Study Finds Increasing Trend in Tillage Intensity in the US

Iowa State University researchers combined survey results and computer modeling to study the trend in tillage intensity in the US in recent years. The results of the study are published in Nature Food.

Thousands of US farmers were surveyed about their tillage practices and it was found that reliance on tillage decreased from 1998 to 2008. Genetically engineered herbicide tolerant crops were introduced in the late 1990s, which helped farmers not to rely on tillage as a method of weed control. However, the survey also showed that tillage intensity started to rise again starting in 2009, which is attributed by the researchers to the growing numbers of weed species with resistance to glyphosate. The results of the survey were entered into ecosystem models to determine how tillage decisions impact soil emissions of greenhouse gases. According to Chaoqun Lu, lead author of the study, as tillage intensity grows, more carbon and nitrogen stored in the soil releases into the atmosphere in the form of greenhouse gases.

The study reveals the relationship between weed resistance, seed technology, and greenhouse gas emissions. The results could help experts have a better understanding of how farm practices can mitigate climate change.

Read more findings from Iowa State University.