eChapters

ABSTRACT
Biomethanation comprises of four interdependent stages in series, hydrolysis, acidogenesis, acetogenesis and methanogenesis. Methanogenesis, the final stage of biomethanation, is accompanied with the reduction of substrates that include organic acids such as CH₃COOH, and others such as CO₂ and CH₃OH to CH₄ by methanogenic and methanotrophic archaea, usually under anaerobic conditions. Strictly anaerobic methanogenic archaea are found in the ruminant intestine, sewage digester, groundwater and deep soil/water etc. In methanogenesis, H₂ acts as the electron donor while substrates CO₂, CH₃OH and probably CoM-S-S-CoB (for CH₃COOH) act as terminal electron acceptors and reduce to methane, a process known as anaerobic respiration. This conversion is associated with the electrogenic proton motive force along with sodium motive force to drive the ATP synthesis by A0A1 ATP synthase, known as respiratory phosphorylation. The mechanism of conversion of methane from CO₂ by methanogens with cytochromes is same as those without cytochromes except that the reduction of heterodisulphide CoM-S-S-CoB is performed by the membrane-bound VhoACG-HdrDE complex for former while by cytoplasmic MvhADG–HdrABC complex for the later.

ABSTRACT
The ‘steel-drum type’ biogas plant installation programme in Punjab was initiated in the early seventies, whose construction works were entrusted on the Department of Agriculture. Because of their high cost and high failure rates then, only the affluent farmers could afford to install. In the meantime, a cheaper Chinese model, also known as Janta type (dome-type replacing the drum-type) plant, became popular but was still out of the reach of ordinary farmers. With dual objectives of cost reduction and efficient biogas production to make it affordable to small farmers, a coordinated research was initiated. Detailed extension surveys were carried out in Ludhiana district which inferred that the farmers did not install the gas-holding steel drum though they purchased it. A significantly low cost Katcha-Pucca plant model of 15m3/d capacity was developed and installed in Sangrur district. Similar digester was tried for Janta model in which the inlet, outlet and dome (gas holder) were masonry works but the digester was a Katcha pit, the dome of the plant being modified to a semi-circular dome. More than 80 such plants are functional in a single village, and more than 40–50% of the plants installed in Punjab and Haryana are these PAU designs. The chapter deals in greater details on the design aspects and the extensive field works carried out to achieve these successes, along with some relevant facts and figures. The write-up is written as a commentary, rather than a typical chapter, for the benefit and interest to the readers.

ABSTRACT
It is impossible to envision a world without energy provisions and has become inevitable and an integral part of a nation’s prosperity. It has unparallel contributions towards the socioeconomic empowerment, industrial growth, and technological advancements, as also in mitigating greenhouse gas (GHG) emissions. Judicious utilisation of energy sources without infringing upon the sustainable energy demand is the need of the hour. Taking India’s huge bovine strength into account, biogas technology has the potential to transform the standard of living of rural millions. Effectively implementing the Govt. of India’s National Biogas and Organic Manure Programme (NBOMP) could save precocious demand on electricity, fertiliser and firewood while promoting self-sustainable organic farming. In this chapter, the cost and benefit analyses of biogas technology (involving biogas plants of different capacities) are discussed along with the long-term approach at the grassroots level to promote digested slurry for organic farming. The commercialisation and carbon crediting of biodigester technology is also narrated. It is necessary to chalk out a revenue model to commercialise slurry at the grassroots level to economically empower the beneficiaries, from family-type to industrial-scale biogas plants. Small-scale biofertiliser hubs at district level may be organised to collect dry slurry from the beneficiaries and process them further to make it market-ready through entities operating at the national level developing manure for agricultural practices, as also feeding materials for animal husbandry practices.

The State of Karnataka is located between 11.50° to 18.50° N latitudes and 74.25° to 78.50° E longitudes and covers an area of 19.1 m ha which accounts for 5.8 percent of the total geographical area (TGA) of the country. Out of the total 19.1 m Ha in Karnataka the net cultivated area (2010-11) was 10.5 M Ha, net irrigated area 3.49 m Ha and net rainfed cultivated area 7.01 m ha. Karnataka has the largest area under rain-fed agriculture (Fig. 8.1). Nearly 55% of total food grain production and 74% of oilseeds production come from rainfed agriculture in Karnataka. Therefore rain-fed agriculture plays an important role in total food grain production in the state. Further the rain-fed agriculture has substantial untapped potential, which can be brought to use by increasing the crop yields in the dry land areas through the adoption of proper dry-land production technologies. The climate of the state is determined mainly by the geographical location with respect to the Sea, monsoon winds and physiography.

