Fossilized seabird guano · 0-12-0
Organic Seabird Guano Fertilizer, 0-12-0, in Powder and Granular
Four particle grades, from 6,000 mesh micronized powder to 2–4 mm granular. Total phosphate, a seven-element heavy metal panel and a certificate for the lot we would ship are published on this page, not held back for the enquiry stage.
- ECOCERT inputs attestation
- EU 2018/848 · USDA NOP · JAS · GB
- 25 / 40 / 1,000 kg
- Custom ratio on request
Read it as a data sheet
The product
Organic Seabird Guano Fertilizer: Granules and Powder for Bulk Supply
Rutom Bio mines fossilized seabird guano and mills it into graded organic inputs. Two forms leave the plant. Micronized powder is milled to 2,500, 5,000 and 6,000 mesh; granular is screened to 2 to 4 mm. Both sit inside our ECOCERT inputs attestation, and both ship in commercial quantities rather than retail bags.
The specification is 0-12-0. Nitrogen tests at 0.3%, potash at 0.5%. Neither figure is a typo and neither is something we would rather you overlooked. Weathered deposits lost their nitrogen to rainfall centuries before anyone mined them, and what stayed behind is a calcium phosphate carrying trace minerals.
Same two words. Different product.
If you have read that seabird guano is rich in nitrogen, you were reading about fresh material. The confusion costs real money when a purchase order is written against the wrong assumption.
Fossilized is the operative word. What we mine sat in an arid deposit long enough for the soluble fraction to leach away, leaving a stable mineral that stores like rock phosphate. That stability is why it ships in tonnes.
Powder and granular do not share a data sheet. Ask for the one that matches your grade.
Ask for the grade data sheet
Milled
The guano rock is milled to 2,500, 5,000 or 6,000 mesh. Nothing is added at this stage, so the powder’s analysis is the deposit’s analysis.
Granulated
Powder, bentonite and water go onto a pan granulator and build into pellets. The binder runs at roughly 5%, and it is why the granular data sheet does not read the same as the powder’s.
Dried
Granulation puts water in, so drying takes it back out before the pellets are screened to 2–4 mm. A pellet dried short crumbles in the bag and gains weight in a humid hold.
Tested per lot
Lot data goes out before shipment rather than with it, so the decision stays yours while it is still a decision.
The difference shows up in the documents, not in the analysis line.
None of this separates us from Down To Earth, Roots Organics or True Organic. They sell weathered seabird guano too, at 0-11-0 and 0-12-0, and it works. A buyer holding two quotations for organic guano fertilizer at the same NPK cannot tell them apart from the label alone.
The comparison
What You Can Verify Before You Buy
Two bags carrying identical NPK can differ in ways the label was never designed to show. That is not a claim about which grows a better crop. It is a claim about how much a buyer can check before money moves.
We read the product pages of four established seabird guano brands. All four give an NPK figure, a “derived from” statement and an application rate. None publishes total phosphate. None publishes a heavy metal panel. None offers a lot-specific certificate. All four sell one particle size.
Here is the comparison, our own figures in the last column.
← Scroll the table sideways →
| Published? | Down To Earth | Roots Organics | True Organic | Planet Natural | Bu arada |
|---|---|---|---|---|---|
| Stated analysis | 0-11-0 | 0-12-0 | 6-12-0 | 0-10-0 | 0-12-0 |
| Available phosphate | 11.0% | 12% | 12% | 9% | 12% |
| Total phosphate | not published | not published | not published | not published | 33.09% |
| Calcium | 20.0% | not published | ✓ | 8% | 28.3% (Ca) |
| Ağır metaller | not published | not published | not published | not published | 7 elements |
| Batch analysis | not published | not published | ✓ | not published | per lot |
| Particle sizes | one | one | one | one | 4 grades |
| Custom ratio | no | no | no | no | yes |
| Pack size | 5 lb | 3–40 lb | 4 / 25 lb | retail bag | 25 / 40 / 1,000 kg |
“not published” = the figure does not appear on that product page. Competitor pages checked August 2026.
Four rows deserve a sentence each.
Total phosphate
The number printed on any bag is available phosphate, the fraction a crop can take up this season. Total phosphorus includes everything still bound in the mineral, released gradually as soil biology works on it. Our powder tests at Total P₂O₅ 33.09% against Available P₂O₅ of 12%. Nobody else in the table gives the first figure, so nobody can be compared on it.
