Strategic reductions in phosphorus, potassium and nitrogen work best when driven by soil biology and sound agronomy
As I scroll through ag social media, I find a world is buzzing with strident thoughts: “liquid fertilizer is better than dry,” “anhydrous nitrogen is bad,” “the timing of the application is wrong,” and countless other critiques about how nutrients should be managed. Everyone seems to have a strong opinion, often tied to a product, a practice, or a trend.
At the end of the day, however, your farm has to make money, and nutrient management decisions have to be grounded in return on investment, not noise. From rethinking long-held assumptions about phosphorus and potassium, to being cautious with nitrogen reductions, to understanding the critical role of soil biology and carbon, managing macronutrients has become less about chasing silver bullets and more about building systems that consistently support yield and profitability.
Rethinking Phosphorus and Potassium
What was once a taboo idea — reducing or even eliminating phosphorus and potassium inputs — has now gained momentum in mainstream agriculture. The management of these two nutrients can have a very significant impact on bottom lines as fertilizer prices creep northward. Nearly all of my clients have the ability to eliminate these two inputs. Some consideration has to be made for soil type, the crop being raised, and the end goal on the farm, but on acres where Total Nutrient Digestion tests show adequate levels of phosphorus and potassium, reductions from 50 to 100 percent are very feasible.
However, what ultimately allows for this reduction is a fully functional soil biology system. This is where the water gets muddy in a hurry — with all of the different microbial stimulants and biological products on the market. Making these nutrients accessible goes well beyond an individual product.
If you spend your money on a miracle drug, don’t be surprised when it’s not the cure and you see no response. Yes, some products may produce a positive change, but experience says that if you want a consistent response, you have to build a full program that supports biology.
I get very excited when growers see no difference in yield when they eliminate bulk fertilizer applications by focusing on a biological system. In today’s world, this may mean an extra $100 to the bottom line.
Nitrogen: A Different Standard
If I were to caution against reducing any nutrient, though, it would be nitrogen. This is a nutrient that, as a farm manager, you have to earn the right to reduce. I have experienced a handful of growers reducing nitrogen beyond 20 percent and having a yield reduction.
We can argue over nitrogen efficiency programs and their effectiveness, and you will find that many growers have mixed results. Many of these mixed results come from the timing of the application. As I continue to put years behind me, I am coming to the conclusion that the time for a nitrogen efficiency program may only be when nitrogen is applied at high levels well ahead of the planter. This is an area I look to learn more about through on-farm trials.
The Role of Carbon
One piece that cannot be ignored is carbon. I used to not pay much attention to carbon, but more and more growers are coming back to me with higher yields where they had an abundance of carbon. I can count on one hand how many times in college we talked about carbon as being an essential input. Understanding how crops burn through this element is critical. The rise in inputs such as chicken litter, humic acid, and biochar is directly related to carbon. If you can’t grow it, you have to apply it.
When looking to achieve nutrient reduction, the process and product selection can become a never-ending maze. From a long-term perspective, simply adding the right cover crop mix to your farm can do a lot of the heavy lifting and is something I recommend even to growers looking for a short-term fix. Having those living roots working with the microbial community is definitely a big part of the equation.
However, if your operation does not use cover crops, or you simply want a quicker response, there are some answers. A fall biological soil primer has been proven to supply many of the benefits of cover crops without worrying about managing living plants. It allows growers to eliminate phosphorus and potassium fertilizers in many cases.
There are many biological products on the market these days. Some even go so far as to promise specific levels of nutrient replacement or your money back. But living systems in the soil do not work on marketing promises. Experience has taught me that even the best microbial products are not successful in every single instance. This is where it is critical for growers investing money in these products to work with trusted advisors that understand the systems and how to fix them, even if a product seems to fail.
The biggest takeaway here is to not think of these products as the first thing you can eliminate from your budget. These products are parts of a bigger program, a shift in management that often results in lower input costs that maintain yield and/or increase profits.
The Total Picture
What we do at planting dictates so much of the success of the season. Upfront biology and plant support are vital to success. I’ve seen time and time again where a biological fertility system that minimizes stress and moves nutrients into the plant during times of stress is literally the difference between producing a harvest and having to bring out the shredder.
Everything I ask growers to do revolves around supporting biology, even when discussing foliars. In extreme dryland cases, it is not impossible to see stress reduction and nutrient access result in a 100 percent increase in yield, or a field having a more uniform yield that justifies harvest. Choose products because they are needed, not just because it is something that has always been done or recommended by the local supplier. A classic example of this is nitrogen management, where plants are stressed by an unneeded application that is backed up by sap data.
Supporting biology, applying the right nutrient at the right time in the right form, and not just pumping on more nitrogen is how I have repeatedly saved growers money on their total program while also experiencing significant yield increases. We can’t change the markets with agronomy, but we can change the ROI. The best investment for your farm in 2026 is an agronomist that understands these relationships and how to navigate the myriad of new and existing products being marketed to every farmer.
Navigating the many companies, products, and systems all wanting a piece of your farm can be a daunting task. Focus on building functioning biological systems, and you will be able to reduce inputs, increase production and experience a successful growing season. Allow biology to pay you back in 2026.
