eChapters

4.1. Information and Communication Technology

Refers to technologies that provide access to information through telecommunications.

Similar to IT, but focuses on communication technologies.

Includes the Internet, wireless network, cell phones, and other communication medium.

5.1. Diffusion

Process by which an innovation is communicated through certain channels over time among the members of a social system.

6.1. Etawah Pilot Project (1948)

Started in 1948 by Mr. Albert Mayer of USA at Etawah district in UP

Funded by the Government of UP.

6.1.1. Objectives

To know the degree of productive and social improvements, through self confidence and cooperatives

To find how quickly these results could be attained

To know whether the results remain permanent even after the special pressure is withdrawn

To assess how far the results were reproductive in other places.

7.1. Sriniketan Project (1914)

Shri Rabindra Nath Tagore in 1914 established a rural reconstruction institute at Sriniketan involving youth from a group of 8 villages.

Maintained a demonstration farm, a dairy and poultry unit, an outdoor clinic, a department of cottage industries and a village school.

Villages were expected to approach these agencies through village workers who lived in villages to obtain solution of their more pressing problems.

Scheme of land development and tree plantation were given due importance.

Experiment on paddy, sugarcane and cotton were undertaken.

8.1. Terms and definitions

8.1.1. Extension program

A written statement of situation, objectives, problems and solutions which has been prepared on the basis of an adequate and systematic planning effort and which forms the basis of extension teaching activities in a specific area for a given period.

9.1. Rural Sociology

Science of rural society.

Study of sociological life in rural setting to discover their conditions and tendencies and to formulate principles of progress.

A.R. Desai: Rural Sociology involves the study of human relationships in rural situations.

10.1. Social value

Ideas which help an individual to discriminate whether a particular object or behaviour is good or bad, desirable or undesirable.

Norms: Times rules which govern the action

Normative behavior: People are expected to behave in accordance with the values held by the individual.

S.C. Dood defined the value as “desiderata” i.e., anything desired or chosen by someone, sometime.

Value may be considered as attitude-related attribute that are projected upon people, objects and situations.

11.1. Definition

Jones: Variations or modifications of any aspect of social process, social patterns, social interaction or social organization.

Gillin and Gillin: Variations from the accepted modes of life; whether due to alteration in geographical conditions, in cultural equipment, composition on the population or ideologies and whether brought about by diffusion or inventions within the group.

Davis and Mac Iver: Change in the relationships.

12.1. Women in Agriculture

Women are actively involved in various agricultural activities.

Analytical chemistry is a branch of chemistry dealing with the determination of constituents of a substance or mixture of substances.

1.1 Qualitative Analysis

Qualitative analysis deals with the identification of the constituents of a substance, mixture of substances, or solutions and the way in which component element or a group of elements are constituted.

1.2 Quantitative Analysis

Quantitative analysis is concerned with the determination of quantitative contents of individual element or group of elements or compound present in the substances. This branch of analytical chemistry is of enormous scope and importance in science, industry and agriculture. The quantitative analysis can be divided into several categories based on the different methods employed for their quantitative measurements such as:

2.1 Beakers

Beakers are the one of most important vessels used in laboratory which is made up of heat resistant glass.

They are available in various capacities ranging from 10 to 3000 mL.

For convenience of pouring solution, spout is provided in the beaker.

They are used to perform titrations & for boiling solutions, etc.,

Beakers are constructed in tall and low forms.

Instrumental methods of chemical analysis are the quantitative methods of analysis that use, as principal measuring devices, instruments other than those employed in conventional gravimetric and volumetric determinations.

The main basis for this method of analysis is the physical property of any particular element or compound being analyzed. These properties include:

Practice to calculate the weight / volume of reagents required to prepare the following standard solutions.

Preparation of Standard Solution - (1 M, 0.1 M, 1 N, 0.1 N, 0.5 N, 5%, 10%, 20%, 10 ppm, 20 ppm, 100 ppm)

5.1 Volumetric Techniques or Titrimetric Analysis

Acid Base Neutralization Reactions-Acidimetry & Alkalimetry

Oxidation –Reduction Reactions-Oxidometry (Permanganometry) & Dichrometry

Principle

Standard solutions are the solutions of accurately known concentrations. There are two types of standard solutions viz., primary and secondary.

A known quantity of the substances is dissolved in a volumetric flask and the volume is made upto the mark. Standard solutions prepared in this way are known as primary standard. This method can be used for preparation of standard solutions of substances which satisfy the following conditions.

More often, if the reagent is not a primary standard, a secondary standard solution must be prepared. The chemical is dissolved and made up or diluted to the desired concentration and then it is standardized against a primary standard or against another reliably known secondary standard solution. Such solutions are called as secondary standard solutions.

Principle

Equal volumes of all acids / bases containing their gram equivalent weights per litre of the solution react completely with each other.

Soil is analyzed to know the nature of soil, to classify and advocate to farmers about the peculiarities of the soils and how much of fertilizers should be applied for better crop production.

A composite soil, of course, can not be moved to into a laboratory. The value of the laboratory work depends upon care in sampling. Each soil sample needs to be a fair representative of the specific area or horizon worth sampling.

If the sample is to be a representative of an area, it is necessary to take large number of samples spread over the area, pool them and sub-sample it so as to get a sample of desired size. For soil survey work, samples are collected from a profile which is typical of the soil of the surrounding area.

Principle

Soil moisture content is determined by drying a known quantity of soil sample in an electric oven at 105° C to 110° C and finding out the loss in weight.

Bulk density is the mass per unit volume of soil including pore space. The normal range of bulk density in most soils is ranging from 1.02 to 1.80 g / cm³. The bulk density of coarse textured soils will be on the higher side while organic soils will have lower bulk density.

Particle density is the mass of soil per unit volume excluding pore space. Pore space is that fraction of soil volume not occupied by solid particles.

Principle

The bulk density and percent pore space are determined from the apparent and true volumes of the soil measures by adding a known quantity of water to a measuring cylinder contain a weighed quantity of soil.

(International/Robinson’s Pipette Method)

Principle

This method is based on Stoke’s law. According to this law, the rate of fall of a particle in liquid is directly proportional to the square of its radius.

