American women, it turns out after one year of experimenting, are not wild about joining the Army or doing the jobs formerly restricted to men if they do sign up.

"The military is not a very romantic business," said Army civilian manpower chief Robert L. Nelson. "And the women don't like the dirty jobs in the Army any more than the men do," he added in discussing the Army's first year of allowing women to do formerly "men-only" jobs ranging from repairing tanks to loading ammunition.

Yet, the Carter administration's strategy for sustaining the all-volunteer force depends heavily on attracting more women as the nation's pool of young men dwindles in the 1980s.

The Army, which has the biggest need for volunteers, is under orders to increase its current force of 57,000 women officers and soliders to 91,500 by October 1983, raising female representation from 8 to 13 percent of the total Army.

Critics contend that adminstration leaders, who so far have opposed returning to the draft, are putting women into a desperate attempt to save the all-volunteer force, which came into being in 1973 after the Vietnam war.

"It's absolutely wrong," Nelson said, "to sayd if we don't get enough women it's the end of the volunteer Army." All the Army would have to do to fill its ranks, Nelson insisted in an interview in his Pentagon office, would be to lower admittance standards.

He did acknowledge, however, that women have not been joining the Army in the desired numbers, are shunning many of the new jobs opened to them over the last year and are dropping out of the service in greater numbers.

But Nelson stressed that many women are performing the toughest job in the Army and doing them exceptionally well. "I don't think they've let us down," he said.

To widen the net, the Army recently lowered entrance standards for women. Instead of continuing to require a high school diploma and a score of at least 50 of a possible 100 on the entrance exam, women now can qualify for the Army if they have a diploma and score 31 percent (Men may score as low as 16 percent if they have a diploma, otherwise they must score 31 percent.)

Nelson said lowered standards "should open up a whole new market" of women, stressing that the Army is still experimenting with the best ways to attract and use them effectively.

The Army is not meeting recruiting goals, signing up only 73 percent of the total sought.

Last year, the Army opened to women almost all jobs except direct combat. Only 22 out of 346 jobs are closed to women, officials said.

However, now that the novelty of filling a man's job has worn off, women are resisting service just behind the lines with the field artillery, or struggling with the nuts and bolts on a tank, or loading ammunition or slinging hash on the chow line.

"You're up against the outside perception," Nelson said, because even if a woman trains herself to be a mechanic in the Army, a garage is unlikely to hire her once she is discharged.

Another problem, he said, is that too few women have had time to become sergeants in the manuals skills to serve "as role models" for other women.

Apparently more and more women are becoming disillusioned once they have tried Army life. The Army said 42 percent of enlisted women are failing to complete tours now, compared to 37 percent in fiscal 1975, first full year of the all-volunteer Army.

In contrast, the dropout rate for enlisted men with high school diplomas has fallen in that same period from 37 to 30 percent, according to Mary manpower officials.

One policy implication is that men are a better bargain than women for the Army on a strictly dollars-and-cents basis.

The counterargument is that the Army must learn to recruit and train more women because, despite their higher peacetime cost, having enough trained women would enable the Army to shift from peace to war with little turbulence, assuming enough men can be recruited.

"This is all new for the Army and its recruiters," Nelson said. The Army has been wide open for women for only a year now, he added. "We're come a long way, but we still have a long way to go and a lot more to learn."