eChapters

Introduction The increase in population has led to the demand for good quality food. Consumer food demand is a key factor in the development of many agricultural and food policy and high-quality food products with longer shelf lives is increasing all the time. Over recent years, Packaging has revolutionised the marketing and delivery of food goods, especially fishery products. The introduction of modern packaging technology and innovative packaging material processes paved the way for convenience products. In 2018, the value of fish and fish products exported was USD 164 billion because of improved chilling, packaging, and transportation technology has resulted in increased commerce in live, fresh, and chilled fish, which accounted for around 10% of global fish trade and 78% of the total amount shipped was for human consumption (Sofia 2020). When both fish and terrestrial meat exports for human consumption are considered, fish exports have been larger in value terms since 2016. (51% versus 49%). Furthermore, increased utilisation of fisheries and aquaculture products minimises loss and waste, which can assist reduce strain on fisheries resources and support sector sustainability.

Climate Change - An overview The most studied topic in recent years was climate change, due to its increasing importance. Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle or due to anthropogenic activities, since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas. The process of raising the earth’s temperature is known as global warming. Climate change is one result of global warming in different places on the planet. Many people think that climate change means only global warming or an increase in temperatures. But the rise in the temperature is only the beginning of the story. Because in the Earth system everything is connected to one another, changes in one area or in one aspect of the system can influence changes in other areas. The consequences of climate change include flooding, intense droughts, water scarcity, wildfires, rising sea levels, melting polar ice, catastrophic storms and declining biodiversity. Adapting to climate change consequences protects people, businesses, livelihoods, infrastructure and natural ecosystems. It covers current impacts and those likely in the future.

Introduction Technology is the application of knowledge and/or equipment in undertaking and accomplishing certain activity. Fisheries technology is a systematically organized knowledge and materials applicable to production problems to help to boost the present level of fish productivity and or extend the existing range of production. Fisheries technologies are wide range of importance; Technological innovation in aquaculture is leading an evolution in aquaculture practices, thereby reducing losses and increasing efficiency. Technology in aquaculture affects many areas of fishery, such as seed production, feed production and management, pest and diseases management, production, harvesting, marketing, processing, etc. Induced breeding technology in Indian Major Carps transformed the growth of aquaculture sector from traditional to intensive aquaculture practices and led to success of modern aquaculture industry. Mechanization in fishing increased the harvest with less time and minimal human drudgery. Fish processing technologies improved product shelf-life, reduced fish loss and added value to the products.

Introduction Hokersar wetland (34°06’ N latitude, 74°05’ E longitude), a Ramsar site and a protected wildlife reserve is located in the northwest Himalayan bio geographic province of Kashmir, back of the snow-draped Pir Panchal. The wetland shelters about two million migratory water-fowl during winter that migrate from Siberia and the Central Asian region. The wetland is fed by two inlet streams Doodhganga (from east) and Sukhnag Nalla (from west). It is the only site in Kashmir with remaining reed beds and serves as a migration route for specifically 68 waterfowl species from Siberia, China, Central Asia,and Northern Europe, including the Large Egret, Great Crested Grebe, Little Cormorant, Common Shelduck, Tufted Duck, and endangered White-eyed Pochard (Ramsar, 2021).

Introduction Fishermen of Gulf of Mannar coast were largely depending on traditional fishing gears, and they were mainly exploiting the coastal fishery resources before 1960’s. After the introduction of trawl gears and mechanized fishing boats during 1960’s fishermen were more comfortable with plenty of fish catch, especially the high-valued demersal shrimps. The fishing effort was also increased at a tremendous pace in this region with the addition of stern trawlers. Due to this increment in the fishing effort, the fishery resources and their life-supporting systems such as coral reefs and sea grass beds are seriouslydisturbed.

Introduction NGOs (Non-Governmental Organizations) are organisations with professional staff that work to lessen human suffering and advance developing nations. The number of Non-Governmental Organizations (NGOs) in India is close to 3.4 million, and they work in a range of sectors, from disaster relief to advocacy for underserved and neglected groups. It is a nonprofit organisation that operates without interference from any governmental body. It is taskoriented and organised by people with common interests in a local, national, or international setting. It performs a variety of services and charitable tasks. Particularly, some are structured around particular concerns, such as health, the environment, or human rights. These make up a sizeable portion of civil society and bring about quick social change. They have developed into a vital and vocal platform for civil society participation in public affairs (Desai, 2014.).

