Two and a Bud 58:137-140, 2011

RESEARCH PAPER

Vermicompost quality as influenced by different species of earthworm andbedding material

J.S. Bisenl, A.K. Singh, R. Kumar, D.K. Bora and B. Bera*Darjeeling Tea Research and Development Centre, Tea Board, Kurseong, Dist. Darjeeling -734203, W.B, India.* Director (Research), Tea Board of India, Kolkata

ABSTRACT

Slow rate of decomposition and mineralization of organic matters are major limiting factors in adequate nutrientavailability to the plant in the Darjeeling tea soils. Results indicated that the organic carbon was higher in tea wasteand weed biomass, ranging from 29.10 to 32.65%, while it was lower in Eupatorium sp. ranging from 22.75 to24.8%. At harvest, pH and organic carbon of vermicompost went down ranging from 4.81 to 7.13 and 17.5 to21.70% respectively. The C: N ratio was recorded narrow in all the treatments ranging from 11:1 to 13:1 than thepre-inoculation stage. Highest total Nitrogen content (1.84%) in the final produce was recorded in tea waste +cowdung with Eiseniajoetida followed by Eupatorium + cowdung with local worm (1.75%), and tea waste + cowdung with Eudrillus euginae (1.67%). Highest Phosphorus (1.04%) and Potassium (1.46%) contents were recordedin Eupatorium + cowdung with local worms. The pH ofvermibed wash was recorded in decreasing order with timespan of decomposition irrespective of the treatments. The maximum multiplication rate was in local worm followedby Eiseniajoetida and Eudrillus euginea.

INTRODUCTION

In recent years, earthworms have been identified as one ofthe major tools to process the biodegradable organicmaterials (Julka and Senapati, 1987; Greig Smith et al.,·1992). The utilization of waste materials through theearthworm has given the concept ofvermicomposting. Thevermitech approach utilizes waste management process byinvolving earthworms (Satchell, 1967). Improvement of soilthrough vermiculture has now become a popular part oforganic farming. Vermicmpost is accepted as humus bio­fertilizer, soil fertility booster, soil activator and soilconditioner with required plant nutrients, vitamins,enzymes, growth hormones and beneficial microbes likenitrogen fixing, phosphate solubilising, denitrifying anddecomposing bacteria. "The Green Revolution" th~t waspromoted in early part of 20th century, was a boost to foodproduction without foreseeing its ill effects. The recentrealizations to maintain ecological balance for sustenanceof agricultural production, farmers and scientists alike areaiming at fmding an alternative to chemical agriculture.India has a long tradition of agriculture with a rich heritageof ecofriendly agriculrure technologies. The tropical climateprevailing in India is very congenial for farming. Taking in

1 Corresponding author: e-mail: jsbisen30@gmaiLcom

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consideration such favourable environmental conditions,early farmers developed such technologies which were usedto reap a big harvest throughout the ages. But after 1950,when green revolution was introduced, there was a suddenhike in consumption of chemical fertilizers, pesticides,insecticides and hybrid seeds. Unfortunately suchextravagant use of these technologies and interference innatural processes in so called modern agriculturaltechnologies seem to have failed in maintaining harmonywith nature. As a result even sustainability of agricultureas a whole is at stake. Therefore an experiment wasconducted during 2009 with the objectives to find the bestsource of bedding material in relation to the nutrient statusas well as the multiplication of earthworms and to fmd outthe best species of earthworm vis-a-vis different beddingmaterials.

MATERIALS AND METHODS

The study was conducted at Darjeeling Tea Research andDevelopment Centre, Kurseong, situated at Lat. 26° 55'N,Long. 88°12'E, altitude 1240 a.m.s.l. To explore the scopeof vermicomposting with the help of locally availableorganic wastes and to study the performance of three species

of earthworm (Eisenia foetida, Eudrillus euginea and alocal species) in the production ofvermicompost by usingdifferent bedding materials (Eupatorium glandulosum,mixed weed biomass and tea waste with cowdung at 2: 1ratio), an experiment was conducted at Darjeeling TeaResearch and Development Centre, Kurseong, duringAugust to November, 2009.Three types of beddingmaterials which are abundant in this region, viz. tea waste,mixed weed consisting mainly polygonum sp., Ageratumsp., Urtica dioica, grasses etc. and Eupatoriumglandulosum (alone) mixed with one week old cowdung at2: 1 ratio (weight basis) were used. Three species ofearthworm used were Eisenia foetida, Eudrillus eugineaand a local worm. The tea waste and chopped weeds weremixed thoroughly with cowdung at 2: 1 ratio and filled inwooden boxes of50cm x 30cm x 30cm size treatment-wise

with three replications of each. Boxes were covered withgunny bags and kept for another fifteen days for pre­decomposition. Need-based sprinkling of water was doneto maintain the moisture level and to induce decompositionprocess.

