Interview with a Ukrainian Agronomist on Variable-Rate Seeding in Zones with Unstable Climate Conditions_Cover_OneSoil Blog

A Ukrainian agronomist on variable-rate seeding in zones with unstable climate conditions

Reading time — 10 minutes
Evgeny shares how OneSoil helped him conduct variable-rate fertilizer application and seeding.
Evgeny is an agronomist at Petrov Farms in the south of Ukraine. Last year, the folks at Petrov Farms tried their hand for the first time at variable-rate fertilizer application and seeding using OneSoil's maps. We asked Evgeny about this new experience and the challenges he faced.
Evgeny is an agronomist at Petrov Farms in the south of Ukraine. Last year, the folks at Petrov Farms tried their hand for the first time at variable-rate fertilizer application and seeding using OneSoil's maps. We asked Evgeny about this new experience and the challenges he faced.
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The most important thing in zones with unstable climate conditions is to act fast to prevent moisture from evaporating away
I’ve been in agriculture for three years now. I started working at Petrov Farms right after I graduated from an agricultural university. It’s a private farm, just like most Ukrainian agricultural producers. It covers an area of 3,500 hectares. By Ukrainian standards, it’s neither a big farm nor a small one. We’ve been doing quite well and stay on top of upgrading our equipment fleet.

We grow winter wheat, barley, and rapeseed. We also plant corn, sunflower, and sorghum. We make money on selling grain. We sell part of it right away and store the rest to sell later at a higher price. Overall, our yield is average for the region or slightly above average.
Depending on the season, we have anywhere from 30 to 50 employees at the farm. We have 30 full-time employees. These are agronomists, agricultural equipment operators, metalworkers, accountants, and economists who work year-round. We have about 20 seasonal workers who do fieldwork.

South Ukraine (Black Sea littoral zone and Cisazovia) is in a zone with unstable climate conditions. Our yield largely depends on nature and the climate. Our challenge every season is a lack of moisture. For instance, it rained only once from January to April. None of the farms around here use irrigation systems. The pay-off is too slow, and our fields are too far from water sources. The most important thing to do in these conditions is to act fast to prevent moisture from evaporating away.
Photo of Rapeseed field in April_OneSoil Blog
Rapeseed field in April. Our agronomist Filipp took the photo for this article
We decided to try variable-rate fertilizer application out of curiosity
I use the normalized difference vegetation index (NDVI) to track crop growth. We don't always have an opportunity to visit the fields, and NDVI shows you which part of the field is doing alright and which isn't doing so great. The NDVI-based productivity zones from the OneSoil app correspond to the ones we identified in our last soil analysis. We conduct one every 3-4 years and do grid sampling on our own. That's why we wanted to see how productivity-zone-based variable-rate fertilizer application works, so we decided to try it out.

We applied ammonia nitrate in our first and second fertilizer applications to winter crops in March. We used 80 kilograms per hectare for the first fertilization run and 70 kilograms per hectare for the second one. We bought a special spreader for variable-rate fertilizer application, created a prescription map in the OneSoil app, and headed to the fields. We don't expect quick results. Obviously, one time is not enough to level the field out.
But what I can say is that variable-rate application based on productivity zones saves us money.
This spring, in April, we tried variable-rate seeding for the first time. The truth is, in mid-February, our agronomists found out that the wheat crops in some fields died because there were no typical winter conditions for this region. The temperature varied a lot, going from 15−16°C in the day to -5 to -7°C at night. Most likely, the wheat resumed vegetation, but couldn’t survive the temperature fluctuations.

We didn’t want the fields to sit empty, so we decided to reseed them. In one of these fields, covering 120 hectares, we tried out variable-rate seeding. If we can increase yield using a proven technique, why not take advantage of it? We planted sunflowers from Syngenta (a Sumiko hybrid) in the dry soil. We hoped that we’d get rain soon enough, which would provide enough moisture for seeds to sprout. We used experiments conducted by Usevalad Henin to determine our sowing rate (Note from OneSoil: Usevalad Henin is a precision farming specialist at OneSoil and agricultural chemist). We decreased the rate for low-productivity zones and increased it for high-productivity ones. We ended up with three different sowing rates: 66K, 56K, and 37K seeds per hectare.
Prescription map with sowing rate for sunflower_OneSoil Blog
Prescription map with sowing rate for sunflower
A Fendt 1050 Vario heavy tractor and Kinze 3660 planter were used. All equipment was brand new. We needed some time to get the hang of them, but we walked away with good impressions. The planter works without overlaps or gaps. To make sure that was the case, after sowing, I visualized the file from the onboard computer in the OneSoil app. We expect that accuracy alone will be enough to get some increase in yield. Later on, we'll install yield monitoring equipment on our combines so we can see how many tons were yielded and in which part of the field after the harvest. Taking into account the sparse rain this spring, we hope for an average increase of 0.4−0.5 tons/ha.
Map the farmer got after sowing. From the OneSoil app_OneSoil Blog
This is the map we got after sowing. The OneSoil app lets you track the rate you applied in different parts of the field, at what speed the equipment ran, and the time it took
For now, we’re just keeping an eye on the crops. We’re curious to see if the seedling vigor and development are different when variable-rate seeding is used. The only thing we’re not so happy about is our inability to monitor all processes ourselves (Note from OneSoil: due to the coronavirus pandemic, Ukraine’s transportation system has faced restrictions, limiting movement). That said, everyone on the ground is working as usual. The guys are following the recommended safety measures and going on less personal errands. We’ve got everything under control in the fields.
There's almost no way you can get this information for free in Ukraine
Precision farming is when you can track all the processes happening in the field from the comfort of home. But to do so, you need special software, the right equipment, sensors, and monitors to track the quality of field operations.

We acquired special equipment this year. I also use the OneSoil web app. I calculate the fertilizer quantity for variable-rate application, create seeding maps, review reports on the work done (Note from OneSoil: files derived from equipment can be visualized in the OneSoil web app), and monitor fields using the NDVI index. If something's not quite right, you can easily spot it using the vegetation index. I immediately let the agronomists on the ground know, and they visit the field to find out what's going on. It may be moisture or a pest.

The OneSoil app also makes it easy to track growing degree-days and accumulated precipitation. As far as I know, there's almost no way you can get this information for free in Ukraine.
But here it is, publicly available. All the charts appear on the same page, which saves tons of time and helps analyze yield.
Let’s imagine a situation where the productivity in one field is 5 tons/ha, but 2.5 tons/ha in another even though they’re only 3 kilometers away from each other. We look at the temperatures during the blooming period and see that the temperature was high in the field with lower productivity. High temperatures make sunflower pollen sterile, and blooming doesn’t occur. In these cases, yield drops. The growing degree-days chart helps identify the reason why.

Interview conducted by Tanya Kovalchuk
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