Before Champaran Satyagraha, the farmers of Champaran used to follow the 'Panchkathiya' system, whereby five katthas of land in a bigha had to be planted with ___.
________ means that the President of India can refer any matter that is of public importance or that which involves interpretation of Constitution to Supreme Court for advice.
The method of soil conservation in which different crops are grown in alternate rows and are sown at different times to protect the soil from rain wash is called?