How to Choose the Most Profitable Corn Hybrid for Variable-Rate Seeding?
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Results of a Field Trial.
How to choose the most profitable corn hybrid for variable-rate seeding_Cover_OneSoil Blog
Do all corn hybrids react equally well to variable seeding rates? Last year, OneSoil teamed up with the Ukrainian agro-industrial holding Astarta-Kyiv to test this in practice with a field experiment. Five hybrids were chosen for the experiment: KWS 4484, KWS 381, MAS 24.C, DKC 3730, and GRAN 6. I'll tell you how the experiment went and what seeding strategy proved to be the most successful for each hybrid in this article.

Astarta-Kyiv is a major agro-industrial holding in Ukraine with about 230,000 hectares of land. The holding is engaged in crop farming, sugar production, soybean processing, and dairy farming.

Astarta-Kyiv works with AgriChain, which develops a website for agricultural business management. The holding uses the website to keep track of its production processes, land, and crops. AgriChain is also continuously working on studying and testing technologies and equipment that can be used to increase agricultural companies' performance. AgriChain recommends to its clients field-tested technologies that it integrates into its tools. We started our experiments with Astarta thanks to AgriChain's initiative.

The first one took place in Poltava and Vinnytsia Regions. Soils in these regions are predominantly podzolized and low-humus chernozems and grey forest soils.
Usevalad Henin
Usevalad is an expert in GIS and agricultural chemistry. He has been developing precision farming tools since 2013. He is also the co-founder of OneSoil.
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Philip Kondratenko_OneSoil Agronomist
Usevalad Henin
Usevalad is an expert in GIS and agricultural chemistry. He has been developing precision farming tools since 2013. He is also the co-founder of OneSoil.
Do all corn hybrids react equally well to variable seeding rates? Last year, OneSoil teamed up with the Ukrainian agro-industrial holding Astarta-Kyiv to test this in practice with a field experiment. Five hybrids were chosen for the experiment: KWS 4484, KWS 381, MAS 24.C, DKC 3730, and GRAN 6. I'll tell you how the experiment went and what seeding strategy proved to be the most successful for each hybrid in this article.

Astarta-Kyiv is a major agro-industrial holding in Ukraine with about 230,000 hectares of land. The holding is engaged in crop farming, sugar production, soybean processing, and dairy farming.

Astarta-Kyiv works with AgriChain, which develops a website for agricultural business management. The holding uses the website to keep track of its production processes, land, and crops. AgriChain is also continuously working on studying and testing technologies and equipment that can be used to increase agricultural companies' performance. AgriChain recommends to its clients field-tested technologies that it integrates into its tools. We started our experiments with Astarta thanks to AgriChain's initiative.

The first one took place in Poltava and Vinnytsia Regions. Soils in these regions are predominantly podzolized and low-humus chernozems and grey forest soils.

Contents

How I conducted the experiment

The first thing I did was analyze the productivity zones in the fields of each of the regions chosen for the experiment using the OneSoil web app. To do so, I selected the field on the map in the app, opened the 'Sowing' tab, and filled out the crop rotation. For the next few minutes, OneSoil analyzed the selected field and then displayed its productivity zones.
Here's how you can identify productivity zones in your field. For free
I then had to assess the stability of productivity zones in all fields. To do that, I compared the vegetation index maps for the last 3-4 years in the key plant growth stages. By key growth stages, I mean the phases when vegetation index data and actual yields are maximally related. If the pattern was roughly the same for years, the field's productivity zones could be considered stable, and vice versa. For the experiment, I selected fields with stable productivity zones, and I'll explain why below.
To see what the vegetation zones in a field looked like on any given day over the past 3-4 years, check out the OneSoil web app. You'll have to spend a little time, but it's well worth it
After I'd selected the fields for the experiment, I moved on to creating prescription maps. The test seeding rates were 65,000, 77,000, and 90,000 seeds per ha and were selected for all fields by Astarta-Kyiv's agronomists. My job was to distribute seeds so that each zone had three seeding rates, which served as the principle behind the seeding maps.
Prescription map for KVS 381 hybrid_OneSoil Blog
This is a prescription map for sowing the KWS 381 hybrid that I created using the Qgis app
The next step was to analyze the yield maps. I identified homogeneous plots in each productivity zone, small areas of up to 0.4 ha with approximately the same seeding rate and yield at each point. In my experience, this area needs to be passed over twice by the combine. For each homogeneous plot, I calculated the average yield rate and then used that to assess whether yield was trending up or down.
Homogeneous zones on the yield map_OneSoil Blog
This is what homogenous plots looked like in one of the fields

What was important to consider in the field trial

The productivity zones in the experimental fields must be stable. If they are from year to year, it means that field productivity is independent of the crop and climate conditions. Using this approach, you can avoid climate factors affecting the experiment results and assess the corn hybrid's role in increasing or decreasing yield.

It's important to calibrate combines and use yield monitoring systems. Otherwise, you won't be able to track the effect the seeding rate has on the result, or you'll get unreliable yield values.

How the hybrids reacted to variable-rate seeding

KWS 4484. In all productivity zones, yield increased when the seeding rate was reduced to 65,000 seeds per hectare. That means that the seeding rate for this hybrid can safely be reduced in the future.

KWS 381. In low- and medium-productivity zones, the yield also increased when the seeding rate was decreased. In high-productivity areas, yield grew when the seeding rate was increased to 90,000 seeds. As such, the seeding strategy for this hybrid depends on the productivity zone.

MAS 24.C. In medium-productivity zones, the seeding rate had almost no effect on yield, while in low-productivity zones, yield increased when the seeding rate was reduced. However, in high-productivity zones, yield grew with an increased seeding rate.

DKC 3730. In low- and medium-productivity zones, yield increased with a decreased seeding rate. In high-productivity zones, yield decreased when using a seeding rate of 65,000 seeds per ha. No difference in yield was observed when the seeding rate was 77,000 or 90,000 seeds per ha. It turns out that you can use the moderate seeding rate in high-productivity zones for this hybrid.

GRAN 6. In high-productivity zones, yield grew when the seeding rate was increased to 90,000 seeds per ha. The moderate seeding rate worked best in medium-productivity zones. The seeding rate didn't affect yield in low-productivity zones.
Experiment results_OneSoil Blog
Comparative table of yield by productivity zones

Conclusions and recommendations

I confirmed that variable-rate seeding works for corn and can increase the profitability of production. However, different hybrids respond differently to variable rates. I observed this both in this experiment and at other agricultural holdings in Ukraine and around the world.

If you plan to bet on increasing profitability using variable-rate corn seeding, it's important to test different hybrids and choose the one that increases yields for precisely your field and climate. This experiment's results are appropriate only for Astarta-Kyiv and the fields where the experiment was conducted.

If you decide to conduct a field experiment, be sure to carefully analyze the field's productivity zones, test different seed distribution strategies, and use a combine with a yield monitoring system.

If you want to discuss this article and share your own experience, please join our Telegram community!
Usevalad Henin
Create a seeding map with OneSoil
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