Introduction Organ-On-a-Chip (OOC) is a developing trans-disciplinary technique that shares similarities with tissue engineering and lab-on-a-chip technologies. It has benefited from recent advancements in microtechnology (particularly microfluidics), cell biology, physiology, and tissue engineering and is motivated by the need for reliable, low-cost in vitro drug screening models. It can be characterized as a microfluidic-based perfusion device that facilitates an invitro cell (co-)culture and tries to reproduce certain structure(s), function(s), and important elements of human or animal metabolism of a particular tissue or organ in healthy and pathological physiology. Important features of live organs are such as extracellular microenvironments, spatiotemporal cell-cell interactions, and physiologically important tissue microarchitecture.

Introduction Shrimp farming is a lucrative sector in the food production industry. According to SOFIA (2020), 9.4 million tonnes of crustaceans were produced in 2020 worldwide, with 4.96 million tonnes coming from Penaeus vannamei. India is one of the largest global producer and exporter of farmed shrimp. In India, shrimp production increased significantly after introducing Pacific white leg shrimp, Penaeus vannamei, in 2009. Among the cultured shrimp species, Penaeus vannamei is the leading species under culture in India, with an estimated production of 7.12 lakh tonnes (MPEDA, 2020). Intensification of culture and diversification of species provoke the incidence of diseases making diseases the major constraint in aquaculture, leading to tremendous losses. Shrimp diseases are of viral, bacterial, fungal and parasitic origin.

Introduction A genome marker or a genetic marker is words commonly used to refer to a marker, which is identical to the term “marker.” Genes, genetic variants, or random sequences can all be represented by markers. Markers act as milestones or signposts while creating DNA and genomic maps. Markers are DNA sequences that are frequently identified by their position in a genome. The transmission of traits or the risk of sickness within families can be tracked using markers. It is essential to the continued existence of the species and boosts an organism’s ability to adjust environmental conditions. In conjunction with other evolutionary forces like genetic drift and selection, genetic diversity inside an individual evolves, leading to divergence at the population/ communities, species, as well as higher order taxonomic levels (Askari et al., 2013). Numerous fields, including evolutionary research, resources management and conservation, and genomic improvement programmes, can benefit from the conclusion derived from genetic variety data (Liu and Cordes, 2004).

Introduction Fish oil is the major source of essential Fatty acids (EFA) for humans. Generally, Fish requires three long-chain highly unsaturated Fatty acids (HUFA) for their normal growth and development including reproduction like docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6) (Sargent et al. 1993a, 1995, 1997). Like the terrestrial mammals, DHA, EPA, and ARA are all involved in maintaining the cell membrane structure and function of fish but majorly EPA and DHA are considered. Moreover, the EPA and DHA are the major currency as fatty acid for the synthesis of phospholipids, Prostaglandins, and energy etc. However, the biosynthesis of EFA in fish changes in accordance with the relative bioconversion capacity of the PUFA (Linoleic acid and α-Linolenic acid) as shown in figure 01.

Introduction The ecological stability and food web of intertidal environments are significantly influenced by macroalgae. The majority of marine organisms, including macroalgae, coral reefs, sponges, and the organisms that they are associated with, are well known for producing secondary metabolites and bioactive compounds, which increase their value in a variety of industries, including food, neutraceuticals, pharmaceuticals, and others. Among them, seaweeds play a vital role in promoting health by offering a variety of phytochemicals with antioxidant, antibacterial, anticancer, and antiviral action (Ngo et al. 2012). Worldwide, there have been more than 20,000 macroalgal species identified. In South Asian nations including China, Japan, and Korea, it has been used as sea vegetables. India now has 841 macroalgal species identified,including 434, 191, and 216 species of red algae, brown algae, and green algae, respectively (Oza and Zaidi, 2001).

