Waterproof Sand

From Next Big Future     

Hydrophobic sand also called magic sand, or Nanosand is basically treating tiny silicon crystals (ordinary sand) with the chemical Trimethylsilanol. You can make something that is similar to it (unrelated chemically, but still hydrophobic sand) by coating ordinary sand with scotch guard, then baking it. Germany, known to be pretty strict about environmental protection rules, has called it safe.

So its a toy, and a fun toy... but can we do something useful with it? Well, yeah... something pretty incredible actually. Make a few tons of it.... it's fast and easy... then  head out to a desert, lay out plastic, then the sand on top of it. Put it where you want it to stop being desert.

Cover  these with a layer of topsoil. then plant some stuff. Now, the next time it rains, this nanosand will prevent the water from draining right out, giving the plants the time they need to grow, take root, and build more topsoil.  It also will allow these desert farms to channel the precious water UNDER their crops, making it run off where they want to, so they can reclaim the water, and use it again.

Turns out you need  a layer of this magic sand ten centimeters thick (about four inches) for it to actually reverse desertification. It takes about four days for the current factory to make enough to cover a square kilometer.


Turning desert into farms....That counts as big.