Principle

When water is ponded inside the concentric metallic rings driven into the soil, the rate of recession (fall) of the water level, or the rate of water withdrawn from a supply source used to maintain a constant head of water on the soil surface, gives the infiltration rate of the soil.

During infiltration of water into the soil, appreciable lateral movement of water may also occur. To avoid the error due to this lateral movement, two concentric rings are used. Equal heights of water are to be maintained in both the rings. The infiltration is measured in the inner ring only. The rate of water intake per unit area varies markedly with the size of the rings and the depth of the soil to which they are driven into. Infiltration rate studies are preceded by the profile, initial soil moisture and any other problems of the region in which the soil is located.

(Keen-Rackzowski/Hilgard Apparatus Method)

Principle

With the capillary rise of water, the soil immediately above a water table gets saturated. The height upto which the soil is saturated depends on the texture, structure and packing of the soil mass. The experimental technique discussed herein permits approximation of maximum water holding capacity while determining the amount of water held in the soil at the point of saturation.

The pH is defined as negative logarithm of hydrogen ion concentration or the log of the reciprocal of the hydrogen ion concentration (Sorenson, 1906).

Principle

A glass electrode in contact with hydrogen ions of the solution acquires an electric potential which depends on the concentration of hydrogen ions. This is measured potentiometrically against some reference electrode which is usually a calomel electrode. The potential difference between glass electrode and calomel electrode is expressed in pH units.

Two electrodes are used in the determination of pH. One is reference electrode which provides a standard voltage and is usually a saturated calomel electrode which has two layers of saturated solution of KCl and mixture of solid HgCl₂ and Hg. The outer tube is usually 5-15 cm long, 0.5-1 cm in diameter. The mixture of solid HgCl₂ + Hg paste is contained in an inner tube that is connected to the saturated KCl solution in the outer tube by means of small opening. The resistance developed by this type of electrode is 2000-3000 Ohms.

The outer electrode is glass electrode that consists of a tube enclosing a lead wire made up of Ag coated with AgCl. This wire is again enclosed in a wax insulation. To the tube at the bottom is attached a glass bulb made up of a special kind of glass which is sensitive to hydrogen ions. The thickness of the glass membrane varies from 0.03 to 0.1 mm and has a resistance of 50 to 500 mega Ohms.

When these electrodes are dipped in solution, the saturated solution of KCl comes out of reference through small holes and forms an invisible ionic bridge between electrodes through which current passes. The hydrogen ions are absorbed by glass electrode and depending upon the amount of hydrogen ions present in the solution, an electric potential develops between electrodes. This potential difference is measured in terms of pH units by suitable Galvanometer.

The Electrical Conductivity (EC) of the soil is a measure of soluble salts present in the soil and is expressed as millimhos/cm or dSm^-1.

Principle

As the amount of the soluble salts in a solution increases, the electrical conductivity also increases. This electrical conductivity is measured in terms of resistance offered to the flow of current using a conductivity bridge.

It is known that solutions offer some resistance to the passage of current through them, depending upon the concentration of the soluble salts present. Hence, EC is measured in terms of electrical Resistance between parallel electrodes immersed in the soil water suspension.

In such a system, the solution between the electrodes becomes the electrical conductor to which the physical laws relating to resistance are applicable. The electrical resistance ‘R’ is directly proportional to the distance ‘L’ between the electrodes and inversely proportional to the cross sectional area ‘A’ of the conductor.

[Titrimetric/ Walkley and Black (1934) Method]

Introduction

The role of soil organic matter, in relation to soil fertility and physical conditions, are widely recognized. The organic matter is the source of plant nutrients which are released inassimilable forms during microbial degradation. A major proportion of N (95 – 99 % of the total), P (33 – 67 % of the total) and S (75 % of the total) in soils occur in organic combinations, which mineralize to release the nutrients in inorganic forms to be used by plants. Nevertheless, it serves as a reservoir of plant nutrients, in promoting water storage, and in regulating microbial activity.

The organic matter content of a soil varies from 0.344 % in very sandy arid soils to more than 86 % in Peats and Mucks. Soil organic matter contains 5 % N, and 0.5 % each of P and S, thereby, having a N:P:S ratio of 10:1:1. The organic matter content of a soil is estimated by the amount of organic carbon (C) present, as this element represents, on an average, 52 – 58 % of the organic matter, and the C:N ratio is 10 – 15. In the sub-soil, the average organic carbon amount is 36 – 44 % (40 %), and the C:N ratio is < 8. In order to find out the amount of humified organic material, the organic carbon content is multiplied by 1.724, which represents the ratio between the humus and the organic carbon (100/58) and is known as the ‘von Bemmlen factor ’.

The organic matter content of soils is estimated from the organic carbon, determined by using the ‘Titrimetric method / Walkley and Black method. The Titrimetric determination, also known as the ‘wet-digestion method’ involves a rapid titration procedure for the estimation of organic carbon content of soils.

[Alkaline Permanganate / Subbiah and Asija (1956) Method]

Introduction

Nitrogen (N) is found in the arable horizon of the soil, mostly in organic material. In the soil solution, organic N is gradually transformed into ammoniacal (NH₄ ⁺), nitrite (NO₂ ^–) and nitrate (NO₃ ^–) nitrogen by microbial processes. Organic-N is, in itself, of very little use to plants, as it can not be absorbed as such. It is, therefore, necessary to estimate the different forms of mineralized or available N. The NO₃ ^–_N and NO₂ ^–-N together, hardly, exceed 1 % of the total N in normal soil.

The available N in soil refers to a fraction of the total N which is converted into forms accessible to the plants. This constitutes, on an average, only 0.5-2.5 % (rarely 5 %) of the total N in a soil at any given time. Nitrogen is, generally, absorbed by plants as NO₃ ^–, under oxidized environment (upland condition), and as NH₄ ⁺, under reduced condition. NO₂ ^– is sometimes, detectable, but the amount is, generally, very small vis-a-vis NH₄ ⁺ or NO₃ ^– and, hence does not warrant its determination. The sum total of NH₄ ⁺ and NO₃ ^–- N is smaller than the total N, which becomes available to plants and the difference being attributed to the mineralization of the organic N, during the crop growth cycle.

