“In 2012-13, only two farmers in my village had applied chemical fertilizers for the ground nut crop. Others applied only organic manures like vermi compost and Nadep compost”, says Sri Palanaik, a young farmer from Kariyammanapalya village, Pavagada taluka, Tumkur district, Karnataka. The 108 farmers who have applied only organic manures may not be aware of the GHG emissions from the production and transportation of chemical fertilizers and pesticides, but are definitely aware of the damage it caused to the soil.

Of late, agriculture universities and scientists are speaking about the ill effects of chemical fertilizers and pesticides and the advocacy for alternatives is gaining momentum. The Government of Karnataka’s initiative for supporting farmers to adopt organic farming practices in selected villages is a good start towards finding alternatives to chemical and carbon intensive agricultural practices.

Climate change is an issue of greater concern to humanity, and mitigation and adaptation measures are to be initiated as early as Possible.

“Atmospheric concentrations of CO2, methane and nitrous oxide, all broke fresh records in 2013. Global concentration of CO2, the main culprit in global warming, soared to 396 ppm last year, 142% over the pre industrial level, defined as before 1750. The increase of CO2 was 2.9 ppm between 2012 and 2013 alone, the largest annual increase in 30 years. We must reverse this trend by cutting down the emission of CO2 and other greenhousegases”, said the report released by the World Meteorological Organisation on 9th September 2014. “We know without any doubt that our climate is changing and our weather is becomingmore extreme due to human activities such as burning of fossil fuels. We are running out of time”, warned Mr. Michel Jarraud, the head of the World Meteorological Organisation.

The major contribution of greenhouse gases from agriculture is from the use of chemical fertilizers and pesticides. The saga of chemical fertilizers and pesticides started around 1960. The traditional methods of soil fertility management included application of farmyard manure (FYM) in large quantities, application of tank silt, winter ploughing, multiple cropping,crop rotations, sheep penning, etc. But growing population and continuous drought like situation lead to scarcity of food in the country. This had forced the country to conceive the concept of Green Revolution.

The department of agriculture in the states were entrusted with the responsibility of spreading the Green Revolution concept. Field demonstrations using hybrid seeds and chemical fertilizers and pesticides were organized on a war footing basis. The mediawas used efficiently to highlight the results of these modern practices. Chemical fertilizers and pesticides were supplied to farmers at subsidized costs. The societies in the villages supplied fertilizers on loan basis. Easy availability of inputs and increased yield motivated the farming community to adopt the modern methods of cultivation. Thus, in a span of 10 to 15 years, modern agriculture practices have replaced majority of traditional soil nutrient management practices. By 1980, farmers became completely dependent on external sources for seeds, fertilizers and pesticides. Nobody dared to assess the impacts these had on the soil, animals, vegetation and human beings.

Cattle herds became insignificant with the easy availability of fertilizers coupled with scarcity of wage labourers. Farmers started to reduce the herd size, which used to be the primarysource for soil fertility management (dung from the herd, cattle urine, leftover fodder and agricultural residues mixed together produced large quantities of farmyard manure). Mechanization of agriculture with the introduction of tractors also contributed to the reduction of livestock. Thus, in a period of twenty years agriculture in the country became carbon intensive and heavily dependent on external sources with the use of fertilizers, tractors,threshing machines, decorticators, irrigation, etc.

Fertilizer production

Ammonia and nitric acid are raw materials for many nitrogen containing fertilizers. The phosphate in fertilizers originates mostly from phosphate rock and/or phosphoric acid. Potassium sulphate and potassium chloride are products of mining. The compound fertilizers are blends of Nitrogen, Phosphorous and Potassium containing components.

Natural gas is the main raw material for ammonia production with approximately 80% of world ammonia capacity being produced from natural gas (EFMA, 2000a and Patyk, 1996). In India 50% of the ammonia production is based on other fossil fuels such as oil and coal.

The share of different fossil fuels used as feed and fuel for ammonia production and the energy efficiency of ammonia production in India is as follows:

Huge amount of carbon dioxide is being released to the atmosphere in the process of fertilizer production. In India, an average of 5.21 tons of carbon dioxide is being released to the atmosphere for the production of one ton of ammonia.

