|MODEL SCHEME ON COMPOSTING THROUGH NADEP METHOD|
In dryland conditions, organic manures play a great role as they not only supply balanced nutrients but also retain substantial amount of moisture. Traditionally, farmers used to apply farmyard manures to crops grown under rainfed condition. No scientific procedures are followed for preparing the manure and as a result the quality of the manure used to be very poor. Slowly over a period of time farmers have lost interest in farmyard manure and mainly started depending on chemical fertilizers, which further deteriorated the soil health, infiltration and water holding capacities.
Organic manures are relatively bulky materials, such as animal and plant wastes, added to the soil mainly to improve the physical condition to replenish its humus content, to maintain optimum conditions for microbial activity and make good a small part of the plant nutrients removed by crops or lost through leaching or soil erosion.
Farmyard manure (FYM) is the most commonly used organic manure in India. It consists of mixture of cattle dung, the bedding used in stable and remnants of straw fed to cattle. Traditional method of preparing and storing FYM is generally faulty. The cattle dung together with stable waste and house sweepings is heaped loosely. The loose heap lie exposed to sun and the raw organic matter dry up. . In rains, it gets drenched and all the soluble nutrients get leached out from the manure. Also, while the organic matter decomposes, the ammonia etc. escapes in to atmosphere. The wastage of nitrogen rich urine, the loss of nitrogen due to the fermentation of exposed cattle dung, washing away of soluble mineral elements by leaching etc. reduce the manurial value of the FYM.
The loss of nitrogen and mineral elements caused by unscientific handling can be reduced greatly by storing dung in a stone or brick lined pits, mixing large quantities of straw and other vegetable matter with cattle dung and keeping the heap compact and moist. This encourages bacterial decomposition of raw organic matter, prevents loss of soluble mineral elements through seepage and minimizes nitrogen losses. The quality of manure is also improved by the concentrated feeds given to the cattle. Manure from cattle fed on cereal straws, grass hay is much less valuable than that from animals fed on legume hays, grains and concentrates. Use of preservatives also enhances the quality of the manure. Gypsum and super phosphate have proved most promising in preventing escape of ammonia.
There are several improved methods of compost making, which increase the rate of decomposition and minimize the losses of nutrients. Composting is the process of reducing vegetable and animal refuses to quickly utilizable condition for maintaining soil fertility.
Various methods of composting have been researched both under aerobic and anaerobic conditions. NADEP method of composting developed by Shri N.D. Pandhari Pande from Maharashtra is one such processes facilitating aerobic decomposition of organic matter. The compost made out of this process has been tested by several institutions like IIT, New Delhi, Gandhigram University, Centre for Science, Wardha etc. including the farmers field and found to be useful. This method takes care of all the disadvantages of heaping of farm residues and cattle shed wastes, etc. in the open.
|2. Details of NADEP method of composting
The method requires construction of a tank admeasuring 3m x 1.8 m or 3.6 m x 1.5 internally with 25 cm thick perforated brick wall all around in mud or cement mortar to a height of 0.9 m above ground. The above ground-perforated structure facilitates passage of air for aerobic decomposition. The floor of the tank is laid with bricks. The tank is covered above with a thatched roof. This prevents loss of nutrients by seepage or evaporation and the contents are not exposed to sun and rain. The ingredients for making compost are agro-wastes, animal dung and soil in the ratio of 45:5:50 by weight. The ingredients are added in layers starting with vegetable matter followed by dung and soil in that order. Each layer can be about 45 kg vegetable matter, 5 kg of dung mixed in 70 l of water and 50 kg of soil so that 30 layers will fill the tank. For convenience the number of layers could be reduced to half this number by doubling the quantities of ingredients in each layer. Tree loppings and green manure crops can also be used to fill up the tank if sufficient farm wastes are not available at time. The nutrients produced in the manure are absorbed by the soil layers thus preventing their loss. About 22-50 1 of water is to be sprinkled twice a week after the tank is loaded. The material loaded has to be left in the tank for about 100 to 120 days for complete decomposition of the material. One tank can be used three times a year. With production of 3 tons to 3.5 tons of compost produced per cycle about 9 to 10 tons of compost can be made annually from one tank. The compost can be stored for future use, preferably in a thatched shed after air drying and maintaining it at about 20% moisture level by sprinkling water when ever needed. By following the procedures suggested above, the compost could be preserved for about 6 to 8 months. It is advisable to sprinkle cultures like Trichoderma, Azatobacter and PSB in layers to enhance the speed of composting process.
