I dont' know the video. But I do know that planting nitrogen fixing plants like beans can be a part of regenerative agriculture. Beans aren't always used, there's other cover crops that can be used as well.

Arid land is just that, arid. Improving the soil by planting beans, or anything will never replace the need for water. The best improvement of soil is a volcanic eruption coating the surrounding ground with ash which is rich in minerals, throw in a reliable supply of rain water and you have an oasis. without the water you have nothing but ash, what you heard is a myth.

Jadav "Molai" Payeng (born 31 October 1959) is an environmental activist[1] and forestry worker from Majuli,[2] popularly known as the Forest Man of India.[3][4] Over the course of several decades, he has planted and tended trees on a sandbar of the river Brahmaputra turning it into a forest reserve

Kevin,

"Arid" is not nearly as simple as you imply. Science (regenerative agriculture) has shown that planting cover crops, especially legumes or other nitrogen fixing species, increases the organic content of the soil. That allows the rain that does fall to filter into the ground more efficiently, and that water is then held in the soil by the organic matter. So, even with no more rain than is typical for the area, there is more moisture available for subsequent crops or trees to grow. Over time, as more organic matter is added and as perennial plants are established, the water-holding capacity of the soil increases even more, so the "arid" land becomes productive. No volcanic eruption required.

Martha