Diagnosis and Recommendation Integrated System is a new approach to interpreting leaf or plant analysis and a comprehensive system which identifies all the nutritional factors limiting crop production and increases the chances of obtaining high crop yields by improving fertilizer recommendations.

1. Chavda Bharat N.
M.Sc.(Agri.) Soil Science
& Agril. Chemistry,
N.M.C.A., N.A.U.,
Navsari
“Diagnosis and Recommendation Integrated
System”

2. CONCEPT
• DRIS is a new approach to interpreting leaf or plant analysis which
was first developed by “Beaufils” (1973) named as Diagnosis and
Recommendation Integrated System (DRIS).
• It is a comprehensive system which identifies all the nutritional factors
limiting crop production and increases the chances of obtaining high
crop yields by improving fertilizer recommendations.

3. • There is a set of optimum ratios among the nutrient elements (N/P or
N/K or K/P) within a given plant for promoting the growth of the
plant.
• DRIS mainly uses the “nutritional balancing” concept (Relationship
among nutrients) in the detection of nutritional deficiencies or excess
in the plant.
• Nutrient balance is a part of the proper interpretation of DRIS system
because nutrient interactions to a larger extent determine crop yield
and quality.
• The nutrient ratios are helpful to obtain special indexes which are
called “Nutrient Index” or “Beaufills nutrient Indexes” (BNI).

4. • BNI are actually expression of the supplies of nutrients relative to
each other.
• An abnormally high concentration of one or more nutrients will
decrease the index values of other nutrients.
• There will be positive and negative values for the nutrient index. The
nutrients with positive indexes appeared to be in “excess” and
nutrients with negative indexes appeared to be “deficient” in plants.

5. To develop a DRIS for a crop, the following requirements
must be met whenever possible
1. All factors suspected of having effect on crop yield must be defined
2. The relationship between these factors and yield must be described
3. Calibrated norms must be established
4. Recommendations suited to particular sets of conditions and based
on correct and judicious use of these norms must be continually
refined.

6. Establishment of DRIS Norms
• In this phase a large number of sites where a crop is growing are
selected at random in order to represent the whole production area
of a country, state or district.
• At each site, plant and soil sample are taken for all essential element
analyses.
• In addition, detailed of soil treatments, climatic conditions, cultural
practices and other relevant type of information are recorded and
stored in a computer for ready access.

7. • Second, the entire population of observation is divided into two
subpopulation on the basis of vigour, quality and yield.
• Each element in the plant is expressed as the percentage of N in the
dry matter or ratios N/P, N/K, or products N-P, N-K.
• Each forms of expression which significantly discriminates between
the high and low-yielding sub-population is retained as useful
diagnostic parameter.
• The mean values for each of these forms of expression then
constitute the diagnostic norms.

8. Criteria to interpret the DRIS index (I DRIS) by nutrient application
potential response (NAPR†) (Wadt, 1996).
Nutritional Status Criteria Type of nutrient application
potential response
Deficiency I DRIS A < 0,
| I DRIS A | > NBIa †† and IA is
the index of lower value.
Positive, with higher probability (p)
Deficiency-prone I DRIS A < 0 and
| I DRIS A | > NBIa
Positive, with low probability (pz)
Sufficient | I DRIS A | = NBIa Null (z)
Excess-prone I DRIS A > 0 and
| I DRIS A | > NBIa
Negative, with a low probability (nz)
Excess I DRIS A > 0,
| I DRIS A | > NBIa and IA is
the index of higher value.
Negative, with a higher probability (n)
††NBIa = Nutritional Balanced Index average.

9. Determination of relative NPK requirement

10. Abcdehf hfh
Source : Sumner, Isolutions, 22(5) : 68 (1978).

11. • Irrespective of the age of the crop when leaf samples were taken, the DRIS
approach diagnosis that phosphorus is more required than potassium, which is
more required than nitrogen (eg., P > K > N). Using the critical value norms, the
diagnosis would only have been possible after the 80-days stage. Thus the DRIS
approach results in greater flexibility in diagnosis.
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12. • Although this discussion of the DRIS approach has dealt only with the
nitrogen, phosphorus, and potassium requirements of corn, it has
been successfully applied to other crops, including sugarcane, rubber,
soybeans, potatoes, wheat, sunflower, alfalfa, and ryegrass.
• Also, norms for calcium and magnesium in com have been established
and additional norms for other essential nutrients are expected in the
future.

