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Liquid & Granular Nitrogen Fertilizer: A Certification-First Spec Guide to UAN 32 and ASN 26-0-0+13S

When buyers search for liquid and granular nitrogen fertilizer, the useful question is rarely just how much nitrogen is inside the bag or tank. Urea ammonium nitrate solution and ammonium sulfate nitrate can both be called nitrogen fertilizers, but their nitrogen forms, sulfur content, physical handling, application routes, and compliance documentation are different. For buyers in the research and evaluation stage, the practical answer is to build a specification-and-certification checklist before comparing suppliers.

In simple terms, UAN 32 is a liquid nitrogen fertilizer containing 32% nitrogen in urea, ammonium, and nitrate forms. ASN 26-0-0+13S is a granular fertilizer that typically contains 26% nitrogen and 13% sulfur, with ammonium and nitrate nitrogen. Neither is universally better. UAN 32 fits liquid application systems such as fertigation, while ASN fits granular base fertilization and top dressing where sulfur is also part of the crop nutrition plan.

UAN 20L drum

Problem Definition: What Needs to Be Verified in Liquid and Granular Nitrogen Fertilizer Sourcing?

The nitrogen fertilizer category is broad. A liquid fertilizer with the same N concentration can be based on different nitrogen carriers, and a granular product with sulfur may change how the product should be positioned in a crop nutrition program. Buyers evaluating import or distribution options need to separate the product-specific parameters from general industry descriptions.

There are several common evaluation gaps:

  • Confusing nitrogen content with nitrogen availability behavior. Nitrate nitrogen, ammonium nitrogen, and urea nitrogen behave differently in soil.
  • Ignoring sulfur content. ASN 26-0-0+13S supplies sulfur; conventional high-N granular fertilizers such as urea do not.
  • Overlooking physical parameters. Liquid density, pH, freezing point, granule size, and moisture affect storage and application.
  • Treating certification as one generic set of papers. Certifications are issued for specific standards, product scopes, and markets.

This article uses public product and company data from TAIAN RISSO CHEMICAL CO., LTD., also referred to as Risso Chemical, to make the checklist concrete. The same verification logic can be applied to other suppliers.

Industry Background: Why Certification and Nutrient Form Are Gaining More Attention

The fertilizer industry is being asked to improve efficiency while maintaining crop yield. One commercial research report by SNS Insider / Market Research valued the global liquid fertilizers market at USD 15.49 billion in 2025 and identified nitrogen as the largest revenue contributor. Reported liquid fertilizer market sizes vary by scope and product definition, so this estimate should be treated as directional rather than as a precise figure.

At the same time, regulatory pressure is increasing in some regions. EU nitrogen targets recommend a 20% cut in chemical fertilizer use by 2030 to help meet Green Deal nutrient-loss goals, according to material published by Re Soil Foundation / Nature Food. This is one reason why buyers are paying more attention to products that allow accurate application, balanced sulfur nutrition, and measurable nutrient management.

Liquid UAN products and sulfur-containing granular products are not automatically more efficient. Their value depends on whether they are matched to the right application system and crop requirement.

Detailed Solution: How to Read UAN 32 and ASN Fertilizer Data

The detailed solution below is built from product specification and certification data. Buyers can use it as a reference when comparing UAN 32 liquid and ASN granular fertilizers.

UAN 32 Fertilizer

UAN 32 Fertilizer is a liquid nitrogen fertilizer with a total nitrogen content of 32% N. It is supplied as a liquid solution and contains urea nitrogen, ammonium nitrogen, and nitrate nitrogen. This combination is the basis for the triple-nitrogen-source description often used for UAN products.

Typical UAN 32 specifications include:

  • Appearance: clear to slightly yellow liquid
  • Density: approximately 1.32–1.34 g/cm³ at 20°C
  • pH: typically 7.0–8.0, which places it in a near-neutral range
  • Freezing point: approximately -10°C
  • Main composition: urea + ammonium nitrate + water

UAN 32 Fertilizer is commonly used for fertigation, foliar application, and soil application. Its liquid form enables accurate metering, flexible split applications, and compatibility with irrigation and liquid fertilizer equipment.

ASN 26-0-0+13S Fertilizer

ASN Fertilizer, also shown in the product model range as ASN (ANS), is a granular ammonium sulfate nitrate fertilizer. The grade 26-0-0+13S typically supplies 26% nitrogen and 13% sulfur. Nitrogen in ASN is present as ammonium nitrogen and nitrate nitrogen. This dual-nitrogen granular profile is why ASN is often described as a nitrogen-sulfur synergistic granular fertilizer: one granule supplies both sulfur and nitrogen in two mineral nitrogen forms.

