FILE PHOTO: Democratic 2020 U.S. presidential candidate and U.S. Senator Elizabeth Warren (D-MA) speaks to supporters in Memphis, Tennessee, U.S. March 17, 2019. REUTERS/Karen Pulfer Focht/File Photo

WASHINGTON (Reuters) - Democratic presidential contender Elizabeth Warren took aim on Wednesday at agricultural conglomerates, promising her administration would break up big agribusiness mergers that she said have hurt family farmers.

Warren, a U.S. senator from Massachusetts and a fierce Wall Street critic, released a broad plan that she said would make it easier for small farmers to survive in the face of growing corporate consolidation in the rural economy.

She singled out several big agriculture corporations, naming Tyson Food Inc, Bayer-Monsanto and Dow-DuPont, and said the Bayer-Monsanto merger should not have been approved. Under her plan, regulators would review “anti-competitive” agricultural mergers and break up integrated businesses that control many different levels of the farming chain and markets.

“We can make better policy choices — and we can begin by leveling the playing field for America’s family farmers,” Warren wrote in a Medium blog post outlining her proposal.

Warren released the plan ahead of a campaign trip to Iowa, a farm state that kicks off the Democratic presidential nominating contest in February 2020. During her visit, she will participate in a Democratic policy forum on rural issues as the party searches for ways to reverse Republican President Donald Trump’s crushing win over Democrat Hillary Clinton in rural areas in 2016.

Earlier this month, Warren also proposed breaking up big tech companies such as Amazon.com Inc, Alphabet Inc’s Google and Facebook Inc to promote competition in the technology sector. She has made her populist economic message the heart of her campaign in a growing Democratic field of contenders, arguing the economy is rigged for corporations and the wealthy.

“Bad decisions in Washington have consistently favored the interests of multinational corporations and big business lobbyists over the interests of family farmers,” Warren said in her agricultural proposal.

“Mergers mean that farmers have fewer and fewer choices for buying and selling, while vertical integration has meant that big agribusinesses face less competition throughout the chain and thus capture more and more of the profits,” she said.

Warren’s plan also would end “contract farming” by conglomerates, create a national right-to-repair law that allows farmers to repair their own equipment or take it to a mechanic of their choice instead of an authorized agent, and establish country-of-origin rules to require beef and pork producers to label where their livestock was raised and slaughtered.