DRAFT UGANDA STANDARD  
  DUS 1576  
Second  Edition  
2022 -mm-dd 
 
 
 Reference number  
DUS 1576: 2022  
© UNBS 2022   
  
Biofertilizers  — Specification  
 DUS 1576 : 2022  
ii © UNBS 2022  – All rights reserved  
 Compliance with this standard does not; of itself confer immunity from legal obligations  
A Uganda  Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2022   
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Uganda  National Bureau of Standards  
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Uganda  
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Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2022:2022  
© UNBS 2022  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Description  ................................ ................................ ................................ ................................ .... 2 
5 Requirements  ................................ ................................ ................................ ................................  3 
5.1 General requirements  ................................ ................................ ................................ ..................  3 
5.2 Specific requirements  ................................ ................................ ................................ ..................  3 
6 Hygiene  ................................ ................................ ................................ ................................ ..........  4 
7 Weights and measures  ................................ ................................ ................................ ................  4 
8 Packaging  ................................ ................................ ................................ ................................ ...... 4 
9 Labelling  ................................ ................................ ................................ ................................ ........  5 
10 Sampling  ................................ ................................ ................................ ................................ ....... 5 
10.1  Scale of sampling  ................................ ................................ ................................ .........................  5 
10.1.1  Lot ................................ ................................ ................................ ................................ ..................  5 
10.1.2  Sample size  ................................ ................................ ................................ ................................ ... 5 
10.1.3  Sam pling method  ................................ ................................ ................................ .........................  6 
10.2  Test samples and reference samples  ................................ ................................ .........................  6 
10.2.1  Samples for microbiological tests  ................................ ................................ ..............................  6 
10.2.2  Samples for other tests ................................ ................................ ................................ ................  6 
10.2.3  Reference samples  ................................ ................................ ................................ .......................  6 
Annex  A (normative)  ................................ ................................ ................................ ................................ . 7 
Annex  B (informative)  ................................ ................................ ................................ ...............................  8 
Bibliography  ................................ ................................ ................................ ................................ ...............  9 
 
 DUS 1576 : 2022  
iv © UNBS 2022  – All rights reserved  
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives (MTIC) established under Cap 327 , of the Laws of Uganda , as amended .  UNBS is mandated to 
co-ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on Technical Barriers to Trade (TBT)  Agreement  of the World Trade Organis ation 
(WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical Committee 
is established to deliberate on standards in a given field or area and consists of key stakeholders including 
government, academia, consu mer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS/TC 222 , Agrochemicals and 
Veterinary Drugs . 
This second  edition cancels and replaces the first edition ( US 1576 :2015 ), which has been technically revised.  
This revision was undertaken to incorporate more microorganisms in the table for microbiological limits . The 
revision was also under taken to address the specific requirements for the biofertilizers  and test methods   
 DUS 2022:2022  
© UNBS 2022  – All rights reserved  v 
 Introduction  
Fertilizer s are  natural or artificial / synthetic  substance s applied to soil or to plant tissues to supply  plant nutrients 
and chemical elements that improve growth and productiveness of plants. Fertilizers en hance the natural fertility 
of the soil or replace chemical elements taken from the soil by previous crops.  
Biofertilizers are  substances, which  contains living microorganisms, which , when applied to seed, plant 
surfaces, or soil, colonizes the rhizosphere  or the interior of the plant and promotes growth by increasing the 
supply or availability of nutrients to the host plant.  
Fertilizers directly increase soil fertility by adding nutrients. Biofertilizers add nutrients through the natural 
processes of fixin g atmospheric nitrogen, solubilizing phosphorus or nutrient mobilization to stimulate plant 
growth through the synthesis of growth promoting substances. They can be grouped in different ways based on 
their nature and function.  
Most biofertilizers are produ ced from microorganisms such as Rhizobium, Azotobacter, Azospirillum, 
phosphate -solubilising bacteria. Other types include Mycorrhizal biofertilizers, pota ssium -mobilizing 
biofertilizers, lactic acid producing bacteria  and zinc -solubilising biofertilizers.  
The use of biofertilizers offers economic and ecological benefits by way of soil health improvement and ferti lity. 
This standard contributes to the fertilizer policy of Uganda, which  aims to improve the present fertilizer market 
structure, conduct and per formance. This standard aims to ensure availability of high quality fertilizer products 
for efficient use by the farmers through setting a viable environment that attracts private investment in the 
fertilizer sector.  
The objective of this standard is to en sure that biofertilizers on the market are appropriately tested through the 
quality criteria provided while ensuring that farmers obtain only certified products and as well aid the industry in 
the manufacture of quality biofertilizers. This standard will a lso promote the safe use of biofertilizers and promote 
fair trade . 
 