Calcium
Seabird guano is a calcium phosphate, so calcium is not a bonus ingredient. It is most of what you are buying by weight. Published figures across the US market run from 8% to 20%. Ours reads 39.55% as CaO, roughly 28.3% elemental calcium, the basis a US guaranteed analysis uses.
Batch analysis
A typical analysis describes what the material usually does. A lot certificate describes what this shipment actually did. Only one of those is evidence. Only one helps if a customer disputes the delivery.
Custom ratio
A grower on r/OrganicGardening summed up the retail problem in one line:
Looking for 5-10-10 organic fertilizer but can’t find it.r/OrganicGardening
Shelves carry fixed formulations. If the ratio you need is not among them, no amount of shopping produces it. We blend to a specified target and can supply a suspension concentrate alongside the dry forms, which is the practical answer to that post.
Why the gap exists
None of this makes the four brands careless. Retail channels do not require a lot certificate, because a homeowner buying 5 lb has no laboratory to check it against. The gap becomes a problem when the same product moves into a commercial supply chain, where a distributor registering it, a blender formulating against it, or a certifier auditing an operation all need documents the retail format never had to produce. Searches for seabird guano for sale return that channel almost exclusively, and it was built for a different buyer than you.
Before you buy seabird guano from anyone, including us, ask for those four things. We publish them here because a buyer holding two quotations has no other way to separate the material, and because a supplier who cannot produce them on request has already told you something useful about how the material is handled upstream.
Put the same four questions to every supplier on your list, including us.
Ask us those four questionsSpecification
Garantili Analiz
Below is the specification in the format a US buyer expects, with one addition: two columns instead of one. The left is what we guarantee on every shipment. The right is what an independent laboratory measured on one lot.
| Parametre | Guaranteed minimum | Batch tested June 2025 |
|---|---|---|
| Toplam Azot (N) | 0.3% | — |
| Available P₂O₅ | 12% | — |
| Total P₂O₅ | 30% min | 33.09% |
| Çözünür Potasyum (K₂O) | 0.5% | — |
| Calcium (as CaO) | 28–40% | 39.55% |
| Magnesium (as MgO) | 3.0% | 3.20% |
| Silica (SiO₂) | 10% | — |
| Nem | 1.2% max | — |
| Parçacık boyutu | 2,500 / 5,000 / 6,000 mesh | — |
Derived from: fossilized seabird guano. No fillers and no blending agents. Granular 2–4 mm uses the same source material with roughly 5% bentonite as a binder, which shifts the analysis slightly — ask for the granular data sheet rather than assuming it matches the powder.
Method numbers, not adjectives
The batch figures come from SGS-CSTC, report MCHGZ2500817-01A, dated 13 June 2025. Total phosphate was determined by AOAC 958.01-2005; calcium and magnesium by AOAC 965.09-2005.
The method numbers matter more than the results, because they let your own laboratory reproduce the work. A result without a method is an assertion. A result with a method costs a few hundred dollars to check.
Reading the numbers
The available phosphate figure of 12% is our factory internal control value. That third-party report covers total phosphate, calcium, magnesium and heavy metals; it carries no available phosphate line, so this one number does not have the same backing as 33.09%. We would rather write that sentence than set two figures side by side and let them look equally solid. Ask every supplier the same question about their own numbers. If you want help reading what comes back, the order to read it in is set out in our guide on how to read an organic fertilizer certificate of analysis.
Calcium appears as CaO because Chinese laboratories report the oxide. US guaranteed analyses report elemental calcium, and the conversion factor is 0.7147. Compare like with like. Otherwise the same material looks far richer on one document than another. The same trap catches magnesium, reported here as MgO and on a US label as Mg. Phosphorus runs the other way: US labels use the oxide form P₂O₅ and always have, which is why a bag says 12% rather than the 5.2% elemental phosphorus it contains.
One note on behaviour rather than numbers
The gap between 12% available and 33% total is the slow release fraction: phosphorus held in the mineral lattice, becoming plant-available over later seasons rather than in the first eight weeks. That is why guano goes in ahead of demand instead of in response to a deficiency, and why a soil test six weeks after application understates what you put down.
Anything not listed in the table is not in the product. No filler bulking the weight, no coating, no undeclared micronutrient package. The silica is native to the deposit rather than added, and the bentonite in the granular grade holds a pellet together rather than extending the volume.
A batch certificate belongs to a lot. A typical analysis belongs to a brochure.
Request the batch analysisThe panel nobody else prints
Heavy Metals
Phosphate minerals concentrate trace elements. That is geochemistry, not a manufacturing defect. Every phosphate fertilizer carries some load. The real question is whether the supplier measures it and shows you the panel.
