Along Southern Avenue, which marks the boundary between the Distric of Columbia and Prince George's County, many apartments are similar on both sides of the line.

But when census employes fan out next month to get forms from households that did not mail them in, those working in Washington will earn $2.90 for each regular form they collect. those in suburban Maryland just a few steps away will get $2.20 for doing the same work.

The 32 percent differential, which has stirred some complaints Census Bureau policy to pay more for temporary workers in big cities than in suburbs or small towns.

"Traditionally, it's been harder to enumerate in the central cities," said Michael Chen, chief of the administrative planning staff of the bureau's national field division. "It's harder to contact people, and they're not always as cooperative . . . . also, we must be a little more competitive, in the job market market to recruit the people we need."

The bureau's policy is sharply different from the regulations the federal government uses in paying workers at virtually all other federal jobs. According to a spokesman for the Office of Personal Management, civil service workers are paid at a uniform national rate or at rates that are established for particular labor markets, which include both cities and their adjacent suburbs.

The dual wage rate already has provoked criticism in the Washington area where recruiters are still seeking applications for 4,000 temporary workers needed to complete the count here.

About 1,500 workers are needed in the city, and about 2,500 in the suburbs. Under a nationwide census policy, people are supposed to be hired for jobs only in the communities where they live unless shortages develop.

"There's a lot of griping about it," said Janet Carver, manager of the bureau's Arlington office. People applying for the jobs there are baffled to discover they can't earn the same pay that workers in Washington can earn, she said.

Suburban census managers attempted to get the policy reversed "but it didn't do any good," Carver said. Census officials decided they had to establish a boundary somewhere for different wages and the borders between the central cities and their suburbs was it, she said.

Even in the city, though, local census officials complain that pay is too low and has hampered recruiting. Census managers throughout the area say they expect to have enough people to get the work done even though far fewer had applied than they expected would apply.

"Sometimes I feel kind of ashamed to offer this pay," said George Hill, manager of the census office for Northeast and Southeast Washington. "These rates were planned quite a long time ago, and they didn't take into account the skyrocketing inflation that hit us today."

In the city, workers going door-to-door collecting census forms can expect to average $4.45 an hour, according to census officials, compared to an average of $4 an hour for this type of work in the suburbs.

For clerical jobs, where workers get straight hourly pay, the rate is $3.75 per hour in the city and $3.55 per hour in the suburbs.

Nationally, the census bureau is seeking 275,000 temporary workers, and it is having problems recruiting them almost everywhere.

"Next to a military campaign, this is the biggest operation the government has mounted," said Ken Field, a public information officer for the Census Bureau. "But we still don't have all the applicants we want, and people can still come in and apply."

Although census forms were delivered by the post office last week, Field said, the door-to-door follow-up work for households that don't mail them back will start in mid-April. How long it continues depends on how great the mail-response is, although officials expect it to be completed by the end of May.

Besides pay rates, the hiring of census workers has been complicated this year by political rules and efforts to attract more black, Hispanic and other minority group members.

Traditionally, many census workers have been recruited through the political party that occupies the White House.

In a jan. 25 memo from the bureau's national headquarters, local managers were instructed to put the names of all persons recommended by Democratic leaders on special 3-by-5 cards and to consider them first in filling all jobs.

"Throughout the recruiting process," the memo declared, "preference will be given to candidates recommended by the political party of the incumbent administration."

This rule remained in effect until last Monday, when a revised memo was issued. It removed the requirement that recommended Democrats had to be first in line, but allowed managers to consider party recommendations if they wish.

Late last week, William Skidmore, deputy general counsel for the Commerce Department which includes the Census Bureau, said the party preference requirement was "an error."

"No one knows where or how that crept in," Skidmore declared. "It was not the policy, and as soon as we heard about it, we got rid of it."

Skidmore said the requirement violated the Civil Service Reform Act of 1978, which the Carter administration had backed.

Locally, the managers of all four surburban census offices are active Democrats, although the two managers in Washington are career census employes.

"All things being equal, political preference counts," said Carver, a former chairman of the Springfield Democratic Committee who said she was recommended for her own job by Rep. Herbert Harris. "But practically speaking, there just aren't that many people looking for these jobs, and around here there aren't very many political recommendations."

To get more minority employes, the Census Bureau established a rule that workers must not just come from the county or town where they work but must actually live in the neighborhood where they go door-to-door and "identify" with its "dominant culture."

Richard C. Burt, director of the bureau's national field division, said it is against federal law to ask people what their race is before they are hired.

Instead, job applicants must fill out a "cultural familiarity questionnaire." It lists the 17 races and ethnic groups mentioned on the census form itself. Each applicant is required to mark with a 1 "the culture with which you identify most," and place a 2 beside "a second culture with which you are very familiar."

If no one from the "dominant culture" in a neighborhood applies for a job or passes the qualifying test, managers are required to hire someone from that group who lives nearby. Only if they still can't find someone from the desired group are they allowed to hire anyone else, Burt said.

"We are attempting to hire in direct proportion to the population of each area," Burt explained. "We feel that's the way we can get a better census because we'll have people who can do a better job."

To follow these rules, local census offices are carrying out an extensive mapping operations pinpointing the exact area, called an enumeration district, in which each applicant lives.

"Boy, that's causing a lot of work for us," one local manager declared. "But we're trying."