Organic Fertiliser Bulk Supplier: Nutrient and Certification Checklist (2026)

Finding the right organic fertiliser bulk supplier is less about a label and more about evidence: a guaranteed nutrient analysis, a clear feedstock description, and certification paperwork that your own certifier or buyer will accept. Organic products vary far more than synthetic ones, so two products sold under similar names can differ several-fold in nitrogen, moisture and biological activity. This guide compares nutrient content across common organic fertiliser types, explains how certification works in different countries, and sets out the questions to ask before you request a quote. It is written for growers, resellers and agronomy businesses buying in commercial quantities of 10–25 MT or more, in Australia and overseas.

Key takeaways

• Organic fertilisers usually have a lower and more variable nutrient analysis than mineral fertilisers, so compare them on nutrient delivered per tonne, not on the product name.
• “Organic” on a bag does not always mean “certified for use in organic production”. The meaning differs between countries and between standards.
• Ask for a Certificate of Analysis, the feedstock list and the certification or listing document that your certifier or buyer actually recognises.
• Biological organic fertilisers should be judged on both the nutrient analysis and clear information about any microbial component.
• Match the product to a soil test and a crop plan, and confirm in writing what is quoted, the order size and the delivery terms.

What bulk organic fertiliser actually includes

The phrase “bulk organic fertiliser” covers a wide range of materials with very different nutrient profiles, release patterns and handling characteristics. Knowing which family a product belongs to is the first step in judging whether it suits your crop and your system.

Animal-based and composted products

These include composted and pelletised poultry manure, other composted manures, blood meal, feather meal, and blood and bone. They supply nitrogen and often phosphorus and some potassium, along with organic carbon. Composting stability matters: a poorly composted manure can carry weed seeds, excess salts or ammonia, and may behave unpredictably in the field.

Plant-based, mineral and natural-source inputs

Plant-derived meals, seaweed products, humates and composted green waste mainly provide organic matter, trace elements or growth-supporting compounds rather than high nutrient loads. Natural mineral sources, such as rock phosphate or certain potassium and sulphur sources, can be accepted in some organic standards but not others, depending on how they are produced and processed.

Biological organic products

A biological organic fertiliser generally combines an organic carrier with microbial or biologically active components. These products are often used alongside, not instead of, a nutrient-based program. We cover how to assess them in a later section.

At Natures Fertilizer Pty Ltd, we supply organic and biological organic fertiliser in commercial quantities alongside compound, blended, water-soluble and mineral products, so a single order can be planned against one soil test.

Comparing nutrient content in organic fertilisers

Nutrient content is where buyers most often get caught out. A bag that looks comparable to another on price per tonne may deliver far less nitrogen, phosphorus or potassium once moisture and carrier material are accounted for.

Why organic analyses are lower and more variable

Organic materials are made from biological feedstocks, so their analysis shifts with the diet of the animals, the plant material, the composting process and the moisture content. Fertiliser regulations in many countries require a declared analysis, but the tolerance allowed can be wider than for manufactured products. Always check whether the figure is stated on an as-received (wet) basis or a dry-matter basis, because a product with 25% moisture will deliver about a quarter less nutrient per tonne than its dry-basis figure suggests.

Typical nutrient ranges at a glance

The ranges below are indicative only and are included to show relative scale. Actual products vary, so use the supplier’s Certificate of Analysis for any real decision.

Material	Indicative nitrogen (N)	Indicative phosphorus (P2O5)	Indicative potassium (K2O)	Notes
Composted poultry manure (pelletised)	2–4%	2–4%	1–3%	Check moisture, salinity and composting stability
Blood meal	11–13%	Low	Low	Nitrogen-dominant; relatively quick to mineralise
Feather meal	11–14%	Low	Low	Nitrogen release is typically slower than blood meal
Blood and bone	3–7%	3–8%	Low	Ratio of blood to bone drives the analysis
Rock phosphate (natural)	None	20–32% total	None	Availability depends on reactivity and soil pH
Composted green waste	1–2%	Low	Low	Mainly organic matter and soil conditioning
Potassium sulphate (SOP)	None	None	About 50%, plus about 17–18% sulphur	Acceptability under organic standards depends on source and process

Comparing products on nutrient delivered per tonne

A simple calculation keeps comparisons honest. A 25 MT load (roughly 27.6 short tons, or about one full 20 ft container) of a product declared at 3% N contains about 750 kg of nitrogen. To supply the same 750 kg of N from urea at 46% N takes about 1.63 MT. That does not make one option better than the other. Organic nitrogen is released as the material mineralises, which depends on temperature, moisture and the carbon-to-nitrogen ratio, and organic matter brings benefits that urea does not. It does mean you should compare cost, freight and handling per kilogram of nutrient, as well as the agronomic role of each product. Our guide on how to read a soil test report helps you set the nutrient target before you compare products.

