IJERD – International Journal of Environmental and Rural Development (2013) 4-1

Research article
erd

Effect of Organic Materials from Agro-Industrial Wastes(Molasses and Distillery Slop) on Earthworms under
Vermicomposting Using Cassava Waste
RATCHANEE WONGKOGSOONG
Faculty of Agriculture, Khon Kaen University, Thailand
Email: wks.ratchanee@gmail.com, chulee_b@kku.ac.th

CHULEEMAS BOONTHAI IWAI*
Faculty of Agriculture, Khon Kaen University, Thailand

MONGKON TA-OUN
Faculty of Agriculture, Khon Kaen University, Thailand
Received 16 December 2012

Accepted 30 January 2013(*Corresponding Author)

Abstract The increasing of waste nowadays necessitates agro-industrial waste
management, and vermicomposting technology has been offered as a viable method.
However, before application of this method, a study of the effects of waste on earthworms
is required. The objective of this study is to investigate the effects of organic material onearthworms as a result of the vermicomposting process. The experiment was conductedusing completely randomized design with three replications. A toxicity test wasadministered to determine the effects of organic material (molasses and distillery slop
from cassava industrial wastes) on the survival and growth of earthworms invermicompost. The study found that after 7 days, 100% of the earthworms could survive
under concentrations of molasses at rates of 1.25 - 3.75% and concentrations of distillery
slop at rates of 6.25 - 25%. In addition, the application of organic materials (molasses anddistillery slop) mixed with cassava industrial wastes increased the growth of earthworms.
The earthworms had a survival rate of 67-100% after 4 weeks in the vermicompost
treatment when molasses was mixed with cassava pulp and cassava peel, but without
cassava pulp and cassava peel, the earthworms could not survive. Similar results were
found with the application of distillery slop mixed with cassava pulp and cassava peel.
Therefore, suitable rates of molasses and distillery slop use for earthworm survival are
1.25 - 3.75% and 6.25-25%, respectively. In conclusion, molasses and distillery slop canbe used with cassava industrial waste material in the vermicomposting process.
Keywords organic material, earthworms, vermicompost

INTRODUCTION
Agro-industry   has   been   expanding   rapidly   in   developing   countries   in   order   to   serve   peoples’  consumption. This expansion and its effects on the production process have led to increasing
amounts of industrial wastes and environmental pollution. Vermicomposting technology wasrecently offered as a viable method for organic waste management. After decomposition of waste
by earthworms, vermicompost is useful for agricultural sectors (Toncho, 2007; Iwai et al., 2011).
The use of earthworms for organic waste management is considered a brilliant means fordecomposition as their use is convenient and low cost. Vermicompost can be developed as highquality fertilizer and changes of chemical, physical and biological properties can be implemented.
In addition, it has been found that vermitechnology produces more nutrients: 26-82% nitrogen, 9094% phosphorus and 26-75% potassium (Iwai et al., 2011). Organic carbon is a food source thatincreases the growth and reproduction of earthworms and microorganisms in compost and is an
important factor for organisms. A lot of molasses and distillery slop, currently, has been producedⒸ ISERD95

