Specs are compiled from manufacturer listings and verified buyer reviews and can change over time — please confirm the key details on the product page before buying.
If you grow corn, you know the mid-season moment when the lower leaves start to yellow and the stalk feels thin — that is your crop crying out for a nitrogen side-dress. The right high-nitrogen fertilizer keeps those stalks thick and the ears filling out all the way to harvest. This guide walks you through the exact products that deliver that boost without burning your plants.
I’m Rikta — the founder and writer behind Lawn Gear Lab. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
Below I break down the top options for a fertilizer to side dress corn, from pure prilled urea to liquid formulas, with the nitrogen percentages and real-world results that actually matter when your plants are knee-high.
Quick Picks
- Prilled Urea – 10 lb (2 x 5 lb Bags), 46% Nitrogen, 98.5% Purity — Best Overall
- Adoric Urea 46-0-0 Nitrogen Fertilizer 20LB Granules for Lawns — Largest Bag
- CountryMax Urea Fertilizer 46-0-0, 10LB Bag – High Nitrogen Lawn Fertilizer — Fast Green-Up
- Supply Solutions Urea 46-0-0 Nitrogen Fertilizer to Stimulate Lush Growth (5 lbs) — Versatile Coverage
- Duda Energy 5 lb Prilled Urea 46.0% Minimum Nitrogen Commercial Grade 98.5+% Purity — Entry-Level Value
- Leaves and Soul Urea Fertilizer 46-0-0 High Nitrogen Fertilizer – 5 lbs — Home Garden Starter
- Petramax Liquid Nitrogen Fertilizer 28-0-0 NPK – 1 Gallon — Liquid Convenience
How To Choose The Best Fertilizer To Side Dress Corn
Side-dressing corn means applying nitrogen when the plants are about knee-high, right as they start their rapid growth spurt. The wrong product — or the wrong rate — can burn roots or wash away before the corn ever gets the benefit. Here is what to look for.
Nitrogen Content (the N in NPK)
Corn is a heavy nitrogen feeder, so the first number in the NPK ratio (the percentage of nitrogen) is the one that matters most for side-dressing. A product like 46-0-0 delivers a concentrated nitrogen punch with zero phosphorus or potassium — which is exactly what you want when your soil already has those two elements from your early-season fertilizer. The higher the N number, the less product you need to haul to the field.
Form: Prilled vs. Granular vs. Liquid
Prilled urea is made up of small, round pellets that dissolve quickly once they hit moisture in the soil, so the nitrogen gets to the roots fast. Granular urea has a slightly larger, more irregular shape and tends to release a bit more slowly. Liquid nitrogen, like a 28-0-0 formula, gives you the option to spray directly onto the soil surface and is often absorbed within a day or two. For corn, a prilled or granular dry product is the most common route because you can place it in a band beside the row and let rain or irrigation carry it down.
Volatilization Risk (The Urea Factor)
Urea converts to ammonia gas when it sits on the soil surface without being worked in or followed by rain. If you broadcast dry urea on a dry day and get no moisture within 48 hours, you can lose a significant amount of nitrogen to the air. This is why many corn growers incorporate side-dressed urea lightly into the soil, or apply it right before a predicted rain. Some products include a urease inhibitor to slow this conversion, but the ones here are straight urea — so timing your application to moisture is key.
Quick Comparison
| Model | Best For | Nitrogen Content | Weight | Form | Amazon |
|---|---|---|---|---|---|
| Prilled Urea – 10 lb (2 x 5 lb Bags) | Best Overall | 46% | 10 lb (2 x 5 lb) | Prilled | Amazon |
| Adoric Urea 46-0-0 20LB | Largest Bag | 46% | 20 lb | Granules | Amazon |
| CountryMax Urea 46-0-0 10LB | Fast Green-Up | 46% | 10 lb | Granules | Amazon |
| Supply Solutions Urea 46-0-0 | Versatile Coverage | 46% | 5 lb | Granules | Amazon |
| Duda Energy 5 lb Prilled Urea | Entry-Level Value | 46% | 5 lb | Prilled | Amazon |
| Leaves and Soul Urea 46-0-0 | Home Garden Starter | 46% | 5 lb | Granules | Amazon |
| Petramax Liquid Nitrogen 28-0-0 | Liquid Convenience | 28% | 1 Gallon | Liquid | Amazon |
In‑Depth Reviews
1. Prilled Urea – 10 lb (2 x 5 lb Bags), 46% Nitrogen, 98.5% Purity
Two sealed bags of pure prilled urea that deliver 46% nitrogen right when corn needs it most.
