Irvin Holmes, 73, a federal agricltural statistician for more than 30 years, died Thursday at Holy Cross Hospital in Silver Spring after a heart attack.

Mr. Holmes, a native of Kansas, graduated from the University of Iowa. He came to Washington in 1928 as a statistician with the Labor Department. In 1929 he joined the Agriculture Department and moved to Michigan where he became assistant federal agricultural statistician for the state of Michigan, a position he held through 1937.

Mr. Holmes returned to Washington in 1937 and worked for the Agriculture Department until 1944, when he became assistant chief of the agricultural division of Census Bureau. He then returned to Agriculture as a statistician until his first retirement in 1960.

In 1964, Mr. Holmes was asked to return to the Census Bureau as an agricultural consultant with the bureau's special task force that planned the 1969 agricultural census, the first taken by mail. He retired for a second time in 1972.

Mr. Holmes wrote articles for specialized publications, including the Journal of the American Statistical Association, the American Pototato Journal, the Journal of Farm Economics and the Michigan Farmer. He helped write a number of Agriculture Department Crop Reports and articles for Census Bureau publications.

Mr. Holmes received Superior Service Awards from the Agriculture Department and the Census Bureau.

He is survived by his wife, Pauline, and a son, Richard, both of the home in Takoma Park, Md.