Guide to laboratory

1 Guide to laboratory establishment for plant nutrient analysis FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONSRome, 2008 FAOFERTILIZERAND PLANT NUTRITION MotsaraNew RoyFood and Agriculture OrganizationRomeItalyThe designations employed and the presentation of material in this informationproduct do not imply the expression of any opinion whatsoever on the partof the Food and Agriculture Organization of the United Nations (FAO) concerning thelegal or development status of any country, territory, city or area or of its authorities,or concerning the delimitation of its frontiers or boundaries. The mention of specificcompanies or products of manufacturers, whether or not these have been patented, doesnot imply that these have been endorsed or recommended by FAO in preference toothers of a similar nature that are not 978-92-5-105981-4 All rights reserved.

2 Reproduction and dissemination of material in this informationproduct for educational or other non-commercial purposes are authorized withoutany prior written permission from the copyright holders provided the source is fullyacknowledged. Reproduction of material in this information product for resale or othercommercial purposes is prohibited without written permission of the copyright for such permission should be addressed to:ChiefElectronic Publishing Policy and Support BranchCommunication DivisionFAOV iale delle Terme di Caracalla, 00153 Rome, Italyor by e-mail FAO 2008iiiContentsAcknowledgements viiPreface viiiList of acronyms, abbreviations and chemical symbols x1.

3 Introduction 12. The basics of an analytical laboratory 3 laboratory safety measures 4 laboratory quality assurance/control 5 Standard operating procedure 6 Error, precision, accuracy and detection limit 6 Quality control of analytical procedures 7 Preparation and standardization of reagent solutions 113. Soil analysis 17 Available nutrient content of soils 17 Soil sampling 17 Dispatch of soil samples to the laboratory 20 Preparation of soil samples for analysis 20 Analytical methods 224. Plant analysis 77 Sample collection and preparation for analysis 80 Analytical methods 815. Water analysis 91 Important characteristics of irrigation water 91 Collection of water samples 94 Analytical methods 946. Mineral and organic fertilizer analysis 101 Sample collection and preparation 102 Analytical methods 103iv7.

4 Biofertilizer assay and production 123 Types of microscopes and their use in the laboratory 124 Examination of microbes by staining techniques 125 Culture media 127 Isolation and identification of important microbes 133 Inoculation of culture medium 138 Fermentation 139 Measurement of microbial growth 139 Quality control of biofertilizers 143 Commercial production of biofertilizers 146 References and further reading 151 Annexes1. Floor plan of a soil, plant, water and fertilizer analysis laboratory 1572. Floor plan of a biofertilizer laboratory and production unit 1593. Items required for a soil, plant and water analysis laboratory 1614. Items required for a fertilizer testing laboratory 1675.

5 Items required for a microbiological laboratory 1716. Summary of plant nutrient estimation methods 1777. Automation of analytical procedures 1798. Examples of laboratory registers 1879. Grades of chemicals and glassware 18910. Equivalent and molecular weights of compounds 19111. Soil sample information sheet 19312. Colour change of solutions owing to pH change 19513. Glossary of biofertilizer terms 19714. Units and conversion factors 203vList of tables1. laboratory types, with analysis capacity2. Strength of commonly used acids and alkalis3. Data sheet for recording hydrometer readings4. Soil reaction ratings5. Lime required to reduce soil acidity6. Lime requirement for different pH targets7. Chemical characteristics of saline, non-saline sodic and saline sodic soils8.

6 General interpretation of EC values9. Wavelengths and corresponding colour ranges10. Commonly used extractants for micronutrients11. Critical limits for DTPA-extractable micronutrients12. Parameters for estimation of micronutrients using an AAS13. Specifications for preparing micronutrient standard solutions14. General sufficiency or optimal range of nutrients in plants15. Typical plant parts suggested for analysis16. Critical nutrient concentrations for 90-percent yield for various crops17. Parameters for micronutrient estimation by AAS18. Suitability of irrigation water for semi-tolerant and tolerant crops in different soil types19. Specifications of commonly used biofertilizers20. Micro-organism-specific media21. Plant nutrient solution22. Chemicals required for the production of Rhizobium biofertilizer23.

7 Chemicals required for the production of Azotobacter biofertilizer24. Chemicals required for the production of Azospirillum biofertilizer25. Chemicals required for the production of PSMs viList of figures1. Soil texture classes according to proportions of sand, silt and clay2. Standard curve for organic carbon on spectrophotometer3. Standard curve for P on spectrophotometer4. Standard curve for K on flame photometer5. Standard curve for Zn on an AAS6. Standard curve for Cu on an AAS7. Standard curve for Fe on an AAS8. Standard curve for Mn on an AASviiAcknowledgementsThe contribution of Roy to the conceptualization, initiation and inputs in the preparation and finalization of this publication is duly acknowledged. Special thanks are due to Motsara, who assisted FAO in several field projects related to this subject and contributed to shaping this document.

8 Thanks also go to Thomas and P. Bhattacharyya for peer reviewing the chapters on soil and biofertilizer, respectively, and for their publication provides practical guidelines on establishing service laboratories for the analysis of soil, plants, water and fertilizers (mineral, organic and biofertilizers). A service laboratory needs information on a methodology that is widely acceptable, taking into consideration the ready availability of chemicals, reagents and instruments while ensuring a reasonable degree of accuracy, speed and reproducibility of results. The method needs to be easy to understand for practising technicians who are required to adopt it in a routine manual, with simple procedural steps, is considered as providing the best help to the laboratory technicians.

9 This publication provides various analytical methods for estimating soil constituents with the objective of assessing soil fertility and making nutrient recommendations. It describes methods for analysing plant constituents in order to determine the content of various nutrients and the need for their application. For assessing the quality of irrigation water, it presents standard methods for estimating the various parameters and constituents utilized, electrical conductivity, sodium adsorption ratio, residual sodium carbonate, the ratio of magnesium to calcium, and boron content. In providing the methodology for fertilizer analysis, special consideration has been given to the fact that fertilizers are often statutorily controlled commodities and are traded widely among Guide also examines biofertilizers.

10 It discusses the bacterial cultures that serve either as a source of nitrogen, such as Rhizobium, Azotobacter and Azospirillum, or for improving the availability of soil phosphorus, such as phosphate-solubilizing microbes. It provides methods for their isolation, identification, multiplication and commercial production. The Reference section includes sources for further detailed Guide details the equipment, chemicals and glassware required in order to establish a composite laboratory with facilities for soil, water and plant analysis. Similarly, it details the requirements for establishing a fertilizer testing laboratory and a biofertilizer testing/production laboratory . To save on the cost of some of the common equipment, facilities and supervision, the analytical facilities required for various materials can be combined.