  DRAFT UGANDA STANDARD  DUS 1576: 2022  
 
© UNBS 2022 – All rights reserved  1 
 Biofertilizers  — Specification  
1 Scope   
This Draft Uganda Standard specifies requirements, sampling and test methods for biofertilizers.  
This standard does not include requirements for conventional chemical fertilizers . 
 
2 Normative references   
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document. For dated references, only t he edition cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
US EAS 38, Labelling of pre -packaged foods — General requirements ; 
US ISO 4832, Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of 
coliforms - Colony -count technique ; 
US ISO 6579 -1, Microbiology of the food chain — Horizontal method for the detection, enumeration and 
serotyping of Salmonella — Part 1: Detection of Salmonella spp ; 
ISO 7 251, Microbiology of food and animal feeding stuffs — Horizontal method for the detection and 
enumeration of presumptive Escherichia coli — Most probable number technique ; 
ISO 10390 , Soil, treated bio-waste  and sludge – Determination of PH; 
ISO 11465 , Soil quality — Determination of dry matter and water content on a mass basis — Gravimetric 
method ; 
 
3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
ISO and IEC maintain terminological databases for use in  standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
3.1  
biofertilizer  
any substance derived directly or indirectly from part of microorganisms or product of microorganisms or 
botanical in their natural or modified forms that are manufactured /are produced , sold or represented for use in 
the improvement of the physical conditi on of soils or to aid plant growth or crop yield   
2 © UNBS 2022  – All rights reserved  
 3.2  
fertilizer  
any substance or mixture of substances manufactured, sold or represented for use as a plant nutrient or in the 
improvement of the physical conditions of soil or to aid plant growth or crop yields  
3.3  
efficacy  
ability of a fertilizer or supplement to fulfil any label claims and to produce a desired or intended result based on 
the labelled guarantees and directions for use  
3.4  
efficacy assessment  
evaluation of product performance in order to  establish appropriate label claims, active ingredient guarantee 
and usage patterns  
3.5  
soil conditioner  
product used to alter the physical, chemical or biological characteristics of soil  
3.6  
active agent/ingredient  
living agent in a biofertilizer to whi ch the improvement of the physical condition of soils or aid in plant growth or 
crop yield are attributed  
3.7  
base or carrier material  
a medium that can carry the microorganisms in sufficient quantities and keep them viable under specified 
conditions, eas y to supply to the farmers  
 