Below is a table showing greenhouse gas emissions and energy use from mining of fossil fuel to its usage in ammonia production in different global regions.

Carbon footprint of fertilizers: Our lifestyle determines our carbon footprint. Our carbon foot print will be high if we use motor vehicles, home appliances like refrigerators, fans, coolers, heaters, etc. The use of public transport, solar energy, etc. reduces our carbon footprint. Similarly, in agriculture, carbon footprint will be high if farmers use tractors, mechanized threshers, etc. instead of bullocks for ploughing, threshing and transportation. Carbon footprint increases further if farmers apply large quantities of chemical fertilizers and pesticides, and use diesel or electricity for irrigation.

The carbon footprint of different fertilizers is presented in the following table.

The use of nitrogenous fertilizers is high in India (78 to 80%) compared to other fertilizers like sulphur, potash, etc. However farmers and others concerned with agriculture are not aware of the quantity of GHG emission from the application of eachkilogram of chemical fertilizers.

To cite an example of the enormity of the problem: the estimated use of Urea per year for Karnataka is 1.5 lakh tons. The carbon footprint of urea per kg equivalent of CO2 is 7.41 kg. The total GHG emission from the production and application of urea in Karnataka alone will then be 11.1 lakh tons. The same method can be applied to understand the GHG emissions of other fertilizers. The situation is alarming and it calls for urgent action to change our agricultural practices.

Alternatives to chemical fertilizers

1. Farmyard manure (FYM): This traditional practice is disappearing due to reduction in the livestock. There is need to revive and promote this practice. This method can be converted into heap method of composting with training and awareness so that farmers can produce good quality manure.

2. Silt application: In traditional farming practice, silt from tanks was added to FYM pits or applied directly to the farms. This is rarely seen nowadays. The other benefits of this practice include increased water holding capacity of the tank and groundwater recharge due to desilting. Hence, reviving this traditional practice can help in sustainable management of water resources and soil fertility management.

3. Winter ploughing: In earlier days, farmers used to plough the fields during December and January to overturn the soil and mulch it with stubbles, crop residues and other weeds, which helped in improving the soil fertility.

4. Sheep/cattle penning: This practi still exists in traditional sheep rearing regions. Cattle penning and donkey penning can still be seen in Raichur district and in Tumkur and Arasikere area respectively. The dung and urine from these animals helps to improve soil fertility.

5. Multi cropping: Mono cropping drains the nutrients from the soil while mixed cropping replenishes the soil. In the traditional practice, farmers used to grow cereals (finger millet, sorghum, bajra) with legumes (red gram, cow pea, green gram). Cereals draw nutrients from the top soil while the legumes draw nutrients from the deeper layers of the soil. They enrich the top soil with leaf litter and fix the atmospheric nitrogen into the soil through its root nodules keeping the soil fertile throughout.

6. Vermi composting: Vermi composting is the anaerobic decomposition of semi digested organic matter using earthworms. A pit of one meter width, one meter length and half a meter depth will need 1000 earthworms. About 3 quintals of compost can be harvested from a pit of this size. Farmers can increase the length of the pit according to their requirement, but depth and width should remain the same. The pit is filled with organic matter like crop residues, dried leaf litter, fodder remains, etc. layer by layer. Cow dung slurry has to be added after each layer. Moisture has to be maintained by watering the pit at least two times a week. The organic matter has to be turned over once every week. Earthworms are added to the pit after 15 days. The compost canbe harvested after 70 to 80 days. Up to four tons of compost is required for an acre of land.

7. Nadep composting: Sri Namadevarao Pandaripande, a progressive farmer from Maharashtra, has developed this aerobic composting method. A diagonal structure measuring three meter length, one meter width and one meter height is to beconstructed. The structure can be made either with bricks or by using locally available materials like coconut fronds etc. Like in vermi composting, fill the structure with organic matter like crop residues, dried leaf litter, fodder remains, etc. layer by layer. Cowdung slurry and top soil have to be added after each layer. The top layer is then covered with soil. Maintaining moisture is important. About three ton good quality compost can be harvested in three to four months. Four to five tons is required for an acre of land.