Introduction Feed is a major source of nutrition in semi-intensive and intensive culture systems. Fish fed with formulated feed is used for their growth, maintenance, and reproduction. Feed Energy utilized for maintenance is mainly for health and survivability. In intensive aquaculture, animals almost exclusively depend on an external supply of high protein feed (generally >20%), usually based on fishmeal (Beveridge and Little, 2002) because of its high protein content, better bioavailability of amino acids, palatability, and unknown growth factors. Hence fish fed with a fish meal-based diet exhibits better growth performance, feed conversion, and fish health than fish fed with other animal and plant-based protein sources (Hardy and Tacon, 2002; Pike and Barlow, 2002; Tacon, 2003; Cook et al., 1996). Still, Global fish meal production is annually decreasing since 1994 due to increased human utilization and increased use of fish residues and by-products, increasingly replacing whole fish for fish meal (FAO, 2020). Hence many scientists were passionate about replacing the fish meal with an alternative feed ingredient without compromising growth.

Introduction “Xenobiotics” are “foreign compounds,” which are alien to the organism and removed from their natural environment. Xenobiotics are substances that are either alien to an organism or do not form a natural part of its diet. Compounds including pharmaceuticals, food additives, & environmental toxins are examples of xenobiotics. Normally, these substances are removed from the body by being broken down into compounds and then being expelled through the kidney, bile and lungs. For the pharmaceutical business, enzymes that metabolize xenobiotics are crucial because they are in charge of breaking down medicines. Similarly, xenobiotic transporters influence how long medications remain in the body.

Nanomaterials are a rapidly growing technological sector with diverse applications. These nanomaterials are categorized into distinct groups according to their shape, size, and materials used in their fabrication. The synthesis of nanomaterials follows different strategies that are tailored to their specific applications. This chapter describes the different approaches used for the synthesis of nanomaterials, including top-down, bottom-up, and hybrid approaches. Furthermore, this chapter discusses the advantages and disadvantages of each fabrication method and explores the diverse applications of nanomaterials across multiple fields.

Surface-Enhanced Raman Spectroscopy (SERS) may detect and identify chemical and biological species ultrasensitively. Through localized surface plasmon resonance (LSPR) effects, metal nanostructures boost analyte Raman signals. This chapter covers current advances and essential principles in metal nanostructures for SERS chemical detection. It discusses SERS fundamentals and enhancing processes, such as metal nanostructure size, shape, and composition. Top-down and bottom-up processes including lithography, chemical synthesis, and self-assembly are used to create repeatable and controllable metal nanostructures. The complex interactions between light, metal nanostructures, and analyte molecules are best understood by combining theoretical modeling and experimental observations. 

Nanomaterials have emerged as promising candidates for revolutionizing sensing and detection technologies, offering unprecedented capabilities in sensitivity, selectivity, and miniaturization. The current chapter provides a concise overview of recent advancements in the utilization of nanomaterials for sensing and detection applications. It encompasses a diverse range of nanomaterials, including nanoparticles, nanotubes, and nanowires, each exhibiting unique properties that enable enhanced performance in sensing applications. The integration of nanomaterials into sensing platforms has demonstrated remarkable progress in various fields, such as environmental monitoring, healthcare diagnostics & security applications.

This section explores how nanoparticles have a significant influence on sensing and detection, explaining how they have revolutionized analytical capabilities. Our trip through many kinds of nanomaterials, such as metal nanoparticles, semiconductor nanomaterials, and carbon-based structures, aims to explore their distinct features and how they might be used for novel sensing methods. The intricacies behind sophisticated sensor technologies are clarified through an examination of plasmonic sensing, quantum dot applications, and conductive nanomaterial responses. In order to improve selectivity, the chapter emphasises surface modifications and biomimetic coatings as key components of strategic functionalization techniques.

Nanomaterials, a cornerstone of nanotechnology, encompass a broad array of particles showcasing remarkable properties and diverse applications. This chapter outlines the classifications and applications of various nanomaterials, including organic, semiconductor, metal, metal oxide, and carbon-based nanoparticles. Each type offers unique characteristics, such as biodegradability, optical and electrical properties, making them valuable in fields like drug delivery, electronics, and catalysis. Furthermore, this study focuses on the interactions of nanoparticles with living organisms, emphasizing their impact on immune systems across plants, invertebrates, and humans. 

