Robert J. Samuelson rips into our federal farm programs with all the energy that only a well-fed critic could muster {"The Absurd Farm Bill," op-ed, Aug. 1}. Amid ample grain and dairy supplies, he decries the subsidies spent on these commodities using logic that would lead an economist whose house has never burned to cancel his fire insurance.

While Mr. Samuelson is perturbed by the politicians and producer organizations that he blames for perpetuating the farm programs, he positively stomps his feet because from consumers, "there's been barely a peep of public outcry." He's puzzled, but that's because he fails to draw the connection when he observes that U.S. consumers spent only 20 percent of their disposable income on food in 1960 and spend a mere 14 percent today -- less than consumers in any other country.

Could it be that the average consumer has concluded -- as he or she guides the grocery cart from fresh produce to dairy to baked goods to meat, frequently choosing to pay more for packaging and convenience than for the foodstuffs inside, and encountering lines only at the cash-dispensing machine and the checkout counter -- that nothing is really amiss here?

Even former secretary of agriculture John Block, who during his USDA tenure was a harsh critic of farm programs and who now heads the Wholesale Grocers' Association, now recognizes the value of our farm programs in ensuring food security and price stability. On the pages of The Post {Free for All, Feb. 3}, Mr. Block wrote: "Farming is a volatile industry in which weather plays a great role. In 1987, for example, our grain supplies stored under government loan were referred to as a surplus, but with the drought of 1988 that 'surplus' miraculously became a valuable 'reserve.' Even the most adamant critics must admit that our farm programs played a role in ensuring abundance in times of national emergency."

Mr. Samuelson claims that only two-fifths of farm production (feed grains, dairy products, peanuts, rice, cotton and sugar) is subsidized, while producers of beef, chicken, eggs and pork, for example, fend for themselves in the "free" market. Such a conclusion fails to recognize, however, the critical role that our feed-grain program plays in stabilizing feed costs for the livestock industry.

The 1988 drought mentioned by Mr. Block was among the most severe of this century. It shriveled the U.S. corn crop by nearly 40 percent. Yet, because the United States had nearly a seven-month's supply of corn in storage, the drought caused barely a ripple in feed grain prices, and livestock producers were not forced into the type of massive herd liquidations that usually are triggered by such a calamity. (It's no coincidence that my own state of Nebraska ranks second in the number of cattle on feed and has more corn stored in the farmer-held reserve program than any other state.)

According to a recent study by the University of Missouri's Food and Agricultural Policy Research Institute, the buffer stocks made possible by our farm programs saved consumers an estimated $40 billion by holding down food costs following the 1988 drought.

In 1989, U.S. food marketing sales totaled $686 billion, including $276 billion spent on food in grocery stores and an additional $44 billion spent on packaged distilled spirits, beer and wine, according to USDA. That same year, taxpayer spent $10.6 billion on farm programs -- less than 1 percent of the federal budget and only 1.5 percent of total food marketing sales.

Mr. Samuelson apparently believes that this food insurance premium is unnecessary, and he would have American consumers cancel their policy. As our experience with the 1988 drought proved, the time to buy insurance is before you need it. J. ROBERT KERREY U.S. Senator (D-Neb.) Washington