Introduction

The rate of increase in anthropogenic CO₂ concentration of the atmosphere is increasing at an alarming rate from 1.7 µmol mol-1 yr-1 in 2009 (Tans 2009) to 2.2 µmol mol-1 yr-1 in 2013 (WMO 2013). At this rate, its level in the atmosphere will reach around 450 µmol mol-1 by the turn of century from its current concentration of 400 µmol mol-1, leading to increased global warming and concomitant climate change. There is, thus, a very strong scientific interest in finding ways to slow or reverse this trend. Mitigation strategy of diverting CO₂ from atmosphere to soil by adopting appropriate agricultural practices such as conservation agriculture (CA) is a recognized such method (Lal 2008 a, b). Broadly, CA has three major components- reduced tillage, crop residue management, and intensive cropping. Conservation tillage practices which include reduced tillage (RT) and no-tillage (NT) have been amply demonstrated as the agricultural practices that are very helpful in this direction (West and Post 2002; Franzluebbers 2010).

Introduction

Homegardens are traditional agricultural systems, particularly common in the tropics characterized by a high plant diversity (Kumar and Nair 2004, 2006; Scales and Marsden 2008; Galluzzi et al. 2010), maintain high level of productivity, stability, sustainability and equitability (Soemarwoto and Conway 1992), serve as a refuge for wildlife (Perfecto and Vandermeer 2008), contributing significantly to the household diet by producing a large variety of food commodities (Kumar and Nair 2004; Wiersum 2006; Pulido et al. 2008; Kortright and Wakefield 2011; Kumar 2017; Kumar and Tripathi 2017), nutritional supplies (Mendez et al. 2001; Perrault and Coomes 2008; Vlkova et al. 2010; Balooni et al. 2014), supplementary cash income for owner (Huai et al. 2011; Arifin et al. 2012; Yang et al. 2014) and important spaces for transmission of cultural heritage (Galluzzi et al. 2010). Many native or endangered species can be found in homegardens (Albuquerque et al. 2005; Akinnifesi et al. 2010; Milow et al. 2013), and they are niches for domesticating semi-wild species (Akinnifesi et al. 2010). Plants grown, intentionally or unintentionally, in homegardens are important for household subsistence and economy.

2.1 Overview of the CDM Project Cycle

The ultimate governing body of the CDM is the Conference of the Parties/Meeting of the Parties to the Kyoto Protocol (COP/MOP). The COP/MOP is the annual meeting of the signatories to the Kyoto Protocol and is responsible for managing the CDM Executive Board and for overseeing its work. The Executive Board supervises the CDM process under the authority and guidance of the COP/MOP; it is fully accountable to the COP/MOP. The Board decides on rules for the implementation of the CDM, as well as making the final decisions about acceptance of methodologies, registration of projects and issuance of CERs. The Board is composed of 10 members and 10 alternates. The CDM Executive Board created an A/R Working Group to specifically oversee LULUCF under the CDM. The A/R Working Group provides guidance to LULUCF project developers and, using expert reviewers, makes recommendations on acceptance or rejection of LULUCF methodologies.

“Natural” means an ecosystem not influenced by man and resources means that reserve stock of supply which living things can take from nature for sustenance of life. In reference to man, natural resources can be defined as those natural reserve stocks of supply which man utilizes for his sustenance and welfare. The reservoirs of natural resources are the sun,  the  atmosphere,  the  lithosphere  and the  hydrosphere.  Natural resources include energy, air, water, soil, minerals, plants and animals. The nature of resource depends upon many factors such as scientific and technological development of the society, profession of that particular society, and culture.

6.1    Hydrological Cycle
    
6.2    Global Surface Waters
    
6.3    Surface Water over India
    
6.4    Ground Water Potentials in India
    
6.5    Influence of Drought on Water Resources, its Fauna and Flora
    6.5.1    Effects on Fauna and Flora
    
6.6    Influence of Changing Climate on Droughts and Water Resources
    6.6.1    Global warming and droughts at global scale
    6.6.2    Global warming on water resources at global scale
    6.6.3    Global warming and droughts at national scale in India
    6.6.4    Global warming impacts on water resources at National scale
        
References

Key words : Participatory GIS (P-GIS), Geo-Participatory Rural Appraisal (Geo-PRA) Social Mapping, Resource Mapping, Seasonality Maps, DGPS.

