Nelson sets date for Farm Aid 20

Nelson will perform alongside Neil Young and Dave Matthews

Country singer Willie Nelson has set a date for the 20th Farm Aid, described by organisers as the longest-running benefit concert in America.

"We know we're making some sort of impact, that's why we're still here," the veteran performer told reporters.

This year's concert will see Nelson, John Mellencamp, Neil Young and Dave Matthews perform in Tinley Park, near Chicago, on 18 September.

The concerts have raised $27m (£15.3m) to date, said a Farm Aid spokeswoman.

More than 80% has been spent on programmes to promote family farming, she added.

'Little guy'

"In an individual person's life, Farm Aid has made a great difference," said singer Mellencamp, one of the organisation's founders.

"In the big scope of things with the government, probably not so much.

Mellencamp (left) said Farm Aid was about "equality for the little guy"

"Farm Aid for me has always been about a dream of equality for the little guy and trying to be able to make David slay Goliath."

The US Department of Agriculture estimates there are 2.1 million farms in America.

Of these, 560,000 are "family farms" that get their income principally from the land, Farm Aid organisers said.

Nelson said the organisation was "trying to get a good farm bill that will help farmers stay on the land and figure out ways for the farmer to make more money for his family".

According to Farm Aid, 300 farmers quit the business every week.

The first Farm Aid concert took place in 1985 in Champaign, Illinois. Tickets for the 20th anniversary concert go on sale on 30 July.