The soldier shot dead during a live fire exercise at Otterburn Training Area has been named as 24-year-old Conor McPherson.
His commanding officer Lieutenant Colonel Alasdair Steele paid tribute to the "capable" and "hugely committed" soldier.
Private McPherson, from Paisley, Renfrewshire, enlisted into the Royal Regiment of Scotland in May 2014 as a combat infantryman.
The soldier had previously trained in both Kenya and France and had hoped to join machine gun platoon.
He was moving up in the army and was set to join a junior leadership course at the start of next year.
Police and Ministry of Defence accident investigators are looking into the circumstances surrounding the incident, which happened on a firing range during a night exercise.
Scottish First Minister Nicola Sturgeon sent her condolences to the soldier's family, friends and colleagues.
She said: "Our Armed Forces do a difficult and dangerous job at all times, and this is another stark reminder of that. My thoughts are with all who loved this brave soldier."