Martin Espada, the Puerto Rican poet-scholar, will visit the College on March 19-21, under the auspices of the AADS Program and the department of Foreign Languages. An internationally recognized poet, Espada is currently professor of creative writing at the University of Massachusetts, Amherst. He has published several award-winning collections.   His latest work is, "A Mayan Astronomer in Hell's Kitchen." His "Zapata's Disciples" won an Independent Publisher Book Award. He will read from his poetry on March 20 at 8 p.m. at the Montgomety Hall Upper Commons, visit with students in the introductory course to the AADS Program, and see students  learning Spanish.