Organic certification: what “certified” means and how to verify it

Certification is the second major point of difference between suppliers, and it is the area most prone to assumptions. The word “organic” is used loosely in fertiliser marketing, and its legal meaning depends on where you operate.

Product status versus farm certification

In many fertiliser regulations, “organic fertiliser” simply describes a carbon-based material of plant or animal origin. That is not the same as the product being approved as an input for certified organic production. Conversely, a farm certified under an organic standard must use inputs that its certifier permits. The certifier, not the fertiliser supplier, decides whether an input is acceptable for your operation, so always check with them before ordering.

Standards differ by country

Organic production standards are broadly aligned in principle through the global framework set by IFOAM – Organics International and the Codex Alimentarius guidelines, but the rules are applied nationally or regionally. Examples include the European Union organic regulation, the USDA National Organic Program in the United States, and, in Australia, a national standard administered through approved certifying bodies. Input lists such as the OMRI listing are widely used in North America. A product accepted under one scheme is not automatically accepted under another, and some inputs, such as certain mined minerals or manure from conventional livestock systems, carry conditions.

If you grow for export, the rules of the destination market and your buyer’s specification may matter as much as the standard in your own country. In Australia, exporting produce labelled organic requires certification through an approved scheme, so check the current requirements with your certifier.

Documents worth requesting

• A Certificate of Analysis showing nutrient content, moisture and, where relevant, heavy metals and pathogen indicators.
• A feedstock declaration describing the raw materials used.
• Any certification or input-listing document, with the standard, the scope, the issue date and the expiry date.
• Confirmation of whether the document covers the specific product, or only the producer or site.

Biological organic fertiliser: separating claims from evidence

Biological organic fertiliser is one of the most heavily marketed categories, and also one of the hardest for buyers to evaluate. A structured set of questions is more useful than trusting a product name.

What the term usually describes

The term typically refers to an organic base, such as composted material or a fermented organic carrier, that contains or is combined with beneficial microorganisms or biologically derived compounds. The intent is to support nutrient cycling and soil biology while supplying some nutrients. The term is not standardised internationally, so the detail on the specification sheet matters more than the label.

What to ask about microbial content

• Which organisms are present, identified to genus or strain level where possible?
• Is a count (for example colony-forming units per gram) stated, and at what point, at manufacture or at delivery?
• What is the storage guidance and the stated shelf life, given that heat and moisture reduce viability?
• Is the carrier material itself declared and tested?

Why the nutrient analysis still matters

Even when the biological component is the selling point, the product still has a nutrient analysis, and your agronomist will want it to calculate rates. Treat microbial claims as a supporting feature, and ask for trial or field evidence that is relevant to your crop and climate. Be cautious about any product that promises to replace a nutrient program entirely without data.

Questions to ask an organic fertiliser bulk supplier

Use the lists below as a checklist when you send an enquiry. They apply to any supplier, including us, and they will quickly show which suppliers can document what they sell. For general supplier due diligence, our bulk fertiliser supplier buyer’s checklist covers the wider commercial points.

Product and analysis questions

1. What is the declared analysis (N, P, K, S and key trace elements), and is it stated on an as-received or dry basis?
2. What is the moisture content, and how consistent is it from batch to batch?
3. What are the feedstocks, and are any of them from intensive livestock or other sources my certifier restricts?
4. How is the product stabilised or composted, and how is that verified?
5. Is a Certificate of Analysis available, and does it relate to the batch I will receive?

Certification and traceability questions

1. Is the product certified or listed under a standard, and which one?
2. Does my certifier or buyer accept that standard for my crop and destination market?
3. What is the scope and expiry date of the certificate?
4. How is traceability maintained from feedstock to my delivery?

Commercial and logistics questions

1. What is the minimum order quantity for this product and destination?
2. In what formats is it supplied (bulk, bulka bag or bagged), and how does that affect spreading or handling?
3. Will the quotation confirm the lead time, rather than an informal estimate?
4. What are the payment terms and method?

Matching organic inputs to soil tests and crop programmes

An organic product is only the right choice if it fits what the soil and the crop need. A supplier that asks for your soil test before recommending a product is usually a better partner than one that starts with a product.

