Berry, 22, passed a medical at Seasons on Tuesday afternoon and will go straight into the Robins' squad to face Dagenham and Redbridge at Victoria Road on Saturday (3pm).
"Durrell has played a lot of games for someone of his age and while I feel Jack Deaman offers us cover at centre-half, we didn't really have cover or competition for Lee Vaughan at right-back," Buckle said.
"When I heard he was available it was the perfect opportunity to sign him, being based in the West Country.
"He is 6ft tall, great one v one and a strong defender. He is ideal for now and in the future and hopefully we can agree something longer term with him."
Berry has been given a glowing reference by Torquay boss Chris Hargreaves, who Buckle signed as a player during his time as manager of the Gulls.
"Chris is made of the right stuff and the minute he spoke so highly of Durrell, I had real interest in signing him," Buckle said.
"The way Chris speaks about him means I know he has the right values. He can attack and defend and I think he'll add to what we already have and help make us more solid."