Typical ASN specifications include:

  • Appearance: white to off-white granules
  • Granule size: typically 2–4 mm
  • Moisture: ≤1.0%
  • Main composition: ammonium sulfate + ammonium nitrate
  • Application: base fertilization, top dressing, field crops

ASN is a granular choice when the crop program needs nitrogen plus sulfur and the farm uses granular spreading equipment for base or top dressing.

Manufacturer Example: TAIAN RISSO CHEMICAL CO., LTD.

TAIAN RISSO CHEMICAL CO., LTD. is a fertilizer manufacturer based in the High-tech Development Zone, Taian City, Shandong Province, China. The company was founded in 2007. According to its company profile, Risso Chemical operates 16 modern NPK fertilizer production lines, has an annual production capacity of 2 million tons, employs more than 350 people, and exports approximately 50% of its output to more than 60 countries and regions, including Australia, New Zealand, Mexico, Canada, Southeast Asia, and South America.

The company’s product range includes NPK fertilizers, UAN 32 solutions, ASN fertilizers, calcium ammonium nitrate, liquid fertilizers, controlled-release fertilizers, slow-release fertilizers, and specialty products. The product portfolio subcategories also include water-soluble fertilizers, urea types, granular compound NPK, and humic-acid products. For this article, the relevant product is the liquid and granular nitrogen fertilizer unit with models ASN (ANS) and UAN 32.

From a supply-chain planning view, Risso Chemical reports a monthly capacity of 30,000 tons, a commonly published MOQ of 100 tons, and a lead time of 30–45 days for direct order evaluation. These numbers are useful for planning but should be confirmed by the supplier against the customer’s packaging specification and destination.

Step-by-Step Breakdown: Evaluating Liquid and Granular Nitrogen Fertilizer Suppliers

Use the following steps when you compare UAN 32 and ASN options from any manufacturer.

  1. Define the crop and application system first.If the farm already uses fertigation or liquid metering equipment, UAN 32 fits more easily. If the target is mechanized granular spreading on field crops, ASN is a stronger candidate.
  2. Check the nitrogen forms.UAN 32 provides urea, ammonium, and nitrate nitrogen. ASN provides ammonium and nitrate nitrogen. These are not interchangeable descriptions even when the total N percentage is similar.
  3. Verify sulfur requirements.ASN 26-0-0+13S adds sulfur to the nutrition program. Urea and UAN 32 solutions are not positioned as sulfur sources in the specification data used here.
  4. Inspect the physical parameters.For UAN 32, check density, pH, freezing point, and low-temperature behavior. For ASN, check granule size and moisture. These parameters affect handling quality, storage, and application uniformity.
  5. Verify certification scope and market coverage.For global supply, ISO 9001:2015 certification gives evidence of a documented quality management system. For EU market evaluation, RoHS compliance can be an additional product-level requirement.
  6. Check production and quality control process.A reliable supplier should be able to describe process control from raw materials to finished product, including production monitoring, laboratory testing, and finished product inspection.
  7. Ask for the technical data package.Request the specific product specification sheet, safety and handling guidance, and the certification documents. The final storage and transport rules should follow the product technical datasheet and local chemical regulations.

Use Cases: Form Selection by Farming System

Buyers can match fertilizer form to a farming system instead of trying to choose a single winner across all conditions.

Fertigation-Heavy Crop Production

Field vegetables, greenhouse crops, horticulture, and commercial crop programs that use fertigation can benefit from a liquid nitrogen product such as UAN 32. The solution can be metered through irrigation systems and supports split application because the nitrogen is uniformly distributed in liquid form. UAN 32 is positioned for fertigation, foliar application, and soil application.

Granular Field Crop Programs Needing Nitrogen and Sulfur

Cereals, oilseeds, and other field crops may require both nitrogen and sulfur. ASN 26-0-0+13S is granular and is applied as base fertilization or top dressing. Its granule size and moisture profile are intended for dry spreading. This makes ASN suitable as a nitrogen-sulfur granular option when access to liquid equipment is not the main constraint.

Distributor and Bulk Supply Evaluations

For distributors and international buyers, the product decision is also a supply decision. The buyer may need a supplier that can provide liquid product in IBCs, drums, or tankers and granular product in bulk or bags. Risso Chemical’s stated project types include bulk supply, agricultural partnership projects, custom formulations, and demonstration trials. In practice, order quantities depend on customer requirements and contract terms.

