There are many factors to consider when it comes time to plant corn. Hybrid selection, planting date, soil conditions and weather all play a vital role in one of the most significant activities of any growing season – planting.
Seeding rate is one factor that can perplex many farmers – how do you get the most out of your crop, without wasting money on your primary input? Where is the balance between too few and too many seeds? And how can you tell if you’re doing it right?
While most seed companies will provide a seeding rate recommendation, many of you will want to do the research for yourself. And you should.
What’s changed about seeding rate over the years?
Corn hybrid improvements have led to increased stress tolerance, allowing for higher plant populations – and if all else goes well, more plants mean more bushels. However, in the past, to many, more plants simply meant more competition for resources – leading to decreased kernels per ear, lowered kernel weight and diminished late season stalk integrity.
But new traits, technologies and breeding practices have made for many crop improvements - including enhanced stalk health and ear and kernel features that are less affected by thicker stands.
What do we know?
As you can see from 2017 data from Illinois and Minnesota, the highest yields were achieved in fields where seeding rates were around 36,000-38,000 seeds per acre. In both states, yields increased as seeding rates increased, up to the 36,000-38,000 mark. However, at a rate of 38,000 plus, yields decreased, and we suspect that could be the point at which competition for resources may have caused diminishing returns.
Why does seeding rate matter?
Achieving the ideal seeding rate has an initial primary purpose for crop growth – to optimize light interception by the crop canopy during grain fill. This helps each plant make the most of the available sunlight, improving plant processes and thereby enhancing yield potential.
Take a look under the canopy on a sunny day. If population has been optimized, little to no sunlight will reach the ground below the canopy. Once light interception has been maximized, a field’s response to increasing population will largely plateau.
It’s also important to note plant population needed to maximize yield potential. A field with a higher yield potential will benefit more from higher seeding rates than will a field with a lower yield potential.
So, what seeding rate is right for you?
As we saw in the data above, while we want to maximize seeding rate, there is a point where more seed doesn’t equal higher yields – which means that applying more seeds per acre would simply mean increased seed costs with little to no return.
The key to finding your ideal seeding rate is knowing what’s best for your farm around maximizing profit. For example, if you could get an extra 2 bushels per acre, but had to increase seed costs by 10 percent to do it, would that be worth it? That may depend on the price of corn and the price of seed.
The key takeaway: Seeding rate data shows us that the optimal seeding rate to maximize profitability is not necessarily the one that maximizes yield.
Planting data above is based on real-world farming data. Information on seed hybrids has been aggregated across millions of acres of data from 2017. Maturity range includes 108-114 days in Illinois and 93-106 days in Minnesota.
Seed Finder lets you see how each seed responds to planting conditions your state.