ISSN 0375-1511 Rec. zool. Surv. India: 113(Part-4): 213-227,2013 REPORT ON THE SOIL FAUNA OF BHADRAK AND BALASORE DISTRICT, ORISSA RiNKU GoswAMi, MAYA GHOSH AND DEBDULAL SAHA Zoological Survey of India, M-Block, New Alipore, Kolkata-700053 INTRODUCTION In this study, the assessment of soil fauna in Soil is one of the basic natural resoiirces that the study areas aimed at obtaining a general supports life on Earth. It is a huge ecosystem, overview of soil fauna in the ecosystems of the which is the habitat to several living organisms. region. Perusal of published literature shows no Historically, most of the efforts on biodiversity such systematic study was conducted in these studies focused, especially on aboveground plant areas of our study zone previously. and animal species (Wardle, 2006). However, it is Soil Fauna and their Function in Soil well recognized that in most terrestrial There are many animal groups inhabiting soil ecosystems, the belowground biota supports system. It has been reported that of the total much greater diversity of organisms than does the nirmber of described species on Earth (~1,500,000), aboveground biota, because soils are the central as many as 23 per cent are soil animals (Decaens et. organising entities in terrestrial ecosystems al., 2006). Estimated nirmbers of soil species include (Coleman, and Whitman, 2005). Soil fauna is a 30,000 bacteria; 1,500,000 fungi; 60,000 algae; 10,000 highly diverse group of organisms living within protozoa; 500,000 nematodes; and 3,000 the soil and make soil alive by their activity. They earthworms (Pankhurst, 1997). The represent most classes and orders and are interdependence of soil biological fertility with extremely abundant and species rich (Anderson, physical and chemical characteristics of soil is 1977). They are determining factor in soil established. Among invertebrate soil animals, formation and influence all the properties of soil, nematodes, annelids (mainly earthworms) and including fertility and quality. They play arthropods represent the most numerous and important role in supporting plant comm^unities diversified groups. Among all the groups of soil on the earth surface. One of the major activity of fauna, arthropods constitute the greatest number soil fauna is decom^position and cycling of organic and diversity of soil inhabiting species. Most soil matter in soU. Soil fauna communities, including animals occur in the top 30 cm of soU, although soil inhabiting invertebrates, are known to some also occur at depth. In most environments, improve soil structure by decreasing bulk density, the most abundant soU dwellers are coUembolan increasing soil pore space, soil horizon mixing, (springtaUs) and mites, (Andre et al. 1994, Coleman, increased aeration and drainage, increased water and Crossley 1996) though ants and termites holding capacity, litter decomposition and predominate in certain situations, especiaUy in improving soil aggregate structure (Abbott, desert and tropical soUs. Significant effects of soU 1989). They act as bioindicators of soil health. fauna on soU structure are achieved mainly by three Identifying, cotmting of soU fauna and associated most important groups which are earthworms, abiotic factors can help to assess the functioning of termites and ants (Lee and Foster, 1991). the soil ecosystem indicating soil fatma diversity. 214 Rec. zool. Surv. India Soil organisms perform vital functioiis in the naturally divided into two well-designed tracks. soil to a varying degree depending on the system. 1. The salt tracks along the coasts which is not Soil organisms make up the diversity of life in arable and 2. The arable track, which is called the the soil. They play an important role in the granary of the state. decomposition and cycling of organic matter The climate of this district is generally hot and (OM) in soil systems. Insects, earthworms, and high humid. Max. & min. temperatures are other arthropods chum the soil and promote 42°C&11.4°Crespectively.Average annual formation of soil structure. Earthworm rainfall of the district is 1427.9 mm (15 years burrowing in the soil creates channels for average). aeration, root penetration, reduction in bulk 2. Balasore - Balasore is another important density, enhancement of water infiltration and coastal district of Orissa, lies on the northern miost nutrient cycling. Some soil fauna ingest organic part of the state having 21° 03' to 21° 59' North matter by taking in soil, applying digestive Latitude & 86° 20' to 87° 29' East Longitude. enzymes, and excreting the soil/OM complex, Geographical area of the district is 3634 Km'. Bay thus providing a more readily available food of Bengal is on the east. source for other soil fauna and soil micro- organisms.Earthworms, termites, millipedes, Broadly this district can be divided into three centipedes and woodlice ingest soil particles with geographical regions, namely, their