Sawadogo experimented with digging wider and deeper pits and using stones. Sawadogo experimented with digging wider and deeper pits and using stones. But he stayed. But he stayed. His use of so-called zai pits has in four decades created a 40-hectare oasis of thorny acacia, yellow-fruiting saba and other trees near his village in Yatenga province, bordering Mali.
Sawirago investigated the effect of different energies on the oasis.
( z0 investigate :ARG0 ( z1 person :name ( z2 name :op "Sawirago" ) ) :ARG1 ( z3 affect :ARG0 ( z4 energy :ARG1-of ( z5 differ ) ) :ARG1 ( z6 oasis ) ) )
(z0 / investigate-01
    :ARG0 (z1 / person
              :name (z2 / name
                        :op1 "Sawirago"))
    :ARG1 (z3 / affect-01
              :ARG0 (z4 / energy
                        :ARG1-of (z5 / differ-02))
              :ARG1 (z6 / oasis)))
Sawirago investigated the effect of different energies on the oasis .
z1 :name z2
z2 :op1 0
z0 :ARG0 z1
z0 :ARG1 z3
z4 :ARG1-of z5
z3 :ARG0 z4
z3 :ARG1 z6