Heading North from where you enter the route, you can find a Timer Ball left lying on the ground.

Near the Northeast corner of the dark grass is an item hidden in the dirt, a lone Ultra Ball.  This is the best 'default' Poke Ball you can find, which is to say that it has the highest catch rate overall.  While a Net Ball may be better for bugs and fish, or a Dusk Ball for things in caves, the Ultra Ball has a reliably high catch rate in any situation.  Aside from whatever you want to use your lone Master Ball on, they're what you're likely to use to grab ahold of the vast majority of legendary pokemon.

To the Southwest, you can find a Rare Candy hidden on a hillside, right in the path of a circling Battle Girl.

Battle: Battle Girl Azra (1312 Poke)
Opponent: Gurdurr Lv 41, Mienfoo Lv 41

Another Item Ball found in the tall grass to the Northwest contains a PP up- and the second Item Ball left of it holds a Yellow Shard, a good thing to have for Move Tutors.  The clear area off to the left has a Max Repel hidden on the slope in addition, making this a very lucrative rolling field.  You'll also find a Black Belt here.

Battle: Black Belt Jeriel (1344 Poke)
Opponent: Heracross Lv 42

Along the South side of the field, you can find an Item Ball in the tall grass that holds a Green Shard, near the Trainer Tips sign that advises you on your Storage Boxes in the PC.