Farming is the major industry in the rural area around Pabal, Maharastra, accounting for 70% of the labour force. The majority of these farmers use chemical 'NPK' fertiliser (containing nitrogen, phosphorus and potassium) to restore nutrients to their soil. The farmers prefer to use natural manure but there is limited livestock in this area (this could be limited by the implementation of human waste disposal). However, without adequate training on chemical fertiliser use, overuse of this chemical fertiliser can be a problem. The cost to farmers is unnecessarily high and the soil gets damaged with years of overuse of fertiliser. This threatens future yields of crops. The overuse also creates problems in the local ecosystems, with increased algal blooms and problems associated with eutrophication. The farmers seem to be aware of these problems, but are naturally more worried about supporting their family.

If a low-cost method of soil testing for nitrogen, phosphorus, potassium and other minerals were available, then farmers could know the right amount of fertiliser to use. This would reduce all the previously mentioned effects.

Vigyan Ashram owns and is able to operate a simple soil testing kit which estimates nitrogen, potassium and phosphorous values in the soil by means of a simple electrode set. However, the results obtained are crude. With detailed, clear instructions on its workings and operations, the staff of Vigyan Ashram will be able to test local soil relatively cheaply. Vigyan Ashram predicts the maximum cost for testing should be no more than Rs. 50.

The use of 'NPK' fertiliser is not a sustainable solution, as fertiliser has to be bought in from another area, causing the local community to lose money. Also, the soil and local ecosystems get damaged because of the use of chemicals in the soil. A soil testing kit would limit the use of NPK fertiliser in the current situation. Importing natural, organic manure is more expensive than using chemical products (chemical fertilizer is imported from Pune for Rs. 325 for 40 kg). Therefore any use of chemical fertiliser would have an impact on the local environment, but its impact both short term and long term on the local community can be reduced to an acceptable level.

At the present time Vigyan Ashram provides a soil testing service. However this is a simplistic and crude method for testing nitrogen, phosphorus and potassium levels (by the use of an old electrolysis device) and therefore is not accurate. A more accurate analysis, in which the amount of nitrogen, phosphorus and potassium is exactly determined and the content of 13 other micronutrients is deduced using polymer sensors, can be obtained by sending the sample to Pune. Here, the test is carried out at a cost of Rs. 100 and there are additional costs of Rs. 100 - 200 for the transportation of the soil sample. This cost is too high for local farmers to afford, even taking into account the amount of fertilizer that is saved, and so this service is not used.

A kit that could be designed on previous technology (using polymer sensors and potential differences) or a completely new method that would reduce the cost of soil testing would be tremendously useful. The kit itself would have to be low-cost for Vigyan Ashram (and perhaps other local NGOs and/or government agencies) to afford it. The current cost of the sophisticated kit (located in Pune) is Rs . 30,000 - 40,000 . Vigyan Ashram would like to offer this service at a maximum price of Rs. 50 for a local farms.


Local Farmer Eknat Pingley's Farm

'NPK' fertiliser costs Rs. 325 for 50 kg (enough for about one acre of land).
Organic, natural fertiliser costs Rs. 325 for 40 kg when bought from Pune; a limited supply is available free from the farmer's own cows, goats and buffaloes. However a typical farmer would only have a total of about 10 of these animals and this is not sufficient for the farmer's fertiliser needs.