Nitrogen Efficiency 

Last week we discussed how we interpret the “4 R’s” of Nitrogen use here at AEA. Today we’ll dive deeper into the specifics of how growers can radically decrease their nitrogen use by ensuring it stays in the soil and gets used by the plant. 

The goal: biology providing 100% of a crop’s nitrogen

Nitrogen fixed by soil biology is more valuable than any form of nitrogen you can apply. It is most efficient for plants to receive their nitrogen as amino acids and proteins directly from microbial metabolites produced by the living soil food web. The goal of regenerative agriculture is to develop microbial communities that can provide all of a crop’s N every single year.

While a regenerative management program will approach this goal over time, you’ve still got to grow a crop this year, and with input prices what they are, you need to use your inputs as efficiently as possible. 

That’s where our Nitrogen Efficiency Program comes in. We commonly observe that growers are able to reduce nitrogen application rates by 30%-50% from conventional recommendations in the first year on this program, while producing the same or higher yields.

How to make the most of your applied nitrogen

No matter the form of nitrogen applied, it stands to be leached from the soil unless it’s bound by something. That’s why we developed our Nitrogen Efficiency Program: to keep nitrogen in the soil where it can be used by the plant. Here’s the basic science on how it works. 

First, there are 2 important ratios to keep in mind with soil nitrogen: 

30:1 : The ratio of Carbon to Nitrogen in Soil Organic Matter 

10:1 : The ratio of Nitrogen to Sulfur in amino acids and proteins

• Ensure that either your tank mix or your soil has adequate free sulfur to provide the 10:1 Nitrogen:Sulfur ratio required for protein synthesis. 
• ATS, elemental sulfur, and sulfur-bearing micronutrients are all good sulfur sources.

So, Carbon:Nitrogen:Sulfur must be 300:10:1

Other components: 

• Humic substances like HumaCarb will compound with free N to stabilize it in the tank. 
• Molybdenum is an enzyme cofactor for the nitrate reductase enzyme, which is needed by bacteria to convert nitrates to amino acids.
• Soluble carbon allows for aggressive bacterial development and nitrate conversion. Rejuvenate can provide this. 

Nitrogen Efficiency Formula

 Application rates are calculated according to this formula:

• X = total amount of nitrogen product (not units of N)
• Maintain 10:1 nitrogen to sulfur ratio unit per unit, using ammonium thiosulfate (ATS) or other sulfur
• 1 pint Rebound Molybdenum per acre
• 3% of X as Humacarb
• 3% of X as Rejuvenate (optional)

Use Sap Analysis to monitor nitrogen levels throughout the growing season. Apply what is needed when needed.