By Russel Higgins
Last week the Northern Illinois Crop Management Conference took place at Malta and featured a number of speakers and specialists who shared their expertise.
Here are some of the takeaway comments that I garnered from Dr. Emerson Nafziger. He took a look back at 2014 and posed the question, is this as good as it gets?
- Despite high yields and record-high crop condition ratings (a state average of 200 bushel corn and 56 bushel soybean) a few things could have been better:
- Cool weather (especially at night) can limit soybean plants
- It lowers photosynthesis the next day
- It was warm early so there was no delay in onset of flowering, and had an extended flowering period
- We had successful podsetting, with high pod counts
- Later in the summer reproductive growth stages and leaf drop proceeded normally despite cool temperatures
- For corn, there weren't many known issues with weather, harvest delays were due to wet weather and size of the crop, not slow maturity
So is good weather all it takes?
- In every field in every year, something is the "most-limiting factor" for yields – In corn, it's nearly always water supply
- Other things are "yield-limiting" – and adding or removing or fixing them will increase yield
- But we have to be realistic and thoughtful about management, not just throwing everything we can think of onto the crop on the "slim" chance it will produce super-high yields
That approach sells product, but also in almost all instances, adds expenses that are not always recovered.
At this late date there is still uncertainty among farmers designating acreage in 2015. Across Illinois 11,900,000 acres of corn and 9,800,000 acres of soybean were planted in 2014. Will current commodity prices change this ratio, or will this be a year when producers dedicate a portion of their acreage to a different or a specialty crop? For those considering increasing soybean acreage, can they expect a yield hit or reduction if soybeans are planted on soybeans?
Two long-term studies in western Illinois showed only 4-5% lower yields for continuous soybean compared to corn-soybean rotation. From those studies there is little reason to expect more than ~5% lower yields from soybean following soybean compared to soybean following corn:
- SCN needs be evaluated and managed: plant corn in fields with high counts
- We don't see much need to alter tillage or variety selection
- The threat of more disease is modest – soybean diseases like Sudden Death Syndrome are not expected to be worse following soybean
But still, soybeans following corn is a little safer