After pre-decomposition, 100 worms of each species werereleased in each box on the top of the bedding materialsand allowed to move down. Pre-decomposed and compostsamples (at maturity) were collected for pH, organic carbonand nutrient analysis. The water was sprinkled at regularintervals to keep the culture moist.

RESULTS AND DISCUSSIONS

The pH of all the mixed bedding materials after pre­decomposition were above neutral ranging from 8.20 to8.92 except tea waste which ranged from 6.51 to 6.61 (Table1). At maturity, the pH of final produce declined in all thetreatments to neutral and rartged from 4.81 to 7.13.Decomposition of organic matter leads to formation of

ammonium ions and humic acids, these two componentshave exactly opposite effects on the pH. Presence ofcarboxylic and phenolic groups in humic acids causedlowering of pH while ammonium ions increased the pH ofthe system. Combined effect of these two oppositelycharged ions actually regulated the pH of vermicompostleading to a shift of pH towards neutrality. Theseobservations were in conformity with those obtained byFares et aI., (2005).

At pre-inoculation stage, organic carbon was higher in weedbiomass and tea waste with cowdung and ranged from 32.65to 29.10% as compared to Eupatorium sp. with cowdungwhich was from 22.75 to 24.8%, while at maturity organiccarbon was highest in the vermicompost prepared fromEupatorium + cowdung (21.70%), it was closely followedby Tea waste + cowdung (21.1 0%) while it was lowest inweed biomass + cowdung (17.5%). Duringvermicomposting process, the organic carbon contents inall the treatments declined remarkably. Vermicompostingprocess refers to feeding of earthworm on organic matterand microbial degradation. The combined process bringsabout carbon loss from substrates in the form of carbondioxide. Studies have revealed that earthworm activities

bring about significant decline in organic carbon level ofwaste resources and accelerate wastes stabilization process(Loh et aI., 2005; Suthar, 2006). The organic carbon wasbeing decomposed by the microbial biomass present in thecompost (Mondini et aI., 2003). Similarly, Guest et al.,(2001) observed the decrease in carbon concentration from20 to 16% during composting.

Total nitrogen content at pre-inoculation stage varied widelywhere N content in tea waste was 2.15 to 2.45%. In the

weed biomass it was from 0.87 to 1.79%. Total nitrogencontent in vermicompost at maturity in compost preparedfrom tea waste + cowdung using Eiseniafoetida was 1.84%

Table 1. Comparative performance of three different species of earthworm in relation to the different bedding material andchanges in nutrient status

Treatment

PHO.c.%Total N%CNTotalP% Total %Pl.

MaturityP.I.MaturityPl.MaturityPl.MaturityP.I.MaturityPl.MaturityTI

8106.8323.4620.021.021.5223:113:10.420.960.621.40T2

8.456.7924.821.700.961.6126:111:10.430.900.601.39T3

8.516.6922.7520.410.871.7526:111:10.391.040.691.46T4

6.514.8232.0521.102.151.8415:111:10.340.580.830.99T5

6.594.8129.1020.872.191.6713:112:10.320.540.800.96T6

6.617.1331.4918.052.431.6413:111:10.370.600.881.13n 8.926.9532.2017.51.761.5118:111:10.400.521.031.14T8

8.836.8530.8518.811.791.6217:111:10.430.490.981.08T9

8.586.8732.6519.391.731.4719:113:10.410.500.981.17C.D. at5%

0.790.862.802.380.370.303.27N.S.N.S.0.110.130.22

TI-Eupatorium+Cowdung at 2:I(Eisenia)

T2 - Eupatorium+Cowdung 2:I (Eudrillus)T3 - Eupatorium+Cowdungat 2:I(local)

T4 - Teawaste+ Cowdung at 2:I(Eisenia)TS- Teawaste+ Cowdungat 2:I(Eudrillus)

T6 - Teawaste+ Cowdung at 2:1(local)T7- Weedbiomass+ Cowdung at 2:I(Eisenia)

T8 - Weedbiomass+Cowdung at 2'1(Eudrillus)T9 - Weedbiomass+ Cowdung at 2:1(local)

P.l.-Pre-inoculation

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CONCLUSION

Table 3. Average multiplication rates of different species ofearthworm

The pH of vermibed wash collected at different timeintervals (Table 2) revealed that the pH had a decreasingtrend with span of time. Faster multiplication oflocal wormfollowed by Eiseniafoetida and Eudrillus euginae (Table3) was recorded which might be due to adaptability oflocalenvironmental conditions.

