Boosting soybean yields requires attention to local conditions
As High Yield Team members aim to boost soybean yields this year, it's helpful to remember the diversity of U.S. soybean production.
Farmers in different regions of the country will manage and produce soybean differently because of soil and climate differences. That's why no one production system will fit every environment, and why perceived remedies to fix problems will not apply to every region.
There are three distinct soybean-producing U.S. regions:
- The Midwest
Consists of rolling terrain with deep soils. This region normally has consistent summer rain and moderate temperatures.
- The Midsouth
Contains both alluvial and upland soils. The region often has summer drought accompanied by high temperatures.
- The Southeast
Contains sandy soils and normally has summer drought, high temperatures and possible inundating rainfall from sporadic summer hurricanes.
Harvested acreage and yield, along with percentage of acres planted by May 1, percentage of acres double cropped, and percentage of acres irrigated are presented in the accompanying table for selected states within each region. All values were compiled from data presented in National Agricultural Statistics Service (NASS) publications. All values are five-year averages except the percentage irrigated acres, which are taken from the 2002 Census of Agriculture.
Virtually all of the soybeans in the shown Midwestern states are grown in dryland systems. Soybeans in the Midsouthern states (except Tennessee) have significant irrigated portions. The Southeastern states have virtually no irrigated soybeans, but a significant percentage of their soybeans are double-cropped. Summer weather patterns in the Midwest favor dryland production, whereas weather patterns in the other two regions generally do not.
Virginia is arbitrarily included as a southeastern state because its climate and soils are similar to the other Atlantic Coast states.
Missouri (six percent planted by May 1, 4,986,000 harvested acres and 36.7 bushel-per-acre average yield) and Kentucky (six percent planted by May 1, 1,288,000 harvested acres and 41.5 bushel-per-acre average yield) are not included in the table because portions of their acreage can be arbitrarily assigned to both the Midwest and the Midsouth. A significant portion of the soybean acreage in southeast Missouri is irrigated. About 30% of Kentucky's acreage is double-cropped.
Kansas (five percent planted by May 1, 2,732,000 harvested acres and 31.5 bushel-per-acre average yield) and Nebraska (three percent planted by May 1, 4,700,000 harvested acres and 45.2 bushel-per-acre average yield) are not included in the Midwest data because they have significant irrigated acreage.
The three regions have three distinct yield levels. The Midwestern average yield of 44 bushels per acre exceeds the Mid-south average yield of 35.6 bushels per acre, which exceeds the southeast average yield of 29.0 bushels per acre. The yield data indicate that production limitations and conditions are more restrictive to soybean yield potential in the Midsouth and Southeast.