A number of agricultural crops, such as cotton, corn, cabbage, wheat and soybeans have become addicted to air pollution from power plants, according to a Tennessee Valley Authority researcher. The crops have learned to obtain their sulfur nutrients from sulfur dioxide pollutants in the atmosphere instead of from fertilizer, report J. C. Noggle, a TVA soil chemist. If these pollutants -- some 15,000 tons daily -- are removed, crop damage from withdrawal symptoms will cost farmers $300 million a year in the seven-state TVA service area. Currently, TVA, under court pressure, is spending $6 million a year on a program that is expected to cut its sulfur dioxide emissions 40 percent by 1983. Noggle does not question the need for the cleanup. He says only that "air pollution is complex and this is just one little parcel of it. But if we clean up the air, then the cost of putting sulfur back into fertilizers should be considered in the costs of the cleanup." Noggle's research was supported by the Environment Protection Agency, but some of its own scientists take a dim view of his results. Said one: "The notion that it is . . . even marginally acceptable to continue supplying sulfur (from pollution) instead of fertilizer is just that -- fertilizer."