Synthesis of nanoparticulate metal composites (NMCP) presents a multitude of advantages compared to conventional dosage forms. Acne, a multifactorial skin condition, predominantly involves the pilosebaceous unit and is primarily caused by bacterial species such as Propionibacterium acnes and Acne vulgaris. A staggering 95% of the global population is afflicted by acne. Leveragitng NMCP strategies holds immense promise for innovating novel, efficacious, and low-dose treatments for managing acne. This review delves into various nanotechnological methodologies tailored for effectively addressing acne. Methods: This review encompasses recent advancements pertaining to NMCP carriers aimed at treating acne.

Nanomedicine, an interdisciplinary field at the intersection of nanotechnology and medicine, has emerged as a promising avenue for addressing complex health challenges. One area of significant interest is the application of nanotechnology in maintaining and improving gut health. This chapter provides a concise overview of the current state of research in nanomedicine's role in promoting gastrointestinal well-being.

Nanoparticles, with their unique physicochemical properties, offer novel approaches for targeted drug delivery, imaging, and diagnostics in the gastrointestinal tract. Engineered nanoparticles can navigate the harsh conditions of the digestive system, delivering therapeutic agents precisely to the intended sites within the gut.

Despite substantial advances in the diagnostics and treatment of diseases, parasitic infections are a major global health issue causing significant mortality and morbidity. Currently, chemotherapeutic antiprotozoal drugs, anthelmintic and anti-ectoparasitic agents are used to treat, but resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nano medicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types ofparasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. 

The main objective of nanomedicine broadly defined as the comprehensive monitoring, repairing and improvement of all human biological systems, working from the molecular level using engineered devices and nanostructures to achieve medical benefit. Nanomedicine is the nanomachine of diagnosing, treating, and preventing disease and traumatic injury, relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body. Nanotechnology applications in medical science can be essential in achieving this goal. These applications involves extensive surveillance, control, creation, repair, and defence of all biological human systems, employing designed nanodevices and nanostructures which works in molecular level.

Nanotechnology has been successfully applied in various fields such as agriculture, biochemistry and medicine. However, its application in food systems has been new and is yet to be scrutinised. It offers a range of physical and chemical benefits that can be employed in production, development, fabrication, packaging, storage and food distribution systems. These novel nanomaterials such as nanocapsules, nanocomposites, nanoemulsions, nanoencapsulation, nano packaging, nanotubes and nanosensors have been used to improve food quality with better shelf life. However, there is concern about the safety of these nanomaterials, especially because of partial knowledge about the effects of these materials on human health.

Nanotechnology has emerged as a revolutionary force in the food industry, providing innovative solutions to improve food quality, safety, and usefulness. Researchers have devised novel ways to numerous issues in food production and preservation by harnessing nanoparticles' unique traits, such as their high surface area-to-volume ratio and customizable physicochemical characteristics. Nanotechnology-enabled food additives provide a wide range of benefits, including improved texture, taste, color, and nutritional value, as well as increased shelf life and microbiological safety. Furthermore, nanoparticles are effective transporters for bioactive chemicals, allowing for targeted and regulated release within the food matrix.

The increase in population and global industrialization has led to environmental pollution, which is a significant threat to the health of the ecological system. Different measures are recommended to remediate polluted areas effectively. The applications of nanotechnology in medicine, cosmetics, sports, textiles, and pharmaceuticals have increased over the years. Another approach to remediate the adverse effects of pollutants on the environment is by utilizing nanotechnology for contaminant remediation. Biogenic nanoparticles are tiny particles produced by biological entities such as fungi, bacteria, yeast, and algae. These biogenic nanoparticles are efficient in removing pollutants like heavy metals, pharmaceutical waste, dyes, and hydrocarbon waste. 

The hazardous toxic metals like cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr), which have detrimental health effects, are naturally discharged into the atmosphere in various ways viz., industrial wastes, anthropogenic sources, etc. Heavy metal pollution of the atmosphere has become a frightening ecological concern that has created serious threats to the ecosystem. These metals have been identified as group I, human carcinogens due to their persistence in the surroundings and bio-magnification in biological systems. Thus, the removal of heavy metals from the atmosphere becomes a serious matter from the biological and environmental point of view. In the past following techniques adoptedfor toxic heavy metals remediation were classified are bioadsorption, ion exchange, membrane filtration, flotation, and solvent extraction techniques.