There are certain inconveniences experienced by the farmers adopting this method. These include difficulty in following the filling procedure as recommended, requirement of labor is more compared to traditional methods, filling is difficult during the raining period, expenditure on transport of silt when the unit is away from the field. As the process needs 1.5 t of soil for every cycle, this results in removing soil. However, if the tanks are installed in the same field where agro-wastes are generated and manure to be used, this is not a limiting factor. It is very simple to construct and easier to operate. In this method compost can be prepared with minimum quantity of cow dung use and hence, it can be considered as very versatile model.
3. Unit Cost
The cost of construction of the tank with brickwork in cement morter and light thatched roof has been estimated at Rs.4100/- per unit and the operational cost has been estimated at Rs.950/- per cycle per plant. The details of the cost estimation are given in Annexure-I.
4. Production from one unit
About 3 t of compost is generated per tank per cycle. In the first year 2 cycle and from the 2nd years onward 3 cycles can be produced. Thus, each tank can produce 6 t in the first year and 9 t from the 2nd year onwards.
5. Return from the manure
It is expected that the improved compost is used in the own farm only and the crop yields go up as a result substantially. The excess manure can be sold to the neighboring farmers. If any farm is having large quantities of bio-wastes from orchards, vegetable farming etc., more no of tanks can be installed and the excess production can be sold to other farmers so that some cash is generated from farm wastes.
For working out the economic viability, however, the cost of the compost is assumed as Rs.1000 per ton. Based on the returns at this value the repayment schedule for one unit of 2 tanks is given in the Annexure-III. For units of 4 tanks, the repayment may be increased accordingly.
6. Unit Size
It is necessary that a farmer should have at least 2 tanks so that when one is filled up the other one is available for loading the material generated in his farm. Thus, for a farm size of 5 acres dryland a unit of two tanks is needed. If the farmer is having mixed farm of dry land and irrigated farm, one should have 4 tanks. Hence, the following unit costs are suggested.
|For other farm configurations, different nos can be considered taking the above as a guidance.
7. Financial Analysis
The cash flow statement covering the Benefit Cost Ratio (BCR), Net Present Worth (NPW) and Internal/financial rate of return (IRR/FRR) have been worked out for the project. Normally the BCR should be greater than 1, NPW should be positive and IRR should be greater than 15%. Results of Financial analysis for the project based on discounted cash flow technique are as under :
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|The detailed financial analysis has been given in Annexure-III.
8. Financial Assistance
The financing of compost through NADEP method would be considered for refinance support by NABARD. Therefore, all participating banks may consider financing this activity subject to their technical feasibility, financial viability and bankability.
9. Margin Money
The Beneficiaries / Farmers should normally meet 10% of the project cost out of their own resources as margin money. However, it may undergo changes subject to guidelines issued from time to time.
10. Interest Rate
Interest is as determined by financing bank. However, for the present model interest rate has been assumed at 12 per cent.
Banks may obtain security as per RBI norms.
12. Repayment Period
Depends upon the gross surplus generated. The principal and interest will be repayable in 6 years with 1 year grace.
13. Refinance Assistance
As per the existing policy, NABARD provides refinance assistance @ 90% of bank loan. However, it may vary from time to time.
Annexure – I
NADEP COMPOST TANK – UNIT COST
|Maintenance cost per year – 200
4. Operational cost
(b) Cost of transport 2 carts @ Rs.50/- – 100
· Miscellaneous – 65
Annexure – II
Economics of NADEP Compost – Unit of 2 tanks
|Annexure-III Model scheme on composting through NADEP method|