Economic Assessment of the Benefits of Chloro-s-triazine Herbicides to U.S. Corn, Sorghum, and Sugarcane Producers

U.S. crop producers derive substantial economic benefits from the chloro-s-triazine herbicides atrazine, simazine and propazine. These triazine herbicides generate yield gains for U.S. crop farmers, and in many cases, also reduce total costs for herbicides. Atrazine, the most widely used triazine herbicide, is the keystone of herbicide-based weed control in corn and other regionally important crops in the U.S. Corn acreage, yields and prices have increased over time so that the three-year average value of corn produced in the U.S. has increased more than 2.7 times, from $18.6 billion in 1990-1992 to $50.9 billion in 2007-2009. Over this same period, crop production practices also evolved, including the widespread adoption of transgenic crops and reduced tillage systems. Given these and other changes since previous economic assessments of the producer benefits from triazine herbicides, an update assessment seems warranted. The primary benefit of atrazine and the other triazine herbicides to farmers is improved weed control that increases harvested yields and usually reduces costs, as alternative herbicides are less effective and/or more expensive. Based on yield loss and herbicide cost changes estimated using models, the economic value of the yield losses prevented by the triazine herbicides are estimated to range between $3.0 and $3.3 billion per year for U.S. corn, sorghum, sweet corn, and sugarcane farmers. Most of these benefits accrue to Midwestern field corn farmers using atrazine, but farmers in other regions and growing these other crops also derive substantial benefits. The annual yield benefits and net herbicide cost savings from triazine herbicides are worth an estimated $2.36 to $2.65 billion for U.S. field corn growers, $341 million for U.S. sorghum growers, $210 million for U.S. sweet corn growers, and between $60 and $120 million for U.S. sugarcane growers. Atrazine and the other triazine herbicides generate other types of benefits for farmers not accounted for in these reported values. Atrazine works well with other herbicides, often enhancing the value of less efficacious herbicides. Atrazine also increases the value of crop rotations by reducing weed populations and weed seed banks in crops commonly rotated with atrazine-treated crops. Atrazine also serves as an important tool for managing herbicide resistance, helping to preserve future weed control benefits for other herbicides. Finally, atrazine provides effective weed control that has aided adoption of conservation tillage and no-till systems in corn and other crops. Reducing or eliminating tillage reduces soil erosion and associated negative environmental impacts of agriculture, which improves water quality and further enhances the sustainability of U.S. crop production. Because specific dollar-denominated estimates of the value of these benefits to farmers are not included in this assessment, the estimated $3.0 to $3.3 billion in benefits per year should be considered a lower bound on the full value of the benefits generated by atrazine and the other chloro-s-triazine herbicides in U.S. crop production.