[Bray’s Method (Bray and Kurtz, 1945) – Acid Soils]

Introduction

The term available phosphorus (P) refers to the inorganic form, occurring in the soil solution, which is almost exclusively ‘orthophosphate’. This orthophosphate occurs in several forms and combinations, and only a small fraction of the total amount present may be available to plants, which is of direct relevance in assessing the P fertility level.

The phosphate concentration in solution is governed by heterogeneous equilibria in which it takes part. This situation can be represented as follows:

P adsorbed in solid phase ↔ P in the soil solution ↔ P precipitated

The phosphorus absorbed by plants from soil solution comes from the soil solution in which it exists as inorganic orthophosphate ions viz., H₂PO₄ ^–, HPO₄ ^2– and PO₄ ^3–. The most accessible ion is H₂PO₄ ^–, with the greatest activity coefficient, followed by HPO₄ ^2–. The quantity of P accessible to the plants is influenced by a series of soil properties. The relative abundance of these ions is, however, relatively dependent on the soil pH. For soils having a pH between 4.5 and 7.5, ions of H₂PO₄ ^– as well as HPO₄ ^2– exist in soil solution. At a pH of 7.2, H₂PO₄ ^–and HPO₄ ^2– ions have an equal activity, and, when the pH is strongly alkaline (>8.3), ions of HPO₄ ^2– predominate in solution. Above pH of 9.0, the trivalent ion (PO₄ ^3–) becomes more important than H₂PO₄ ^–, but even at a pH of 12, the HPO₄ ^2– concentration is still greater than that of PO₄ ^3–. Soluble phosphorus may be adsorptively retained at the surface of colloidal particles. This retention is more marked when the higher amounts of clay and sesquioxides are present. Relatively, the available inorganic P tends to accumulate in its most stable state under prevailing conditions, thus, in calcareous soils, the available inorganic P would be acid-soluble, whereas, in acid soils the adsorbed P would be more available. In flooded soils, with low oxidation potential, certain forms of P, normally considered as unavailable, for example, iron and phosphate, can be regarded as available. In most soils, the main source of orthophosphate is organic matter unless, of course, direct fertilization, with soluble phosphate, has been made.

(Neutral Normal Ammonium Acetate Method)

Introduction

The total potassium (K) content of a soil varies from 0.05 to 2.5 %. The total K is distributed in mineral form (lattice – K, 90-98 %), fixed non-exchangeable or temporarily retrograded K (1-10 %) and exchangeable plus water soluble K (1-2 %). Exchangeable K represents an average of 2 – 15 % of the sum of exchangeable bases and 1 – 3 % of the total capacity for cation exchange. The K concentration in the soil solution is on an average 0.08 – 3 meq/litre. Both water soluble and exchangeable K are most accessible to the plant. Available K can, thus be separated into that, immediately available, which is water soluble and exchangeable, and that, potentially available or fixed. The neutral normal ammonium acetate extract contains both water soluble and exchangeable K. K extraction by this extractant is considered as a suitable index of K availability in most soils, based on crop response correlation study. Thus, the K extracted by this method is equated as the available K.

[Williams and Steinbergs (1959) Method]

Introduction

Sulphur (S) occurs in numerous forms in soil, viz., sulphites, sulphates, sulphides and in organic compounds. It is considered that the most accessible form is ‘sulphate’ (SO₄ ^2–). The organic forms of S compounds become assimilable, especially following, microbiological transformation into SO₄ ^2–. The mineralization of organic S in a soil depends primarily upon the N:S ratio, and any SO₄ ^2– formed may be fixed against extraction, particularly if much Fe or Ba is present or if the soil is very acid. Despite the fact that the plants absorb S almost exclusively as SO₄ ^2–, mobility of SO₄ ^2– in soil may not always yield satisfactory results in accordance with the time of sampling, while assessing SO₄ ^2– availability.

[Shoemaker, Mc Lean and Pratt (SMP) Method, 1961]

Introduction

For proper plant growth, the soil should have a pH between 6.5 and 7.5, though there are certain plants which can grow satisfactorily at low pH, for example, tea, and at high pH, for example, sugar beet. In India, acid soils are located mostly in Eastern, Southern and South Central parts though some soils, at higher elevations, in North India are acidic.

In order to achieve maximum yield and sustained productivity through efficient soil management practices, it is essential to lime an acid soil, as it has considerable influence on soil environment, besides correcting soil acidity.

Several methods have been proposed to determine the lime requirement of acidic soils, to raise the pH around 6.5. The soil pH value alone, however, is not a good criterion for lime recommendation, because of variations in the exchange acidity of soil, and the nature of crops which may not require as high as this pH to produce maximum yield. Of these various methods proposed, the Shoemaker / SMP method was found satisfactory.

The recent trend of liming is to use it as a fertilizer rather than as amendment so as not to disturb heavily the natural environment while ensuring sustained productivity.

[Schoonover (1952) Method]

Introduction

Sodic (Alkali) and Saline-Sodic soils are characterized by the presence of large amounts of sodium, as high as 15% or more, on their exchange complex. As a result of this, the pH of soils increases beyond 8.0, causing nutritional imbalances, elimination of soil organic matter, deterioration of soil physical condition, etc., besides affecting the soil biotic community. Gypsum (CaSO₄. 2H₂O) is commonly used for the management of such soils, when applied in right amounts and size.

Principle

A given weight of soil is equilibrated with a known amount of Ca solution, and the amount of Ca, left in the solution is determined by EDTA titration. The difference between the amount of Ca added and the Ca left in the solution, gives the amount of Ca exchanged. In practice, gypsum of about 1/3 of the value, obtained by this method, is satisfactory in most cases.

Plant absorbs large number of elements from the soil and other sources during their growth and development. But all these elements are not essential for plant growth. Seventeen mineral elements are known to be essential for the growth and development of all plants. A list of essential nutrients, their source and forms by which they are absorbed by plants are presented in Table 1.1.

