Preface Soil, plants, water, fertilizers and manures are materials of common interest in the field of agriculture and forestry. Methods applicable to the analysis of chemistry soils, plant, water, fertilizers and manures are as numerous and varied as the field of chemistry itself. The extraction of a chemical constituents from the interested materials is purely a soil chemistry procedure, while determination of the extracted constituents is an analytical process, a few methods of analysis are accurate and precise. No doubt, a few good books are available for analysis of soil, plant, water and fertilizers but they are not comprehensive and not covered all relevant procedures and principles for soil, plant, water and fertilizers in single book. In this book, I have complied together almost tested, proven and routinely used methods for the determination of nutrients in soil, plant and fertilizers and analysis of quality parameters in water, effluents and other polluted water. All essential parameters, which are concern with plant growth and environment, are duly covered. Besides systematic presentation of chapters, relevant principles, concepts and critical interpretations are included in this book, which will help the readers to understand the subject with ease. This book would meet the needs of teaching, research, advisory services, soil and plant testing laboratories and those interested in monitoring the nutrient contents of effluents/ polluted soil and water. It should be of interest to all these laboratories, R & D centre, and academic institutions interested in soil science, plant analysis, environment management, fertilizer production and environmental engineering. I have duly acknowledged the sources of diagrams and tables that have been reproduced from text books and other publications. The author is ready to accept ideas and suggestions to improve the quality of the book, if any. The ultimate of aim of the author is to provide single comprehensive hand book on soil, plant, water, fertilizers and manures to the readers.

The role of plant nutrients in crop production is well established. Estimation of nutrients contents and forms in materials, which are involved in nutrient supply and dynamics is a crucial step in scientific nutrient management and crop production. There are 16 essential plant nutrients. These are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), sulphur (S), zinc (Zn), manganese (Mn), copper (Cu), boron (B), molybdenum (Mo) and chlorine (Cl). These nutrients have to be available to the crops in quantities as required for a yield target. Any limiting or deficient nutrient (s) will limit crop growth.

Introduction In chemical laboratories, the use of acids, alkalis and some hazardous and explosive chemicals is unavoidable. In addition, some chemical reactions during the analysis process may release toxic gases and, if not handled well, may cause an explosion. Inflammable gases are also used as a fuel/heating source. Thus, work safety in a chemical laboratory calls for special care both in terms of the design and construction of the laboratory building, and in the handling and use of chemicals. For chemical operations, it is also necessary to provide special chambers. The air temperature of the laboratory and work rooms should be maintained constant at 20–25°C. Humidity should be kept at about 50 percent. Temperature and humidity often affect soil and fertilizer samples. Temperature also affects some chemical operations. Hence, maintaining the temperature and humidity as specified is critical.

Introduction Soil is the main source of nutrients for the plants. Soil also provides support for plant growth in various ways. Knowledge about soil health and its maintenance is critical to sustaining crop productivity. The health of soils can be assessed by the quality and stand of the crops grown on them. However, this is a general assessment made by the farmers. A scientific assessment is possible through detailed physical, chemical and biological analysis of the soils. Essential plant nutrients such as N, P, K, Ca, Mg and S are called macronutrients, while Fe, Zn, Cu, Mo, Mn, B and Cl are called micronutrients. It is necessary to assess the capacity of a soil to supply nutrients in order to supply the remaining amounts of needed plant nutrients (total crop requirement - soil supply). Thus, soil testing laboratories are considered nerve centres for nutrient management in crop production systems and plantation forestry. Soils may have large amounts of nutrient reserves in them. All or a part of these reserves may not be of any use to crops because they may not be in plant-available form. For the purpose of estimation or analysis of plant-available soil nutrients, such methods are to be used that have been tested/verified for the correlation of nutrients extracted and their plant availability. This book describes internationally accepted and widely used methods. Apart from nutrients, soil pH estimation is also critical in the assessment of soil health. Generally, plants prefer soils that are close to either side of neutrality. However, there are acid- loving plants and also plants that can withstand high soil alkalinity. Hence, good yields and economic returns from farming are possible in acid and alkali soils. With proper amendments, still higher yields can be obtained in acid and alkali soils. Soil pH also has a considerable influence on the activity of soil micro-flora and on the availability of soil nutrients to crops. It is also important to estimate physical properties such as soil texture, structure, bulk density, soil colour, water content and soil temperature.

Introduction and Scope Plant and soil testing enable scientific assessment of the needs of the plant for nutrient elements and of the capacity of the soil to supply them. The nutrient elements enter the plant in ionic form from the soil solution. Ion transport to the root surface may take place through ion diffusion and bulk transport (mass flow). Mass flow is the sweeping along of ions as water moves to the root. It is particularly important for ions that are not absorbed on soil colloids such as nitrates and sulphates. Because of mass flow, a plant deficient in N can extract all the nitrates from the soil. Potassium, phosphate and the micronutrient cations are absorbed on soil colloids with various degrees of affinity and are greatly retarded in movement with the soil water. Diffusion (movement along a concentration gradient) is the main mode of transport from the solid phase to the root surface for these non-mobile ions. There is also a possibility that some of them are absorbed by a direct exchange of an ion, usually hydrogen, between the root surface and ions absorbed on soil colloids. Most ions are sorbed by the root against a concentration gradient and, thus, the process involves the use of metabolic energy. The fact that nutrient uptake is an active process explains some of its peculiarities. Plants not only accumulate nutrients against a concentration gradient, they are also able to select from the nutrients at the root surface according to their requirements (preferential uptake).