Participatory GIS

Geographical information System (GIS0 and Geographics Information Technologies (GITS) are no more restricted to the elite group of the society. Planners are busy in searching ways in merging community participation with GIS in the context of urban planning, environment equity, sustainable development etc. (Aitken and Michael, 1995, Craig and Ehwood, 1998; Talen, 2000 and Sieber, 2000). In all the cases, common thing is the linking of community participation and GIS in a diversity of social and environmental contexts. Through development, demonstration and modification of methodologies by academics and practitioners the concept of Participatory GIS (P-GIS) emerges. It is an outcome of a spontaneous fusion of participatory forms of development planning with modern information technologies. Experts gave considerable thoughts on the probing questions like whether a bottom up GIS could be successfully developed, how many community participation could be incorporated into GIS and to what context such participation would serve only to legitimize conventional top-down decision making. From these reflections only the concept of people’s participation GIS arose.

1.1 INTRODUCTION

Geographic Information System (GIS) is the new emerging field and grows at very rapid pace. Now GIS is a billion dollar industry with applications in varied disciplines. At present, GIS is being used by professionals from various disciplines. In this decade, GIS is being used by experts who are good in GIS technology for various applications. The development trend indicates that GIS will be used by common man in near future and at the same time, advanced GIS analysis will be carried out by GIS experts.

Any technology is developed out of necessity and GIS is of no exception. When a large amount of data were available for water distribution systems, road network, sewer lines, telecom lines, electricity lines, gas pipe lines, state wise population, natural resources etc, it is important to store, maintain and retrieve the data for applications. It is not possible to manually browse through the large amount of paper records. Also even if the data is available in an unorganized way in the computerized environment, it is not useful. Hence if the data are referred to locations in earth surface and the data are stored in an organized way, it is possible to retrieve and analyse the data for applications. Hence the solution is GIS and developed today into reality. Developed countries are using GIS widely in many areas but developing countries are moving towards the development of GIS database for their resources.

Remote sensing, aerial photography, cartography, surveying and other field instruments for attribute data collection contributes to the data acquisition. Cartography, surveying, geography, geodesy contributes for mapping process. Disciplines like computer science and statistics, mathematics involved in processing and analysing data . Computer science and mathematics involved in storing the data structure.

GIS maps are intelligent. It has many advantages compared with paper map in this digital age.

Spatial data means data which are referenced to earth. Maps, satellite imageries, aerial photographs are example of spatial data. Attribute data which are attached to spatial data are called as aspatial data or non-spatial data.

If these data are brought into GIS then it is stored in a standard format, it is possible to update, share, retrieve, manipulate and analyse quickly. Much of the time and money is saved in case of reproduction and better decisions could be made

If the reader has endeavoured to follow the basic chemistry in the first chapter, he would be in a positions to follow up the various reactions that take place in soils and which hitherto had baffled him. Soils contain particles of various sizes ; some so fine that they would remain suspended in water for a long time; others so coarse that they would be sieved out by even a coarse sieve. Soils contain some salts that can be washed out by leaching with water; they contain some water which can be readily evaporated away by exposing to hot sun or by heating slightly. They also con-tain a little organic matter which can be burnt away or dissolved in alkali. When all the extraneous substances have been completely removed we are left with what we might call soil framework. This framework gives mechanical support to the roots of the plants. Without this framework the plant would not stand up even if it could be supplied with all the food material.

Let us suppose a soil freed from all the extraneous matter by continuous leaching with water or a dilute acid. In the former case the removal of all the extraneous matter is extremely slow, whereas by leaching with dilute acid everything except the soil framework is removed in a short time.

When soils from different localities are subjected to leaching with dilute acid we find that the soil framework in every case, behaves in a similar manner. No matter from what part of the world the soil has been obtained, the properties of its mineral framework only differ in quantity but not in kind.

The crops are very sensitive to climate. The crop production is dependent on climatic parameters like rainfall, light, temperature, relative humidity and carbon dioxide concentration. Each kind of cultivated crop plants has its own optimum growth requirements. Breeding and selection of new cultivars have allowed for a greater adaptability to less favourable growing conditions than was possible in the past, but the inherent climatic requirements of a specific kind of crop have not changed materially.

Weather and climate have also great influence on farm animal production. The environment in which an animal lives is referred to as its habitat. A habitat includes both biotic (living) and abiotic (non-living) components of the animals’ environment. Abiotic components of an animal’s environment include temperature, humidity, oxygen, wind, soil composition, day length and elevation. These potential environmental stressors can directly and adversely affect animal farming. The indirect consequences of weather include their impact on feed quality and availability.

