Scientific inquiry is a journey, not a destination. We all learn this at some point in our education, but sometimes we need a reminder.

Corn silage harvest maturity is a very important contributor in the overall gains made in corn’s value as an ingredient for efficient milk production. Due to its importance, the amount of data generated on the crop is immense. We are often drawn to the potential simplicity of boiling it all down to “one-size-fits-all” guidelines for how to predict and monitor the crop’s maturity.

In some cases, more data can simplify a process and give guidelines more power. However, that is not always the case — there are times when the data does more to muddy the waters while reminding us that Mother Nature is rarely interested in cooperating with “cookie cutter” approaches.

Furthermore, many guidelines are repeated so often, for so long, that they lose their context or become irrelevant to modern practices. Using calendar days from tasseling to harvest originated at a time when harvest whole plant dry matter targets were in the low 30s, compared to the mid-30s targeted today. Kernel milkline offers another example. The idea of one-half milkline also corresponded to old harvest dry matter targets. Today, guidelines are two-thirds to three-quarters milkline, but more important than the change in milkline stage is the recognition that it should not be used as a standalone assessment. It is only useful in combination with evaluating whole plant dry matter and overall plant health.

In other cases, our confidence in the precision of a guideline is just too great. Rarely was there an intent to misrepresent the data; rather, its interpretation suffers the consequences of the classic game of telephone from our childhoods.

Context to the data

A few recent projects have given us the opportunity to look at some entrenched and newer guidelines for predicting and monitoring corn silage dry down.

It has been a humbling experience to say the least.

Not only has this work reinforced the limitation of many current “rules of thumb,” but it has further muddied the waters. For example, we know growing degree days (GDDs) are more accurate than calendar days for tracking plant progress; however, the harder we try to dial in the GDDs needed for silage maturity, the more we see just how differently plants respond to same number of GDDs when other factors vary. For a given field, region, or season, the weather, plant health, plant genetics, soil fertility, and interactions between these factors impact how the plant actually utilizes GDDs.

With these datasets, we can average everything together and come up with an average number of GDDs needed, but with the wide range from high to low, more data does not necessarily provide a stronger guideline. Rather, it can weaken it.

So, is the data useless? I would argue no; we can still benefit from understanding an approximate starting point, but from there we need to do a better job of retaining context and communicating the limitations of our understanding. We are working with the best available knowledge, not the answer.

With 2024 corn silage harvest fresh in our minds, it is a good time to assess how well you hit your corn maturity targets for harvest. If goals were not met, ask yourself if overconfidence in any rules of thumb contributed.

Our increasing body of knowledge still improves the opportunities to develop better systems, but patience is needed, and the water may get muddier before it clears up. In the meantime, nothing beats having “boots on the ground” to monitor fields and manually dry down samples. It is a laborious task but one that is worth it given the value of properly timed corn silage harvest.