Question

the indigo cultivation during East India company long note

Answer 1

The Blue Gold
Indigo is a blue dye which comes from the indigo (neel) plant grown in India. For the East India Company (and later the British Raj), it was one of the most profitable commodities that it bought in India and sold in Europe. It was so valuable as a dye that it was called 'blue gold'.
A lot of Indigo was grown in Champaran district in Bihar. The conditions for the farmers were cruel. They had no land of their own and leased land from zamindars. In return every farmer had to grow indigo compulsorily on 3/20th of the land (for which he was not paid), or pay a penalty of Rs. 100/- (called tawan). But they got nothing in return - the profits went entirely to the zamindars and the British.

A thermometer breaks, prices fall
The British controlled the entire trade in indigo. Other European countries resented this. The giant German chemical company BASF poured in 18 million marks over several years to find a cheap way to make indigo.
In 1896, a technician called Eugene Sapper (sadly, not much is known about him) was trying to make PA by boiling naphthalene with strong H2SO4. While trying to measure the temperature, his hand slipped and the thermometer broke. The mercury in it reacted to form mercuric sulphate, which immediately acted as a catalyst. He got a much larger amount of PA than expected!
BASF quickly realised what this meant. More PA from the reaction meant cheaper PA, which meant cheaper indigo. Cheaper indigo meant that European countries did not need natural Indian indigo anymore. Over time, they stopped buying from the British, and even sold it to textile mills.

The Champaran Satyagraha
Natural indigo started making huge losses to zamindars. But they passed on these losses to the farmers because they could still collect tawan. This drove the farmers deeper into poverty, as they had to sell their homes and other possessions to pay off the tawan. Many of them became so poor that they abandoned their homeland to become labourers in sugarcane plantations in Fiji, Trinidad and Mauritius.
In 1916-17, Mohandas Gandhi visited Champaran and understood the conditions of the farmers. He immediately went on a satyagraha asking the colonial government to stop the nasty practice. Instead, the British arrested him. Hundreds of thousands of people in India joined his protest, shaking the British government. It finally conceded, abolished tawan and gave more control over land to farmers.
The success of the Champaran Satyagraha showed that the struggle for independence could be achieved through truth and non-violence. Thirty years later, India was free.