From 1935 through 1980, cumulative conservation investments in the agricultural sector of the U.S. economy were $19.1 billion, in historical dollars. When 'deflated' to a 1977 base the 'real' total investment from 1935 through 1980 came to $43.0 billion. The corresponding real 'gross capital stock' in 1980 was $20.7 billion. It measures the real full cost of conservation improvements still in service. The net or partially depreciated value of conservation capital was $13.2 billion in 1980. Compared with other farm business assets, the $13.2 billion net capital value of conservation improvements in 1980 amounted to about 3.7 percent of the net value of all land in farms. The net value of conservation improvements in 1980 was about 22 percent as large as the net capital value of all nonresidential structures on farms, and 17 percent as large as the net capital value of farm machinery and other producers' durable equipment.