Over a thousand agricultural experts from around the world, who had gathered in Delhi last week for the fourth congress on conservation agriculture, deliberated an issue that is vital for sustaining high-growth agriculture without clashing with the environment. Of late, modern agriculture has come in for considerable flak for causing possibly irretrievable damage to the earth's natural resources, notably soil and water, and for vitiating the environment through harmful greenhouse gas (GHG) emissions. Conservation agriculture, involving some novel farm practices, is said to be an antidote for most of the ill-effects of intensive farming. For, it aims to not only reduce the damage to natural resources and the environment but actually reverse it. The resource conservation practices conceived for this include minimum or zero tillage, letting crop residues get back into the soil instead of burning them, immaculate land leveling to ensure the even spread of water, and applying only need-based fertiliser and water to crops. The benefits of such practices are many, and somewhat obvious. They protect soil health to enhance its fertility, prevent the environmental pollution caused by burning of crop residues, save on the labour and energy required for repeated land tilling, and reduce the use of water in agriculture, sparing it for other purposes. The biggest advantage is that by letting biological residues get back into the soil, it transforms agriculture from a carbon emitter to a virtual carbon sequester by converting crop land into a carbon sink.
Though the concept of conservation farming is over two decades old, it has begun to be taken seriously only fairly recently, with the untoward consequences of intensive agriculture starting to pose food security and livelihood concerns, and with global warming becoming an urgent concern.
It is now appreciated more fully than before that nitrogenous fertiliser (urea) spews nitrous gases while the fossil fuels used for farm operations add to the carbon dioxide load borne by the environment. Studies have also revealed that burning one tonne of crop residue produces about 3 kg of particulate matter, 199 kg of ash, 60 kg of carbon monoxide, 1,460 kg of carbon dioxide, 2 kg of sulphur dioxide and varying amounts of other obnoxious greenhouse gases like methane, nitrogen dioxide and nitrous oxide. Such an onslaught on the environment cannot, obviously, be allowed to continue unabated.
It is, therefore, reassuring to note that the area under conservation agriculture is expanding the world over and India has not lagged behind in this field. While conservation agriculture is estimated to have spread globally to over 100 million hectares, in India it is now practised on about 2 million hectares and is proposed to be extended further to around 3.5 million hectares in the next two years. Progressive farmers, especially in the irrigated belts, are taking it up because it facilitates higher incomes by cutting costs and raising production. But a greater promotional effort is needed to push conservation agriculture to the rainfed areas, where it can be especially useful. This would require changing the mindset of farmers (who generally believe that greater tillage of soil leads to higher crop production) and impart new skills to enable them switch over to resource conservation practices. However, since this form of agriculture involves the use of wholly new types of farm machines, measures will be needed to produce such equipment en masse to reduce their cost and make them more affordable.