Except carbon (C), hydrogen (H) and oxygen (O), all the other nutrients are obtained by plants largely from soils, fertilizers or manures. It has been seen that the number of nutrients obtained from soil is about 5 times the number of nutrients obtained from air and water. However, most of the plant tissue, in general, from 74 to 99.5% is made up of C, H and O i.e. nutrients obtained from air and water and only 0.5 to 26% of the plant tissue is synthesized from soil constituents. In ordinary (normal) conditions of agriculture, except drought, C, O and H are not limited for plant growth. It is the remaining 14 elements from soil that are usually limiting plant development and hence considerable emphasis is placed on the improvement of soil in respect of greater availability of these 14 nutrients. It may be borne in mind that all nutrients are essential for all crops even though their requirements differ from crop to crop and even among varieties of a given crop. Secondly, all nutrients are equally essential regardless of amounts required. For example, to produce one tonne of grain, wheat may absorb 25, 9, 33, 3.7, 5.3 and 4.7 kg of nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca) and magnesium (Mg), respectively and 56, 624, 70, 24, 48 and 2 g of zinc (Zn), iron (Fe), manganese (Mn), copper (Cu), boron (B) and molybdenum (Mo), respectively. If the crop (any crop) does not get the smallest amounts of micronutrients needed, it cannot make the best use of abundant NPK.

According to Liebig’s Law of minimum which he enunciated in 1855, the growth of a plant is limited by that nutrient which is in shortest supply. This law in fact lays the ground rules for balanced crop nutrition.

Nitrogen (N) is an essential element for all forms of life because it is a major component of amino acids, which are the building blocks of proteins, nucleic acids such as deoxyribonucleic acid (DNA) and other cellular constituents. It is a structural component of chlorophyll in plants, which is used in photosynthesis to make their food. Nitrogen ranks first among the essential nutrient elements required for plants. Its careful management is very important for crop production.

Nitrogen exists as two main stable isotopes (isotopes of a given element have the same number of protons but different numbers of neutrons in each atom) namely, ¹⁴₇N (abundance 99.63%) and ¹⁵₇N (abundance 0.37%). These can be separated by chemical exchange or by thermal diffusion. Both ¹⁴₇N and ¹⁵₇N isotopes of N are stable isotope which do not disintegrate as in case of other radioactive isotope like ³² ₁₅P. There are four other isotopes of N viz. ¹²₇N, ¹³₇N, ¹⁶₇N and ¹⁷₇N, mostly are radioactive having very short half-life and not used in agriculture. The ¹³₇N has a half-life of about 10 min, while other three have half-life of only few sec. The ¹⁵₇N (tracer) isotope is used as a tool for determination of pathways of transformation of N in soil or plant or animal.

The major part of N comes from atmosphere (air). On the basis of volume by volume (v/v), air contains about 78-79% N₂, 20-21% oxygen (O₂) and 0.03% carbon dioxide (CO₂). Most living organisms cannot utilize N₂ gas present in the atmosphere directly because it is present as di-nitrogen form or di-atomic form (N≡N). It is called as an inert gas. Therefore, to break this triple bond, huge amount of energy is required. After breaking of triple bond of N₂ molecules, it combines with other element particularly with O₂ or hydrogen (H) to form oxides of N (NO, NO₂, NO₃ and N₂O) or ammonia (NH₃). Thus, breaking of triple bond is must for forming NH₃ which further can be used as the key material for almost all fertilizers. Therefore, the fixation of N₂ is vital for production of all nitrogenous and complex fertilizers like NP/NPK and nitrophosphates.

Phosphorus (P) is the second most important essential nutrient limiting crop/ plant growth, next only to nitrogen (N). Phosphorus is an important component of nucleic acid like deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is needed for energy storage and transfer, which is the single most important essential function of P. Phosphate compounds act as “energy currency” within plants. The most important common P energy currency is adenosine diphosphate (ADP) and adenosine triphosphate (ATP). The ATP transfers energy for synthesis of ADP. Life is not possible without P. It is the source of energy that powers practically all energy-requiring biological processes in plants. Phosphorus is present in plant as phospholipid such as lecithin and cephalin which appears to be involved in the structural framework of protoplasm. Phosphorus is involved in many important processes such as photosynthesis, cell division, tissue development, and growth in plant. Requirement of P by the crops is less, compared to N and potassium (K). It is present in plant tissues. It is reported that for 5-6 t ha^-1 of wheat grain yield, it removes about 100-120 kg N, 20-30 kg P₂O₅ and 150-180 kg K₂O from soil.

Phosphorus is 11^th most abundant element on the earth crust. However, it is the least mobile element among the major plant nutrients. Its complex chemistry in soil makes it highly deficient nutrient element in most of the arable soils across the globe. Only 0.1% of the total P in the soil is available for uptake by plants because of its fixation as various insoluble compounds depending upon the soil pH. About 43% of the world’s arable soil is P deficient which limits crop growth and production (Roy et al., 2018). In the Indian context, about 80% of the soils are reported to have low to medium available P content (Muralidharudu et al., 2011). Thus, application of P-fertilizers to maintain the soil fertility and sustain crop productivity becomes imperative in today’s input intensive agriculture.

Potassium is the third important essential nutrient element after nitrogen (N) and phosphorus (P) required by all living organisms, including plants and animals. Potassium is essential for many metabolic activities like carbohydrate metabolism, nitrogen metabolism. It is required for the activation of over 60 enzymes in plants. It controls/regulates the activities of various essential nutrients. It is vital to photosynthesis, and synthesis of carbohydrates, starch and proteins in plants. It plays vital role in controlling the opening and closing of stomata in photosynthesis. It also helps in controlling water use by plants by regulating the osmotic pressure of guard cells during transpiration. It plays a major role in transport of water and nutrients throughout the plant in xylem. Potassium improves crop yield and quality of flowers, fruits, vegetables and other field crops in terms of size, shape, colour, taste, shelf-life, and fibre quality. Potassium stimulates the growth of strong stems and provides strength to the plant against some disease by promoting thickness of the outer cell walls. It is required for translocation of assimilates. Under reduced K supply, translocation of NO₃^-, PO₄^3-, Ca²⁺, Mg²⁺ and amino acids is hampered. It also imparts resistance against environmental stresses such as drought, cold and frost. Adequate K can reduce moisture loss from growing plants, thereby giving some drought resistance. It reduces lodging of crops and enhances their winter-hardiness.

