2.0 MATERIALS AND METHODS

2.1 COU-ECTION OF EARTHWORMS

Earthworms used for inoculation in the vetmicoposting pit were

collected from within the C.M.S College, Kottayam, Kerala by hand sorting.

They were then identified as Drawida ghatensis, D. nepalensis, D.

travencorensis and Megascolex konkanensis.

2.2 COLLECTION OF ORGANIC INPUTS

Organic inputs like shredded paper, neem leaves and specimen wastes

( carcasses of Rana hexadadyla and Calotes uersico1or)were collected from the

Zoology Laboratory of C.M.S College, Kottayam and kitchen waste from the

C.M.S College hostel.

2.3 EXPERIMENTAL SET-UP

2.3.1 Design of Vermitech Unit

Vermicomposting was carried out in the vermitech units of C.M.S

College, Kottayam. The vermitech unit is a cement tank measuring 4.8 m x

1.8 rn x 0.75 rn. This tank has 10 outlets opening out into a cement plastered

side channel leading to a small collection pit (Plate la). Vermibed was set in

this tank (Plate lb) . The tank internally was demarcated into five chambers

using welded 3 cm2 wire mesh for loading organic inputs (Plate lc). The

complete unit is sheltered under light roof to protect from rain and direct

sunlight (Plate id ) .

2.3.2 Preparation of Vermibed

Vermitech unit has a basal layer of broken bricks or pebbles (5 m s )

followed by a layer of coarse sand to a thickness of 10 cm to ensure proper

drainage of excess water. This is topped by a layer of garden soil upto a

height of 15 cms after moistening. 250 local earthworms comprising 125

Megascolex konkanensis and 125 Drawida species (D. ghatensis, D. nepolensis

and D. travencorensis) were inoculated into each pit. Small lumps of cowdung

(2 Kg) were scattered over the soil and was covered with a layer of hay upto

10 cm height. Water was sprayed liberally till the entire set up was moist (27-

30%). The units were kept closed with welded mesh to prevent the enby of

predators. Watering and monitoring was continued for 30 days. This duration

enables the worms to stabilize, acclimatise and multiply in number.

After sampling the vermibed for physical, chemical and biological

parameters (see section 2.5), organic inputs in the form of a) Hay (HY) b)

dissected specimen waste (dead autopsied specimens from the zoology

laboratory) (SW) c) Shredded paper (PR) d) Neem leaves (NM) and e)

ktchen waste (KW) were spread on respective compartments to a thickness of

about 5 cms at each time, at an interval of 5 days. The pit was moistened

everyday, and inputs were turned over for aeration once in a week with the

help of a pitchfork. Addition of wastes were done till the 90th day. Watering

and turning continued till the organic matter becomes well decomposed and

then watering was stopped. This compels the earthworms to move into the

lower end of the vermibed and facilitates harvesting the compost without much 4

PLATE 2

a) Megascolex konkanensis

b) Drawida Species

damage to the worms. Harvested compost from each compartment was placed

separately in the form of a cone on solid ground in bright sunlight so that the

earthworms, if any, would move to the base of the cone due to heat and can

be collected and replaced into the pit. The compost was then sieved and

packed in polythene bags inorder to retain moisture (23 + 2%).

2.4 BlOLOGICAL PARAMETERS

Population density and live biomass of earthworm were recorded e v e y

15 days in evey chamber during the vermicomposting process by hand

sampling in triplicate using a quadrant (0.2m x 0.2m x 0 .2~1) . Population

density was expressed as numbers per 0.04 sq m) and live biomass by grn wet

weight per 0.04 sq m. Earthworm numbers and their respective live biomass

were recorded before their addition into the vermicomposting chambers.

2.5 CHEMICAL PARAMETERS

Samplings of the initial vermibed and after evey 15th day from the

date of commencement were done to analyse the following chemical

parameters during the composting process.

Soil pH was measured using a pH meter (Elico, India). Soil water

suspensions in the ratio of 1:5 (Piper, 1944) were prepared to determine the

pH of soils. The same dilution was followed to measure electro-wndudivity of

soils using an electro-conductivity meter. Moisture content of the soils was

determined by the difference in weight noted between the d y weight of soil

( 1 0 5 ' ~ ) with that of the wet weight of the soil taken for dying.

Organic carbon was calorimetrically estimated by modified Walkley -

Black partial oxidation method (Jackson, 1955). Total Kjeldahl Nitrogen (TKN)

was determined as described in Jackson (1958) while available potassium

( K 2 0 ) was determined by flame photometry (Jackson, 1958). Available

phosphate (P,O,) was estimated as recommended by Anderson and Ingmm

(1989).

2.6 CALORIFIC CONTENT

The calorific contents of different feed materials used were estimated

using a bomb calorimeter. The materials were dried in an oven at 60 OC for 36

hrs. They were then powdered in a blender. The powder was then combusted

in a bomb calorimeter. The calorific value of the samples were then calculated

in cals per gm-' dry weight.