You get fast nitrogen to corn roots during the critical knee-high growth window because this prilled form (small round pellets) dissolves quickly in moist soil, with 98.5+% purity and 46% minimum nitrogen content. Two separate 5 lb bags let you carry just what you need to the row without hauling an open 10 lb sack that might clump.
This 10 lb bag holds exactly twice the weight of the Duda Energy single 5 lb bag (10 lb vs 5 lb), so a larger corn patch saves you a reorder. Buyers report the urea “helps that plants grow bigger and stronger” and note it is “easy to apply in the granular form, just broadcast before a rain and let the rain do the work.” Watch out: straight urea can burn if overapplied — stick to about 1 lb per 100 sq ft for corn side-dressing and water it in.
It also works well dissolved in water for a liquid drench, which reviewers found handy for spot-treating smaller garden areas or conditioning straw bales.
The best pick for most corn growers: Pure 46-0-0 prilled urea in a two-bag set that keeps the product dry and gives you flexibility for different row lengths.
One honest limit: The prilled form dissolves fast, so if you apply it on a dry surface with no rain forecast, you risk nitrogen loss to the air — time it to a predicted shower or lightly rake it in.
Reach for this if: You want the highest-purity prilled urea in a practical two-bag format for mid-season corn feeding. Look elsewhere if: You need a product that includes a urease inhibitor to reduce volatilization on dry soil.
2. Adoric Urea 46-0-0 Nitrogen Fertilizer 20LB Granules for Lawns
A full 20-pound bag of granular urea for the corn grower who wants to buy once and cover a lot of rows.
With 20 lb of 46-0-0 urea in one bag, this is the bulk choice among the picks here — it holds exactly twice the weight of the 10 lb CountryMax bag (20 lb vs 10 lb), so you can side-dress a much larger area without restocking. The granules are small and the bag is resealable, which buyers appreciated: one reviewer called it a “great product, resealable bag” and noted the granules dissolve fast (instant release).
Reviewers reported excellent results on lawns and straw bale gardens, with one noting that after liming and rain the yard became “very green” and comparable to a discontinued high-end lawn product. Just be aware that a 20 lb bag of concentrated urea needs dry storage — once opened, moisture will cause clumping if the bag is not resealed tight.
A couple of buyers mentioned the price jumped by over per bag between purchases, so the value depends on when you buy. For corn, the math is simple: at the typical side-dress rate of 1 lb per 100 sq ft, this bag covers about 2,000 sq ft of corn rows.
Best for large plantings: A generous 20 lb bag of 46% nitrogen granular urea that keeps resealing fresh between uses.
The catch: Buyers reported price instability — the cost can shift significantly between seasons, so grab it when the price is right.
This is your pick if: You have a sizable corn patch (or multiple plantings) and want one bag to last the season. skip it if: You only have a small garden and would rather not store a 20 lb bag of nitrogen.
3. CountryMax Urea Fertilizer 46-0-0, 10LB Bag – High Nitrogen Lawn Fertilizer
Professional-grade granular urea that owners mention turns a lawn super green and grows an inch in three days.
The CountryMax 10 lb bag delivers 46% nitrogen in uniform granules that spread easily with a broadcast or drop spreader. One reviewer noted: “In 3 days my lawn was super green and grew an inch!” — a pace that matches what corn needs during its rapid vegetative stage. The 10 lb size is a balance for a medium garden: it covers more ground than a 5 lb bag but is still easy to carry to the rows.
This product is a straight 1:0:0 NPK mix (46% nitrogen, 0% phosphorus, 0% potassium), so it is designed for experienced gardeners who want to control their own NPK blend. Another reviewer noted it “dissolves well in water, to make liquid fertilizer,” which gives you the option to apply it as a soil drench or through a hose-end sprayer if you prefer liquid side-dressing. Just remember that the high concentration means a heavy hand will burn plants — start with half the recommended rate if you are new to urea.
One buyer did report shipping damage where the inner and outer bags were sliced during transit, so inspect the bag on arrival and transfer to a sealed container if you see any tears.
Why corn growers like it
- 46% nitrogen for fast green-up and stalk growth
- Dissolves well in water for flexible liquid application
- 10 lb bag offers generous coverage without being unwieldy
What to watch out for
- Shipping bag sometimes arrives sliced — check before storing
- High burn risk if overapplied to small corn plants
Who this works for: The gardener who wants a proven 10 lb granular urea that can be used dry or dissolved, with a track record of fast visible results. Not ideal if: You prefer a resealable bag or need a product that is guaranteed to arrive with no package damage.