One ofthe biggest issues the world is facing today is the lack of clean and pure water. Due to rising water demands, rigid health regulations, and xenobiotic pollutants, traditional wastewater treatment technologies cannot provide safe water. The present era necessitates innovative approaches to wastewater treatment technologies and improved water resource conservation and management materials. By utilizing innovative nanomaterial, nanotechnology guarantees a continuous provision of potable water and contributes to the preservation of water sources. Nanomaterials expedite rapid processes for the purification, conservation, and reuse of wastewater, complementing other enduring industrial methods. 

Nanotechnology holds immense promise in bolstering environmental protection and sustainability by revolutionizing approaches to monitoring, addressing, and amending environmental pollutants. This paradigm shift extends to resource conservation and energy efficiency through the innovation of more adept technologies. Yet, as we harness the potential of nanotechnology, it is of prime importance to meticulously evaluate its environmental and health implications, instating stringent measures to mitigate risks. Responsible and sustainable development, coupled with effective regulation, is imperative.

Agriculture serve as a backbone in improving economic growth of a country as well as it provides a base in meeting various needs of people in direct and indirect ways. The recent advancement in nanotechnology has shown a path to develop traditional agriculture into a sustainable practice. Several nanochemicals emerged as promising agents for better plant growth, used as fertilizer, pesticides, control weeds and also used as antimicrobial agents in food packaging. Nanotechnology may act as sensor for checking soil health of agriculture fields.

Over the years synthetic pesticides like herbicides, insecticides nematicides etc. have been used to improve crop yield. Indiscriminate application of pesticides ultimately leads to their excess discharge into water bodies during rainfall and causes death of fish and other aquatic life. Also consumption of seafood/fishes may cause biomagnification of chemicals in human body and leads to several lethal diseases like cancer, diabetes, neurodegenerative disorders like Parkinson, Alzheimer, and amyotrophic lateral sclerosis (ALS), birth defects and reproductive disorders. Likewise synthetic pesticides also damage soil texture, soil microbes and soil fertility. Their residues enter into plants and animal systems and further move into animals or humans body through food chain.

Nanotechnology epitomizes one of the most dynamic and transformative fields in modern science and technology. This multidisciplinary domain bridges chemistry, physics, biology, along with engineering, enabling the creation of materials and devices with extraordinary properties and applications. The book chapter reflects the research and patenting trends in nanotechnology. USA leading the global share for most patents granted followed by South Korea, Japan, China and Germany for the top five spots contributing more than 76% of all the granted patents by EPO & USPTO related to nanotechnology. Nanotechnological products in relation to sub-industrial areas of medicine, food, agriculture, cosmetics, environment, and renewable energies are also highlighted in chapter. 

Soil is a natural resource that exists on the planet much before the existence of mankind on it. The human relationship with soil throughout the history of mankind has marked its ability of crop production and influenced the success of civilisation. Such relationships also affirm soil as the foundation of agriculture and food security, supplying all the essential ingredients to plants, as fundamentals to life on planet, and support various biogeochemical cycles on earth’ s terrestrial ecosystem. Prosperity of human society depends on the utilisation of planet’ s resources in creative and productive ways. Of these resources, soil has gained much importance as it provides human to sustain themselves with their capacity to food production, to make significant contribution towards biodiversity and other ecosystem services that are vital for the functioning and resilience of earth’ s environment. Soil occupies a pivotal position in the environment to maintain its quality.

Soil is a dynamic natural body of the uppermost layer of earth’s crust produced by the transformation of mineral and organic substances on the earth’ s surface under the influence of environmental factors over a long period. It is the most basic of all natural resources upon which all living forms on the terrestrial ecosystem directly and indirectly depends. However, soil resources are finite, nonrenewable, fragile and heterogeneous in space and time. As a component of pedosphere, it occurs as interface between the lithosphere and atmosphere and strongly interacts with biosphere and hydrosphere (Figure 1 & 2).

