IN A RECENT EDITORIAL, we cautioned against too rapid a move to gasohol production, citing the risk of a premature commitment to technologies that will soon be obsolete and the danger of pushing up the price of food. In a letter today, five members of the Senate Agriculture Committee respond. The senators believe we have overestimated these risks and underestimated the contribution gasohol can make to the country's energy supply.

It should be said at the outset that the issue here is not whether the country should have a fuels industry based on agricultural and forest products -- on this there is no difference of opinion. The differences arise over how great the potential of this energy source is, how fast it should be pushed, how heavily it should be subsidized and -- above all -- how it should be controlled so as to prevent large increases in the price of food.

Calculating precisely how alcohol production will affect food prices several years from now is difficult because there are so many unknowns: the demand for food and thus for crop land, the price of oil, the type of crop being grown, the efficiency of the distillation process, and more. However, a few factors are clear. Since almost no productive farm land is now being withheld from use, food crops grown for conversion to alcohol will have to compete for acreage with crops now being grown for food. As the price of oil rises, the price at which distillers can sell ethanol will rise equally, and the price of food crops and, eventually, of land will follow. The Office of Technology Assessment has calculated that in the near future no more than two billion gallons of ethanol per year -- that is 2 percent of gasoline use and only 0.2 percent of total national energy needs -- can be produced without increasing the price of food.

This competition between food and fuel does not exist if non-food crops are used. Spoiled crops and agricultural wastes can contribute a small though useful amount, but only forest wastes, timber and perennial grasses can produce large amounts of alcohol. The hitch is that currently available technologies for fermenting cellulose are extremely expensive. Economically competitive processes should become available by the end of this decade, an that is one of the main reasons for holding off on large gasohol and distillery investments.

In short, while alcohol production from food is a promising prospect, economic and technical realities substantially qualify the enthusiastic promises being made. A competition between food and fuel will certainly end up by partially solving one problem while creating several others. Despite the urgency of finding new energy supplies, a modest gasohol program is all that is justified now.