As corn prices continue to fluctuate, more farmers are beginning to inquire about the pros and cons of growing continuous soybeans. When it comes to deciding whether back-to-back soybeans are the right choice for your fields, it is important farmers understand the key management steps that will help them optimize output and achieve the bottom-line results they seek.
Similar to continuous corn, soybeans following soybeans have special pest challenges and nutritional requirements farmers need to address throughout the season. To address these challenges and capture optimum yield potential from continuous soybean fields, it is important to follow these tips:
- Check for soybean cyst nematode (SCN). While fall is the ideal time to complete SCN soil sampling analysis, it may also be completed in the spring. If SCN counts are at 2,000 eggs per cc or higher, planting soybeans in that field is not advised. With lower SCN levels, plant varieties with built-in SCN resistance and use Clariva™ Complete Beans seed treatment for best results.
- Protect against early-season diseases. Last spring’s wet, cool conditions in many areas set the stage for heavy disease pressure in soybean fields. With inoculum from diseases such as Rhizoctonia, Pythium and Phytophthora remaining on soybean plant material after harvest, this infected residue presents a serious disease threat for this year’s soybean crop. Using a seed treatment, such as Warden® CX, may provide the best defense against disease damage and insect damage.
- Minimize weed competition. Reducing early-season weed pressure may help give young soybean plants a strong, vigorous start. A two-step weed-control program is recommended, starting with a preemergence herbicide application that includes residual weed control for longer-lasting protection. A second early-postemergence treatment should include glyphosate (for Roundup Readysoybeans) plus a second mode of action to control glyphosate-resistant weeds and help prevent additional herbicide-resistance issues.
- Don’t ignore fertility needs. A 50-bushel-per-acre soybean crop uses more potassium per acre than a 200-bushel corn crop. Some farmers falsely believe that soybean crops don’t need extra fertilization, but that couldn’t be further from the truth. If soybeans only have access to last season’s leftover nutrients, farmers may be leaving yield potential in the field.
To determine accurate plant nutrient levels, take a soil sample in the fall or spring, while there’s still time to replenish deficient nutrients before the season begins. In addition, in-season tissue sampling at key growth stages (V4, R1 and R3) is vital for identifying and applying deficient nutrients if needed before yield potential is jeopardized.