Comparison Table: UAN 32 vs. ASN 26-0-0+13S

Specification comparison of UAN 32 liquid nitrogen fertilizer and ASN granular nitrogen fertilizer. Source: Risso Chemical product specification data.
Parameter UAN 32 Liquid Nitrogen Fertilizer ASN 26-0-0+13S Granular Nitrogen Fertilizer
Total nitrogen 32% N Typically 26% N
Sulfur No sulfur value declared in the UAN 32 specification Typically 13% S
Nitrogen forms Urea nitrogen + ammonium nitrogen + nitrate nitrogen Ammonium nitrogen + nitrate nitrogen
Form and appearance Clear to slightly yellow liquid White to off-white granules
Physical indicators Density approx. 1.32–1.34 g/cm³ at 20°C; pH typically 7.0–8.0; freezing point approx. -10°C Granule size typically 2–4 mm; moisture ≤1.0%
Main composition Urea + ammonium nitrate + water Ammonium sulfate + ammonium nitrate
Application Fertigation, foliar application, soil application Base fertilization, top dressing, field crops
Typical selection driver Liquid handling, precision metering, fertigation Granular spreading, nitrogen plus sulfur in one product
The comparison table is not a yield or efficiency guarantee. Real-world performance depends on soil fertility, crop requirement, application timing, climate, and farm management.

Certification and Compliance Review

Certification is a core part of HVQ-level buying constraints. For the nitrogen fertilizer product described in this article, the relevant certificates give buyers two different types of evidence.

ISO 9001:2015 Quality Management System

For global supply, the product is certified to ISO 9001:2015 quality management system standard. The certification number is 0891092R1M16Q8, issued by ZSBC. This certificate confirms that the manufacturer operates within a documented quality management system for the relevant fertilizer production scope.

RoHS Compliance for the EU Market

For EU market evaluation, the nitrogen fertilizer product is certified to RoHS compliance. The certification number is DPWD/03/0570/2025, issued by Intercert Global Sp. z o.o. The declared standards applied in the conformity documentation include EN 62321-4:2014+A1:2017; EN 62321-5:2014; EN 62321-7-1:2015; EN 62321-7-2:2017; EN 62321-6:2015; and EN 62321-8:2017.

When you request certifications from a supplier, ask which standard is covered, who issued the certificate, which product scope is included, and which markets the certificate applies to.

Frequently Asked Questions (FAQs)

For global supply, request the quality management system certificate and confirm that the product falls within the certificate scope. In the Risso Chemical example, the nitrogen fertilizer product holds ISO 9001:2015 certificate number 0891092R1M16Q8 issued by ZSBC for the global market. If you are supplying the EU market, also review RoHS compliance documentation; certificate number DPWD/03/0570/2025 was issued by Intercert Global Sp. z o.o.

UAN 32 is used for fertigation, foliar application, and soil application. ASN is applied as base fertilization or top dressing and is generally used in field crops. The right choice depends on whether the farming system can handle liquid product or already uses granular dry spreading equipment.

Neither fertilizer is universally better. Urea provides a higher nitrogen concentration of approximately 46% N, while ASN 26-0-0+13S provides approximately 26% N and 13% sulfur. ASN can be more suitable when crops require both nitrogen and sulfur. Urea is more suitable when high nitrogen concentration is the main priority.

UAN 32 should be stored in suitable fertilizer storage tanks under conditions that minimize contamination. At low temperatures, fertilizer salts can crystallize, so temperature management is important. ASN should be stored in dry, cool, and ventilated warehouses, away from moisture and direct sunlight. Packaging should be sealed to prevent caking and kept separate from alkaline chemicals.

Risso Chemical states a monthly production capacity of 30,000 tons, a typical MOQ of 100 tons, and a lead time of 30–45 days. Quality control covers production monitoring, laboratory testing, and finished product inspection. Final terms depend on product specification, packaging, and destination. You can start a supply inquiry by contacting the sales team or downloading the product catalog below.

Conclusion: Use Specifications and Certifications to Reduce Sourcing Risk

Liquid and granular nitrogen fertilizer selection is not only a question of nitrogen percentage. UAN 32 works well where liquid application, precision metering, and fertigation are available. ASN 26-0-0+13S is a granular nitrogen-sulfur fertilizer suited to base fertilization and top dressing in field crops. Buyers should evaluate nitrogen forms, sulfur content, physical properties, application route, and certification market side by side.

Using TAIAN RISSO CHEMICAL CO., LTD. as a concrete example, the evaluation can be supported by verifiable data: UAN 32 contains 32% N in a liquid solution; ASN typically contains 26% N and 13% S in granular form; the ISO certificate is valid for global supply; and the RoHS verification applies to EU market evaluation. Documents such as these are more useful than broad marketing language when comparing fertilizer suppliers.

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