 1. A mineral that forms an original component of rock is called

a. Primary         b. Secondary

c. Essential         d. Accessory

ABIOTIC FACTORS: Environmental influences produced other than by living organisms for example, temperature, humidity, pH and other physical and chemical influences. Contrast it with ‘biotic factors’ - meaning effects due to biological components.

Ours is a Living Planet because ours is a Water Planet. The health of the Living Planet depends on the health of its water resources. Ironically, the health of its water resources is at stake. And so of its life! The waters of the Earth are in the grips of pollution. Much of the water is already polluted and the rest is increasingly becoming polluted. Water pollution, indeed, is one of the worst problems life on Earth is faced with. Water pollution is halting human progress and is phenomenally affecting all walks of human civilization. Water pollution is even putting a question mark on our sustainable future. This chapter presents the causes, magnitude, and consequences of water pollution and also suggests ways and means to prevent and control water pollution and also attempts to manage water resources.

Most of the ecosystems prevailing on Earth have ceased to be virgin. They are now modified following anthropogenic designs. The Blossoming of a community in its climax stage is a rare sight. As human intervention with nature has gone on increasing, all types of biodiversity - genetic, species and community, and alpha, beta, and gamma - have been put under stress. The Earth has already lost much of its diversity due to anthropogenic factors and now it seems to be under severe stress due to climate change, which is also largely due to human-induced environmental disruptions.

Continuous loss of biodiversity at an alarming rate is posing a serious threat to life on earth. With this dismal state of the environment, we cannot usher in a sustainable future. We do not have the right to snatch the future from our younger generations. The Earth belongs to our children more than it does to us. The Earth belongs to future generations more than it does to present generations. Conservation of biodiversity is a matter of ethics. Ethics has the human face of biodiversity. Economic attributes of biodiversity have importance, but ethics of life 

Wastewater is defined as water that has been altered by certain substances, resulting in changes in its physical, chemical, or biological properties. These changes render it unfit for certain uses, such as the purpose of drinking. Since almost all of man’s daily activities are dependent on water, therefore ‘waste’ is discharged into the surroundings as a result of these actions. There are a number of substances that can be harmful to the environment and make people sick, including chemicals, detergents, household cleaners, dirt, microorganisms (germs), and body wastes. The water supply generates a great deal of wastewater, so it is essential that it is treated in order to reduce the amount of waste that it generates. Essentially, wastewater treatment ensures that a healthy environment is created and public health is protected by removing the majority of pollutants found in wastewater through the treatment process. Consequently, wastewater management plays an important role in protecting the planet, and public and economic health, as well as social, economic, and political stability.

Rainfed farming has a distinct place in the Indian agriculture, occupying 67 % of cultivated area contributing 44 % of food grains to our national food basket, supporting 40% of human and 65% of livestock population. The system is characterized by resource poor farmers, poor infrastructure and low investment in technology inputs. Even when full irrigation potential of the country is realized, 50% of the net sown area is continued to be rainfed. The important problems encountered in rainfed areas are unfavorable weather, limited choice of crops and varieties, low cropping intensity and unstable productivity. The research work done by the net work of AICRPDA (All India Co-ordinate Research Project for Dryland areas) centres and SAUs (State Agricultutal Universities) indicated that the production in rainfed environment could be enhanced by 200 % compared to the productivity of farmers’ field by adopting improved cropping systems and agro techniques.

10.1. Introduction

Irrigation facilities are created by the Government at huge cost for supplying water to the farmers for raising crops to increase agricultural production. The major and medium irrigation projects are planned, constructed, managed, operated and maintained by the Irrigation Departments, wherein certain procedures and rules are evolved and followed to the delivery schedule of canals, frequency of supply and distribution of water to the farmers, and closing of canals. The creation of such facilities resulted in ushering the green revolution in the sixties and seventies in the production of food grains and also employment generation in the country, thereby improving the socio-economic condition of Indian farmers. However, optimized management of irrigation water is the key to the sustainable development of agriculture and livestock. Since management of water for irrigation is highly location-specific, depending upon agro-ecological and socio-economic conditions, type of irrigation project and land use pattern, it differs from project to project and region to region in the country.