It is taken up by the plants as K⁺. Being a basic element, it takes part in neutralization of the acidity in plants caused by several organic acids produced. It does not form organic compounds in the plant system. It is the most mobile element in the plant. Thus, it can move through all the plant system due to osmotic pressure. When any plant sample is dipped into water, some K comes out. This shows that it is highly mobile.

Potassium is also required for animal nutrition and human beings. Potassium is essential for many metabolic functions. It maintains salt balance between cells and body fluids. Adequate K is essential for nerve function and preventing muscle cramps. It is routinely added to many animal feeds. Since K⁺ is not stored in the human body, dietary replacement is required on a regular basis. Government agencies state that diets containing foods that are good sources of K and low in Na may reduce the risk of high blood pressure and stroke.

5.1. Importance of Secondary Nutrients in Agriculture

Secondary nutrients such as sulphur (S), calcium (Ca) and magnesium (Mg) are the macronutrients that are required in relatively large amounts for crop growth. Among the secondary nutrients, Ca is the 5^th most abundant element in the earth’s crust while, Mg and S are ranked 8^th and 13^th, respectively. The average S content of the earth’s crust ranges from 0.06 to 0.10%; whereas, Ca in soil solution of temperate region soils is 30 to 300 ppm and soils of tropical areas is 8 to 45 ppm (Tisdale et al., 1997). In case of Mg, its’ concentration ranges from 5-50 in temperate region and 120-2400 ppm in tropical region. The Ca and Mg are the most abundant cations occupying the exchange sites of the soil colloids. Thus, most soils with the possible exception of highly weathered, leached acid soils, contain enough Ca and Mg for crop growth. In soils, occurrence and reactions of S are different from those of Ca and Mg. The plant available S is SO₄^2- ion which is relatively mobile in soil solution. Like nitrogen (N), S is also subjected to chemical and biological oxidation-reduction reactions. On the other hand, Ca and Mg are much more stable and they exist in soil as Ca²⁺ and Mg²⁺ cations and present in association with soil colloidal fraction similar to that of K. In general, Ca and Mg are the most abundant cations occupying in the exchange site.

Secondary nutrients in soils may be lost due to several reasons such as (i) crop removal, (ii) leaching, (iii) erosion, and (iv) volatilization. The amount of Ca and Mg attain importance in areas where soils are either strongly alkaline or acidic. These soils are often deficient in Ca and Mg. The Ca deficiency is most widespread in acidic soils. The alluvial soils of the Indo-Gangetic Plains (IGP), being neutral to moderately alkaline in reaction, have sufficient bases on their exchange complex and Ca deficiency is, therefore, rarely found in these soils. However, alkali soils may contain inadequate quantities of Ca due to dominance of Na⁺ on the exchange complex. Magnesium deficiency is found in sandy soils with low exchangeable Mg²⁺, acid soils and those with high in native or applied K. Alkali soils have high exchangeable Na⁺. The Ca²⁺ is a suitable ion to replace this Na⁺ from the exchange complex when Ca²⁺ is supplied through gypsum (CaSO₄.2H₂O). The replaced Na⁺ forms Na₂SO₄ which is then leached down to remove the salt away from the root zone of the crops. Gypsum also reacts with Na₂CO₃ to form CaCO₃ and Na₂SO₄ which is leached down the profile. A thorough leaching of the soil with irrigation water should be done after application of gypsum to free it from Na₂SO₄.

Iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), nickel (Ni), boron (B), molybdenum (Mo) and chloride (Cl) elements are known as micronutrients. The micronutrients are also called as trace elements or minor elements as they are required very small quantities by plants. The elements Fe, Zn, Cu, Mn and Ni are known as micronutrient cations and B, Mo and Cl are known as micronutrient anions and they behave accordingly in soils. Among these elements, Fe content in soil as well as plant is the highest and sometimes higher than phosphorus (P) and sulphur (S). In plant, the concentration of micronutrients often found up to 100 mg kg^-1, except that of Fe and Mn which may go up to 500 mg kg^-1 (dry weight basis). Another element, cobalt (Co) is also regarded to be essential for the growth of certain higher plants and animals, and likely to be included in the list of micronutrients. The importance of micronutrients has been realized during the past four decades when micronutrient deficiencies were observed in most of the soils in our country, where intensive agriculture is practiced.

Fertilizers have played a pivotal role in enhancing food grain production in India especially after the introduction of high yielding and fertilizer responsive crop varieties during the green revolution era. However, there are certain problems associated with fertilizers because of their relatively low nutrient use efficiency (NUE) or nutrient uptake by crops. The fertilizer use efficiency is 30-50% for N, 15-20% for P, 70-80% for K and 8-10% for S. In case of micronutrients, the use efficiency is only 1-2%. The low NUE is typically the result of higher release rate of fertilizers than the absorption rate by plants, and/or transformation of fertilizers/ nutrients to forms that are not bioavailable to crops.

Application of N and P fertilizers at levels exceeding plant requirements due to low acquisition efficiency leads to significant environmental consequences in many parts of the world due to losses, such as nitrate (NO₃^-) leaching, NH₃ volatilization, and nitrous oxide (N₂O) emission. Excessive use of fertilizer N affects the groundwater. Similarly, excessive use of N and P fertilizers leads to surface runoff which in turn causes eutrophication in aquatic ecosystems. These negative environmental consequences associated with fertilizer inputs further emphasize the need of technological approaches to improve nutrient management in modern agriculture. As such, there is great need in developing innovative fertilizers to minimize the losses of nutrients and increase their efficiencies.

