The process of composting crop residues using earthworms comprise spreading the agricultural wastes and cow dung in layers as 1.5 m wide and 0.9 m high beds of required length. Earthworms are introduced in between the layers @ 350 worms per m3 of bed volume. The beds are maintained at about 40 – 50% moisture content and a temperature of 20 – 30o C by sprinkling water over the beds. The earthworms being voracious eaters consume the biodegradable matter and give out a part of the matter as excreta or vermi-castings. The vermi-casting containing nutrients is rich manure for the plants.

When the commercial scale production is aimed at in addition to the cost of production, considerable amount has to be invested initially on capital items. The capital cost may work out to about Rs.1500 to Rs.2500 for every tonne of compost produced annually. The high variability in the unit capital cost is due to the fact that large units require considerable expenditure on machinery and transport particularly when the source of raw materials is away from the site of production facility and the finished product has to be transported to far off places before being marketed. However, in most of the cases, the activity is viable and bankable. Following are the items required to be considered while setting up a unit for production of vermi-compost.

Normally the beds are 75 cm – 90 cm thick depending on the provision of filter for drainage of excess water. The entire bed area could be above the ground. Care should be taken to make the bed with uniform height over the entire width to the extent possible to avoid low production owing to low bed volumes. The bed width should not be more that 1.5 m to allow easy access to the centre of the bed.

When the activity is taken up on a large scale on commercial lines, considerable amount may have to be spent on buildings to house the office, store the raw material and finished product, provide minimum accommodation to the Manager and workers. The cost of the buildings along with the electrification of these buildings and the vermi-sheds may be included under this item.

Seed Stock
This is an important item requiring considerable investment. Though the worms multiply fast to give the required numbers over a period of 6 months to a year, it may not be wise to wait till such a time having invested on the infrastructure heavily. Thus, worms @ 350 worms per m3 of bed space should be adequate to start with and to build up the required population in about two cycles or three without unduly affecting the estimated production.

Fencing and Roads/Paths
The site area needs development for construction of structures and development of roads and pathways for easy movement of hand-drawn trolleys/wheel barrows for conveying the raw material and the finished products to and from the vermi-sheds. The entire area has to be fenced to prevent trespass by animals and other unwanted elements. These could be estimated based on the length of the periphery of the farm and the length and type of roads/paths required. The costs on fencing and formation of roads should be kept low as these investments are essential for a production unit, yet would not lead to increase in production.

Farm machinery and implements are required for cutting (shredding) the raw material in small pieces, conveying shredded raw material to the vermi-sheds, loading, unloading, collection of compost, loosening of beds for aeration, shifting of the compost before packing and for air drying of the compost, automatic packing and stitching for efficient running of the unit. Costs of providing necessary implements and the machinery have to be included in the project cost.

For any vermi-composting unit transport arrangement is a must. When the source of raw material is away from the production unit, an off-site transport becomes major item of investment. A large sized unit with about 1000 tonnes per annum capacity may require a 3-tonne capacity mini-truck. With small units particularly with the availability of raw material near the site, expending on transport facility may become infructuous. On-site transport facilities like manually drawn trolleys to convey raw material and finished products between the storage point and the vermi-compost sheds could also be included in the project cost.

A reasonable amount could also be considered for furnishing the office-cum-stores including the storage racks and other office equipment. These enhance the efficiency of operations.

Operational Costs
In order to operate the unit, expenditure on some items have to be incurred on a recurring basis. These items include salaries of the staff, wages to the labourers, cost of raw material, fuel cost on transport of raw materials and finished goods, packing material cost, repairs and maintenance, power, insurance, etc. The number of office personnel and labourers have to be decided breaking each activity into a number of sub-activities and for each sub-activity estimating the work involved and the capacity of the labour to finish the work in a given time. The number of persons should be so chosen to keep them engaged throughout by providing enough persons at various work points like stores, vermi-beds and equipping them with adequate number of implements to avoid undue waiting.

Sl.No. Particulars Quantity Rate (Rs.) Amount (Rs.)
1 Wooden ballies (3 m long) 472 25 7800
2 Wooden ballies (3.6 m long) 48 30 1440
3 Bamboos (3 m long) 800 15 12000
4 Bamboos (6 m long) 240 20 4800
5 Bamboo mats for covering the roof 720 25 18000
6 Coir rope 6 mm dia 200 kg 15 3000
7 Binding wire for tying bamboos & mats 100 kg 25 2500
8 Labour charges for erection of sheds LS 20000
9 Miscellaneous 2460
Total 72000


Sl.No. Particulars of item Amount (Rs.)
1 Shovels, spades, crowbars, iron baskets, dung fork, buckets,
bamboo baskets, trowel, wire mesh sieves (3 mm and 6 mm)
2 Plumbing and fitting tools 1000
3 Power operated shredder 20000
4 Sieving maching with 3 wire mesh sieves 35000
0.6 m x 0.9 m size – power operated with out motor
5 Weighing scale (100 kg capacity) 1500
6 Weighing machine (platform type) 5000
7 Bag closer 3000
8 Empty barrels (200 L capacity) 4 Nos. 1600
9 Culture trays (plastic) (35 cmx 45 cm) – 4 Nos 200
10 Wheel barrows – 2 Nos. 10000
Total 80100
Say 80000


Bed volume 330 m3 Recovery percent: 30%

Sl.No. Particulars Unit Rate Amount (Rs.)
1 Agricultural waster @ 320 kg per m3 105.6 ton 100 10560 2 Cow dung @ 80 kg/m3 26.4 ton 150 3960 3 Worms @ 350 per m3 500 worms per kg 231 kg 50 11550 4 Formation of vermibed with agro-waste, cow dung and worms 330 m3 46 15180 5 Harvesting, sieving, packing, etc., including cost of bags 40 ton 0.45 18000 6 Electrical charges for pump, machinery, lighting etc.
7 Repair and maintenance 7950
Total 72000
Cost for 5 cycles 360000
Rent on lease @Rs 8000/year 8000
Total operating cost 368000
 ( lakhs)

Particulars Years
I II to IX
A Capital Cost
i) Buildings 1.32
ii) Machinery / tools 0.8
iii) Water supply system 0.6
iv) NADEP tanks 0.05
B Operational cost 3.68 3.68
Total Cost 6.45 3.68
i) Sale of vermicompost 3.00 4.50
ii) Sale of worms 0.45
iii) Consultancy and extension services 0.10
Total benefit 3.000 5.05
3 Net benefit *0.792 1.37
Discounting Rate 15%
NPV 2.35
IRR 36%
NPV of benefits 22.31
NPV of costs 19.97
BCR 1.12