4.1 Demographic Profile of Watershed Communities

• Population Distribution: Examining the spatial distribution and density of population within watershed areas, including rural settlements, urban centers, and peri-urban zones. Analyzing population distribution within watershed areas involves understanding how people are distributed across various types of settlements, including rural, urban, and peri urban zones. Here's a breakdown of each:

a. Rural Settlements: These are typically smaller communities dispersed throughout the watershed area, often engaged in agriculture, forestry, or other primary industries. Population density in rural areas tends to be lower compared to urban centers. The distribution of rural settlements can be influenced by factors such as terrain, availability of natural resources, and historical land use patterns.

b. Urban Centers: Urban areas within watershed boundaries consist of cities and towns with higher population densities and more developed infrastructure. These areas are characterized by a concentration of economic activities, services, and amenities. Population distribution within urban centers can vary widely, with some areas experiencing high population density in downtown cores and others having more spread-out suburbs.

3.1 Introduction
Understanding the Earth’s atmosphere—its intricate dynamics, ever-changing weather patterns, and long-term climate trends—hinges critically on the quality and detail of the observations we collect. While remote sensing technologies offer broad perspectives from a distance, a fundamental and indispensable category of atmospheric data comes from in situ observations. The term “in situ,” meaning “in place” or “on-site,” precisely describes the nature of these measurements: they are direct, physical readings taken within the atmospheric volume itself.
These direct observations are the bedrock of meteorological science. They provide the ground truth for atmospheric conditions, offering unparalleled precision in measuring parameters such as temperature, humidity, atmospheric pressure, wind speed and direction, and the characteristics of precipitation. Unlike indirect sensing, in situ methods involve instruments physically interacting with the air, yielding highly accurate and localized data points. This granular detail is crucial for a multitude of applications: it allows for the precise calibration of remote sensing instruments, provides essential validation for complex numerical weather prediction models, and enables scientists to dissect and understand fine-scale atmospheric processes that influence local weather.

Weather, while often benign and essential for life, can also manifest in powerful and destructive forms, posing significant threats to human life, property, and the environment. This chapter, “Weather Hazards,” will delve into the detailed nature of these potentially dangerous atmospheric phenomena.
We will explore a range of significant weather hazards, including severe storms such as thunderstorms, tornadoes, and hailstorms, which can bring intense winds, torrential rainfall, and damaging projectiles. We will also examine the characteristics and impacts of tropical cyclones (hurricanes, typhoons), known for their devastating winds, storm surges, and widespread flooding. Furthermore, we will discuss the dangers associated with extreme temperature events, including heat waves, characterized by prolonged periods of excessively hot weather, and cold waves, marked by extended periods of dangerously cold temperatures. We will also cover the challenges posed by heavy snowfall, blizzards, and ice storms.
For each hazard, we will investigate the meteorological conditions that lead to its development, the typical characteristics and intensity scales  used to classifyit, and the primary impacts it can have on society and the natural world. Understanding the formation, behavior, and potential consequences of these weather hazards is crucial for effective forecasting, issuing timely warnings, and implementing mitigation strategies to enhance safety and resilience.
Join us as we embark on a detailed exploration of the forces of nature that can transform familiar weather into formidable hazards.

Data pre-processing is a crucial step in data analysis and machine learning that involves preparing raw data for further processing and analysis. Proper preprocessing helps in improving the quality of the data, which in turn enhances the performance of machine learning models. Smoothening VIS-NIR spectra enhances signal quality by reducing noise, crucial for better spectral data interpretation. Key methods include Savitzky-Golay and moving average filters, wavelet transform (WT), and frational derivatives.
Savitzky-Golay Filter: The Savitzky-Golay filter is widely used for smoothing spectral data. It preserves the original shape and features of the signal better than simple averaging filters.Savitzky-Golay Filter fits low-degree polynomials to successive subsets of data points using linear least squares, effectively preserving the signal’s original shape and features, making it ideal for spectroscopy. Moving Average:Moving Average is a simple method that reduces random noise by averaging neighboring data points. While effective, it can sometimes blur sharp features.
Wavelet Transform: Wavelet transform is effective for denoising spectral data, especially when dealing with non-stationary signals.Wavelet Transform (WT) decomposes spectral data into multiple scales, providing both time and frequency information. It is particularly useful for identifying features like peaks and trends. WT includes Continuous Wavelet Transform (CWT), Discrete Wavelet Transform (DWT), and Maximal Overlap Discrete Wavelet Transform (MODWT). Fourier Transform Filtering: Fourier transform can be used to remove highfrequency noise components from the spectra.
Median Filter: Median filtering is useful for removing outliers and preserving edges in the spectral data.
Fractional derivative:Fractional derivative generalizes traditional derivatives to non-integer (fractional) orders, allowing for arbitrary order derivatives. This provides a flexible, nuanced approach to modeling and analyzing complex, nonlinear, or memory-dependent behaviors.