4. Supply Solutions Urea 46-0-0 Nitrogen Fertilizer to Stimulate Lush Growth (5 lbs)
A 5-pound bag of granular urea with published coverage rates for turf, trees, and vegetables including corn.
Supply Solutions includes specific coverage guidance on its label — for vegetables and flowers, the rate is 2.5 cups per 100 sq ft. That gives you a clear starting point for corn side-dressing without having to guess the rate. The product is straight 46% urea nitrogen in a granular form, so it follows the same rules as other dry urea: apply before rain or incorporate it lightly to avoid nitrogen loss to the air.
One buyer mentioned that this “high-quality fertilizer quickly turned yellow lawn rich green within 3 days after watering” — a speed of response that corn leaves will show as well. Another reviewer specifically mentioned it “works for my corn needs.” The 5 lb bag is an entry-level size for a first-time corn grower or for someone with a small patch of 10-20 hills.
The main caution comes from a reviewer who warned, “BE CAREFUL WITH THIS!… spilled spots killed grass, took months to recover.” That is the reality of 46% nitrogen — even a small spill on foliage or concentrated soil can scorch. Use a spreader or measure carefully and sweep up any granules that land on the corn leaves.
A good first bag for smaller gardens: Gives you published rates for vegetables and a real-world track record of fast green-up, all in a manageable 5 lb size.
The caution is clear: Overapplication or spills can burn plants badly — start with a conservative rate and water in immediately.
Grab this if: You want a modest 5 lb bag with official coverage rates for vegetables and corn, and you will be careful with application. Pass if: You need a larger quantity for multiple rows of corn.
5. Duda Energy 5 lb Prilled Urea 46.0% Minimum Nitrogen Commercial Grade 98.5+% Purity
A small 5-pound bag of prilled urea that delivers the same 46% nitrogen as the big bags for a small test patch.
At just 5 pounds, this Duda Energy prilled urea is the same purity and nitrogen content (46% minimum, 98.5+% purity) as the 10 lb two-bag set but in a single smaller package. That makes it a smart choice if you are trying out urea for the first time or have a small corn planting where a 10 lb bag would sit open and clump. It holds exactly 80 ounces (compared to 160 ounces in the CountryMax 10 lb bag), so the weight difference is a clean 2.0x — you get half the material for a smaller commitment.
Customers note that the prilled form is “easy to apply in the granular form, just broadcast before a rain and let the rain do the work.” Others noted it dissolves “better than butter” for tie-dye applications, which tells you how quickly it goes into solution if you want to make a liquid feed. One reviewer summed it up: “The Urea helps that plants grow bigger and stronger.”
Plan for about 1 lb per 100 sq ft, so this bag covers roughly 500 sq ft of garden bed.
What works
- Same commercial-grade prilled urea as the larger pack
- Easy to test-apply without storing a big bag
- Dissolves quickly for liquid side-dressing
The limit
- Only 5 lb — covers about 500 sq ft at the standard corn rate
- No resealable bag, so transfer to an airtight container after opening
Best for first-timers: A low-commitment 5 lb bag of prilled 46-0-0 that lets you test urea side-dressing before buying a 10 lb or 20 lb bag. Not for large plots: You will need multiple bags for a substantial corn patch.
6. Leaves and Soul Urea Fertilizer 46-0-0 High Nitrogen Fertilizer – 5 lbs
A sturdy, moisture-proof bag of granular 46-0-0 urea that a reviewer called “pure Urea, great value, full control.”
This Leaves and Soul urea comes in a 5 lb bag that earned praise for its “excellent moisture-proof bag” — a detail that matters because urea clumps fast in humidity. One buyer in Seattle noted the product “clumps quickly in humidity” but still gave it 5 stars for its pure nitrogen content and flexible application (foliar spray at 5-10g/L for new plants). The manufacturer states it is made in the USA, and reviewers confirmed the granules are “even texture, easy to spread.”
For corn side-dressing, the 46-0-0 ratio is the standard, and this granular form works well for banding beside the row. One reviewer applied it with a pump sprayer and found it easy to mix, while another used a broadcast spreader and saw the lawn “green up well after 2 weeks.” Both methods can be adapted to corn — just water it in after application so the nitrogen moves down to the root zone.
The main trade-off is that the 5 lb bag is small, so if your corn rows cover more than about 500 sq ft you will need two bags. Also, one reviewer found “no significant greening” on a weak lawn, which suggests the product works best when the soil is already somewhat healthy — it is a booster, not a soil fixer.
A solid small-bag choice: Good moisture-proof packaging and flexible use (dry or liquid) at a reasonable price for a test run.