The organic constituents of soils or soil organic matter is the most essential components of soil consisting of plant and animal residues at various stages of decomposition, cells and tissues of living or nonliving organisms and the substances synthesized by their decomposition. Soil organic matter exerts profound effect on soil productivity as it acts as source and sink of plant nutrients especially nitrogen and sulphur. It also involves in major biochemical processes to transform or release of plant nutrients into their available forms. Thus, it plays vital role in soil fertility maintenance, through increasing cation exchange capacity and improving soil physical properties, such as bulk density, aggregation, water retention capacity and also supports all kinds of biological activities in soil. The soil organic matter mostly concerns only with dead organic fractions formed from the decomposition of original plant and animal residues using as a source of food and energy by the soil microorganisms. It can be distinguished into –

Soil Colloids A colloid, also known as colloidal solution or colloidal system, is a mixture in which finely divided particles (less than 1µm in size) known as dispersed phase are suspended in a medium, called dispersion medium. The particles must be dispersed in a medium and both the dispersed phase and dispersion medium may be solid, liquid or gaseous which leads to numbers of possible colloidal systems. In soil, the clay fraction (< 2µm in size) together with finer fractions of some organic matter forms the composition in a state of colloidal nature, known as soil colloids. The soil solids as dispersed phase predominates in the dispersion medium (soil solution). As such, colloids in a soil are referred to as ‘sol’. Clay colloids display the most reactive fractions of soil governing their distinct properties such as adsorption and exchange of ions, zeta potential, flocculation and other electrokinetic phenomenon.

The major components of soil consisting with mineral and organic matter, water and air produces a three phase systems of solid, liquid and gas. Many of the soil properties influencing crop growth and other uses depend mostly on the relative proportions of these components as well as the size, shape and arrangements of the solid matters. The physical properties of soil have strong significance in sustaining agricultural productivity. Fertiliser alone or in conjunction with suitable crop varieties and plant protection measures cannot be sufficient towards improving crop productivity unless the soil physical properties are maintained at satisfactory level. Improvement and restoration of physical properties in soil are necessary for protection of soil resources against degradation. The physical properties of soil discussed in this chapter includes soil densities, texture, structure, porosity and consistency of soils and colour of the soil.

Water is absolute necessary constituents for the survival and growth of all the living substances on earth. It is the most essential ingredients for many of the physiological and metabolic process in plants, like photosynthesis to form sugars, translocation of cell constituents and maintenance of cell turgidity. Soil, being an adsorbent of water received from precipitation or rainfall acts as reservoir to meet requirement by plant during growing season. Water retained in the soil serves as solvent to dissolve salts and nutrients and as a carrier to translocate them for absorption by plants. It plays significant role in weathering reaction, soil forming processes and profile development. Water is also important for growth and activities of microorganisms influencing decomposition of organic matter, transformation of mineral nutrients and other physical, chemical and biological properties in soil. This chapter deals with the retention and movement of water in soils to obtain better understanding of soil-water-plant-atmosphere relationships.

Temperature is the measure of the thermal state of a body with respect to its ability to transfer heat. Soil derives its heat almost entirely directly from the sun and losses much of it back into the atmosphere. The major processes for heat transfer in soil are: Radiation, Convection, Conduction and Latent heat exchanges between soil and atmosphere. The most important source of which is the incident radiation supplying almost all the heat energy for the biosphere and also determines the thermal regime of soil. Soil temperature or thermal regimes of soil is an extremely important property of soil as it regulates plant growth directly and influences moisture and aeration status in soil, soil structures, microbial activities and decomposition of plant residues and the availability of plant nutrients . It is controlled mainly by its thermal properties and radiation exchange over the surface and their variations within the soil. The quantity of incident solar radiation and heating the soil depends on the several factors such as exposure and latitude, albedo, soil colour, slope vegetation and composition of soil.

The solid phase of a soil system makes up a mixture of inorganic and organic materials. The inorganic fraction of soil originated from the weathering of rocks and minerals consists of rock fragments and minerals of varying sizes and composition. Hence, this inorganic soil fraction composed by soil minerals also referred as mineral fraction of soil and is caused due to alteration of mineralogical composition of soil by bioclimatic factors. A great deal of attention is being paid to the composition of minerals in soils, their formation and distribution over the earth’s surface. Soil genesis or pedogenosis (a more useful term as soil belongs to pedosphere) deals with the processes of formation and development of soil. The branch of soil science that integrates the studies of genesis, morphology and classification of soils as natural body is called Pedology. The process of weathering of rocks, pedogenesis and development of soil profile are described successively in this chapter.