In addition, current agricultural activities contribute up to 20-30% to the annual atmospheric emissions of greenhouse gases (GHGs), such as methane (CH₄) and carbon dioxide (CO₂). Even higher contribution is being noted for N₂O (about 60%), which is a potent GHG and catalyst for stratospheric ozone depletion, with more than 300 times the global warming potential than CO₂. Its emission is closely related to mineral fertilizer input. High fertilization rates lead to N and P losses with negative impacts on atmospheric GHGs concentrations and water quality.

There is an urgent need to improve NUE in agricultural systems, and to manage biogeochemical cycles in a sustainable way. This includes the development and application of modern technology as alternatives to conventional fertilization. There is a need to reduce the use of fertilizers/nutrients in agricultural systems by increasing NUE. The recent development in smart fertilizer delivery systems including nanofertilizers or the new generation fertilizers is a good alternative to commercially available fertilizers to improve the NUE and enhance resource utilization. Smart fertilizers may be a solution to enhance food production and environmental quality.

The Fertilizer (Control) Order

The Fertilizer (Control) Order (FCO) is a set of legally enforceable executive orders issued by the Govt. of India under the Essential Commodities Act, 1955 passed by the Parliament. This order came into force in 1957, essentially to regulate the sale, price and quality of fertilizers in India. Amendments are made from time to time as per the exigencies and need of the hour and therefore a large number of amendments were made over a period of time. Consequently, after an overall review of the various provisions of the order, a revised Fertilizer (Control) Order 1985, was issued, which came into effect on September 25, 1985. The FCO consists of five Schedules comprising of different activities as mentioned in Figure 8.1, besides forms of registrations and appendices.

Schedule I comprises Part A and B. While Part A contains the specifications of different fertilizers (e.g. minimum nutrient content, maximum moisture content, range of physical parameters, maximum levels of impurities/ contaminants, etc.), that can be marketed in India (no material not performs the specifications as in the FCO cannot be sold as fertilizer), Part B lists the tolerance limits in plant nutrients and physical parameters for various fertilizers. Schedule II encompasses again two parts, with Part A describing the procedures for drawal of samples of fertilizers, and Part B describing detailed methods of analysis of fertilizers.

Schedule III encompasses four parts namely, Part-A, Part-B, Part-C and Part-D. While Part-A contains specifications of different biofertilizers, Part-B contains tolerance limits of biofertilizers, Part-C describes the procedures for drawal of sample of biofertilizers, Part-D describes the methods of analysis of biofertilizers. Schedule IV also encompasses four parts. Part-A contains specifications of organic fertilizers, Part-B contains tolerance limits of organic fertilizers, Part-C describes the procedures for drawal of sample of organic fertilizers, and Part-D describes the methods of analysis of organic fertilizers. Schedule V also contains of four parts. Part-A contains specifications of non-edible de-oiled cake fertilizers, Part-B contains tolerance limits of non-edible de-oiled cake fertilizers, Part-C describes the procedures for drawal of sample of non-edible de-oiled cake fertilizers, and Part-D describes the methods of analysis of non-edible de-oiled cake fertilizers.

Introduction

Food is the basis to sustain a healthy life as evidenced from its consumption through centuries by human. There are plenty of plenty of foodstuffs available these days as part of new product development and flexible global participation of researchers and food technocrats. Their researches brings a lot reforms in traditional recipes through newest technological concepts (functional or nutraceutical) that address much of safety aspect for consumers health and is the prime focused concern for now (Keservani, et al 2014). Even than strict labeling policies is the present hour need to stay fit and fine. Safe and wholesome supply of foods, high pace food demands, increase in processing aspect, minimization of fraudulent practices are the key points that somehow require laws and standards during transportation, storage, marketing and storage.

Nation’s growth resides in their healthy people that contribute flawless to acquire achievements in overall growth of country. So availability of healthy food is must which can only be governed through strict standards and regulatory agency’s regulation. Journey of food from “Production to consumption”, “Farm to fork”, “Unstable to table” and “Boat to throat” are the activities where these agencies abide their regulations by way of laws and standards. Indian market somehow lacking its policy to organize food regulation appropriately hence is segmented in two types of food products viz;

Introduction

Baking is not a new concept to us. Baking process dates thousand years back since the Paleolithic age. During those days, the baking was done by simply grinding the grains, mixed with water and baked on the hot rocks. The bread produced that time was not leavened but flat. Ancient Egyptians have the credit for development of baking between 2600-1200 BC. Roman Empire also had the popularity of the art of baking and bakeries were in existence in Europe too during Middle Age. Baking was considered a highly respected profession under the Roman Empire. The art of baking has travelled a long journey since then. The bakery and confectionary has undergone a gradual evolution with time. Great technical progress stared in the nineteenth century. Development of automatic machines reduced the task of the manual labour and because of this development the bakers could perform many more tasks with the machines. Today’s baking has a dependency on the machines. All the work is performed by the automated machines whereas the bakers only control the machine operations. The baking process has become easier, the efficiency has increased and the quality of the products has improved because of these high-tech machines. The preparation of bakery products using traditional methods has also improved over the time to minimize the energy and time consumption. Today’s consumer is very much concerned about his/her health and look for the healthy options in baked products. The trend has led to various innovative formulations for the baked products so that the health benefits may also be provided not only the calories. This chapter will discuss various advancements and trends in different types of bakery and confectionary products.

Advancements on sugar processing

India has popped out as one of the largest sugar processing country throughout the world. Through the collaboration of research and development carried out in the field of sugar processing, this industry has witnessed the vast changes in term of technology. Important considerations such as productivity improvement and cost reduction were the main objectives in the field of sugar processing. Sulphur dioxide was earlier used but afterwards lime treatment in clarified juice helped in the processing of white sugar from sugar cane. Since then the continuous progress and improvement has been made and advanced techniques are introduced for manufacturing of sugar with modern tools.

