Maryland's Bob Calhoun opened with a school-record leap of 26 feet 5 inches yesterday in the trials of the long jump at the National Collegiate Athletic Association track and field championships. He was second to Stanford's James Lofton (26-11 3/4) entering the final round.

Earlier, 12 men qualified for today's discus final, led by hometown favorite Dave Voorhees of Oregon at 199-7. Keith Gardenkrans of Brigham Young was second with 195-6, followed by University of Texas-El Paso Svein Walvik (193-3) and Florida's Dock Luckie (190-3).

An early afternoon crowd of 6,000 was greeted by warm weather and gentle breezes as Maryland's Dennis Ivory and Calhoun joined 10 other jumpers for the three qualifying rounds leading immediately to the final, with the top eight men advancing.

Richard Rock of Southern Illinois took the early lead in the first flight of jumpers with 25-4 3/4, followed by the 25-2 of Florida's Joe Neal. The other two jumpers in the flight, Stanford's Darrin Nelson and Ohio University's Al Ogunfeyimi, fouled on their first two jumps.

Ivory's first effort was 24-5 3/4 and his next was 24-5. Ivory would just as soon forget his last jump. As he approached the takeoff board, he chopped his steps badly in an attempt not to foul and the result was predictable - a meagher 22-10. Ivory's 24-5 3/4 was not good enough to get him into the final.

Washington hammer thrower Scott Neilson on his second throw in the trials, put the 16-pound ball out 237-5, breaking his day-old NCAA record of 236-9.

In the second 400-meter relay semifinal, the Terrapins' foursome of Calhoun, Greg Robertson, Andre Lancaster and Renaldo Nehemiah used good baton exchanges to finish third behind Southern California (39.50) and Cornell (39.83) in 40.00. The mourth qualifier was Michigan in 40.09.

Maryland's first three legs left Nehemiah in a good position as he received the stick. A decent anchor leg was all the Terrapins needed to qualify for today's final, and Nehemiah provided that, briefly challenging Cornell's Neal Hall for second, then easing off when he couldn't catch him.

After a brief rest, Calhoun returned his attention to the long jump, turning in the 26-5 on his first try to temporarily take over the lead from Lofton.