Classification means the process of ordering or grouping of objects having large number of population and wide variations into shorter one in a systematic manner with selected characteristics. Soils being the natural objects have no exception with other objects to classify them in a best possible way. Thus, soil classification refers to the systematic categorization of soils into various groups, classes or any simpler form based on the similar properties and other distinguishing characteristics. The main purposes of soil classification are to organize knowledge, easy remembering of the soil properties for each group and better understanding about the components and the relationships among individuals and various groups of soils. Various soil classification systems have been evolved during the past for categorizing the soils into various groups but the Soil Taxonomy has been now accepted as most scientific system of classification.

Soil survey is essentially a systematic examination of morphological, a set of other variable soil characteristics, description, classification and mapping of soil in an area alongwith a report making an interpretation to predict their potentials for various uses particularly for crop production.

Activities of Soil Survey Soil survey is composed of the following activities –

1. Anticipation of soil variability - The initial activity of soil survey is obtained by classifying the surveyed data according to different land forms and existing land uses either through field traversing, or aerial photo or by satellite images of the concerned area.

2. Characterisation and classification – This is done on the basis of soil profile description supported with soil analytical data.

3. Soil mapping - This is performed by showing the distribution of types of soil or soil mapping units based on already classified soils with their landforms, and land uses or their combinations.

4. Interpretation - It is the process of making prediction about the potentials of soils for various uses like choice of farm practices – agriculture, horticulture, forestry, pastures etc. and their management practices.

Soil acidity is most conveniently measured by pH of soil suspension with water. Pure water undergoes dissociation into hydrogen and hydroxyl ions and are in equilibrium with undissiociated water molecules Thus, H2 O ??? ??? H+ + OH- (1) and in presence of another H2 O molecule, H+ converts to H3 O+ H+ + H2 O ??? ??? H3 O+ (2) Since water is a weak electrolyte and dissociates as per Eqn. 1, the ionic product of water can be written as – KW = aH+ x aOH- = (CH+ x COH– ) x ( fH+ x fOH-) (3) where, a, C, and f represents the activities, concentrations and activity coefficients of respective ions. In pure water and in dilute solutions the activity coefficients are approximately unity thus the product of concentrations of H+ and OH-1 is the ionic product of water and at ordinary temperature (250 C) this has a constant value of 10-14 gm ions per litre so, Kw =(CH+ x COH–1) = 10-14 gm ion per litre (4) such that, CH+ = COH–1 = 107 gm ion per litre Therefore, if hydrogen ion concentration of an aqueous solution exceeds this value, (10-7gm ion per litre), the solution is said to be acidic then there will be a proportionate decrease of OH- concentration to maintain the constant value of ionic product.

Salt affected soils can be defined as the soils containing excess amount soluble salts in their profiles in a proportion that adversely affect to soil properties and ultimately on crop growth. The soluble salts present in these soils are composed primarily with calcium, magnesium and sodium as cationic and chlorides sulfates and carbonates as anionic constituents along with the presence of potassium, nitrate and others as minor quantities. All soils invariably contain some soluble salts, but they cause harmful effects on crop growth only when accumulates in excess amount in soil solution or increase their concentration in exchange complex of the soil. Based on the presence of sodium salts and the predominance of sodium in the exchange complex, salt affected soils are classified into main categories of 1) Saline soils – contain excess soluble sodium in soil solution with little or no sodium content in exchange complex, 2) Alkaline (Sodic) soils – contain appreciable quantity of sodium adsorbed in exchange complex of soil but may or may not contain soluble sodium salts in soil solution. These soils are also divided into following types –

The living organisms in the terrestrial ecosystem have unique characteristics of taking up the substances from atmosphere and soil for the synthesis of their own cellular component or as a source of energy. The supply and absorption of chemical compounds required for the growth and metabolism of the organisms may be defined as nutrition and the compounds required by them are called nutrients. The process by which the nutrients are converted to cellular material is known as the metabolism. Out of 118 chemical elements so far detected in the modern periodic table, 92 elements from hydrogen to uranium are naturally occurring, a large portion (more than sixty) of such have been detected in the plant tissues. But, the elements which take part in the nutritional requirement and metabolic processes of the plant are said to be essential elements, others which do not participate in such processes are considered non-essential.

