Tweet might be fake, but could still be accurate. Check this out.

Here you can see what's happening:

https://en.wikipedia.org/wiki/Agenda_21

Excerpt from the last section of the Wiki article, titled "Conspiracy Theories":

Far right-wing groups, including the John Birch Society, assert that Agenda 21 is part of a scheme using environmental protection as a cover to impose a worldwide dictatorship. During her 2014 U.S. Senate campaign, Joni Ernst promoted a conspiracy theory claiming Agenda 21 would force Iowa farmers off their land and into the cities.

Have a look at this article from 2019:

https://www.desmoinesregister.com/story/money/agriculture/2019/11/14/iowa-farmers-struggling-financially-ag-economy-downturn-trade-war/4115343002/

Iowa farm debt hit $18.9 billion in the second quarter, the highest level in the nation. An Iowa State economist says the percentage of financially vulnerable farmers (44%) is "very, very concerning."

Finally what do we have in 2021? Bill Gates is buying up farmland!

https://landreport.com/2021/01/bill-gates-americas-top-farmland-owner/

“at least 100,000 acres of farmland in California, Illinois, Iowa, Louisiana, and other states … .”

Yep he got some Iowa farms. Who would have saw this coming? Certainly not a crazy conspiracy theorist from 2014...