13. In summary, the DRIS system has a number of distinct advantages over the classical
critical level approach in making diagnoses for fertilizer recommendation purposes:
• The importance of nutritional balance is taken into account in deriving
the norms and making diagnoses.
• The norms for the elemental content in leaf tissues can be universally
applied to the particular crop, regardless of where it is grown.
• Diagnoses can be made over a wide range in stages of crop
development, irrespective of cultivar.
• The nutrients limiting yield either through excess or insufficiency can
be readily identified and arranged in order of their limiting importance
on yield.

14. • Time of Sampling DRIS:
The percentage of certain plant nutrients may drop rapidly from early
to late stages of growth. This tendency is portrayed in a large decline in the
nitrogen, phosphorus, and potassium concentrations in corn. Hence stage of
growth for sampling must be carefully selected and identified.
• Surveys of DRIS:
Analysis of plant samples from many fields gives a general indication of
the levels of nutrients. To permit interpretation these levels, of course, must
be compared with critical levels observed in controlled plots. This method
has been particularly useful in obtaining preliminary information on elements
such as zinc, boron, cobalt, and copper.

15. • Routine Use of DRIS :
Quantitative plant analyses are employed extensively in research to
obtain another measure of the effect of treatment; however, crops on a
commercial scale, such as sugarcane and pineapples, are analyzed periodically in
many areas.
Plant analysis is another helpful tool in evaluation the nutrient status of
the plant. It must be considered along with soil testing and crop-management
practices in diagnosing problems. Its use in crop logging is a case in point.
• Crop Logging of DRIS:
A critical nutrient concentration approach is used in the crop log system
and nutrient concentrations in leaf sheaths 3, 4, 5 and 6 are utilized for diagnosis
of calcium, magnesium, sulfur, and micro-nutrient deficiencies.
It uses complex indices based on tissue nutrient concentration, sheath
moisture, and other factors to diagnose nitrogen, phosphorus, and potassium
deficiencies.

16. • Isotopic Dilution Techniques for DRIS :
Two isotopic dilution equations have been developed by researchers in
the United States and Europe. Equations for the two approaches are given
below.
Fried and Dean (or A value): 𝐴 = 𝐵(1 − 𝑦) ÷ 𝑦
Larsen (or L value): Y = x(C0 - C)/C
where A or Y = Available phosphorus in the soil
Bor x = Amount of phosphorus applied to soil
y= Fraction of phosphorus taken by the plant from B
C= k x total phosphorus in the plant
C= k x phosphorus taken by the plant from x
k=Proportionality constant

17. • Potential sources of error in both the A and L-value techniques are
related to the assumptions that
(1) the amount of nutrient absorbed from the soil is
independent of the rate of fertilizer application, and
(2) the utilization percentage of the fertilizer is the same for all
rates of application.
• These assumptions are not always correct because uptake of soil
phosphorus as well as fertilizer phosphorus is known to vary with
increased rate of application.

18. Roney et al. (2017) studied on foliar diagnosis indexes for corn by the
methods diagnosis and recommendation integrated system (DRIS) and
nutritional composition (CND). Their result are given below as table….
Fertilization potential response (%)
DRIS CND
Nutrient High and
Very High
Null Low and
Very Low
High and Very
High
Null Low and Very
Low
N 41.6 36.0 22.5 41.6 36.0 22.5
P 39.3 39.3 21.3 49.4 29.2 21.3
K 37.1 38.2 24.7 37.1 38.2 24.7
Ca 25.8 42.7 31.5 25.8 46.1 28.11
Mg 16.9 34.8 48.3 16.9 34.8 48.3
S 22.5 56.2 21.3 31.5 49.4 19.1
Fe 50.6 28.1 21.3 48.3 30.3 21.3
DRIS—Diagnosis and Recommendation Integrated System; CND—Diagnosis of Nutritional Composition.

19. Conclusion
• With the advent of DRIS, researchers were setting to this system of
nutritional diagnosis in order to increase their efficiency.
• The use of DRIS is still being widely disseminated in the world, DRIS
brings results consistently good in assessing the nutritional status of
plants, showing the nutritional balance, a fact which is not observed
with traditional systems (sufficiency range and critical level).

20. References
Beaufils, E. R. (1973). Diagnosis and Recommendation Integrated
System (DRIS): A general scheme for experimentation and
calibration based on principles developed from research in plant
nutrition. Pietermaritzburg: University of Natal.
Introductory Soil Science by Dilip Kumar Das
Roney, M. G., Leonardo, A. A., Junia, M. C., Luiz, P. D., André, M. X.
and Felipe, O. X. (2017). Foliar diagnosis indexes for corn by
the methods diagnosis and recommendation integrated system
(DRIS) and nutritional composition (CND). Communications in
Soil Science and Plant Analysis, 48(1): 11-19.