Examining the value of the weed control benefits, Mitchell used market price and input cost data from USDA from 2007 to 2009. For example, Mitchell uses the USDA’s Heartland Region, which is the central part of the Cornbelt, and says without atrazine, revenue losses would range from $31 to $36 per acre. He calculated that at $9,000 to $10,000 per farm based on only 281 acres of corn per farm, for a total of $2.2 to $2.7 billion for the four state heartland region. Losses in the other regions are millions of dollars per year and account for 25% to 30% of all US losses.
For those 281 acres of corn, described as average for Cornbelt farms, Mitchell says without atrazine, herbicide costs would be $750 or $177 million per year. The impact on net income in the Heartland region is about $10,000 per year, but when all US agricultural regions are tabulated, the net income loss climbs above $2.36 billion. With the loss of yield from the lack of atrazine, Mitchell says the average per acre revenue in his 2007 to 2009 period would be $547 using ERS data and $616 using NASS data. When combining income loss from corn, sorghum, sweet corn and sugar cane, Mitchell says the total would range from $3.0 to $3.3 billion per year, with 60% of the benefit in the Heartland region. He is quick to note that because current crop prices are 33% higher than in the 2007 to 2009 period, benefits would be increased by 33%.
Mitchell also looked at other benefits, which included the way atrazine enhanced the performance of other herbicides. Using the research of a number of weed scientists, he reports:
1) Atrazine enhances the broadleaf spectrum of bromoxynil, and it complements the grass, control of acetochlor, where atrazine provides the broadleaf control.
2) Atrazine enhances the broadleaf weed control value of other less efficacious herbicides and complements the efficacy of grass herbicides, which generates economic benefits for crop farmers.
3) Atrazine cannot be used on soybeans, but by providing effective weed control in corn, atrazine reduces the weed seed bank and subsequent interference pressure from weed species that can be difficult to control in soybeans.
4) Atrazine improves herbicide-resistant weed management by providing a low cost and effective alternative mode of action to glyphosate and other non-triazine herbicides in corn.
5) Maintaining the availability of atrazine as an alternative mode of action is particularly important for herbicide resistance management since no new herbicide modes of action have been released for agronomic grain crops since 1990.