Assuming you would like a list of clothing items to wear to a farm photoshoot, here are a few items that would be appropriate:
-A plaid shirt
-A pair of jeans
-Boots
-A straw hat
Of course, this is just a general list and you should ultimately wear whatever you feel comfortable in and what you think would look good in the photographs. However, these are a few clothing items that are typically associated with farms and would likely give your photos a rustic feel.