(1.40%), Eupatorium + cowdung using Eudril/us eugenae

(1.3<J01o) and was lowest in tea waste + cowdung using Eudrilluseugenae (0.96%). The status of P and K contents invermicompost depends on acid production during organicmatter decomposition process by the microorganisms and isthe major mechanism for solubilisation of insoluble phosphorusand potassium. Also, the presence of large number of microflora in the gut of earthworm might play an important role inincreasing P and K contents in the process of vermicomposting(Sharma, 2008).

No. of earthworm Total earthworm Doubling time ofinoculated present after earthworm, days

70d s.

100 463 55100 368 63100 489 52

Eisenia foetida

Eudrillus eugineaLocal sp.

Earthwonn sp.

followed by Eupatorium + cowdung using local worm(1.75%) while it was lowest in the compost prepared fromweed biomass+ cowdung using local worm (1.47%). Thenitrogen content in vermicompost after incubation wasrecorded in decreasing trend in tea waste and weed biomassbut in Eupatorium it gained in final produce as comparedto pre-inoculation. The loss of total N content may be dueto leaching through vermibed wash during the composting.Gunadi et aI., (2002) demonstrated that earthworm activityenriched the nitrogen profile of vermicompost throughmicrobial mediated nitrogen transformation, throughaddition of mucus and nitrogenous wastes secreted byearthworms.

Initially at pre-inoculation stage, C:N ratio was wider butat maturity it was narrower in all the treatments. In most ofthe treatments, the C:N ratio was recorded 11:1 while it

was little wider 12: 1 in tea waste + cowdung using Eudrillus

eugenae, Eupatorium+ cowdung with Eisenia foetida 11: 1.The decrease in C:N ratio in the vermicompost as comparedto the initial organic substrates, might be due to relativeincrease in total nitrogen on loss of dry matter (organiccarbon) as CO as well as water loss by evaporation duringmineralization2 process. The decrease in C: N ratio overtime might also be attributed to increase in the earthworm

population (Nedgawa and Thompson, 2000), whic~ le~ torapid decrease in organic carbon due to enhanced OXidatIOnof the organic matter.

The available P content at pre-inoculation stage was higher inEupatorium + cowdung using Eudril/us eugenae (0.43%)followed by Eupatorium + cowdung using Eisenia foetida(0.42%) and minimum was in tea waste + cowdung usingEudril/us eugenae (0.32%). Highest content ofP was recordedat maturity in Eupatorium + cowdung using local worm(1.04%) followed by Eupatorium + cowdung using Eiseniafoetida (0.96%), Eupatorium + cowdting using Eudrilluseugenae (0.90%) and was lowest in weed biomass + cowdungusing Eudril/us eugenae (0.49%). Available K content washighest in Eupatorium + cowdung using local worm (1.46%)followed by Eupatorium + cowdung using Eisenia foetida

The pH of all the vermicomposts prepared from the wastesranged from acidic to neutral. Their C: N ratio reducedconsiderably at maturity. Maximum N content was foundin Tea waste + cowdung with Eisenia foetida followed byEupatorium + cowdung with local worms while P and Kcontents were highest in Eupatorium + cowdung with localworms.

ACKNOWLEDGEMENTS

The authors are grateful to Tea Board for giving them anopportunity to conduct the experiment and extending their

Table2. Changes in pH ofvermibed wash collected at different time intervals of vermibed wash

pH

50DAI

TreatmentsPre inoculation

7DAI15DAI22DAI30DAI40DAIor

Tl. Eupatorillm+ Cowdllng at 2:I(Eisenia)8.28.758.377.457. IS6.686.83

n. Eupatorillm+ Cowdllng 2: I (Elldrilills)8.458.608.127.337.036.996.79

n.Ellpatorium+ Cowdllng at 2:I(local)8.518.298.446.207.247.126.69

T4. Tea waste + Cowdllng at 2: I(Eisenia)6.515.435.144.954.914.924.82

T5. Tea waste + Cowdllng at 2: I(Elldrilllls)6.596.104.874.604.514.764.81

T6. Tea waste + Cowdllng at 2: l(local worm)6.615.564.948.224.494.737.13

n.Weed biomass + Cowdung at 2: 1.(Eisenia)8.927.119.107.818.077.376.95

T8. Weed biomass + Cowdllng at 2:1(ElldrilIllS)8.838.778.628.197.887.296.85

T9. Weed biomass + Cowdung at 2: l(local)8.588.798.567.487.757.406.87

0.13

0.180.090.190.080.080.10Sem±C.D. at 5%

0.400.530.270.560.230.250.30

DAI- Daysafterinoculation.

139

support during the study. They are also thankful to Mr. R.K.Chauhan for his valuable contribution during preparationof the manuscript.

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