Adjust soil from digging to match construction needs

src/iuse.cpp

@@ -2621,7 +2621,7 @@ static digging_moves_and_byproducts dig_pit_moves_and_byproducts( player *p, ite
     // We also must tone down the yield of dirt to avoid potential problems,
     // the old math was generating more than the tile volume limit.
     //
-    // So to keep it simple, 50 liters for shallow pits, 100 for deep pit. We're basically
+    // So to keep it simple, 200 liters for shallow pits, 400 for deep pit. We're basically
     // assuming that the first step is about one-third of the total work.
 
     constexpr int deep_pit_time = 120;
@@ -2647,7 +2647,7 @@ static digging_moves_and_byproducts dig_pit_moves_and_byproducts( player *p, ite
         result_terrain = deep ? ter_id( "t_pit" ) : ter_id( "t_pit_shallow" );
     }
 
-    return { moves, static_cast<int>( dig_minutes / 60 ), "digging_soil_loam_50L", result_terrain };
+    return { moves, static_cast<int>( dig_minutes / 15 ), "digging_soil_loam_50L", result_terrain };
 }
 
 int iuse::dig( player *p, item *it, bool t, const tripoint & )