DRIS

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 All factors suspected of having effect on crop yield must be defined The relationship between these factors and yield must be described Calibrated norms must be established 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. abcdegb

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): Larsen (or L value): Y = x(C - C )/C where A or Y = Available phosphorus in the soil B or 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 d iagnosis indexes for corn by the methods diagnosis and recommendation i ntegrated s ystem (DRIS) and n utritional c omposition ( 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). F oliar 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.

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