in an Organic and Conventional Potato Crop. Biological Agriculture and Horticulture 20: 99-110.
Waite, S. 2000. Statistical ecology in practice. 1st ed. 414 pp. Prentice Hall Publishing.
Whittaker, R.H. 1972. Evaluation and measurement of species diversity. Taxon 21: 213–251.
CAPTCHA Image