TBS/AFDC 10 (5442) P 3 
  
DRAFT TANZANIA STANDARD  
 
 
 
Foliar -Fertilizers -Specification   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
TANZANIA BUREAU OF STANDARDS  
 
 
 TBS/AFDC 10 (5442) P 3 
 Foliar -fertilizer — Specification  
 
 
0    FOREWORD  
 
Foliar fertilizers are formulated specifically for foliar feeding, optimizing nutrient uptake through stomata 
(plant pore in the leaves. Their popularity has stemmed from the fact that they can be used as a quick  
measure to correct nutrient deficiencies in  plants. They also stimulate the plant to absorb more nutrients 
from the soil. Foliar feeds are formulated to cater for specific plant needs and mainly for specific stages of 
crop growth.  
 
 
This method of application is best suited for relatively low mobil e elements such as calcium  and the 
micronutrients. It also avoids the problems of nutrient interactions and unfavorable soil pH which results in 
nutrient unavailability as may be the case in soil applied fertilizers.  
 
 
This standard has been prepared to encourage safe use of foliar fertilizers, promote fair trade practices 
and ensure safety of consumers.  
 
 
In the preparation of this Tanzania Standard, considerable assistance was derived from the following 
standard;  
 
 
 KS 2228: 2014  Foliar fertilizer (inorganic) — Specification  
 US 1660:2017 Inorganic foliar fertilizer — Specification  
 
 
In reporting the results of a test or analysis made in accordance with this Tanzania Standard, if the final 
value observed or calculated, is  to be rounded off, it shall be done in accordance with TZS 4   
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 TBS/AFDC 10 (5442) P 3 
 1   Scope  
 
This Tanzania standard specifies requirements and methods of sampling and test for foliar fertilizers  
2 Normative references  
 
The following referenced documents are indispensable for the application of this standard . For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
 
TZS 4 Rounding off numerical values  
 
AOAC 928.02, Chlorine (water -soluble) in fertilizers  
 
AOAC 965.11, Cobalt in fertilizers  
 
AOAC 975.01, Copper in fertilizers  
 
AOAC 975.02, Zinc in fertilizers  
 
AOAC 980.01 , Iron in fertilizers  
 
AOAC 980.02 , Sulfur in fertilizers  
 
AOAC 982.01, Boron (acid - and water -soluble) in fertilizers  
 
AOAC 983.04, Sodium in fertilizers  
 
AOAC 984.01, Magnesium (acid -soluble) in fertilizers  
 
AOAC 2006.03, Arsenic, cadmium, cobalt, chromium, lead, molybdenum, nickel, and selenium in fertilizers 
— Microwave digestion and inductively coupled plasma -optical emission spectrometry  
 
ISO 7888, Water quality —Determination of electrical conductivity  
 
TZS 156 , Fertilizers and soil conditioners —Vocabulary  
 
TZS 1173 , Solid fertilizers — Simple  sampling method for small lots  
 
 
3 Terms and definitions  
 
For the purpose of this standard, the terms and definitions given in TZS 156  and the following apply ; 
 
3.1 Foliar  
Of or relating to a leaf or leaves  
 
3.2 
foliar fertilizer  
a liquid  or water soluble -fertilizer  applied to a plant’s foliage in a fine spray so that the plant can absorb the 
nutrients through its leaves.  
 
3.3 
electrical conductivity  
a measure of the total soluble salts, or the soluble nutrients (or ions) present in a fertilizer  TBS/AFDC 10 (5442) P 3 
  
3.4 
Chelating compounds  
specific kind of chemical compound that is more easily dissolved and absorbed than other types of 
molecules and chemical compounds. It is made up of a metal ion and a chelating agent that creates multiple 
soluble bonds to the ion.  Chelat ing compounds  are sometimes added to fertilizers to enhance a plant's 
ability to absorb nutrients.  
 
 
4 Requirements  
 
General requirements  
 
4.1 Physical  
 
The material shall be an aqueous solution or if in solid form it shall be completely soluble in water.  
 
