WASHINGTON (AP) _ People and what they do are highlighted in the Agriculture Department's 1990 yearbook announced Monday.

The 200-page book, ''Americans in Agriculture: Portraits of Diversity,'' is about ''the people of American agriculture, their jobs, their lives, their goals and their families,'' said editor Deborah Takiff Smith.

Agriculture Secretary Clayton Yeutter added in the book's foreword: ''The intiative and creativity and plain hard work of these millions of people are the key to our efficiency and our ability to compete in the world marketplace.''

This year's edition of the yearbook is divided into six sections about:

-Those who work in the U.S. food and fiber sector, and key factors about American farmers, farms and farm workers.

-Farmers from dozens of states, from New England to the West Coast, and from the deep South to the Midwest. -A banker, wholesaler and a food technologist, who are among 16 million people who work in the pipeline after products leave the farm.

-Several scientists delving into the workings of nature.

-A few people involved in agricultural education.

-Introductions to some of the government workers and volunteers supporting agriculture at the local, state and federal levels.

As a special focus, the 1990 yearbook observes the centennial of the ''1890 institutions,'' the historically black land-grant colleges and universities. The book includes a history of these schools and a number of profiles of scientists, farmers, teachers and students connected with the schools.

The USDA yearbook officially began in 1894, although annual volumes of reports were issued in the 1840s, when federal agriculture was under the commissioner of patents.

Annual reports were continued after USDA was created in 1862. Copies of the reports were distributed to Congress, a practice that continues.

Each senator gets 350 books and each member of the House about 300. Some are also provided to committees and other Capitol Hill offices.

Free copies are available to constituents. Or the books can be ordered for $10 each from the Superintendent of Documents, Washington, D.C. 20402. The yearbooks also will be sold at government bookstores in many cities.