A veto threat from President George W. Bush has persuaded Congress to take another crack at a new five-year farm bill. But so far, key lawmakers are suggesting minor repairs to a system that demands comprehensive reform.

The system those lawmakers would perpetuate dumps billions of dollars a year in taxpayer subsidies on farmers of a few crops, whether they need aid or not. The largest commercial farmers reap the bulk of the subsidies, while most growers get little or nothing.

Subsidies spur overproduction, wasting resources and harming the environment. They impede efforts to open more foreign markets to U.S. products. They're especially uncalled for now, when biofuel demand has sent farmland values and crop prices soaring.

In separate farm bills last year, House and Senate agriculture committee members rejected a plea from Bush to bar subsidies from farmers earning more than $200,000 annually.

The modest programs they included to benefit fruit and vegetable growers in Florida and other states weren't enough to outweigh all that was wrong with the bills.

Lawmakers who voted last year to maintain the status quo in farm policy, have a chance to redeem themselves. They need to reject any new bill that stops short of real reform. If they don't, Bush needs to follow through on his veto threat.