Introduction Irrigation water always contains some soluble salts irrespective of its source. The suitability of waters for a specific purpose depends on the types and amounts of dissolved salts. Some of the dissolved salts or other constituents may be useful for crops. However, the quality or suitability of waters for irrigation purposes is assessed in terms of the presence of undesirable constituents, and only in limited situations is irrigation water assessed as a source of plant nutrients. Some of the dissolved ions, such as NO3, are useful for crops. Sometimes, effluents and domestic sewage water is utilized for irrigating field crops. For using these water safely in the farming system, assessment of undesirable pollutants and organic and microbial constituents with regard to their suitability is fore-most important. Determination of organic constituents is generally carried out under two categories viz., (i) organic substances that quantify an aggregate amount of organic C and (ii) individual or specific organic substances, such as benzene, DDT, methane, phenol and endosulphan. Important determinations are the chemical oxygen demand (COD), which gives the total organic substances, and the biochemical oxygen demand (BOD), which gives the amount of total biodegradable organic substances in the water sample.

Introduction The main objective in analysing fertilizers is to assess their quality. The analysis examines both their physical and chemical composition. The quality of fertilizers is stated by the manufacturers and, in most countries, it is statutorily notified. Hence, analysis is carried out to determine whether the stated quality meets the statutorily notified standards or not. Together with the statutory notified composition of the fertilizers, the testing methods are specified. In situations where the testing methods are not notified, the prevalent standard methods are followed. Generally, the term fertilizer refers to mineral fertilizers, which are manufactured chemical products of standard composition, while the term manures refers to organic manures, compost, agro-industrial wastes, etc. The compositions of organic fertilizers, unlike mineral fertilizers, are quite variable and, thus, difficult to regulate precisely. Fertilizer quality is notified in terms of physical and chemical characteristics. The physical parameters include moisture content and particle size. The chemical parameters refer to the amount and form of nutrients, and to various impurities that may be toxic to plants above a critical limit, e.g. biuret in urea. The efficiency of a fertilizer depends on its form of nutrient content. A phosphatic fertilizer may have water-soluble, citrate-soluble, water-insoluble or citrate-insoluble forms of phosphate. A nitrogenous fertilizer may contain ammoniacal, nitrate and amide forms of N in various proportions.

Introduction In view of the accepted importance of analysis, the workload on soil, plant and water testing laboratories has increased considerably in recent years. Therefore, analytical methods have needed to be accelerated through the automation of instruments. Almost all instruments either contain inbuilt computers or can interface directly with micro processors, thereby simplifying instrument operation and providing versatility for the analyst. Most operations can be performed through keyboard commands. This type of instrument automation enables:

References and Further Reading Baker, D.E. and Suhr, N.H. 1982. Atomic absorption and flame emission spectrometry. Methods of soil analysis, Part 2. 2nd edition. Agronomy Monogram. Madison, USA, ASA and SSSA. Bear, F.E. 1964. Chemistry of the soil. American Chemical Society. Black, C.A. 1965. Methods of Soil Analysis, Soc. Agron. In., Madison, USA. Chopra, S.L. and Kanwar, J.S. 1991. Analytical agricultural chemistry. New Delhi, Kalyani Publishers. Day, P.R. 1965. Particle fractionation and particle-size analysis p. 545-56. In C.A. Black et al (ed.) Methods of soil analysis, Part 1. Agronomy 9:545-567. Gee, G. W., and J. W. Bauder. 1979. Particle size analysis by hydrometer: a simplified method for routine textural analysis and a sensitivity test ofmeasured parameters. Soil Sci Soc. Am. J. 43:1004-1007. FAI 1985. Fertilizer (Control) Order. India. FAO 1998. Guidelines for quality management in soil and plant laboratories, by L.P. van Reeuwijk and V.J.G. Houba. FAO Soils Bulletin No. 74. FAO. 2004. Integrated nutrient management – A glossary of terms, by H.L.S. Tandon and R.N. Roy. Rome. Gee, G. W., and J. W. Bauder. 1986. Particle-size Analysis. P. 383 - 411. In A.L. Page (ed.). Methods of soil analysis, Part1, Physical and mineralogical methods. Second Edition, Agronomy Monograph 9, American Society of Agronomy, Madison, WI. U.S. Salinity Lab. Staff. 1954. Methods for soil characterization. p. 83-147. Diagnosis and improvement of saline and alkali soils. Agr. Handbook 60, USDA, Washington, D.C. Gupta, P.K. 2000. Soil, plant, water and fertilizer analysis. Jodhpur, India, Agrobios. Hanway, J.J. and Heidel, H. 1952. Soil analysis methods as used in Iowa State College Soil Testing Laboratory. Iowa Agric., 57: 1–31. Hesse, P.R. 1994. A text book of soil chemical analysis. Delhi, CBS Publishers and Distributors.