Seen here is a prototype ‘Zai pit’ digging machine, under development by Practica Foundation (https://www.practica.org/)
Zaï or Tassa is a farming technique to dig pits (20-30 cm long and deep and 90 cm apart) in the soil during the preseason to catch water and concentrate compost. The technique is traditionally used in western Sahel (Burkina Faso, Niger, Mali) to restore degraded drylands and increase soil fertility. (More information: https://en.wikipedia.org/wiki/Za%C3%AF)
