General view of the fertilizer distribution testing apparatus used in the U.S. Department of Agriculture's Fertilizer Machinery Laboratory located at the Arlington Experimental Farm in Rosslyn [Arlington], Virginia. The apparatus consists of a 66-foot long track equipped with 25 one-foot hoppers through which fertilizer passes into weighing cans. The apparatus was used to measure the amount of fertilizer deposited by a distributor in each foot of travel and could run at speeds of 1.5, 2.5, and 3.5 miles per hour.

Established by an act of Congress in April 1900, Arlington Farm served as the main field laboratory for the Bureau of Soils, U.S. Department of Agriculture, until 1941.