The Echuca man, 18, who cannot be named for legal reasons, had sex with his girlfriend four times in March and April this year when the girl was 13 and 14 years old

Bendigo County Court heard the pair  began communicating on Facebook and met in person about a week later.

Crown prosecutor Penny Marcou told the court the pair then "became boyfriend and girlfriend" and commenced a sexual relationship.

She said on one occasion, the pair had sex at the girl's home. 

On another occasion, the man took the girl to Crusoe Reserve in Kangaroo Flat and had sex with her at the football oval.

He was arrested after the girl told her parents they'd had sex.

He pleaded guilty on Tuesday to one charge of sexual penetration of a child under 16, which encompassed each act.

Ms Marcou tendered the girl's victim impact statement and told the court the man had no prior convictions.

She also said the prosecuton were not asking for a jail term given the circumstances of the offending.

Defence lawyer Kate Youngson told the court both her client and the girl had affection for each other and said the sex was consensual. 

She said the man had been honest with police and had not tried to disguise their relationship, telling them he had hoped it would continue for some time.

Judge Graeme Hicks said given the pair were both teenagers, the age difference could not be described as substantial.

He said the man's guilty plea and full admissions to police showed he felt genuine remorse for his actions and warranted a significant discount of sentence.

Judge Hicks described the man as  an independent person and "a young man of good character " with good prospects of rehabilitation

He sentenced the man to a 12-month community corrections order requiring 100 hours of unpaid work.

He also ordered the man report to the sex offenders register for the mandatory 15-year period.

The maximum penalty for  the sexual penetration of a child under 16 is 10 years' jail.