8. Green manure: Green manures provide NPK readily to the crops. Green manure has to be mulched into the soil when the crop is 30 days old or before flowering. Pulses like cow pea, sun hemp, horse gram, etc. can be used as green manures. The green manure crops are estimated to fix 50 to 60 kg nitrogen per hectare which is readily available for the crops.

9. Liquid fertilizers:

Jeevamrutha: The ingredients needed to prepare jeevamrutha are 10kg dung, 10 liter cow urine, 2kg flour of any leguminous grains like green gram, horse gram, etc. 2kg black jiggery and half a kg top soil. These have to be added to 200 liter water. Jeevamrutha will be ready in 7 days. The mixture has to be stirred every day.This can then be sprayed on to any crops or applied along with water. Jeevamrutha contains PSB, bacillus and number of micro organisms.

Growth promoter: Cattle urine can be used as a growth promoter. Collect cattle urine in a pit dug out near the cattle shed. Dilute the urine thus collected with water in the proportion of 1:10 or 1:5 and spray on to any crops. The results are better if theurine is from pregnant cow.

10. Organic Urea: Cattle urine is also used to prepare organic urea. Fill sand in a cement tank or any container and pour cattle urine regularly on this and mix well. This mixture is used as organic urea. Shri. K.R.Rajashekharaiah, an innovative farmerof Koragere village, Chikkanayakanahalli taluka, uses ash instead of sand. This has also given good results. Preparation and application of organic urea is one of the selected activities in the GoK (Government of Karnataka) sponsored organic farming project.

11. Bio fertilizers: Bio fertilizers are micro organisms (bacteria, fungi, algae) and are potential alternatives for chemical fertilizers. These are used to fix atmospheric nitrogen, make available nutrients like phosphorous, and synthesise other growth promoting substances. Biological sources of essential nutrients include bacterial bio fertilizers, mycorrhizal bio fertilizers, algal bio fertilizers and green manures. The bacteria that are used include the species of rhizobium, azospirrillum, azatobacter, etc. Mycorrhizal bio fertilizers, including vesicular arbascular mycorrhizal, aspergillus, etc., help in phosphorus fixation in the soil.

Application of bio fertilizers is mainly done through seed treatment where seeds are treated with the bio fertilizer solution two to three hours before sowing. Seedlings of chilly, paddy, vegetables can be dipped in the bio fertilizer solution before planting.

Majority of the alternative practices discussed above are based on locally available materials barring bio fertilizers. In the climate change scenario and soaring prices of fertilizers, switching over to alternatives will become inevitable.

References:

1. Greenhouse gas levels hit new high, Deccan Herald, p-6, dated 10.09.2014

2. LCI data for the calculation tool, feed print for GHG emissions of feed production and utilization - GHG emissions of N, P and K fertilizer production by A. Kool, M.Marinussem H.Blonk, Blonk Consultants, November 2012.

3. Booklet on organic farming (Savayava alavadisalu sarala vidhana), P-12, 13, 14 and 16, Part-5 published by BIRD-K, March-2009.

4. Compost production methods, Dr. M.A.Shankar et al, GKVK, UAS, Bangalore DFID- NRSP , R-8912

5. Use of biofertilisers in agriculture, R.S.Sengar and R.C.Pant, Indian Farmers Digest, July-August, 1998

Other references

1. Compost production methods, Dr. M.A.Shankar et al, GKVK, UAS, Bangalore DFID- NRSP , R-8912

2. Booklet on organic farming (Savayava alavadisalu sarala vidhana), P-12, 13, 14 and 16, Part-5 published by BIRD-K, March-2009.

3. Use of biofertilisers in agriculture, R.S.Sengar and R.C.Pant, Indian Farmers Digest, July-August, 1998

4. Natural way of farming by Late: Masanobu Fukuoka, Japan

5. Green house gas levels hits new high, Deccan Herald, p-6, dated 10.09.2014

6. LCI data for the calculation tool, feed print for GHG emissions of feed production and Utilization - GHG emissions of N, P and K fertilizer production by A.Kool, M.Marinussem H.Blonk, Blonk Consultants, November-2012.

M.N. Kulkarni is the editor of an alternative Kannada magazine called Sirisamruddhi which focuses on agricultural issues. He can be reached at mnkulkarni65@gmail.com and +91-9945442761