Nitrogen Inputs: Combating your Budget’s New Nemesis through Regenerative Agriculture
May 4th, 2022
by Advancing Eco Agriculture
Nitrogen input prices have skyrocketed across the agricultural industry. What can growers do to protect this season’s crop performance and their bottom line?
The answer lies in a stable, slow-release, plant-available approach to profitable nitrogen management.
Right Source: Not all forms of nitrogen are created equal.
Understand that each source of nitrogen will be utilized differently by plants and soil biology. One form of nitrogen will produce different crop responses than another.
Protein nitrogen is the ideal and most efficient source of nitrogen. These diverse microbial amino acids and proteins can be absorbed by the plant directly from the soil. Microbial populations fix and process atmospheric N. Access to biologically stable nitrogen is integral to a regenerative approach. Fields with higher microbial activity often require only a fraction of the applied N to produce an equivalent response as fields applied with high rates from conventional sources. Compost, plant-based fermented amino acid products, fish hydrolysates, and corn steep liquor are examples of protein nitrogen.
Urea is the second most efficient form of N. While it seems more expensive, the per-unit cost of urea is balanced by the fact that much less plant energy and water is required to convert amine nitrogen into complete plant proteins than other synthetic forms, and it is relatively gentle on soil microbes.
To further maximize urea N, dry urea can be liquified on the farm. Liquid urea can then be combined with nitrogen efficiency enhancing materials like molybdenum and humic substances, and applied in multiple smaller shots, rather than larger amounts less frequently, which is almost always less efficient.
Ammonium is the third most efficient form of nitrogen for crop metabolization. NH4 fertilizers saturate the market, including dry ammonium sulfate and liquid UAN 28% or 32%. Application rates of soluble ammonium N beyond what a crop can immediately use benefit from the addition of molybdenum and humic substances to extend plant availability and buffer negative results to soil biology.
Nitrate is the fastest to absorb but the least efficient form of N for crops to metabolize. Plants use a significant amount of their photosynthetic energy to convert nitrate to amino acids and proteins. If utilizing nitrate, it is crucial to maximize nitrogen efficiency practices. Molybdenum is the critical enzyme cofactor of the nitrate reductase enzyme, which is responsible for converting nitrate into plant and microbial proteins. Humic substances can be employed to slow the rapid release of nitrate into soil systems.
Note: Nature maintains a balance of 10 parts nitrogen to 1 part sulfur. Disturbing that balance results in loss of biology, carbon, and nitrogen. It is important to always include a minimum of 1 part sulfur for every 10 parts nitrogen being applied.
Right Rate & Right Time are inseparable
Don’t apply more nitrogen than soils and plants can use before it is volatilized, compounded, or washed away. This advice stands the test of time.
Timing nitrogen availability to match demanding growth phases makes perfect sense. This means there is a tight window for applications. Input savings and crop quality gains can offset the investment of any equipment modifications or purchases to match needs.
More nitrogen is required at vegetative growth phases, while excess nitrogen is highly undesirable for seedlings or senescing plants. A corn crop is able to access adequate biological nitrogen even in relatively poor soils until V4-V5.
Winter wheat grows fastest in mid-spring—that’s when to apply N, not in fall or winter.
Right Place: Soils and the crop itself
The right place for nitrogen is in the crop itself. We are free to explore all the relevant pathways for uptake, including dry and liquid soil applications, foliar applications, side-dressing, and biological uptake from nitrogen-fixing bacteria, fungal activity, release from soil organic matter, and crop residues. Reconsider applying all nitrogen to the soil itself as a preplant or at-planting operation.
The best temporary home for soil-applied nitrogen is in living microbial biomass. Diverse populations of microbes in the immediate vicinity of applied N can mop up excess nitrogen from being lost to the atmosphere, storing and releasing it to roots later. Nitrogen compounding products can help with slow and steady release of early applications.
Side-dressing or fertigation of nitrogen later in the season provides the opportunity to use the 4R’s to best advantage by supplying N when and where needed—to the roots when plants are at their maximum of vegetative growth.
With AEA's Nitrogen Efficiency Program, growers can work smarter, reduce nitrogen usage, and save money.
Advancing Eco Agriculture works with growers to create customized crop programs, combining our biological and mineral nutrition products with regenerative practices.