 A study by Chuck Benbrook concluded that the spread of glyphosate-resistant weeds had increased US herbicide use.That study cited a 23% increase (.3 kilograms/hectare) for soybeans from 1996–2006, a 43% (.9 kg/ha) increase for cotton from 1996–2010 and a 16% (.5 kg/ha) decrease for corn from 1996–2010.However, this study came under scrutiny because Benbrook did not consider the fact that glyphosate is less toxic than other herbicides, thus net toxicity may decrease even as use increases.