CREATE TABLE table_48558 ("Tournament" TEXT, "Surface" TEXT, "Week" TEXT, "Winner and score" TEXT, "Finalist" TEXT, "Semifinalists" TEXT)

What was the surface that was played on during the week of March 16?
SELECT "Surface" FROM table_48558 WHERE "Week" = 'march 16'
SELECT "Surface" FROM "table_48558" WHERE "Week" = 'march 16'