Iowa arrived in town Saturday with a pure drop-back quarterback and an offensive line that allowed 13 sacks in the first three games.

So this was Nebraska's big chance to increase its not-so-grand total of two sacks in two games.

"We felt we've been deficient in sacks," Husker first-year defensive coordinator Craig Bohl admitted. "Later on in the game, we finally got a push, and that's what we needed."

What Bohl meant is Nebraska got in Iowa quarterback Scott Mullen's face, which isn't always easy to do, considering he stands 6-foot-6, has a reasonably quick release and possesses adequate mobility. But the Huskers sacked him six times, including five in the second half, of their 42-13 triumph at Memorial Stadium.

Nebraska middle linebacker Carlos Polk wasn't exactly effusive in his praise of the pass rush, saying only that it's "getting better."

Said Bohl: "That's got to come - that's the plan."

To that end, Bohl unleashed a pass-rush scheme called "Cobra." The principles are true freshman rush end Benard Thomas, defensive tackles Loran Kaiser and Jeremy Slechta, rush end Kyle Vanden Bosch and Polk.

"(Cobra) means you have five heat-seeking missiles," Bohl said.

Two of them - Polk and Vanden Bosch - came up with sacks Saturday. So did defensive back Keyuo Craver, weakside linebacker Randy Stella, rush end Chris Kelsay and nose tackle Junior Tagoa'i.

Nebraska held Iowa scoreless in the second half, and the Hawkeyes managed only 88 total yards after halftime.

But Mullen found enough rhythm to complete 19 of 40 passes for 252 yards and a touchdown, with two interceptions. Husker free safety Troy Watchorn's 39-yard interception return for a TD completed the scoring with 55 seconds left in the game.

In the first half, Bohl said, Iowa was picking up Nebraska's blitzes.

"They stung us a couple times," he said.

But Nebraska made adjustments at halftime, and its front five - the four down linemen, plus middle linebacker Carlos Polk - applied more pressure on Mullen in the second half.

The Huskers surprised the Hawkeyes by blitzing Craver out of the "dime" coverage package.

Mullen, though, had success finding receivers on short routes over the middle of the field.

"I think they have an excellent short, controlled passing game," Bohl said. "Quite frankly, I don't think we adjusted to it very well early in the game. As the game progressed, I think we made the adjustments."

Yet it was the short stuff that added up and allowed Iowa to sustain drives.

"We did some things to try to throw them off-kilter, but I don't know if we ever completely shut it down," Bohl said. "I think we managed it."

Of course, Nebraska wants to do better than "manage."

"Personally, I was frustrated," Bohl said. "I was frustrated in the first half and I was frustrated at halftime."

Nebraska's primary objective was to avoid giving up the big play. But the Huskers allowed a 29-yard first-quarter TD pass to Kevin Kasper and a 46-yard completion to Kasper in the second quarter on which Craver appeared to bite on Mullen's pump-fake.

Hawkeye running back Ladell Betts carried 20 times for 75 yards, with 24 of them coming on the third play from scrimmage.

"We started slow from the get-go," said Polk, whose nine tackles tied strongside linebacker Scott Shanle for the team lead. "Right now, it's disappointing, because we're playing down to the opponents' level. We're sitting back and waiting; we're not attacking."

Reach Steven M. Sipple at 473-7440 or ssipple@journalstar.com.