Ramjeawon (2004) reported that farmers and agriculture workers grow sugar cane and beet root for sugar production,providing about 20 kg per capita and that is equivalent to almost 13 percent energy requirement. Fechter et al. (2001) reported that production of the white sugar was focused more on juices rather than molasses which were taken as the raw material. Various processes such as ultra-filtration, de-mineralization and de-colorization were used for the production of white sugar. The traditional refining process wascheaper, and effective in terms of purification and juice purification was the method used for the processing of white sugar directly from the sugar cane. Crystallization was one of the process which is used for increasing the recovery of sucrose and it reduces the molasses production. Chromatography was used in the sugar industry for the separation of sucrose. Another method was ion exchange demineralization which was used in the sugar industry for the removal of minerals from the liquid sugar. Later adsorption has been incorporated to be used de-odorization and de-pigmentation. Membrane filtration is latest technique used in the process which was used for maintaining the quality of white sugar by removing unwanted particle from the juice. Velásquez et al.,(2018) reported that thermal processes are also used for the production of sugar from sugar cane. Non centrifugal cane sugar processing is used for this purpose and the product is obtained by evaporating the sugarcane which has the unique flavor and aroma. Later the product is used as the sweetener and has a traditional characteristics flavor and optimum nutrition.

Introduction

Food processing comprise of techniques employed to transform raw ingredients into final food product or to preserve the food product. Food processing industry as well as at domestic scale the food processing methods aim at providing processed food products for daily consumption by humans and animals. Food processing aims at increasing the shelf life, preserve, make nutritious or ready to eat foods, and getting the best quality final products. There are various techniques and methods which come under food processing such as drying, dehydration, fermentation, pickling, freezing, mixing, pumping, pasteurization, cooking and homogenization etc.

Rheological properties of foods are greatly influenced by various unit operations and processing methods or conditions such as heating and mechanical treatments. Processing of different food products such as dairy, fruit and vegetable products like jams and purees, chocolates, dough development etc. and basic make up of foods such as fats, proteins and others such as emulsifiers, hydrocolloids etc. affects the rheological properties of food product and which ultimately affects the quality of end product. Apart from processing conditions the compositional variations have a great impact on the textural or rheological properties of foods. The changes in rheological characteristics of a food product reflects the alterations in the molecular structure of the food material, this can aid in revealing the changes in product structure during different processing methods or conditions. In designing of various processes such as cooling, freezing and equipment design information about thermal properties is crucial. Moreover, in order to design storage structures for foods and refrigeration equipment the knowledge of thermal properties is important (Becker et al. 2003).

For rheological measurements various tests and techniques are available, such as steady and dynamic shear measurements. From the steady shear properties flow properties of the sample can be revealed whether the flow is Newtonian or Non Newtonian. In case of dynamic shear rheological properties information on viscoelastic characteristics can be withdrawn in terms of storage and loss modulus and depending on the predominance of each modulus the nature of sample can be predicted i.e. whether viscoelastic solid or viscoelastic fluid (Bhardwaj et al. 2019). Apart from these measurements, other rheological measurements are available for specific food materials, such as farinograph, alveo-consistograph, mixograph etc. are meant for study of rheological properties of dough. So, accordingly, depending upon the food material choice of rheological measurement can be made. To study the thermal transitions DSC (Differential scanning calorimeter) and DTA (Differential thermal analysis) are commonly employed. Dynamic measurements as a function of temperature or time are made in these techniques to detect the endothermal and exothermal changes. These techniques can be used to determine the phase transitions in various foods, for instance, crystallization and melting of water, lipids and other food components; denaturation of protein; gelatinization of starch and others (Roos 2015).

India is the largest producer of pulses and contributes around 25% of total global pulse production. In addition, it is also world’s biggest consumer (27% of world consumption) and importer (14%) of pulses in the world. Pulses account for around 20 per cent of the area under food grains and contribute around 7-10 per cent of the total food grains production in India. Though, pulses are grown in both Kharif and Rabi seasons, Rabi pulses contribute more than 60 per cent of the total production. Gram is the most dominant pulse having a share of around 40 per cent in the total production followed by tur/arhar at 15 to 20 per cent and urad and moong at around 8-10 per cent each. Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh and Karnataka are the top five pulses producing states in India. Considering the nutritional importance of pulses and its products in Indian diet, the production and availability are not sufficient. Since independence, grain production has grown dramatically but pulses production and its availability have declined. On the other hand, the per capita availability of cereal and millets has increased in spite of a four-fold increase in population. The consumption ratio of cereal-to-pulse has risen from 6:1 to 12:1.

Pulse processing is the major need of developing nations as it is the most acceptable and cheap source of protein and hence can help combating Protein Energy Malnutrition (PEM). In addition, the identification and recognition of various newer and improved processing methods can provide the basis for further development of legume processing industry. Traditionally, home cooking is applied for consumption of pulses since ages. Modernization has no doubt created a lot of ease and developed various techniques to make different edible forms of legumes/pulses. Many advancements have been happened in traditional processing methods (milling, fermentation, roasting, boiling, steaming etc). and resulted into new products. Improved techniques for efficient milling of legumes into dhal (dehusked splits) are an important area of investigation. A systematic method that eliminates wastes and losses has great significance in the Indian dietary pattern. New systems for processing legumes come under several main categories, namely, improved decortications and milling techniques; quick-cooking pulses; canned pulses; pulse flakes, expanded snack foods etc. Such new and innovative processing technologies presented in this chapter can be applied and used in developing nations. Present chapter will discuss both traditional and non-traditional means of pulse processing.

