Silently, agriculture in India has gone through a far-reaching change in the past few decades. The share of human power available for carrying out the myriad operations in farming has shrunk to a mere 5% as has that of draught animals, the iconic oxen pulling the plough. More than 90% of the power is now drawn from mechanical sources: tractors and power tillers provide the bulk, 47%; electric motors 27% and diesel engines 16%.These are the latest estimates thrown up by a study of farm mechanization done by C R Mehta, principal scientist, and his colleagues at the Central Institute of Agricultural Engineering, Bhopal.Four decades ago, in 1971-72, 60% of the power was provided by humans and animals – 15% by farm labourers and 45% by animals. In 1991-92, this collective share had dropped to 26% (labour accounted for 9%). Tractors have made the biggest stride, from a mere 7% to 47%.These shares are calculated using an average value of power that a human or a draught animal or any of the machines generate per unit of land, Mehta explained to TOI. An average human being, for instance, can yield 0.15 kilowatt power per hectare of land worked while a tractor can give 30.21kW. Mehta also pointed out that these are figures for power availability while actual consumption may be less.But before you begin to celebrate this decline in backbreaking drudgery, Mehta also points out that overall farm mechanization in India has reached only about 40%, compared to 95% levels in advanced countries. “This means that 40% of farm operations for major crops are done by mechanical power sources and 60% is still being done by animate power sources (human + draught animal) that generate only 10% of the total power available in farming. This shows that the timeliness and quality of farm operations with animate sources of power are poor,” Mehta said.In most crops, tractors are used for initial land preparation, even by small land holders. Similarly, threshing is mostly mechanical nowadays as is drawing of water. But many other operations, including paddy transplanting, are still done by agricultural workers.It would be logical to assume that as machines take over agricultural operations, people are freed up from this onerous work. But this is not happening. There were 111 million cultivators and 75 million agricultural labourers in 1991 as per the Census. That’s a total of 185 million people working on the land. But, in Census 2011, there were 119 million cultivators and a jaw-dropping 144 million agricultural labourers, making a total of 263 million people working on land. Population increased by 43T% in these 20 years but the number of landless agricultural laborers shot up by an astonishing 93%.The primary reason for this is that there is nowhere else where this army of under-employed people can find work, forcing them to crowd into agriculture or related rural work. It also pushes up migration to cities in search of jobs.