4 Description  
Biofertilizers are products containing carrier based (solid or liquid) living microorganisms which are agriculturally 
useful in terms for instance of nitrogen fixation, phosphorus solubilisation or nutrient mobiliz ation, to increase 
the productivity of the soil and/or crop.  Biofertilizers are  most commonly referred to the use of soil 
microorganisms to increase the availability and uptake of mineral nutrients for plants.  
Whether the existence of a microorganism incre ases the growth of plants by making nutrients more available 
or replacing soil nutrients or increasing plant access to nutrient, as long as the nutrient status of the plant has 
been enhanced by the microorganisms, the substance that was applied to the plan t or soil containing the 
microorganisms, can be characterized as a biofertilizers .  
Biofertilizers, known as microbial products, act as nutrient suppliers and soil conditioners that lower agricultural 
burden and conserve the environment. Good soil conditio n is imperative to increased crop production, as well 
as human and/or animal health welfare. Thus, the materials used to sustain good soil condition, are treated as 
environmental matters. However, there are still some problems to be met on the use of micro bial products. More 
precise quality control must be made in favour of the customers. With this in mind, we will do our best to develop 
better production techniques and to improve the management system for microbial products   
Although the effects of biofert ilizers are different among nations due to variances in climate and soil conditions, 
the importance of biofertilizers  on environmental conservation in the 21st century must not be ignored. In the 
same manner, various biotechnologies should be accepted for  increasing the biofertilizers  effects with concern 
for the environment . 
 DUS  2022: 2022  
© UNBS 2022  – All rights reserved  3 
 5 Requirements  
5.1 General requirements  
5.1.1  The biofertilizer shall comply with existing regulatory requirement and shall be fully registered as 
required under the Agricultural Chemicals Control Act. It shall have undergone a complete efficacy assessment 
and environment impact assessment . 
5.1.2  The base or carrier material used in the manufacture / or produced  of biofertilizer shall be either solid or 
liquid, be free from contamination and appropriate for the intended purpose . 
5.1.3 The biofertilizer shall be presented in an appropriate form to aid its application. It may be in the form of 
dry powder, granules or liquid . 
5.1.4  The biofertilizer shall not contain substances that are likely to be detrimental or injurious to vegetation, 
animals, public health or the environment when used according to the directions provided by the manufacturer. . 
5.1.5  The biofertil izer shall not contain substances that would, when applied in amounts commonly used or 
as specified in the directions for use, leave in the tissues of a plant a residue of a  poisonous or harmful 
substance.  
5.2 Specific requirements  
5.2.1  Biofertilizers sha ll comply with the specific requirements stipulated in Table 1 when tested in accordance 
with the methods therein . 
Table  1 — Specific requirements for biofertilizers  
S/
N 
o Character
istic Limit  Test 
meth
od Rhizobi
um Azotoba
cter Azospiril
lum Phosph
ate- 
solubilis
ing 
bacteria  Potassi
um- 
mobilizi
ng 
biofertil
izer Zinc 
solubilis
ing 
fertilizer  Lactobaci
llus spp.  
i.  pH* 6.5 – 7.5 3.0 – 5.0 ISO 
1039
0 
ii.  Moisture 
content, % 
m/m (for 
biofertilizer 
produced 
using solid 
base 
material)  30 – 40 ISO 
1146
5 
iii.  Efficiency 
character  Shall 
show 
effective 
nodulatio
n on all 
the 
species  The strain  
shall be 
capable of 
fixing at 
least 10 
mg of 
nitrogen  Formation 
of white 
pellicle in 
semisolid 
nitrogen 
free 
bromothy
mol blue 
media  Phosphat
e 
solubilizin
g capacity 
in the 
range of 
minimum 
30% or 
minimum 
5mm Minimum 10 mm  
solubilisation zone in 
prescribed media 
having at least 3 mm 
thickness  Shall show 
effective  
fermentatio
n and 
digestion 
process of 
organic 
waste  -  
4 © UNBS 2022  – All rights reserved  
 listed on 
the 
packet  
Nodulati
on test 
shall be 
positive  per gram 
of sucrose 
consumed  solubilisat
ion zone 
in 
prescribe
d media 
having at 
least 3 
mm 
thickness  suppress 
disease 
and 
perform 
growth -
regulatory 
effects on 
fungi, yeast 
and other 
bacteria  
iv.  Nitrogen 
fixation  Above 
20 mg/g 
of 
glucose  n/a n/a n/a n/a n/a n/a - 
* The pH for phosphate -solubilising bacteria, potassium -mobilizing biofertilizers , and zinc -solubilising biofertilizers in liquid form shall be 
5.0 – 7.5 
 
5.2.2  Biofertilizers that are produced from solid carrier material shall pass through a 0.15 -mm – 0.212 -mm 
(150-µ – 212-µ) sieve . 
6 Hygiene  
6.1 Biofertilizers shall be produced and handled under hygienic conditions and in appropriate premises in 
order to prevent contamination of the product . 
6.2 Biofertilizers shall comply with the limits for microorga nisms  specified in Table 2 when tested in 
accordance with the methods specified therein . 
Table  2 — Microbiological limits for biofertilizers  
S/No  Microorganism  Limit  Test method  
i.  Total coliforms, max  5 X 102 US ISO 4832  
ii.  Salmonella spp. 25 g, max  Absent  US ISO 6579 -1 
iii.  Escherichia . coli, CFU/g, max  Absent  ISO 7251  
NOTE  The active agent/ingredient in biofertilizers may be from bacterium, fungus, nematode, virus or protozoan.  
 
