The National Agricultural Statistics Service (NASS) conducted the 2012 Agricultural Chemical Use Survey among soybean producers in 19 states: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Carolina, North Dakota, Ohio, South Dakota, Tennessee, Virginia, and Wisconsin. These states accounted for 96% of the soybean acreage planted in the United States in the 2012 crop year. All 2012 soybean chemical use data refer to these “program states” and are based on 2,491 individual questionnaires.
Nitrogen (N), phosphate (P2O5), and potash (K2O) are the most widely used fertilizer materials on soybeans. Farmers applied phosphate and potash to 37% of acres planted to soybeans, at an average rate of 49 and 80 pounds per acre, respectively, for the 2012 crop year. They applied nitrogen to 27% of planted acres, at an average rate of 16 pounds per acre.
The pesticide active ingredients used on soybeans are classified in this report as herbicides, insecticides, fungicides or other chemicals. Herbicides were used most extensively, applied to 98% of soybean planted acres. Insecticides and fungicides were applied to 18% and 11% of planted acres, respectively. Among herbicides, glyphosate potassium salt was the most widely used (59% of planted acres), followed by glyphosate isopropylamine salt (30%).
The survey asked growers to report on the pest management practices they used on soybeans. Pests are defined as weeds, insects or diseases. Soybean growers reported practices in four categories of pest management strategy:
- Prevention practices keep a pest population from infesting a crop or field through various preceding actions.
- Avoidance practices mitigate or eliminate the detrimental effects of pests through cultural measures.
- Monitoring practices involve observing or detecting pests through systematic sampling, counting, or other forms of scouting.
- Suppression involves controlling or reducing existing pest populations to mitigate crop damage.
Scouting for weeds was the most widely reported monitoring practice, used on 94% of soybean planted acres. Among avoidance practices, crop rotation was practiced on 84% of planted acres. The most widely used pest prevention practice was no-tillage or minimum tillage (67%). Maintaining ground covers, mulches, or other physical barriers was the most reported suppression practice (35%).
The same practices were also the top practice in their categories in 2006, the last time NASS conducted the soybean chemical use survey.