SGS-CSTC MCHGZ2500817-01A · 13 June 2025 · AOAC 2006.03-2006 · figures describe one lot
An Australian guano producer states the principle bluntly on its own site: a reputable brand shows cadmium, lead and mercury on the label, below the applicable standard, and testing of this kind is mandatory for fertiliser labelling. If a seller cannot produce the test, the product may not fall under fertiliser labelling regulation at all.
Not one of the four US products in our comparison publishes a heavy metal figure. One sends buyers to a third-party database to look it up, which is a strange thing to do with information you are holding.
Check these against the limits in your own market. Organic input standards, mineral fertilizer regulations and individual certifier rules each set their own thresholds, and they do not agree. A figure clearing one framework can fail another. So the useful question is never whether a material is safe in the abstract. It is whether it clears the standard you register under, at the rate you intend, in the country you ship to.
Two things decide arsenic in practice: the annual loading your application rate produces per hectare, and the threshold in the standard you register under. Both are arithmetic once you have the figure. Neither is possible without it. We publish the panel so you can run that check before ordering rather than after the container clears customs. We send the panel for the lot quoted, not this one.
We send the panel for the lot quoted, not for the one published here.
Ask for the metals panelGrade selection
Particle Size and Form
Four grades leave the plant. The right one follows from how the material reaches the root, not from price per tonne.
Matching grade to method
A suspension concentrate is available too, for buyers who would rather handle liquid seabird guano than disperse dry powder.
Mesh is the specification most often skipped at quotation, and most often regretted. Fine grades stay in suspension long enough to pass an emitter. Coarse grades settle out and block it. A grade that plugs an irrigation line stops being cheap, so fix grade against application method before comparing price. Powdered seabird guano at 2,500 mesh is the general-purpose choice for spray and open irrigation.
Guano powder is a mineral suspension rather than a solution, so it needs agitation in the tank and it will drop out of a static line overnight. Plan for a recirculating tank or an injector, not premixing and walking away.
Granular behaves in the opposite direction. It sits where the spreader put it and breaks down over months, right for a base application and wrong for anything you need this week.
Buyers ask which grade is strongest. None of them is.
It is the same material milled differently: a tonne of 6,000 mesh and a tonne of granular carry the same phosphorus. What changes is how fast it reaches a root and what equipment can deliver it. Grade is a delivery decision. Treating it as a potency decision is how buyers pay a premium for fineness they cannot use.
Rates and timing
Application rates
Starting points for a 0-12-0 material. A soil test overrides all of them.
| Method | Oran |
|---|---|
| Bed preparation | 2–5 lb per 100 sq ft, worked into the top 3 inches |
| Transplants | 1–3 tbsp per plant, mixed through the backfill |
| Established plants | Side dress once during the growing season |
| Drip and fertigation | 1:800 to 1:1000 in water, agitated |
The first two rows are the spread US retail suppliers publish, not figures we measured. They are labelled as borrowed because the rest of this page is not: the analysis, the seven metals and the batch spread are ours.
Field-scale broadcast rates are deliberately absent. They follow from soil test phosphorus and crop removal, not from a bag label. Send the soil report with your enquiry.
Guano is a phosphorus input: it belongs in the ground before roots need it, not once deficiency shows in the leaf. Over-application has two ceilings: the calcium load and the salt index. Phosphorus a crop cannot use stays where you put it, so the excess is money parked in the soil. Timing, mixing order and the reasoning behind these rates are in our field guide to using seabird guano.
Pelletized seabird guano and seabird guano pellets are the terms most buyers use for the granular grade. If your specification calls for pellets, send the size tolerance and we will confirm whether 2–4 mm meets it before quoting, not after delivery of something that will not fit your spreader.
Send the application method and we will fix the grade before price comes up.
Check the grade for your method
Mined material, honestly described
Batch Variation
Ask any supplier of a mined input for their analysis, and the honest answer is a range, not a point. Ours runs 28–40% CaO depending on which part of the seam a lot comes from.
Colonies did not deposit evenly, weathering did not proceed evenly, and milling changes particle size, not the mineral underneath.
A buyer who has read around will object here. The same Australian producer warns that a phosphorus figure given as a range, say 9 to 11 percent, can indicate material blended from several deposits of uneven quality. The warning is correct, and a range can mean two very different things.
