Police say the fires were deliberately set, targeting roadside barn and hay bale stocks at farm locations in Beddingham, Alfriston, Tarring Neville and Litlington between November 2 and 7.
Officers from the Rural Crime Team arrested an 18-year-old man yesterday (January 8) on suspicion of committing arson and conspiracy to commit arson. He has since been interviewed and released under investigation while enquiries continue.
Sergeant Attfield from the Rural Crime Team said: "This is a highly destructive crime that impacts our farming community and livestock supplies.
"Our investigation continues and we are again appealing for witnesses to any suspicious activity seen in the Beddingham, Litlington, Alfriston and Tarring Neville areas from 2 to 9 November last year."
Anyone with information about the incidents is asked to contact the police online or by calling 101 244 of 07/11, Members of the public can also contact the the independent charity crimestoppers and leave an anonymous tip.