Like the Nitrogen cycle is circular, so is my series about it. So let’s get back to the beginning…
I started this little series with five things I wanted you to think about. I’m ending the series today with five answers to common questions. But never fear, we shall jaw about Nitrogen again, friends. And soon, I’m sure.
In temporary conclusion then, I present to you five answers to five questions:
1) What about that 40 pound credit?
Ah, the soybean credit. Many growers mistakenly believe that they should be credited one pound of Nitrogen for every bushel of beans they raise per acre. But that’s not where the 40 pound credit for planting soybeans comes from. The credit comes from the lack of corn residue in your fields. When you’ve planted soybeans, you aren’t left with corn residue on your fields, which requires Nitrogen for decomposition. That 40 pound credit is rather your avoidance of a 40 pound penalty for planting corn after corn. (Not to say that you can’t or shouldn’t plant corn after corn, but such is the cost of business.)
2) A pound of Nitrogen is a pound of Nitrogen, right?
Not really, friends. Or at least not all the time. Mid-year, plants recognize nitrate and ammonium completely differently. Ammonium is their preferred form of Nitrogen. They’ll take up nitrate as well, but at an additional energy cost as they will convert the nitrate to ammonium through a process that burns sugars.
Ammonium and nitrate aren’t equal then, in the world of our plants.
This should compel us to protect ammonium then, as it is the preferred form of Nitrogen for our plants. And here is where the four Rs come into play: right rate, right source, right timing, right placement. Done properly, and with a little assistance from a nitrification inhibitor, this will help protect ammonium in your soil and help you get the benefit you were expecting from your Nitrogen investment.
3) What affects the Nitrogen I put into my soil?
Answer: everything. Literally everything from the amount and type of residue on your fields (see #1) to your soil’s pH to compaction to saturation to etc. There can hardly be a single solution or answer then to a Nitrogen issue. We can sit here and ballpark all day, but the answers to your Nitrogen questions are as idiosyncratic and unique as you are and dependent upon your myriad practices.
4) Can I have N loss even if I don’t have yield loss?
Yep. Nitrogen loss can be masked by many things. In a particularly congenial year, early N loss might be masked by some extra biochemical generosity in our soil (see last week’s article). N loss could also be masked by plants pulling nitrates from ground water. Or a bad stand might not reveal the true extent of N loss. These are just three of many scenarios that hide N loss from us. But just because it is hidden doesn’t mean we shouldn’t be paying attention. Whether we see it reflected in our yields or not, it is a loss that has to be accounted for because if not, it will catch up to us someday, and that day will be less than pretty.
5) What about technology?
I really think that we’re just at the forefront of the emerging technology that will change this game. The technology is going to get more complex and come at us fast. We’ll need to trust faster, be more agile, and be more open in order to keep up. It’s a scary proposition, but exciting, too. The changes in technology that are coming our way are part of our journey and I hope that we can learn to ride this wave.