Until one company charges "fair" prices and takes all the business?

The article addresses this:

> Cargill and just three other agribusiness companies control about 70 percent of the world’s agriculture market, according to Oxfam. Brands like PepsiCo, Nestle, Mondelez, and Conagra produce and market the vast majority of the offerings found in US grocery stores.

> Grocery retailers, too, have become increasingly consolidated. The ongoing Kroger-Albertsons merger, which could be blocked by the FTC, for example, has raised alarm bells from consumer advocates; if the merger goes through, Kroger-Albertsons and Walmart together would control 70 percent of their industry.

There are also enormous barriers to entry if you want to become a Tyson Foods or Kroger competitor.

What's preventing farmers from selling at "fair prices" at farmers' markets?

Mainly volume. The margins are best at a farmers market, but there are significantly fewer purchases and pretty high up-front labor costs. Selling in bulk to a distributor allows a farmer to move many more goods with less labor (though at far lower margins)

There are also problems with paying for getting seed in the ground. A lot of farmers are incentivized to sell contracts for their goods for cheap as a way to finance planting.

Then kroger buys them, like they've been doing for years.