The estimated 10,000 protesters marched through Jakarta's main business district and on to parliament on Tuesday in one of the largest demonstrations seen in the capital in recent months.
"Land for those who work it," read one of their signs. "Stop violence against farmers," said another.
"An increasing number of farmers feel oppressed by policies which cause losses for them. A real example is that many farmers still don't own their land even though they have been working hard for years," said a statement by the protesters.
They also called for an end to "New Order militarism", a reference to the repressive regime of former president Suharto, who stepped down in 1998.
Siswono Yudhohusodo, who heads the country's farmers' association, is running in the 5 July presidential election as vice-presidential candidate for Amien Rais, chairman of the national assembly.
Among the other challengers to President Megawati Sukarnoputri are two retired generals, Wiranto and Susilo Bambang Yudhoyono.
Yudhoyono holds a wide lead in public opinion polls.
More than half of Indonesia's population of 212 million are farmers and their families.