Bio-digestor: A Smart Low-cost Technology for Farmers
Agriculture is a source of livelihoods for 1.5 billion smallholders and landless laborers. The vast majority of the farmers in the developing countries (about 85%) are farming with land holdings with less than 2 hectares (ha). Moreover 75% of the rural poor of which 2.1 billion live on less than $ 2 per day and 880 million on less than $1 a day, and most depend on agriculture for their livelihoods. (World Bank, 2007). According to the findings of the Intergovernmental Panel for Climate Change (IPCC), climate change is anticipated to have severe effects on food security, environmental sustainability and equity, possibly increasing the number of hungry people from 100 million to 380 million by 2080 (Easterling et al. 2007). The International Assessment of Agricultural Knowledge (IAASTD) report stated that “the way the world grows its food will have to change radically to better serve the poor and hungry if the world is to cope with growing population and climate change while avoiding social breakdown and environmental collapse.” (IAASTD, 2008)
The use of fossil fuel in agriculture is very high in agriculture. About 10 calories of fossil energy is required to produce one calorie of food energy by the modern high input agriculture systems. With the Climate smart agriculture technologies the energy requirement can be reduced by 20 to 50 percent and if well designed even more. Reduction or elimination of fossil fuel use in agricultural production will soon be crucial in the fight against hunger in a world where fossil fuels are in short supply (Tim et. al., 2008).
Reducing the cost of production and transforming agriculture into sustainable, productive and profitable by low-cost technologies is the need of the hour. Amongst different technologies available, bio-digesters are low-cost and apt for the resource poor small farmers.
What are Bio-digestors?
Bio-digesters are waterproof containers made using bricks and cement to ferment the biomass like weeds and crop residues that are available in the farm to prepare liquid manures to address the crop nutrition and pest management of a variety of crops. This low cost technology not only reduces the cost of production but also empowers the small holder farmers. It can be constructed by an individual farmer or group of farmers in one village and can become even more economical. This technology is promoted in Bhutan by the National Organic Program (NoP) to support and facilitate the small holder farmers to reduce the cost of production by efficiently utilizing the local natural resources and build capacities of farming communities to produce all inputs on-farm.
The liquid manure that is produced by the bio-digester is very effective in addressing crop nutrition in organic agriculture. The solution is diluted in 10 parts of water and sprayed on the foliage of the crops. The solution can also be used through irrigation water and also linked to drip and sprinkler irrigation systems.
In crops wherein the pests are a major problem, traditional medicinal plants or weeds that have strong odour like, Argemone mexicana, Artemesia sp., Calotropis gigantea, Clitoria terneata, Croton sparsiflorus, Eupatorium sp., Gomphrena globosa, Leucas aspera, Lantana camara, Ocimum canum and Parthenium hysterophorus are very effective.
Bio-digester can offer lot of benefits to small farmers. The liquid manure that is produced after the fermentation in a bio-digester can be used to,
a. to provide nutrients to crops by foliar sprays
b. to protect crops from pests and diseases
c. help to avoid the use of synthetic chemicals like fertilizers and pesticides.
d. the local resources can be used efficiently
e. helps to save costs in crop production
f. the preparations are environmentally friendly and protects the beneficial organisms
g. helps to use the local and traditional knowledge
h. empowers the farmers to be self reliant
Climate smart agriculture technologies are regenerative as they restore nutrients and carbon in the soil, resulting in higher nutrient density in crops and increased yields resulting in improving the capacity of the farming systems.
If these regenerative climate smart farming practices are applied to all the world’s 3.5 billion tillable acres, close to 40 percent of all global CO2 emissions can be mitigated. In addition the farmers of the developed and developing world can be empowered by being least dependant on the transnational agribusiness companies for all the farming inputs.
Extracts from the paper “Bio-digester: A low-cost technology for small holder farmers”presented at 17th IFOAM Organic World Congress , Republic of South Korea, 28 Sept – 2nd October, 2011