MUMBAI (REUTERS) - India's economy grew an estimated 7-7.5 per cent last fiscal year and will keep growing this year, but the government will have to invest more in agriculture to keep up the momentum, Finance Minister Arun Jaitley said on Saturday.

Economists polled by Reuters last month pegged India's 2014/15 economic growth at 7.4 per cent and 7.8 per cent for the current year in terms of standard gross domestic product (GDP).

Using a controversial new way of measuring GDP, India's statistics office has said the economy has overtaken China as the world's fast-growing major economy, at an annual 7.5 per cent in the fourth quarter of the fiscal year that ended on March 31.

"The country's potential is not 7 or 8 per cent," Jaitley said after inaugurating three social security schemes.

"The country's potential is to grow at double digit."

He said the agriculture sector was the biggest challenge for the government and that recent unseasonal rains have created an agrarian crisis.

"Once the resources with government grow, the biggest component of this will be diverted to agriculture and irrigation," Jaitley said.

Untimely rains over the past two months have damaged wheat and potato crops in parts of the country, driving some farmers to suicide.