4.2 Specific requirements  
 
4.2.1  Nutrient guarantees  
 
Foliar fertilizers shall conform to the minimum limits for the following elements, if declared.  
 
Table 1 — Minimum concentration for micro nutrients  
 
SN Element Minimum conc.% Test method 
i) Boron (B) 0.02 AOAC 982.01 
ii) Calcium (Ca) 1.00 AOAC 945.04 
iii) Cobalt (Co) 0.0005 AOAC 965.11 
iv) Copper (Cu) 0.05 AOAC 975.01 
v) Iron (Fe) 0.10 AOAC 980.01 
vi) Magnesiu m (Mg) 0.60 AOAC 984.01 
vii) Manganes e (Mn) 0.05 AOAC 940.02 
viii) Molybden um (Mo) 0.0005 AOAC 2006 .03 
ix) Sulphu r (S) 1.00 AOAC 980.02 
x) Zinc (Zn) 0.05 AOAC 928.02 
Xi) Nickel (Ni) 0.0010 AOAC 975.02 
Xii) Sodium (Na) 0.1000 AOAC 983.04 
 
4.2.2  Electrical conductivity  
 
Inorganic foliar fertilizers shall conform to the Maximum limit of 10 m s/cm for Electrical Conductivity (0.1% 
solution, 25 ºC), when tested in accordance with ISO 7888  
 
4.3 Chelating compounds  
 
If chelating agents such  as EDTA, NTA and IDHA are used, they shall be stated.  TBS/AFDC 10 (5442) P 3 
  
5 Heavy metal contaminants  
 
Heavy metal contaminants in the fertilizers shall conform to the limits given in Table 2 when tested with 
the method specified therein.  
 
Table 2 — Heavy metal contaminants limits  
 
Sn Parameter Limits in mg/kg Test method 
i) Arsenic, As, max. 20.0 AOAC 2006.03  
ii) Cadmium, Cd, max. 30.0 AOAC 2006 .03 
iii) Mercury, Hg,  max. 0.1   AOAC 2006 .03 
iv) Lead , Pb, max. 30.0   AOAC 2006 .03 
 
 
 
6 Sampling  and Testing  
 
6.1      Sampling  
 
Sampling shall be carried out in accordance with ISO 14820 -1. 
 
6.2 Testing 
 
Testing of the fertilizer shall be done as prescribed in the methods of analysis indicated in respective 
standards.  
 
7 Pack aging, marking  and labelling  
 
7.1 Pack aging 
 
The fertilizer shall be packaged in materials that are clean and non -defective that protects the product from 
physical , chemical and moisture (for solid) contamination and withstand multiple stages of handling , 
transportation and storage . 
 
 
 
7.2 Marking and Labelling  
 
7.2.1 The package  shall be indelibly  labeled in either Kiswahili or Kiswahili and English with the following 
information:  
 
a) name of product as “ Foliar fertilizer”;  
 
b) name, address and physical location of manufacturer/packer/importer;  
 
c) guaranteed percentage by weight  of each of the nutrients;  TBS/AFDC 10 (5442) P 3 
  
d) date of manufacture;  
 
e) expiry date;  
 
f) batch/lot number;  
 
g) the form in which nutrient is present;  
 
h) Stage of  crop growth to be applied;  
 
i) name of the chelating material used in case of trace elements;  
 
j) storage instructions;  
 
k) the net weight or volume of the fertilizer in the package;  
 
l) country of origin;  
 
m) disposal instructions and  
 
n) Instructions for use  which should include but not limited to the following:  
 
i) not to be applied during periods of water stress unless when under irrigation,  
 
ii) Timing and frequency of application  
 
iii) recommended weather for spraying.  
 
iv) application rates.  
 
v) informa tion on compatibility with fungicides, insecticides or herbicides . 
 
 
 
7.2.2     Marking  
 
The containers/bags may also be marked with the TBS Standards Mark of Quality.  
 
NOTE – The TBS Standards Mark of Quality may be used by the manufacturers only under license from 
TBS. Particulars of conditions under which the licenses are granted, may be obtained from TBS.