2.7 ANALYSIS OF DRAIN WATER FROM THE VERMlTECH UNIT

The filtrate coming out through h e outlet after pawng ~ Y D U ~ . . the

vermibed layers was analysed for pH, EC, alkalinity, dissolved oxygen, salinity,

nitrogen, phosphorus, potassium, iron and silicates as per standard procedures

recommended by APHA (1976). The pH of water was measured using pH

meter and EC using conductivity meter. Potassium was determined by flame

photometry (using the procedure described by Mackereth et al., 1978).

Dissolved oxygen was determined by Winkler's iodometric method (Winkler,

1888). Nitrates were determined by cadmium reduction method (Elliot and

Porter, 1971), and silicates by molybdo-silicate method (Miillin and Riley,

1955). Phosphate was estimated as referred by Murphy and Riley, 1962 and

Stephens, 1963, and iron by phenanthroline method (Goltetman and Clyrno,

1969). Salinity was estimated by Mohr's titrimetric method. Alkalinity was

determined using the procedure as described by Mackereth et al, (1978).

2.8 MICROORGANISMS IN CASTS

Microbial succession of casts during the vermicomposting process were

studied for 70 days at 5 day intervals from the date of commencement of

addition of organic inputs namely Hay (HY) Laboratoy specimen waste (SW),

Paper (PR), Neem leaves (NM) and Kitchen waste (KW). The castings collected

from each compartments were analysed for 1) fungi 2) actinomycetes 3)

phosphobacteria 4) Azotobader sp and 5) bacteria using serial dilution

method of Timonin (1940). The media used in the study include soil extract

agar for bacteria, Martins rose bengal agar for fungi, Kenknights agar for

actinomycetes , Jenson's agar for Azotobader and Apatite agar for

phosphobacteria. The number of these microorganisms present in the

verrnibed were also assessed before imposing the treatments.

2.9 POT EXPERIMENTS

The evaluation of composts harvested from different organic inputs

were done by studying the impact of this compost on the growth of

Okra (Abelmoschus esculentus), Brinjal (Solanum melongena) and Tomato

(Lycopersicon esculentum).

2.9.1 Experimental Set-up

18 experimental chambers of height 30 cm and width 25 cm were

prepared for the experiments. A layer of broken bricks covered by coarse sand

was placed inside each pot to a height of 10 cm. 6 Kg of sun dried garden soil

was then added to each of the pots. The soil in the pots was then moistened

with water (28 2 2%). The pots were marked K, N, P, S, H and C (each in

triplicate serially numbered 1,2,3).

Soils in pots K,, KP, K3 were topped with 200 grn of kitchen waste

compost, N1, N,, N3 with neem compost, PI, P,, P, with paper waste compost,

S,, S,, S3 with specimen waste compost and H,, Hz, H, with hay compost, C,,

C,, C, served as control pots without any compost.

The experimental set up was regularly watered to maintain constant

moisture 24 2 2%. Depressions (2 cms deep) were made on the top of the

soil and 5 seeds of one of the three species were sown each equidistant from

the other. After germination three healthy plants were retained and their

growth patterns were recorded. The plant growth parameters that were

recorded during the period of study are

1. Date of germination

2. Date of leaf formation

PLATE 3

Plants grown on composts from different inputs

a) Okra (Abelmoschus esculentus)

b) Brinjal (Solanurn melongena)

c) Tomato (Lycopersicon esculenturn)

3. Days taken for fruiting

4. Number of fruits

Fruits were harvested at regular intervals and the yield of fruits from

each plant was recorded. A second dosage of 100 gm of vemicompost from

each source was applied to the respective pots again after 30 days. Counts like

number of leaves, leaf area (cm2) shoot length (cm) and root length (an) were

noted after the third harvest except in tomato where these parameters were

noted after the first harvest. Similar set up were prepared for the other two

species of plants as well.

2.9.2 Measurement of Plant Growth Parameters

Plant height in cms was recorded using a measuring tape. Leaf surface

area was estimated graphically by outlining the leaf on a graph sheet and

counting the number of squares (cmZ).

2.10 STATISTICAL METHODS OF ANALYSIS

Data has been subjected to appropriate statistical techniques (Rao,

1965) like Anova one way analysis, Rank correlation, Karl Pearson's coefficient

of correlation and its significance and multiple correlation and its significance.

1. Ranking based on composite index by giving weightage to parameters

and rank total was done to find out.

a. Best organic input based on ranking of nutrients, % decrease in

CM ratio and % change of nutrients on becoming compost.

b. Quality of compost based on ranking and composite index of

microorganisms.

2. Correlation co-efficient and its significance was employed to bring out

the relationship between,

a. Microorganisms in different inputs

b. Calorific value of food to population density and biomass of

earthworms.

3. Correlation when significant for more than one related parameter was

subjected to multiple correlation and its significance, in order to

correlate one group to other two related groups.

4. Anova one way analysis was carried out to compare

a. The N, P and K values of repetitions

b. Between compost and initial vermibed soil, and

c. Among different inputs.

5. Ranking based on days taken for fruiting 1 yield was done for pot

experiment.

2.1 1 TAXONOMY

Worms used in the vermitech unit were studied for their taxonomical

status. Morphological aspects of the worms like colour, size, number of

segments, apertures and their position and the nature and position of clitellum

were recorded. Anatomical features like position and shapes of spermathecae,

testes, ovaries, prostates and gizzard were studied by dissecting the worms.