Introduction 
Chapter 14 explores the intricate relationship between rural development and agricultural economics, emphasizing their roles in promoting sustainability and food security. This chapter examines various aspects of agricultural policy, agribusiness, farm management, rural entrepreneurship, and sociology, linking these elements to broader economic and environmental concerns. The chapter starts with an analysis of agricultural policy and development, discussing how policy frameworks shape agricultural practices and rural growth. It highlights the importance of effective policies in fostering agricultural innovation, improving productivity, and supporting rural development. Agribusiness and marketing are crucial components of agricultural economics. This section delves into agribusiness strategies and agricultural marketing practices that influence market access, value addition, and overall economic viability for farmers and agribusinesses. Farm management and financial analysis are essential for optimizing agricultural operations and ensuring financial sustainability. The chapter explores principles of farm management, including planning, decision-making, and risk management, along with techniques for financial analysis to evaluate the profitability and efficiency of farming enterprises. Rural entrepreneurship is highlighted as a key driver of economic development in rural areas. This section examines how entrepreneurial activities contribute to rural growth, job creation, and economic diversification, fostering resilience and innovation in rural communities. Rural sociology provides insights into the social dimensions of rural development. The chapter covers the importance of rural sociology in understanding social structures, behaviors, and dynamics within rural communities. It also discusses new concepts in rural sociology that address contemporary challenges and opportunities. The importance of rural development and agricultural economics in food security is emphasized. The chapter explains how these fields contribute to enhancing food security by improving agricultural practices, supporting rural livelihoods, and addressing food supply challenges.

Introduction 
In the rapidly evolving landscape of agricultural sciences, the integration of artificial intelligence (AI) and digital technologies is heralding a new era of innovation, efficiency, and sustainability. As the global population continues to grow and the impacts of climate change become increasingly pronounced, the demand for sustainable food production systems has never been more critical. AI and digital technologies are emerging as powerful tools to address these challenges, offering unprecedented opportunities to enhance food security, improve resource management, and build resilience against climate-related disruptions. AI-driven solutions, such as predictive analytics, machine learning, and precision agriculture, are transforming the way farmers cultivate crops, manage livestock, and optimize supply chains. These technologies enable real-time decision-making, allowing for more efficient use of resources such as water, fertilizers, and pesticides, while also reducing the environmental footprint of agricultural practices. The application of AI extends beyond the farm level, influencing every aspect of the agricultural value chain, from seed selection to post-harvest processing, distribution, and market access. The advent of the Internet of Things (IoT), coupled with advanced sensors and robotics, has further revolutionized agriculture by enabling the continuous monitoring of environmental conditions, soil health, and crop performance. IoT devices collect vast amounts of data, which, when analyzed using AI algorithms, provide actionable insights that empower farmers to make informed decisions. This data-driven approach not only enhances productivity but also contributes to sustainable farming practices by minimizing waste and optimizing resource allocation. Moreover, digital platforms and mobile technologies are bridging the gap between farmers and critical information, making it easier to access weather forecasts, market trends, and expert advice. These technologies are particularly transformative in developing regions, where they can provide smallholder farmers with the tools and knowledge needed to improve their livelihoods and contribute to food security. Additionally, blockchain technology is emerging as a solution for enhancing transparency and traceability in the food supply chain, ensuring that consumers have access to safe and ethically produced food.

Rainfall in India, is a phenomenon that is not just a meteorological event but the very lifeline of the subcontinent, profoundly shaping its landscapes, agriculture, and, most importantly for our study, its diverse aquatic ecosystems and the fisheries they support. India experiences a unique and dominant rainfall regime driven primarily by the monsoon, a seasonal reversal of wind patterns. The arrival, intensity, duration, and spatial distribution of this rainfall have farreaching consequences for the availability of freshwater, the health of rivers, lakes, and wetlands, and the productivity of coastal and marine environments. For aspiring fisheries professionals in India, a thorough understanding of the patterns and vagaries of Indian rainfall is indispensable.
Consider the sheer diversity of aquatic habitats across India, from the snowfed rivers of the Himalayas to the monsoonal wetlands of the Gangetic plains, the brackish backwaters of Kerala, and the vast coastline. The characteristics and productivity of each of these systems are intricately linked to the patterns of rainfall they receive. The monsoon replenishes rivers and groundwater, sustains agricultural practices that can impact water quality, influences the nutrient flow into coastal waters, and can even trigger crucial life cycle events for many aquatic species (Fig. 7.1).

