Lower-Carbon Corn, In a Pass You Already Make
Under Section 45Z, ethanol plants earn a larger credit for fuel made from lower-carbon corn, and nitrogen is the biggest part of corn's carbon intensity (CI) score. Maximum Acre from Sound Agriculture, SOURCE + BLUEPRINT, replaces up to 35 lbs of synthetic nitrogen and phosphorus while still improving yields.
What’s the Latest on 45Z?
USDA’s rule for scoring farm practices takes effect. Nutrient management alone qualifies.
IRS Notice 2026 – 53. Field-level corn scores can now lower a plant’s 45Z rate.
Final treasury regulations for 45Z. Values on this page may change when they publish.
Growers are writing 2027 fertility plans, and the 2027 nitrogen rate is what gets scored.
How a Field Lowers a Plant’s 45Z Rate
The Plant Earns 45Z on Every Gallon
The lower the fuel’s carbon intensity (CI) score, the larger the credit per gallon. Growing the corn is a large part of that score.
Your Field Can Replace the Default
Since September 2026, a plant can use field-level scores from USDA’s calculator in place of the national default for corn, through its low CI-grain program.
Nitrogen Per Bushel Drives the Score
At the same yield, every pound of synthetic nitrogen you don’t apply lowers the score. For example, in Central Iowa at 200 bu/ac, about 11.5 lbs moves it one CI point.
For Growers
How Do I Replace My Nitrogen Without the Risk?
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A Pass You Already Make
SOURCE is 1 oz/ac foliar in a pass you already make. BLUEPRINT goes in the planter box or in-furrow at planting.
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Proven With Less Nitrogen
Where growers replaced 25 lb of N and P, SOURCE delivered a 3+ bu/ac average increase over four years (100+ trials).
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Sound Ag Underwrites It
Replace N and P with SOURCE or Maximum Acre, and if your return doesn’t cover the price of the product, we refund the difference. *Restrictions apply.
Keep your no-till and cover crops. They lower your score too, and replacing nitrogen with Sound adds to what they already do on the same field.
For Ethanol Plants
Put a Nitrogen Path In Your Low-CI Grower Program
Nitrogen rate and yield are core inputs your scoring partner already captures, so there is no separate Sound program to run. Growers replace nitrogen in passes they already make on conventional, reduced-till and no-till fields alike, and Sound helps recruit them.
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Close the Gap to Your Next Tier
The credit pays in steps, so points only count when they carry you across the line. Maximum Acre takes about 3 CI points off each enrolled field, on top of the tillage and cover crop acres you already have, to help you reach the tier you’re targeting
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Sound Helps Growers Adopt
Sound and our dealers work alongside your grain team to introduce your program to growers in your supply shed and help them put a nitrogen plan in place
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Scoring Stays With Your Partner
SOURCE changes one input; the nitrogen rate. Your scoring and verification partner runs each field the way it already does.
Frequently Asked Questions
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The credit is earned by the fuel producer. Plants share value with growers through their low-CI grain programs, and your share is set by your contract with the plant or elevator.
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No. The CI score counts nitrogen. Replacing phosphorus with Sound Agriculture still lowers your fertilizer bill, so it shows up in your savings, but your CI score is calculated based off nitrogen. SOURCE by Sound Agriculture replaces 25 lbs of nitrogen and phosphorus while delivering a 3+ bu/ac average increase.
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Expect field records such as nitrogen rate and yield, and a nutrient budget written before you apply. Each plant’s program sets its own requirements, so ask yours what it needs.
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No. SOURCE by Sound Agriculture is a foliar chemistry that signals the microbes already living in your soil. BLUEPRINT is the biological in Maximum Acre containing beneficial fungi that extend the root system to reach more nutrients.
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CI scores are county-specific. This page uses central Iowa factors from USDA’s calculator and holds yield flat. Your plant’s scoring partner runs your actual fields.
Ask your ethanol plant or elevator about its low CI-grain program and what it pays.
Write your 2027 nitrogen plan with Maximum Acre in it before you apply. USDA’s rule asks for a nutrient budget written ahead of application.
Keep nitrogen rate and yield records by field. Your plant’s program uses them to score your corn.
*Estimates on this page are Sound Agriculture modeling, not an offer of payment. 45Z credits are earned by fuel producers, and any grower payment is set by contract between the grower and the plant or grain buyer. Rule status is as of October 2026. Final Treasury regulations are pending and values may change.
Method. CI points are kg CO₂e per MMBtu of ethanol. Modeled with USDA’s FD-CIC v1.2 (Sept. 11, 2026) using Story County, Iowa factors: about 3.84 kg CO₂e avoided per lb of synthetic nitrogen replaced, and one CI point per 221 g CO₂e per bushel. Values use the 2026 maximum credit of $1.09 per gallon with prevailing wage and apprenticeship requirements met, 2.85 gallons per bushel, and field reductions allocated entirely to ethanol (45ZCF-GREET, Sept. 2026). Per-point values are linear; the statute pays in 0.1 steps and rounds to the cent. Yield is held constant, and only the Sound nitrogen change is counted. Your county’s factors will differ.
Trial results. SOURCE 3+ bu/ac is the average where growers replaced 25 lb of N and P, across 100+ trials over four years. Fertilizer Replacement Guarantee restrictions apply; ask your Sound representative for details.