IJERD – International Journal of Environmental and Rural Development (2013) 4-1

from the sugar and ethanol industries.
OBJECTIVES
The objectives of this study are to investigate the effects on earthworms (Eudrillus eugeniae) ofusing organic material from agro-industrial wastes (molasses and distillery slop) for
vermicomposting using cassava waste; to determine effects on the growth of earthworms; and toanalyze the quality of vermitechnology fertilizer.
METHODOLOGIES
A toxicity test of organic material (molasses and distillery slop) to determine its effects on thesurvival of earthworms
A toxicity test of organic material (molasses and distillery slop) to determine its effects on thesurvival of earthworms was performed with concentrations of molasses at 1.25%, 2.5%, 3.75% and
5% and concentrations of distillery slop at 6.25%, 12.5%, 18.75% and 25% for a period of sevendays. Earthworms (E. eugeniae) used for this study were obtained from Research Developing andLearning Centre on Earthworm for Agriculture and Environment. Adult earthworms (E. eugeniae)
of weights ranging from 0.34 - 0.45 g and lengths ranging from 15 - 18 cm were placed in plastic
containers divided into two sides with five earthworms per section. The control side was filled with
100 g dry weight of soil without contaminant and the other half of the plastic container was filledwith organic material (molasses and distillery slop) in different concentrations with 100 g dryweight of soil. Survival rate of earthworms was observed and data was recorded every day.
A study of the survival and the growth of earthworms as affected by organic materials(molasses and distillery slop) mixed with cassava industrial wastes
This study included 4 sub-experiments with 4 different organic material combinations: 1) Molasses
mixed with cassava pulp; 2) Molasses mixed with cassava peel; 3) Distillery slop mixed withcassava pulp; and 4) Distillery slop mixed with cassava peel. The ratio of cassava industrial wastes
to soil to cow dung was 7:2:1. In each experiment, this ratio was mixed with concentrations ofmolasses at rates of 1.25%, 2.5%, 3.75% and 5% and concentrations of distillery slop at rates of
6.25%, 12.5%, 18.75% and 25%. This experiment used Completely Randomized Design (CRD)with three replications. Adult earthworms (E. eugeniae) of weights and length ranging from 0.340.45 g and length 15 cm-18 cm were released into plastic pot containers containing 100 g dryweight of soil with five earthworms per container . All the containers were kept at a temperature of°
25 ± 3   C. The moisture content was maintained at 60–70% during the study  period. Survival rates
and weights of the earthworms were recorded before and after 30 days.
Statistical analysis: Differences among the treatments were assessed with analysis of varianceusing STATISTIC 8.
Table 1 Chemical characteristic of organic wastes
Parameters
pHEC (mS/cm)
Organic matter (%)
Total nitrogen (%N)
Phosphorus (%P)
Potassium (%P)

Cassava pulp
4.95
0.67
89.57
0.24
0.025
0.36

Type organic wastes
Cassava peel
Molasses
5.45
4.9
1.25
8.18
58
0.49
0.94
0.051
0.18
0.51
3.91

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Distillery slop
4.51
30.85
0.45
0.043
1.688

IJERD – International Journal of Environmental and Rural Development (2013) 4-1

RESULTS AND DISCUSSIONA toxicity test of organic material (molasses and distillery slop) to determine its effects on thesurvival of earthworms
Toxicity tests of the various concentrations of molasses to determine its effects on the survival ofearthworms found that 100% of earthworms could survive under molasses concentrations of 1.25 3.75%, but 73.3% of earthworms could survive under molasses concentrations of 5 %. In addition,
the results of the different concentrations of distillery slop found that after 7 days of testing, 100%of earthworms could survive under concentrations of 6.25 - 25%. According to Toncho (2006), E.
eugeniae can survive at pH 7.0 - 8.0, but molasses has a low pH of 4.9. It also has a high electricalconductivity (EC) of 8.18 (Sharma et al., 2007), which is considered to be very salty. Distillery
slop was found to have an EC of 30.85 mS/cm, higher than molasses, but the earthworms could
survive because the pH was decreased to neutral by fermentation (Pundee,  2006).

Fig.1. The % toxicity test of molasseson the survival of earthworms

Fig.2. The % toxicity test of distillery slopon the survival of earthworms

A study of the survival and the growth of earthworms as affected by organic materials(molasses and distillery slop) mixed with cassava industrial wastes
The use of molasses mixed with cassava pulp and cassava peel: The results of both the use ofmolasses mixed with cassava pulp and mixed with cassava peel demonstrate that earthworm
survival decreases with increasing rates of molasses concentration. After 4 weeks, 100% ofearthworms could survive under molasses concentrations of 1.25% mixed with cassava pulp.
Earthworms could not survive under concentrations of 5 % molasses. On the other hand, the study
found that 100% of earthworms could survive molasses mixed with cassava peel under molasses
concentrations between 1.25 - 2.50% but under molasses concentrations of 3.75 - 5 %, earthworm
survival decreased to 55.56 - 33.33%. In other words, earthworms could survive under molasses
mixed with cassava peel at higher rates than molasses mixed with cassava pulp. The cassava peel
may have absorbed the molasses which would have decreased the toxicity of molasses (Cleasby,1963). Earthworms could not survive 100% because the molasses has a high electrical conductivity(EC) of 8.18 mS/cm and a low pH of 4.9 (Pundee, 2006). According to Toncho (2006), E. eugeniae
can survive at pH 7.0 - 8.0, so these characteristics of molasses are not conducive to the survival ofearthworms.
The use of distillery slop mixed with cassava pulp and cassava peel: The results of the use of
distillery slop mixed with cassava pulp and cassava peel showed that earthworm survival decreases
with increasing rates of distillery slop concentration. After 4 weeks, 77.78% of earthworms could
survive under concentrations of 6.25 - 12.5% of distillery slop. Under distillery slop concentrationsof more than 18.75%, earthworms could not survive 100% because the distillery slop had a highelectrical conductivity (EC) of 30.85 mS/cm and a low pH of 4.51 (Soongsud, 2008). The pH ofcassava pulp was measured at 4.95 which is not conducive to the survival of earthworms. The useof distillery slop mixed with cassava peel found that earthworm survival declined with anincreasing rate of cassava pulp concentration. However, earthworms could survive 100% underⒸ ISERD97