Nitrogen Content in Indian Soil Because of tropical and subtropical climates Indian soils have very low nitrogen content and in the majority of cultivated soil it varies from 0.02% to 0.13%. Low levels of N in Indian soil is primarily attributed to climate and secondarily to cropping. Climate plays the dominant role in determining the nitrogen content in soil through the effect of soil organic matter content. Generally heavy textured soils have higher N content than loamy or sandy soils. Other factors remaining the same, total N content in soil decreases with the increase in annual temperature at a given humidity level, on the other hand, it increases with increasing humidity level at a given annual temperature. Maximum N content in soil occurs in the surface layer of soils and decreases with depth in soil profile. The variation of distribution of N content in soil with depth is attributed by varying accumulation of organic matter in soil profile.

Micronutrients are those elements essential for green plants but required in very small quantity for their growth and development. There are altogether eight micronutrient elements in soil consisting of iron, manganese, zinc, copper, boron, molybdenum and chlorine with the recent addition of nickel. These together with large number of other elements usually present in plants with small concentrations are formed as trace elements. Another element, cobalt is known to be required for microorganisms concerned mainly with nitrogen fixation in legumes affects indirectly the growth of many higher plants, thus, may be considered to be included in the list of essential micronutrient element. Similarly, Vanadium and sodium although present as beneficiary elements for plant growth may also have the possibilities to be enlisted into this group of elements.

Among the various natural resources upon which all living organisms depend, soil is the unique because of its non-renewable in nature, heterogeneity in space and time and susceptibility to degradation inflicted by biotic as well as abiotic agents. Whereas, escalating population demands, in one way, to bring more land under the plough for providing food, fodder, fuel and fibre, simultaneously, on the other way, these finite natural resources are dwindling by leaps and bound, through overexploitations and mismanagement, the combined effect of which leads to land degradation, a serious global threat and major environmental issues in the present times.

Agroforestry is a new name for a set of old practices. The farmers have been practicing agroforestry since ancient times. The general concept of agroforestry is to integrate trees and agriculture so as to create a more diversified landscape, while providing the producers with new environmental and economic benefits. In other words, agroforestry is a method of farming that allows trees and shrubs to grow along with crops and/or livestock, therefore blending agriculture and forestry in the same production system. In fact, man’s association with forest is much older than with agriculture. First man was a food gatherer and hunter in forests. Then he realized that the seeds of the fruits he collected germinated, grew into plants and bore the fruits again and thus man started to cultivate foods. Man’s desire to live in a community created settled agriculture.

A forest is a large area dominated by trees. Many definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing and ecological function. Although a forest is usually defined by the presence of trees, under many definitions an area completely lacking trees may still be considered a forest if it grew trees in the past, will grow trees in the future, or was legally designated as a forest regardless of vegetation type.According to the Food andAgriculture Organization definition, forests covered 4 billion hectares or approximately 30% of the world’s land area in 2006. Forests are the dominant terrestrial ecosystem of earth, and are distributed around the globe. Forests account for 75% of the  gross primary production  of the earth’s  biosphere, and contain 80% of the earth’s plant biomass.

The words ‘system’, ‘sub-system’ and ‘practice’ are commonly used in agroforestry literature. In a broad sense, a system is defined as a group of associated elements forming a unified whole and working together in a well defined regular relation for a common goal. An agroforestry system refers to a type of agroforestry land-use that extends over a locality to the extent of forming a land utilization type of the locality. Sub-system and practice are lower-order terms in the hierarchy with lesser magnitudes of role, content and complexity. However, these terms are used loosely, and almost synonymously. Classification of agroforestry systems is necessary in order to understand and provide a practical framework for evaluating systems and developing action plans for their improvement. Any classification scheme should satisfy the following criteria (Nair, 2008).