The document summarizes the National Quality Control program of Iran's Soil and Water Research Institute. It discusses the history and participants of the program, which has been running regularly for 4 years with over 100 public and private soil and plant analytical labs. It describes the sample preparation process, including drying, grinding, homogenizing and packaging soil and plant samples. Laboratories receive coded samples to analyze for various soil and plant parameters according to national standard operating procedures. Results are evaluated using z-scores and reports are produced. Challenges include late or incomplete results while suggestions involve online reporting and adding quality control to the national laboratory management system.

1. National Quality Control program of
Iran
Soil and Water Research Institute (SWRI),
Agricultural Research, Education and Extension Organization (AREEO)
Email: m.yeganeh@areeo.ac.ir
Mojgan Yeganeh
1

2. Started irregularly
from 2010
Have done regularly
from 4 years ago
National
Quality Control
History
Participants:
More than 100 public
and private soil and
plant analytical labs in
Iran
2

3.  soil samples: air
drying, graining 5
times,
homogenizing,
weighting in 500 gr
packages.
Plant samples:
oven drying,
graining and
homogenizing,
weighted in 10 gr
packages
Sample preparationSampling
Selecting areas
with different soil
properties (6 points)
Selecting 6
different plant
samples
Confidential
coding to samples
Distribution of
samples among
laboratories
according to
random numbers
Sending 2 soil
and 2 plant
samples to each
laboratory
Coding and samples sending
3
Sample Preparation

4.  Soil parameters:
pH, EC, SP, OC,P(available), K(available),TNV,
Fe(available), Zn(available), Mn(available), Cu(available),
Ca(soluble), Mg(soluble), Na(soluble), HCO3, Cl
 Plant parameters:
N, P, K, Fe, Zn, Mn, Cu, Na, Ca, Mg
4
Expected Analysis
All laboratories have to analyze the soil samples
according to technical publications no: 893 and 1024
(national SOPs)
And national plant SOP no: 982

5. 5

6. 6
z<|2|: satisfactory
|2| < Z < |3| : unsatisfactory
z > |3| : criticalZ- score= _______X-Xmean
Sd

7. Reports
7
Producing soil and plant CRMs according to ISO guides 34 and 35

8. Limitations and Difficulties
1
not receiving all the results in the proper time, proper format and required units
2
Lack of motivation for participating to this program in some labs
Using some motivation tools for encouraging or legally forcing laboratories to
participate and try to achieve the best rank they could
1
Suggestions
2
Adding quality control program to our national laboratory management
system, to receive these data online and directly from labs
8

9. Thank you for your attention
9