The distinction is whether the supplier can also produce the lot
Natural variation within a single seam gives you a range ve a batch certificate, because each shipment was tested on the way out. Blending gives you a range instead of a batch certificate, because the mix changes and nobody tracked what went in. So ask for both.
If the range arrives with lot data attached, the range is geology. If it arrives alone, ask what is being averaged. The answer is usually short, and usually revealing.
The next question separates suppliers faster: what happens when a lot comes back out of range. Put it to us too, and expect a procedure rather than a reassurance. A supplier who says it never happens is describing a marketing position; ground material does not behave that way.
Buyers formulating to a target phosphate feel this first. A five-point swing changes the recipe, and finding out after mixing costs more than one email would have. It is why our guaranteed minimum reads 30% total P₂O₅ while a good lot tests at 33%: a registered guarantee has to hold at the floor of the range, not the average.
Lot data goes out before shipment, not with it, so the decision stays yours while it is still a decision.
Ask what happens when a lot comes back out of range. Expect a procedure, not a reassurance.
Put that question to usBuy elsewhere in these three cases
What This Product Is Not For
Three situations where you should buy something else, set out before the invoice rather than after it.
You need the same number every time
Retail brands screen and blend to hold a tight specification across bags, and for small quantities that consistency is worth the premium. What we supply is a mined material with a stated range and a certificate per lot. For a home garden that is more information than anyone needs. Down To Earth or True Organic will serve you better, and their 5 lb packaging beats our minimum by a wide margin. Buy from them without apology. We would tell a family member the same.
You need nitrogen
At 0.3% N this is not the right fit, and no application rate fixes it. Plan a nitrogen source separately: an amino asit gübresi, blood meal, or a fish-based input. Growers running a full organic programme usually end up with two or three inputs where a synthetic user would have bought one bag, and a phosphorus-only guano forces that decision earliest in the season.
Your soil is already alkaline
The calcium that makes this material valuable also pushes pH upward. On calcareous ground it will not help and it may hurt. Run a soil test before ordering rather than after spreading. The mirror image is worth stating too: growers on acid, high-rainfall soils get a second benefit from the same calcium, which is why this material moves better into tropical markets than into arid ones.
None of the three is unusual for a mined phosphate. What is unusual is finding them written down before the invoice instead of discovering them afterwards, which is the only real argument this section is making.
Status, stated exactly
Certification and Documents
Rutom Bio holds an ECOCERT inputs attestation across four programs. Both guano grades are named on it, Guano Granular and Guano Micropowder, under raw material for fertilizer and amendment.
That wording matters more than the logo. An inputs attestation is not organic certification of the product, and ECOCERT prints the distinction on the document: not certified for organic agriculture, attested as suitable for use in organic farming. For a mined input that is the correct status.
We hold CERES confirmations for other products. Seabird guano is not listed on them, so we do not claim CERES for it. It goes on at the next renewal; until that document exists it is not a claim.
We do not hold OMRI listing. Several US brands do, so tell us early if your buyer requires it. Our guide to organic fertilizer certification sets out what each scheme covers; the full certificate library is downloadable.
Check the product name on any document, ours included. If the guano organic fertilizer you are buying is not listed, it is not covered. A document covers a producer and a listed product, never a shipment; that is what the lot certificate is for.
Documents we send on request
- Batch certificate of analysis for the specific lot quoted
- Third-party test report covering total phosphate, calcium, magnesium and heavy metals
- ECOCERT inputs attestation, with scope and validity
- Safety data sheet
- Phytosanitary certificate, prepared ahead of shipment
- Packing list and commercial documents for customs clearance
Paperwork is where organic inputs stall most often. Classification, phytosanitary requirements and organic documentation each have to line up before a container moves, and a mismatch in one holds the other two. We cover classification in a separate note on organic fertilizer HS codes. Raise destination registration early too: several countries require the importer to register the product before a first shipment arrives, and that process runs on the documents listed above.
Name the destination market and we will confirm the certification scope before you order.
Request the document setGetting it to your port
Packaging and Shipping
Standard packaging runs 25 kg bags, 40 kg bags and 1,000 kg bulk bags. If you need a specific bag size or bag marking, raise it at quotation stage rather than after the order is placed.
25 kg
For repackers selling forward in retail sizes.
40 kg
Standard bagged export format.
1,000 kg
Totes for buyers who blend on site. Loaded without pallets.
Freight, terms and storage
Bulk seabird guano in totes suits buyers who blend on site; 25 kg suits repackers selling forward in retail sizes. Bagged goods ship palletised and shrink-wrapped; seabird guano bulk totes load without pallets.