Introduction

Cereals and cereal products comprise a long history of consumption by humans. Cereals are the important source of nutrients and non nutritive health beneficial components and for that reason cereal based food products are consumed as staple food in human diet in developed as well as developing countries. The cereal grains mainly cultivated and consumed as food include rice, maize, wheat, sorghum rye, barley, oats, and millet. Products obtained from cereal grains are flours, grits, semolina, breakfast cereals, extruded product like pasta, puffs and flakes, and bakery products such as bread, biscuits, cakes and tortillas. Moreover, cereals or their components are used as ingredients in the preparation of various food products such as beverages infant foods coatings and processed meats. Initially cereals are consumed as whole or with minimal processing like boiling, grinding and roasting. However, processing like salting, drying, steeping and fermentation of cereals for preparation of cereals based beverages and foods has been practiced since the initiation of cereals consumption as food by human. Increasing consumer awareness and commercialization of cereal products have created interest of food manufacturers in utilization of novel and more efficient technologies with optimized conditions, development of convenient and more health beneficial foods with satisfactory sensory properties and wide variety of foods to ease the choice of consumers. Market full of diverse range of snack foods, breakfast cereals, ready to eat and ready to cook foods, and novel functional foods with variation in appearance, texture and flavor is an indication of evolution of food industry from basic to complicated form focused on efficient and automated operations. In ancient times, fermentation of food was done with the aim of enhancement of shelf life and palatability without clearly knowing the role of microorganisms. Modern fermentation technology uses various operations and specific strains of microorganisms for conversion of bulky and perishable materials into novel foods with more pleasing flavour, enhanced functional properties and extended shelf life. In addition to basic bread, new varieties of bread developed with improved functionality like sourdough bread, gluten free breads and high fibre breads is an example of innovation in cereal fermented foods indicating modification in ingredients, microbial culture and processing technologies as compare to traditional fermentation process. The word “extrudate” is derived from the Latin word “ex” meaning ‘out’ and “trudere” meaning ‘to thrust’. Extrusion technology is turning out to be very popular in food industry due to its versatility, usefulness and cost efficiency. It is well-organized state-of-art technology and plays important role in various food industrial processes such as cooking, mixing, conveying, shearing and shaping of end products. Extrusion cooking is high temperature short time (HTST) with high pressure process, is especially used for preparation of cereal based snacks, fat replacers, breakfast cereals, infant formula, gluten free foods, starch and protein rich cereals food products. A wider range of ready to eat food products with different texture, size and shape is produced by fast and easy extrusion cooking. In epidemiological studies it is stated that whole grain consumption is more health beneficial than refined grains and the reason behind it is that dietary fibre and phytochemicals located in germ and seed coat are generally removed during milling or polishing. Various technologies are developed by food scientists and technologists to preserves the bioactive compounds during processing and or to supplement processed food products with the bioactive compounds during food preparation to maintain the bioactivity and functionality of final products. Utilisation of whole grain flours, composite flours, supplementation of cereal foods with ingredients from fruits, vegetables, plant extracts and legumes, bio-fortification of crops, implementation of genetic engineering to produce crops rich in bioactive compounds are some technologies which are being used in modern food industry to develop value added cereal food products.

Introduction

The farm to fork approach utilizes agricultural products as raw material for processing by industries to obtained value-added products (Mijinyawa et al., 2007). Processing that transforms animal, vegetable, or marine materials into value-added food products for consumers and forms an integral part of agriculture for storage or size reduction into fine particles. One of the major problems associated with processing is the unavailability of processing facilities including appropriate engineering materials for the transformation of agro-based produce into different forms (Ogwuagwu, 2007). This transformation process mainly includes operations like particle size reduction, milling or comminution, etc. utilizing different size reduction forces without making alterations in chemical properties (Enrique, 2012). This enhances the eating quality or appropriateness of foods for advance processing with a more varied range of available products.

Grains are dried small seeds with adhered or removed husks or outer layers processed for consumption (FAO, 2011). The two major types of commercial grain crops include cereals (such as millet, corn, sorghum, wheat, rye and so on) and legumes (such as beans, groundnuts and soya beans). These grain crops are subjected to a milling operation to break them into smaller pieces or more practically appropriate form. The grinding process involves the application of different mechanical forces to overcome the interior bonding forces bringing change in the state of solid grains to different desirable forms such as flour or meal (Kaul and Egbo, 1985). As a result, the physical state of these grains is modified due to a reduction in size and change of shape (Ryan and Spencer, 2008). Most of the actual milling processing that is used in various industries is based on simple operations. But now various technological progress has been initiated that involves the adoption of computer control for various milling operations to improve efficiency and quality while minimizing labor requirements. Hence, the present text highlights the various technological advancements and evaluation techniques employed in milling operations.

Introduction

Fermentation is an alluring procedure of biochemical adjustment of essential nourishment microorganisms and their enzymes accomplish by lattice. Fermentation is a utilized to upgrade bio-accessibility and bioavailability of supplements from various crops and improves organoleptic properties (e.g., appearance, generation of sour taste and new aroma compounds, and textural changes such as consistency or viscosity) just as increase the shelf life of realistic usability. It makes foodstuff safe not just hindering the growth of pathogenic microorganisms because of antimicrobial growth of lactic acid and it also detoxifies aflatoxin. With these advantages, fermentation is a successful method to reduce the risk of mineral deficiency among population, particularly in developing nations where unrefined cereal or pulses are profoundly consumed. Tragically, it is additionally connected with multiplication of microorganisms, for ex., yeast and molds caused food safety concerns, (Omemu et al; 2011), decrease in provitamin A and antioxidant (Ortiz et al; 2017), carotenoids, just as loss of nutrients and minerals (Hotz & Gibson, 2007).

Fermentation is a minimum cost-efficient procedure for production and preservation of nutrient, therefore fermented food is an important piece of the eating regimen in numerous of the world. In the nineteenth century the scientific study of microbiology began, and just because, the scientific procedure of fermentation was comprehended. several classifications have been utilized to sort the assorted exhibit of the fermented nourishment produced dependent on various microorganisms, and food types, and kinds of fermentation included.

The microorganisms associated with fermentation process fall into three classes: bacteria, yeast, and molds. Yeasts are the principal microorganisms for the fermentation of breads, whereas molds is mainly used in processing of cheese and legumes. Bacteria is included only of the fermentation of cereal product. cereal and tuber fermentation are a lactic and acetic acid producing bacteria. yeast is a piece of mix microbial fermentation by bacteria in weaning food; all the more frequently, be that as it may, alcoholic fermentation of yeast may not totally alluring. Four genera of lactic acid producing bacteria are recognized as overwhelming cereal fermentation to be specific, Lactobacillus, Leuconostoc, Pediococcus, and Lactococcus spp. all of which require carbohydrate for the energy. Lactic acid and other natural acids produced from hexoses bring down the pH from about 6.5 to about 3.6. In the event that the pH is beneath 4.0, fermented product retard the growth of pathogens and along these lines ensure fermented items.