Soil parameters, analysis protocols, interpretation, and fertilizer recommendations

The second lab managers’ meeting of the South-East Asia Laboratory NETwork (SEALNET) took place on 19 - 23 November 2018 in ICAR-IISS (Indian Institute of Soil Science), Bhopal, India.

Drs. Sanjay Srivastava and Pradip Dey, ICAR-IISS, Bhopal, India (1st Day)

1. Soil parameters, analysis protocols, interpretation, and fertilizer recommendations Sanjay Srivastava & Pradip Dey ICAR-Indian Institute of Soil Science, Bhopal

2. Soil Testing in India started 1955-56 Parameters : Soil pH, EC, Organic carbon, Available P and K Soil Health Card Scheme (2015) : In addition, Available N, S, Fe, Mn , Zn, Cu, B Need based: Lime and Gypsum Requirement

3. Soil Parameters pH EC Organic Carbon Available Nitrogen Available Phosphorus Available Potassium Available Sulphur Available Zinc Available Iron Available Manganese Available Copper Available Boron Fertilizer Recommendation Nitrogen Phosphate Potash Sulphur Micronutrients

4. Soil Analysis Protocol

5. `Soil Analysis Protocols. . . Analytical methods pH and EC (1:2 soil:water )---pH and EC Meter Organic C: Wet Digestion ( Walkley and Black, 1934) Available N: Subbaiah and Asija , 1956 Available P: Olsen et al 1954 and Bray and kurtz1 1945 methods, Blue colour---Spectrophotometer Available K: Neutral 1 N Amm . Ac.—5 minutes- Whatman 1-Flame photometer Available S: 0.15% CaCl2 extractable S (Williams & Steinbergs 1959) Available micronutrients (Fe, Mn , Cu, and Zn): DTPA extraction (Lindsay and Norvell , 1978) followed by determination at AAS/ICP Available B : Hot water soluble boron: Berger and Troug (1939)

6. Fertilizer Requirement/Calibration General recommendation These recommendation are based on multilocational trials conducted with graded doses of N,P, K fertilizers to arrive at an optimum dose for the particular crop. Recommendation based on the soil fertility rating Most of the recommendation issued from soil testing laboratories in India are based on soil test ratings, the medium soil fertility being equated with general recommended dose. The fertiliser dose is decreased or increased by 25 to 30 percent if the soil is high in fertility or low in fertility as per soil test.

7. Critical limit based recommendation Critical limit is the level of soil available nutrient above which that nutrient no longer primary limiting factor. Recommendation based on targeted yield The recommendation based on this approach are more quantitative, precise and meaningful because it involve both soil and plant analysis Recommendation based on nutrient index Nutrient Index = (NLx1) + ( NM x 2) + (NH x 3) NT Where NL, NM and NH are number of soil samples falling in low, medium and high catagories respectively and NT total number of soil samples. Index modified by Ramamoorthy and Bajaj 1969 < 1.67 low 1.67 -2.33 medium >2.33 high

8. Results/Interpretation/Recommendation. . .

9. `Results/Interpretation/Recommendation. . . Soil Test Rating Zinc Iron Sulphur Boron Copper Manganese Critical level (mg/kg)* 0.6 4.5 10 0.5 0.2 2.0

10. Targeted yield concept The essential basic data required for formulating fertilizer recommendation for targeted yield are ( i ) Nutrient requirement in kg/q of produce, grain or other economic produce (ii) The per cent contribution from the soil available nutrients (iii) The per cent contribution from the applied fertilizer nutrients ( Ramamoorthy et al 1967).

