By Matt Rundle, NK^® Agronomist

Planting depth, timing and variety selection will play a key role in the success of your 2021 soybean crop. But tillage, fertility, fungicides and rotation are also important contributors to optimum yields.

In Part 2 of our Tips for Better Soybean Management series, we continue our review of research presented by Ontario Ministry of Agriculture, Food and Rural Affairs Soybean Specialist Horst Bohner and University of Guelph Associate Professor Dr. David Hooker at the Ontario Agricultural Conference earlier this winter. 

Here are some key management takeaways I noted from their presentations on tillage, fertility, fungicides and rotation and insights on how to fine-tune management for greater soybean success on your farm.

Takeaway #4: Tillage before soybean planting may only produce a slight yield increase but it makes life easier.

Soybeans can be grown successfully using a range of tillage systems. Horst Bohner’s research continues to demonstrate that various forms of spring vertical tillage can produce a two bushel advantage over no-till. He argues that while the yield gain is not substantial, other benefits make it a strong choice for growers. Advantages include a better plant stand, a more level field surface for combining at harvest, and the ability to better manage the increasing amounts of corn residue produced by higher-yielding, bigger corn plants. He notes that these benefits can be realized without damaging soil health. 

However, no-till can certainly be effective. When it comes to planting in true no-till, it’s important to remember that sharp opening discs and effective down pressure are critical for success.

Takeaway #5: Soil fertility is a key management component for growers seeking to optimize soybean yield.

Bohner believes plant nutrition is the fundamental difference between growing a 50 bu/ac crop and an 80 bu/ac crop. He says making P and K available to the plant and getting those nutrients into the plant helps retain flowers, set more pods, and increase seed size.

Bohner notes that 28 site-years of fertility data in western Ontario indicates soils that have background fertility built to moderate levels of P and K out yield low-test fields by 7 bu/ac.  Starter fertilizer can provide a good response in low-test fields, about 5 bu/ac, but without strong base fertility, growers cannot expect to optimize yield potential.

Takeaway #6: Foliar fungicides provide significant value and yield response when soybeans experience high levels of disease.

Bohner’s trial data continues to show that growers can expect at least a two to three bushel return on their foliar fungicide investment, but the benefits are much higher in areas where diseases such as white mould, septoria, Asian soybean rust and other foliar diseases are prevalent. It’s not uncommon to see 50 percent loss due to white mould, cutting a 50 bu/ac crop down to 25 bu/ac.

Foliar fungicides are mostly preventative, protecting the plant from disease as well as safeguarding late-season plant health. It’s important for growers to understand the disease history of their fields and monitor in-season crop and weather conditions to effectively apply fungicides where and when they can offer high levels of crop protection and protect yield.

Takeaway #7: Diverse rotations enhance soybean yield. 

When growers plant wheat to create a corn-soy-wheat rotation, soybeans yield an additional four to six bushels, according to the University of Guelph’s long-term rotational study.