What to know: The 5 lb size suits small gardens, and it will clump in high humidity if the bag is left open.
Pick this if: You want a well-packaged 5 lb bag of 46-0-0 granular urea made in the USA, and you only have a small corn bed. pass on it if: You need a larger quantity or want prilled form for faster dissolution.
7. Petramax Liquid Nitrogen Fertilizer 28-0-0 NPK – 1 Gallon
A liquid 28-0-0 nitrogen with both quick-release and slow-release technology, sprayed straight onto the soil.
Unlike all the dry urea picks above, the Petramax Liquid Nitrogen is a 28-0-0 formula you mix with water and spray. It uses a 2-in-1 release technology: 70% quick-release nitrogen for an immediate green-up, and 30% slow-release nitrogen for sustained feeding between applications. The maker says to mix 5 oz per gallon of water for maintenance or 10 oz per gallon to correct a nitrogen deficiency, and a single gallon treats up to 25,600 sq ft at the maintenance rate (or 12,800 sq ft for deficient grass).
For corn, a liquid side-dress can be an advantage because you can apply it directly to the soil beside the row without the granules bouncing off leaves. One owner reported that “this stuff works great and my lawn has never been so green,” while another said “product does work… it does make the lawn greener.” The liquid form also eliminates volatilization risk because the nitrogen is already dissolved — you do not have to worry about dry urea sitting on the surface and off-gassing.
The trade-off is the nitrogen content: at 28% it is lower than the 46% dry urea products, so you need more volume to deliver the same total nitrogen. It is also the most expensive option per pound of nitrogen among these picks, and it is designed for lawn sprayers rather than traditional banding beside corn rows. If you already own a sprayer and prefer liquid feeding, this is a neat option — but for traditional side-dressing, a dry 46-0-0 urea is the more standard, cost-effective route.
Advantages for corn
- No volatilization loss — nitrogen is already in solution
- Quick + slow release provides both immediate and extended feeding
- Treats up to 25,600 sq ft per gallon at maintenance rate
Considerations
- 28% nitrogen is lower than 46% dry urea — more volume needed
- Requires a sprayer and careful mixing
- Higher cost per unit of nitrogen than dry granular options
Choose this if: You prefer liquid application and want the convenience of a spray-on nitrogen feed that also includes slow-release technology. Pass if: You want the highest nitrogen density at the lowest cost, or you prefer traditional granular side-dressing beside corn rows.
Understanding the Specs
NPK Ratio — The Three Numbers
The three numbers on a fertilizer bag stand for nitrogen (N), phosphorus (P), and potassium (K) in that order. A 46-0-0 product like the ones above contains 46% nitrogen by weight and zero phosphorus and zero potassium. For side-dressing corn, you want a high first number (nitrogen) because corn is a heavy nitrogen feeder at the knee-high stage. The zeros mean the product is pure nitrogen — you only need to use it if your soil already has adequate phosphorus and potassium from your pre-plant fertilizer or soil test.
Prilled vs. Granular — The Size and Shape
Prilled urea is made of small, nearly round pellets about the size of a pinhead — they dissolve quickly when they contact moisture, so the nitrogen gets to the roots fast. Granular urea has larger, irregular-shaped particles that tend to break down more slowly. For corn side-dressing, prilled urea is often preferred because its quick dissolution matches the rapid nitrogen uptake corn needs during its growth spurt. The trade-off is that prilled urea can volatilize (turn into ammonia gas) faster if it sits on a dry surface — so you need rain or irrigation soon after application.
FAQ
When should I side-dress corn with nitrogen?
How much 46-0-0 urea should I apply per corn plant or per row?
Can I mix urea with water and spray it on corn?
What is the difference between 46-0-0 urea and 28-0-0 liquid nitrogen?
Will urea burn my corn plants if I apply too much?
Should I use a product with phosphorus (the middle number) for side-dressing corn?
Does the 98.5% purity listed on some urea products make a difference?
How do I store leftover urea so it does not turn into a hard block?
Can I use lawn urea on my vegetable garden and corn?
What happens if I side-dress corn and it does not rain for a week?
Final Thoughts: The Verdict
For most corn growers, the fertilizer to side dress corn winner is the Prilled Urea – 10 lb (2 x 5 lb Bags) because it combines 46% nitrogen with high 98.5% purity in a practical two-bag format that stays fresh and gives you flexibility. If you want the highest bulk value and have a large corn patch, grab the Adoric Urea 46-0-0 20LB. And for the convenience of liquid application with slow-release technology, the Petramax Liquid Nitrogen 28-0-0 is the liquid choice.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
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