food and contribute to aggregate formation 1. the Coastal belt by mixing organic and mineral matter in their gut. 2. the inner alluvial plain and Some soil fauna contribute to the carbon cycle by fixation (photosynthesis). One group of soil fauna 3. the North-Westem hills. is particularly important in nitrogen cycling. The coastal belt - It is about 26 Kms. wide and Topographical description of the Study Areas shapes like a strip. In this region, sand dunes are noticed along the coast with some ridges. The soil The present study was conducted in the two of this small strip is saline in nature. This region is districts namely, Bhadrak and Balasore of the mostly flooded with brackish water of estuarine state of Orissa in West Bengal, India. The rivers which is unsuitable for cultivation. topographical description of the study areas gives an idea of different ecosystems that prevail in The deltaic alluvial plain - It is a wide stretch these areas. of highly fertile and irrigated land. The soil of this region is mostly alluvial laterite. The soil of 1. Bhadrak - Bhadrak is one of the important Central region is mostly clay, clay loam and sandy coastal districts of Orissa. The area is in the east of loam which is very fertile for paddy and other Bay of Bengal and is located between longitude farm produces. 86° 30' 0 E and latitude 21° 4' 0 N. The area of this district is 1721 Km^.There are 5 types of forests in The north- western hilly region - Nilgiri Sub­ the Bhadrak district. The total forest area is 97 division is mostly gravelly and lateritic soil, which Km'. is less fertile. It is mostly hilly terrain and vegetated with tropical semi-ever green forest. It is a level trac of alluvial soil with a gradual slope eastwards to the Bay of Bengal. A number of Balasore is crisscrossed with perennial and deltaic rivers viz., Salandi, Baitarani, Kansabansa, estuarine rivers because of its proximity to sea. Gamol, Mantel, Genguti, Kochila, Reba and Two important rivers of Orissa, Budhabalanga Kapali pass through and around the district. and Subamarekha, pass through this district from west to east before surging into the Bay of Bengal. This district is divided in to three zones according to its soil condition. 1. Saline Soil, 2. The climate of Balasore district is mostly hot Alluvial Soil, and 3. Sandy SoU. This district is and humid. The average temperature of the GOSWAMI et ah,: Report on the Soil Fauna of Bhadrak & Balasore 215 district varies between 22''C to 32''C and the Collection and preservation of earthworm average rain fall is 1583 mm. The living worms were collected by digging MATERIALS AND METHODS soil with a shovel and hand sorting. The worms The present study was undertaken in August, then dropped in 70 % ethyl alcohol. When the movement of worms stopped, they were removed 2009 to March, 2012 in different types of soil in from alcohol and placed on a piece of blotting different areas of Bhadrak & Balasore district of paper in straight position. They were then Orissa. Soil samples were collected during transferred to a flat bottomed container with 10- monsoon and winter seasons. 500 gms. of soil 15% formalin for fixation for 24 hours. The worms samples taken from each plot. The physico- were then washed in fresh water and preserved chemical parameter namely temperature, pH & in 70-90% alcohol in suitable sized vials . A label moisture were taken during collection of soil with locality, date of collection and name of samples. collector affixed in each vial. Collection and preparation of slides of protozoa SYSTEMATIC ACCOUNT In laboratory soil samples were cultured. 50- Phylum I. SARCOMASTIGOPHORA 100 gms. of soil were taken into Petridish and Subphylum SARCODINA distilled water was added to it. Petridish were Class LOBOSEA then kept in sunlight. After 1-2 days' a small drop Order 1 TESTACEALOBOSEA of water was placed on micro slide and examined Family 1 ARCELLINIDAE through microscope. Testacid of Rhizopod Genus 1 Arcella Ehrengerg, 1830 started growing if present in the sample. Soon as the Rhizopodes are seen, the water in the slide is l.Arcella vulgaris Ehrenberg. dried by using blotting paper. Thus the specimen 2. Arcella discoides Ehrenberg. is fixed. After fixation 1-2 drops of D.P.X. poured 3. Arcelle catinus Penard. upon the speceimen. A cover slip first placed at 45 Family 2 CENTROPYXIDAE degree angle upon the specimen and slowly lowered down with the help of a needle, so that Genus 2 Centropyxis Stein, 1857 D.P.X. will evenly spread devoid of bubbles. We 4. Centropyxis minuta Deflandre. kept this slide for 1-2 days for drying of D.P.X. 5. Centropyxis spinosa (Cash & Hopkinson) This permanent slide was then ready for Deflandre. identification. 6. Centropyxis arcelloides (Penard) & Deflandre. Collection and preservation of Arthropod Family 3 DIFFLUGIDAE For extraction of the soil micro arthropods Genus 3 Dijflugia Leclerc, 1815 fauna, 500 gms.