The last time I saw conditions like this I was working in a wheat field that the year before had 80 bpa wheat cut but had 80 lbs of N in the 6? preplant soil sample. When sowing the my crop I noted there was still a ton of residue left in the soil that had not broken down over the very dry summer. Well the fall was beautiful, great rains and warm temperatures. By Thanksgiving the crop was yellow and the N-Rich strip showing up really well. A soil sample taken Dec 1 showed there was only 5 lbs of N left in the soil, by my estimate the crop had only used 30. It was the microbes tyeing up the rest.
I was asked at a field day, would the immobilized N be mineralized and made plant available. That answer is easy Yes. Then I was asked when and that answer is tough unless you can predict the weather. The cycle is dependent upon moisture and soil temp. Warm wet fall/winter means better chance for early spring mineralization. Dry and or very cold winter looking at a delayed release. Also the spring weather pattern will influence the release. So here are my thoughts on what to do.
First: Given the lack of subsoil moisture at the time of this blog, I see little reason for any plant N to be applied in grain only wheat. For the forage systems I’d keep it at or under 50 lbs until we build our moisture profile.
Second: Do not forgo the in-furrow. A good root system could be critical this season, so make sure your Phosphorus is taken care of. If you ground is marginally acidic 6.0 or less this is even more important.
Third: If I’ve said it once I’ve said it one hundred times. PUT OUT N-Rich strips. Even if you don’t plan to use use the online tool, a consultant or a service provider, putting a strip out in your field will provide SO much information about what your crop and soil is experiencing. All about N-Rich Strips.
Fourth: If wheat is in a tug of wag match with microbial community, the microbes win. This is by no means a bad thing, but the numbers we see today, will not be indicative of what’s available once the N-Cycle kicks back into gear.
Thanks to the Oklahoma Mesonet for always having just the graphs I need.
Questions or comments please feel free to reach out.
Written by: Brian Arnall firstname.lastname@example.org