Denver — Every time you go through a checkout line at the supermarket on a weekly shopping trip, the equivalent of 60,000 acres of US farmland has been washed and blown away through erosion since your previous trip to the market.
Another 60,000 acres is converted into land for houses, shops, roads, power plants, coal mines, and other nonagricultural uses.
This loss of farmland, acceptable in the 1950s and '60s -- a time of large crop surpluses and increasing yields per acre -- is being viewed with alarm by agriculture experts.
"There are many political historians who believe the United States is on the verge of losing its pre-emminent position of world leadership -- from lack of arms superiority, from lack of domestic energy resource alternatives, from lack of technology innovation," Charles E. Little, president of the American Land Forum, has observed. "Maybe one more 'lack' should be added to the list: the inability to protect the greatest body of farmland of any nation on the face of the earth."
In the past, mechanization, fertilizers, pesticides, and irrigation have enabled American farmers to replace land with water and energy. But now, "with the cost of energy skyrocketing, the depletion of soil and water resources [ caused in part by the side effects of technology], and maybe even the climate turning against us, there is a serious question whether American agriculture can continue to 'replace' farmland losses through technology," a study by the National Association of Counties Research Foundation warns. "Evidence is mounting that it cannot: Per-acre yields from US croplands peaked in 1972 and have since then fluctuated rather widely at lower levels."
Those who have studied the situation largely agree that the nation has reached a point where each acre of prime farmland that is developed for other purposes -- such as shopping centers, housing, industrial parks, and so on -- threatens a permanent loss in total US agricultural capacity.
The ultimate implications of this situation appear quite serious. US agricultural exports are expected to top $38 billion his year, about 20 percent of the nation's total exports. These farm exports are extremely important in offsetting the money paid out for oil imports. A reduction in agricultural production would result in greater inflationary pressures on groceries. It could also weaken the US dollar and thereby increase the price of imported goods.
David L. Brown, a sociologist with the Economics, Statistics, and Cooperative Service, estimates that the best farmland is being converted to urban uses at twice the rate of poorer land.
Since the poor land is more easily eroded, the amount of soil blowing away or flowing down US rivers could increase. John F. Timmons, an agricultural economist at Iowa State University, predicts a 72 percent increase in soil erosion through 1985 in the Corn Belt, partly as a result of this trend to poorer land.
Already, some 100 million acres of farmland in the US have been ruined by erosion. Much of this total was lost in the dust bowl of the 1930s. This experience led to adoption of extensive soil conservation practices. But experts have been warning that economic pressures stemming from rising land prices and the end of large agricultural surpluses have led to a relaxation in soil protection measures.
"Of course, this situation cannot continue without impairing the cropland's ability to produce. Either large public and private investments must be made in erosion control improvements and practices or less erodable land must be retained within the cropland base . . .," professor Timmons argues.
The price of agricultural land has been increasing at a rate 2 1/2 times that of inflation.
One result, notes Mr. Little, is that "farmland is in the process of being priced out of the market for farm use."
This reality is the genesis of the adage "Scratch a farmer and you find a developer."
No longer is the opportunity to subdivide farmland into housing lots limited to the fringes of large cities. A US Department of Agriculture analysis of census statistics has disclosed that the long-term trend of population migration from country to city has reserved.
"Increasingly, rural America is scarcely distinguishable from suburban America," Mr. Little observes.
The result is that more family farmers, like the Carlsons of northglenn, Colo., sell their land for housing or even develop it themselves into housing tracts. In 1961 the Carlsons decided that "houses were a better crop" than the wheat and alfalfa they had been growing.
Besides tempting farmers out of agriculture, high land prices also make it difficult, if not impossible, for city dwellers to "return to the land" and farm profitability.
Still, most Americans do not relate the conversion of farmland to other uses with the supply and price of food, says Richard C. Collins of the University of Virginia.
Only two federal agencies, the Agriculture Department and the Environmental Protection Agency, take this factor into account in their planning. Increasingly, states have begun enacting various farmland protection programs. But in general these have not been highly agricultural states.
Such programs entail some form of land-use planning, a concept that as been opposed by farmers who view this as government intrusion on their right to do what they wish with their land. In February farm lobbyists were instrumental in defeating a House bill to authorize studying the problem.