Since herbicide-tolerant transgenic cotton varieties became widely available in 1997, the no-till cotton acreage has nearly doubled in the United States. A recent survey by the National Cotton Council indicates that no-till made up 29 percent of total cotton acres while reduced tillage made up 30 percent of all cotton acres in 2002.

It makes sense to think that the more inputs you add to a no-till field, the bigger the yield you should expect. But herbicides require different thinking, says Chris Boerboom.