A 20 ft container takes approximately 20 tonnes of granular material. Powder loads differently by grade and packing density, so confirm the loading plan before you finalise freight. Phosphate is dense enough that a container hits its weight limit long before it fills, so volume is rarely the constraint.
Terms are EXW or FOB. Phytosanitary certificates are prepared ahead of shipment rather than after booking, which removes the most common cause of delay at origin. Name the destination port early: inspection requirements differ enough between markets to change the document set.
Minimum order quantity and lead time depend on grade, packing, and whether the formulation is standard or custom. Both are confirmed at quotation rather than posted here, because one number that ignores your grade and destination would mislead. Ask, and you will have a specific answer the same day.
Storage matters more than most buyers expect for the fine grades
Powder leaving the plant at 1.2% moisture will pick up water from humid air and cake. Caking does not change the analysis, but it ruins handling and can block the very equipment the fine grade was chosen for. Keep it sealed. Keep it dry. Warehouses in humid ports are where good material most often goes wrong, between arrival and first use rather than in transit.
Minimum order and lead time depend on grade, packing and destination. Ask, and the answer comes the same day.
Get a quotation and loading plan
Next step
Request a Sample
Everything needed to evaluate this material sits above: the specification, the third-party numbers, the heavy metal panel, the grade range, and the three cases where you should buy from someone else. Nothing was held back for the enquiry stage.
A page that withholds the analysis until you ask is testing your patience rather than earning your order. What comes next is a sample of the grade you actually need, with the lot analysis that belongs to it.
Include three things when you write
The grade and pack size you are considering, the destination market so we can check certification scope, and whether you need standard 0-12-0 or a custom ratio.
We send a batch certificate of analysis with the sample rather than a typical analysis, because a typical analysis tells you nothing about the material in the box. Guano fertilizer price depends on grade, packing and freight, so a quotation follows once grade and volume are settled. That is why most guano fertilizer for sale in bulk carries no list price anywhere.
If you are still comparing suppliers, put the four questions from the comparison table to everyone on your list: total phosphate, heavy metal panel, lot certificate, particle size options. They cost nothing to ask. A supplier who answers all four in one reply is worth talking to further, whether or not that supplier is us.
Send the grade and pack size, the destination market, and whether you need standard 0-12-0 or a custom ratio.
Request a sample and batch analysisSSS
Sıkça Sorulan Sorular
Eight questions buyers send most often. If yours is not here, it is faster to ask than to guess.
What is the minimum order quantity?
It depends on grade and packing, and custom formulations differ again from standard ones. Send the grade and destination and we will confirm.
Can you supply a custom NPK ratio?
Yes. We blend to a specified target and can also supply a suspension concentrate. Send the analysis you need and the application method, because together they decide whether a blend is practical.
Is this organic guano fertilizer certified?
Attested, not certified. It carries an ECOCERT inputs attestation under EU, USDA NOP, JAS and GB programs, the status a mined organic input receives. Neither CERES nor OMRI covers it.
What separates the powder grades?
Particle size, which decides the application method. 6,000 and 5,000 mesh pass drip emitters; 2,500 mesh suits foliar spray and open irrigation; granular is for base application.
Why is nitrogen only 0.3%?
Because the deposit is fossilized. Nitrogen leached out over centuries, leaving the phosphate and calcium behind. Fresh guano is a nitrogen product; this is not one, and any organic fertilizer guano sold as high-nitrogen is either fresh material or mislabelled.
Which documents come with a shipment?
Batch certificate of analysis, third-party test report, ECOCERT inputs attestation, safety data sheet, phytosanitary certificate, packing list.
How do I get the analysis for a specific lot?
Ask for it by lot number at quotation stage. Lot data goes out before shipment, not with it.
Does the calcium raise soil pH?
It can. On alkaline ground that is a reason to choose a different phosphorus source; on acid soils the same calcium is a second benefit.
Related resources
Organik Gübre
The category page, if you are sourcing more than phosphate and want the line held to one set of documents.
Organic Fertilizer Supplier in China: A Buyer’s Checklist
This page covers one product. That one covers the supplier behind it: which documents to demand, which claims to test, and what a first order should look like before you scale it.
Last thing
Comparing two quotations and cannot tell them apart?
Send the grade, pack size and destination. You get the specification, the batch certificate of analysis for the lot we would ship, and the heavy metal panel, so the comparison runs on documents rather than adjectives.
Tell us three things
- Grade and pack size
- Hedef pazar
- Standard 0-12-0 or custom ratio
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