7 Weights and measures  
The weight and volume of the package of the product shall comply with the Weights and Measures Act . 
8 Packaging  
The containers, including packaging materials, used to package biofertilizers shall be made only of substances, 
which are safe and suitable for their intended uses. They shall not impart any toxic  substance or undesirable 
odour to the product . DUS  2022: 2022  
© UNBS 2022  – All rights reserved  5 
 9 Labelling  
9.1 In addition to the requirements in US EAS 38, the following specific labelling requirements shall apply 
and shall be legibly and indelibly marked . 
a) name of the product shall be “Biofertilizer”;  a brand name may be used to accompany the product name  
b) active ingredient shall appear in close proximity to the name of the product by specifying the genus and 
species of the microorganism  
c) microbial density  
d) name and address of manufacturer /or producer , exporter, packer and/or dispatcher  
e) type/nature of carrier  
f) batch or code number  
g) storage conditions and instructions as “Store in a cool dry place away from any contaminants’  
h) crops for which it is intended;  
i) date of manufacture /or production ; 
j) expiry date;  
k) net c ontent;  
l) product registration number;  
m) rate and method of application;  
n) directions/instructions for use  and disposal ; and  
o) safety precautions  
10 Sampling  
10.1 Scale of sampling  
10.1.1 Lot 
10.1.1.1  All containers in a consignment belonging to the same batch of manufacture shall constitute a lot. 
If the consignment is declared to consist of different batches of manufacture, containers of the same batch shall 
be grouped together and each group so formed shall  constitute a separate lot  
10.1.1.2  Sample shall be tested from each lot for ascertaining conformity to th e requirements of this 
standard.  
10.1.2  Sample size  
The number of containers to be selected from a lot for testing for microbiological and other requirements shall 
depend on the size of the lot and shal l be in accordance with Table 3.   
6 © UNBS 2022  – All rights reserved  
 Table  3 — Number of containers to be selected for sampling  
Number of containers in the lot 
(N) Number of containers to be selected (n)  
Microbiological  Other tests  
up to 1 300  12 18 
1 301 to 3 200  18 24 
3 201 and above  24 30 
 
10.1.3  Sampling method  
The containers to be selected for testing shall be chosen at random from the lot. Starting from any container, 
count them as 1,2,3 up to r. Every rth containers thus counted shall be withdrawn, r being the integral part of 
N/n, where N is the total number of containers in the lot and n is the total number of container to be chosen (see 
Table 3).  
10.2 Test samples and  reference samples  
10.2.1  Samples for microbiological tests  
The sample containers selected for microbiological  tests (see col. 2 of Table 3) shall be divided at random into 
three equal sets and labelled with all particulars of sampling. One of these sets of sample containers shall be 
for the buyer; another for the supplier and  the third set is the reference.  
10.2. 2 Samples for other tests  
The sample containers selected for other tests (see col. 3 of Table 3) shall be divided at random into three equal 
sets and labelled with all the particulars of the sample. One of these sets of sample containers shall be for the 
buyer, another for the supplier and third is the reference. . 
10.2.3  Reference samples  
Referee samples shall consist of set of sample containers for microbiological tests (see 9.2.1) and a set of 
sample c ontainers for other tests (see 10 .2.2) and shall bear the seals of the buyer and supplier or as agreed 
to between the two . 
 
 
 
 DUS  2022: 2022  
© UNBS 2022  – All rights reserved  7 
 Annex  A 
(normative)  
 
 
 
 
  
8 © UNBS 2022  – All rights reserved  
 Annex  B 
(informative)  
 
 
 DUS  2022: 2022  
© UNBS 2022  – All rights reserved  9 
 Bibliography  
[1] IS 9138:2009, Azotobacter chroococcum inoculants – Specification  
[2] IS 14806:2008, Azospirillum inoculants – Specification .  
[3] IS 14807:2000, Phosphate -solubilizing bacterial inoculant – Specification . 
[4] Guidelines for Registration of Biofertilizers in Sub Saharan Africa 2013, The African Agricultural 
Technology Foundation  (AATF). Simiyu –Wafukho S., Cargele Masso;. Nang‟ayo N., 2013  
[5] Manure bio stabilization  by effective microorganisms as a way to improve its agronomic value , D. 
Hidalgo, F. Corona & J.M. Martín -Marroquín. Biomass Conversion and Bio refinery  (2022) 
 
 
 
 
  
. DUS  1576: 2022  
© UNBS 2022 – All rights reserved  11 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards (UNBS) 
Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by the 
Uganda National Bureau of Standards and in conjun ction with the relevant Uganda Standard. The presence of 
this mark on a product or in relation to a product is an assurance that the goods comply with the requirements 
of that standard under a system of supervision, control and testing in accordance with t he certification mark 
scheme of the Uganda National Bureau of Standards. UNBS marked products are continually checked by UNBS 
for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda National 
Bureau of Standards.  
 
 
DUS 1576 : 2022    
 
ICS 65.080  
Price based on 06 pages  
© UNBS 2022 – All rights reserved