Assistant Agriculture Secretary James R. Moseley yesterday named Roy M. "Mack" Gray as acting chief of the Soil Conservation Service, replacing Wilson Scaling, whose role in enforcing conservation legislation often earned criticism from environmental groups.

Moseley spokeswoman Jane Ade Stevens said Scaling, a Texas cattleman who held the SCS job since 1985, resigned as a result of "mutual agreement" with Moseley. Scaling was not available for comment.

"Mr. Moseley has a strong philosophy that political appointees should come from the private sector and guide and lead their respective agencies for a definitive period of time," Stevens said.

Moseley, confirmed in June as assistant secretary of agriculture for natural resources and the environment, had been expected to make changes among his top subordinates, including Scaling.

In naming Gray as interim replacement, Moseley chose a 55-year-old career professional who has served with the Soil Conservation Service since 1958, most recently as Scaling's assistant for strategic planning and budget analysis.

"Mack has played an integral part in developing the SCS into one of the department's most highly respected and effective agencies," Moseley said in a statement. "He is well-equipped to provide leadership during this transition period."

As the result of conservation provisions enacted in the 1985 farm bill, the Soil Conservation Service was charged with implementing new legislation restricting the draining of wetlands and the plowing of highly erodible land.

Essentially the Conservation Service had acquired an oversight role, and Scaling was frequently criticized for favoring farmers over environmentalists. Moseley's statement, however, praised Scaling as "an excellent leader" at a time "when the SCS was given an unprecedented workload."