IJERD – International Journal of Environmental and Rural Development (2013) 4-1

concentrations of 6.25 -18.75% of distillery slop, but using distillery slop at concentrations morethan 18.75% led to lower survival rates. Cassava peel can absorb distillery slop more than cassava
pulp which decreased the toxicity of distillery slop.

Fig. 3 The % survival of earthworms in the different concentrations of molasses mixed withcassava pulp and cassava peel120100806040
20006.25

12.5

18.75

25

Distillery slop (%)

cassava pulp

cassava peel

Fig. 4 The % survival of earthworms in the different concentrations of distillery slop mixed
with cassava pulp and cassava peel.
CONCLUSION
The study of the survival of earthworms on organic materials (molasses and distillery slop) mixed
with cassava industrial wastes found that the use of molasses mixed with cassava pulp or cassava
peel at molasses concentrations lower than 2.5% resulted in an earthworm survival rate of 100%,
but the use of molasses at concentrations more than 3.75% resulted in lower survival rates. On theother hand, cassava pulp mixed with distillery slop at 6.25-12.5% concentration levels of distillery
slop promoted an earthworm survival rate of 77.78%. The use of distillery slop mixed with cassava
peel, with distillery slop concentration levels of 6.25-18.75% promoted an earthworm survival rateof 100%. High concentrations of molasses and distillery slop have high electrical conductivity(EC), or salinity, which affects the survival of earthworms. Therefore the use of molasses anddistillery slop should be kept at an optimum rate.
ACKNOWLEDGEMENTS
This research was supported by Khon Kaen University; thank to Association of Environmental andThis research project was funded by The National Research Council of Thailand (NRCT) andNational Science and Technology Development Agency (NSTDA) under 2012. Thanks areextended to the Division of Land Resource and Environment, Faculty of Agriculture, Khon KaenⒸ ISERD98IJERD – International Journal of Environmental and Rural Development (2013) 4-1

University for the conveniences and equipment in laboratory test and Integrated Water Resource
Management Research and Development Center in Northeast Thailand and thanks to Prof. Dr.
Machito Mihara for kind support.
REFERENCES
Cleasby, T.G. 1963. The feeding value of molasses. Proceedings of the South African Sugar Technologists'
Association (http://www.sasta.co.za.)
Iwai, C.B., Ta-oun, M., Seripong, S. and Champar-ngam, N. 2011. Vermicomposting: good management
practice for waste, soil and yield safety. Department of Plant Sciences and Agricultural Resources, Land
Resources and Environment Section, Faculty of Agriculture, Khon Kean University, Thailand. 171.
Pundee, K. 2006. Influence of molasses on composting of cassava. Master of Science. Department of Natural
Resource Management, Faculty School of Bioresources and Technology, King Mongkut's University ofTechnology Thonburi. Thailand.
Sharma, P., Setia, R.K. and Dutta, S.K. 2007. Potential use of distillery effluent in agriculture, Indian Journalof Ecology, 34(1), 50-53.
Soongsud, P.    2008.    Utilization of spent wash liquor from ethanol factory for the sugar cane production.  
Master of Science thesis in soil science, Graduate School, Khon Kaen University. Thailand.
Toncho, A. 2007. Earthworm. National science and technology development agency, Patumthani. 260.

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