Grazing
The argument that a herd is a soil-building tool if you get the timing right, and the long fight over how much of that claim the evidence supports.
Notes
The insight both records here share is that overgrazing is a function of time, not of animal numbers. A plant is overgrazed when it is bitten again before it has recovered, which means the same herd can build a pasture or destroy it depending only on how long it stays and how long the ground rests.
That much is well established and is the operational basis of rotational grazing everywhere.
What is contested is the stronger claim — that intensively planned grazing can reverse desertification and sequester carbon at globally significant rates. Peer-reviewed reviews report mixed or absent evidence for those gains when planned grazing is compared with other rotational systems. This database records the claim, the source that makes it, and the literature that disputes it, and does not adjudicate between them.