11. % Contribution of nutrient from fertilizer Contribution from fertiliser (CF) = Total uptake of nutrients in treated plots – (Soil test values of nutrients in fertilizer in treated plots treated plots x CS) CF % Contribution from fertilizer = -----------------------------------  100 Fertilizer dose (kg ha -1 ) Calculation of fertilizer dose The above basic data are transformed into workable adjustment equation as follows : Nutrient requirement in kg/q of grain %CS Fertilizer dose = -------------------------------  100  T - -----  soil test value % C F %CF   = a constant  yield target (q ha -1 ) - b constant  soil test value (kg ha -1 )

12. Tools for Soil Fertility Assessment Soil Testing Laboratories ( STL,Static and Mobile) More than 14 crore soil health cards (SHCs) to be prepared and sent to farmers. 1500 STL can analyze only 15 million samples in one year equal to 45 crore in three years. This is only 30% of the total soil health card need to be generated in three years. Creation of new infrastructure would require 3500 new STLs, would amount to Rs . 20 billion. Soil Testing Kits Several soil test kits are available However, Soil Test Kits (STKs) are subject to human error Estimation of micronutrients was also missing Mini Laboratory ( Mridaparikshak )

13. Smart Soil Pro Measures parameters and displays results Around 15 samples/day Results can be sent to farmer’s mobile A soil health card can be generated by using software

14. Equipments in Mridparikshak Balance Hot Plate Shaker Smart Soil Pro

15. 1. Weigh 3. Shake 2. Transfer & add reagent 4. Filter 5. Transfer 6. Add reagent & develop colour 7. In Cuvette 8. Put in Smart Soil Pro 9. Read Sequence of operations

16. Nutrient Recommendation Select Soil Select Crop

17. Transfer results to mobile

18. Mridaparikshak works on the principle of colorimetry for all the parameters except pH, EC, GR, LR, calcaroeusness and Av. N The results are compared with standard Laboratory estimation procedures. For the soils having pH between 5.5 to 8.5, the results given by Mridaparikshak correspond (90%) to the results obtained by standard laboratory procedures. It is an improvement on existing soil test kits which are qualitative in nature. The STCR calibration equations are embedded in Mridaparikshak for eight important crops which are used for Fertilizer nutrients (N, P, and K) recommendations based on soil test results. For micronutrients, the recommendations are based on Critical Level approach. Mridaparikshak . . .

19. Comparison of results of Mridaparikshak with the results obtained by laboratory

20. pH 0.08 Deviations +/- 3 to 4% EC Deviations +/- 10%, Temperature correction is now introduced OC Range 0.2-1.5%, Available N Indirect, based on Organic C Available P 0.9 kg/ha, Deviation +/- 5% Available K The detection is 1.29 kg/ha for alluvial soils; for black soils it is 2.19 kg/ha; for red soils it is 1.39 kg/ha. The results of available potassium may not directly correspond with the results obtained with neutral normal ammonium acetate in some cases Available S Detection: 1 mg/kg, Deviations within +/- 10% Available Zn Detection: 0.18 mg/kg, The results of Zn may not tally with DTPA extractable Zn in some cases (10-15%). Available B Detection: 0.09 mg/kg, Critical Limit 0.5 mg/kg Available Fe Detection 0.11 mg/kg, Critical limit 4.5 mg/kg Available Mn Detection 0.45 mg/kg, Critical limit is 2.0 mg/kg Available Cu Detection 0.09 mg/kg, Critical limit 0.2 mg/kg Range, Least count/sensitivity, Deviations

21. Extraction of micronutrients through DTPA at different temperature

22. Extraction of micronutrients through DTPA at different pH Lindsay and Norvell, 1978

23. Some considerations. . . Accuracy versus Sensitivity Samples that are at the boundary line of management decision Samples stored and analysed at different ambient temperatures Matrix effect Boron estimation Filter paper

24. Hon’ble Prime Minister Shri Narendra Modi distributing Mridaparikshak to rural youth on July 25, 2015 during 87th Foundation Day of ICAR at Patna

25. ICAR-IISS Bags Mahindra Samriddhi Krishi Sansthan Samman 2016 The award is given to ICAR-IISS, Bhopal in view of the institute’s significant contribution in the area of soil health assessment and management. The institute has recently come out with a mini laboratory “ Mridaparikshak ” that can estimate the important soil health parameters and disseminate the results to the farmers.

26. Thanks