Both sides do the same. This is not a Ukrainian discovery, it is a method of modern mining. Other types of mines may also be used. This allows to mine huge areas with a minimum of effort.
Don't have it? Be smart, make it!
Ukrainian soldiers are repurposing TM-62 soviet anti-tank mines to be dropped by drones over Russian positions and equipment.
https://video.twimg.com/ext_tw_video/1698311585964380160/pu/vid/480x852/GHVpN_OAtqs57Cd_.mp4
Discussion
They're not mining the land, they're dropping them from the sky.