2.1 Introduction 
The world is encountering a severe power and environmental crisis. Adopting sustainable progress is the best means to protect our environment and maximise the use of available resources. The urgent issues, encompassing diverse types of pollution and carbon emissions, highlight the necessity to shift towards renewable energy sources. This shift is essential for diminishing our dependence on fossil fuels, addressing the on-going challenges regarding climate change, and confronting the exhaustion of current energy reserves. Furthermore, mitigating water pollution is an essential component of ensuring ecological sustainability [1,2]. Water supplies are rapidly being contaminated due to diverse contaminants including heavy metals, and harmful chemicals. While industrialization is critical for societal growth, it is critical to recognise the negative environmental consequences caused by numerous processes that emit hazardous substances. Improper disposal of untreated wastewater can negatively impact ecology and biodiversity [3]. As a result, it is critical to use environmentally friendly and sustainable treatment methods that adhere to green development principles. This will bolster industrialization efforts while upholding water pollution safeguards for recovery and reuse. Given the prevailing energy crisis, traditional wastewater treatment facilities have become financially unsustainable due to their high energy consumption. Traditional wastewater treatment is both costly and demands substantial energy resources. Furthermore, these approaches fall short of efficiently eradicating recalcitrant organic waste, heavy metals, and other persistent contaminants. Moreover, many of these treatment processes require regeneration. Microbial fuel cell (MFC) technology has emerged as an ecofriendly treatment option capable of effectively eliminating stubborn organic pollutants and heavy metals over the long term. Microbial fuel cells are chosen over other current treatment methods because to their reduced energy needs and lower chemical usage [4,5]. In addition to lowering energy usage, MFCs possess the ability to produce ample bioenergy, which can help alleviate the energy shortage. This provides a cleaner alternative for generating renewable energy in favour of sustainable development and environmental protection as depicted in Figure 2.1.

Introduction 
Augmented energy demand as well as impacts of employment of fossil coals on human health and environment, stresses and imposes the need to lessen the use of conventional fuels or replace them. Equally, global warming has stretched to a distressing level due to many diverse anthropogenic actions leading to increased pollution. The alternate energy sources are desirable that might be the conspicuous and sustainable approach of enabling environmental remediation, besides meeting the global energy call (Grosser et al 2016, Kanchanasutha et al 2016). A potential solution is generation of Biofuels, either conventional biofuels produced from agricultural crops or advanced biofuels produced from wastes, inedible crops or forestry products (Sreedevi Sarsan et al 2021). Advanced biofuels production especially by the utilization of agricultural and animal wastes using new technologies and processes are gaining increased interest among researchers and general public all over the world. Food waste, municipal trash, animal waste and other wastes can all be utilised as feedstocks to create biogas, a clean and sustainable energy source and thus may be the ideal replacement for traditional energy sources. The raw biomass may be converted into fuel products like biogas by briquetting, gasification, and anaerobic digestion, among other processes (Deepanraj et al 2015). In comparison to landfills, incinerations, and composting processes, anaerobic digestion (AD) is suggested as an inexpensive and environmentally benign technique for the generation of renewable energy (Van Forest et al 2012; Nishio et al 2007; Capson-Tojo et al 2016; Xu, F et al 2018; Cha, M et al 2020). The production of energy-rich biogas and alleviation of issues related to the removal of organic waste are all achieved by anaerobic digestion (AD) of organic solids (Sonakya et al 2001). This is since AD is a highly energy-efficient and ecologically benign technique. In an atmosphere devoid of oxygen, the AD system uses anaerobic microbes to transform the naturally occurring substances in the biomass into biogas. The primary byproduct of AD, biogas, has a methane content of roughly 50-70% by volume and 30- 40% atmospheric carbon dioxide (CO2) when feedstocks are digested under anaerobic circumstances, with small levels of hydrogen sulphide (H2S) (0.1-3% v/v), humidity, and other trace pollutants also present (Sahota et al. 2018). The generation of biogas is known to be influenced by factors such as waste types, pretreatment procedures, the microorganisms or enzymes added, operation circumstances and design of the digestors (Mao et al 2015).