Start with the soil test

Soil test results show which nutrients are short, which are adequate and which constraints, such as pH, salinity or low organic carbon, limit response. Organic products are often chosen to address several of these at once, but their nutrient load is modest, so large deficits can require high rates. Work out the rate in kilograms of nutrient per hectare (or pounds per acre) first, then convert to a product rate. Our step-by-step custom fertiliser blending worked example shows how that conversion is done from soil test to order.

Combining organic and mineral nutrients

Many programs pair an organic base with targeted mineral nutrients, such as urea (46-0-0), DAP or MAP for nitrogen and phosphorus, or potassium sulphate (SOP) for potassium and sulphur. This can be an efficient way to correct a measured gap while building organic matter. However, if your farm is certified organic, mineral fertilisers from synthetic processes may be prohibited, so confirm with your certifier before mixing anything. We blend to a customer’s soil test and can also supply water-soluble products where fertigation is part of the program.

Fit with your production system

Release speed, salinity, odour and spreader compatibility all matter in practice. Pelletised products flow and spread more evenly than loose compost, but may cost more to produce. Perennial crops and pasture can benefit from slow release, while a short-season annual crop might need a faster nitrogen source to meet peak demand.

Ordering bulk organic fertiliser: quantities, delivery and export

Once the product is shortlisted, the commercial details decide whether the supply works for your business.

Minimum orders and packaging

We supply growers, resellers and agronomy businesses in commercial quantities, not home gardeners. Minimum orders are 10 to 25 MT depending on product and destination, and a full 20 ft container is about 25 MT. Packaging options affect handling at your end, so decide early whether you need bulk delivery, bulka bags or bagged product.

Delivery in Australia and export overseas

We blend in Hamilton, South Australia, and deliver Australia-wide. We also arrange export worldwide. Import rules for organic and animal-derived materials vary widely by country, and some destinations restrict manure-based or blood-based products for biosecurity reasons. Check your import requirements with your national authority before ordering. Our guide to exporting fertiliser from Australia explains containers and T/T payment.

Quotes and payment

This website is a catalogue and enquiry point, not a shop, and we do not publish prices. Every enquiry receives an individual written quote, and the quotation confirms the lead time. Payment is by bank transfer only: EFT within Australia and T/T for export. When comparing quotes from different suppliers, put them on the same basis: declared analysis, moisture, format, delivery terms and certification documents. Only then compare the cost per kilogram of nutrient.

Conclusion

Choosing an organic fertiliser bulk supplier comes down to documented nutrient content, clear certification evidence and straightforward commercial terms. Compare products on delivered nutrient rather than product names, confirm what your certifier or buyer accepts, and ask the supplier to put the analysis, feedstock and certificate details in writing. If you send us your soil test and your location, we will provide an individual written quotation for the product and quantity that fits your program.

Frequently asked questions

What is an organic fertiliser bulk supplier?

An organic fertiliser bulk supplier sells organic or biologically based fertilisers in commercial quantities, usually by the tonne or by the container load. Buyers are typically growers, resellers and agronomy businesses rather than home gardeners. A good supplier provides a declared nutrient analysis and supporting documents.

Is organic fertiliser always certified organic?

No. In many fertiliser regulations, organic simply means a carbon-based material from plant or animal sources. Whether it is acceptable for certified organic production depends on the standard your certifier applies, so check with them before you buy.

How do I compare nutrient content between organic fertilisers?

Compare the declared N, P and K figures on the same basis, either as-received or dry matter, and account for moisture. Then work out the kilograms of nutrient delivered per tonne. This lets you compare an organic product fairly against a mineral one.

What is a biological organic fertiliser?

It is generally an organic fertiliser that contains or is combined with beneficial microorganisms or biologically active compounds. The term is not standardised internationally. Ask for the organism details, any counts, the shelf life and the nutrient analysis.

What documents should I ask for before ordering?

Ask for a Certificate of Analysis, a feedstock declaration, and any certification or input-listing document with its standard, scope and expiry date. Confirm that your certifier or export buyer accepts them. We can provide a Certificate of Analysis on request.

What is the minimum order for bulk organic fertiliser from Natures Fertilizer?

Minimum orders are 10 to 25 MT depending on the product and destination. A full 20 ft container is about 25 MT. The written quotation sets out the quantity, terms and lead time for your enquiry.

Can organic fertiliser replace urea or DAP?

It can supply part of the nutrient requirement, but organic products usually have lower analyses, and nutrients are released more slowly. Many programs combine organic and mineral products based on a soil test. Where certified organic rules apply, check which mineral inputs are permitted.

Do you export organic fertiliser overseas?

We arrange export worldwide, with payment by T/T bank transfer. Import rules for organic and animal-derived products differ by country, so check the requirements of your destination before you place an order.