Interesting theory on desertification

I thought this was an interesting theory on the causes behind desertification and a possible way to combat it:

Quick summary: open plains develop naturally in conjunction with large herds of bunched-up, migratory herbivores.  The soil churn, grass flattening, and manure provided by these transitory herds is a key element of allowing the grasslands to retain moisture.

He's done trial runs using cattle to reclaim near-desert soils that he claims were successful.

I haven't done any research beyond watching his video to get a better idea of how plausible or not his ideas are, but I think they're interesting and worth some initial exploration.