1. Introduction
Dyes are compounds after addition to a substrate, for a moment give it a colorthrough a process that modifies the colored substance’s crystal structure (Bafanaet al., 2011). Such varieties of compounds with significant coloring capacityare widely employed in the textile, pharmaceutical, food, photographic, andpaper industries (Zollinger et al., 1987). Dyes can adhere to suitable surfacesthrough methods such as dissolving, forming covalent bonds, complexing withsalts or metals, physically adsorbing, or being mechanically retained (Kirkand Othmer, 2004). The chemical structure and application of dyes determine
their classification. The dye color is produced by a collection of atoms calledchromophores. Chromophore centres, which are responsible for color, consistof various functional groups like azo, anthraquinone,methine, nitro, arylmethane, carbonyl, and others. Additionally, substituents that either donateor withdraw electrons to enhance or create the color of these chromophoresare called auxochromes. Common examples of auxochromes include amine,carboxyl, sulfonate, and hydroxyl groups. There are three methods for dyingtextile materials: batch, continuous, and semi-continuous. Thekind of materialincluding yarn, fabric, fiber, clothing, and fabric structure as well as the generalfiber size of the dye lot, type, and quality standards of the dyed fabric, all playa role in determining the dyeing method used. Among these techniques, theprocess called the batch procedure is the most frequently employed for dyeingtextile materials. (Ogugbue et al., 2011).

Cashew (Anacardium occidentale L.) is a very important horticultural crop which fetches considerable foreign exchange to India. The crop is a native of Brazil and was introduced in India by the Portuguese during 16^th Century. It is grown in India, Brazil, Vietnam, Tanzania, Mozambique, Indonesia, Sri Lanka and other tropical Asian and African countries. The crop is grown within the latitudinal belt of 27°N and 28°S of the equator experiencing a tropical temperature for its growth and development (Rao and Gopakumar, 1994). The trend in productivity has a phenomenal bearing to the distance from the equator. The world production of cashew is estimated to be around 20.8 lakh tonnes. The global productivity level of cashew is 690 kg/ha. Since 2000, the world raw cashewnut production registered an increase of 40 per cent. India’s share in the world raw cashewnut production accounts to about 25 per cent. In recent times, India is facing tight competition from Vietnam and Indonesia in international cashew trade. Since its introduction in the Country, cashew has well adapted to the Indian climatic conditions and is grown in the East and West Coasts of India. Now, India is the largest producer, processor, consumer and exporter of cashew in the world (Bhat, 2009 a). In India, cashew is grown mainly in Maharashtra, Goa, Karnataka and Kerala along the West Coast and Tamil Nadu, Andhra Pradesh, Orissa and West Bengal along the East Coast.

Any living organism in its natural habitat is called a wildlife. It may be plant animal or a microbe. The significance of wild life lies in setting up the balance of population in nature by maintaining food chains and food webs. It acts as the gene banks in relation to breeding of plants and animals for introduction of desirable characters such as high yield of economic product and resistance to diseases. The scientists are performing studies to screen and select useful genes in economically important organisms.

Abstract

Microorganisms inhabiting in the rhizosphere play a vital role in ecosystem functioning. Rhizosphere is an area around the root surface where pathogenic and beneficial microorganisms repose and influence the plant growth and health. These microbial groups of bioagents found in the rhizosphere include bacteria, fungi, nematodes, protozoa, algae and micro-arthropods. Because of their rich diversity, complexity of interactions and numerous metabolic pathways, microbes are an amazing resource for biological activity. These microorganisms require organic matter for their growth and activity in soil and provide valuable nutrients to the plants and hence maintaining the plant health. The most promising fields for the use of bioinoculants are agriculture, horticulture and forestry. There are many reports on the inoculation of bioagents in agriculture and horticulture crops but only a few reports are available in forestry. This article is an overview on various bioinoculants which are used during inoculation and a compilation of scattered reports of bioinoculants in forestry only.

Abstract
 
Within the time scale for soil formation, humans appeared to the planet within the last 1 million years. They shifted their lifestyle from hunter-gatherer to nomadic animal husbandry and finally to cultivation of domesticated crops only within the last 10,000 yrs. Earlier, these crops were cultured in a semi-nomadic style as land was plentiful, so when soil lost its productivity, people abandoned it in favor of new-land. Gradually, as land became scarcer and population exploded, agriculture evolved to continuous cropping of the same parcel of land. This discovered the major concern for soil health. As organic matter is key to soil health, humus is the last stage of organic matter decomposition. Humus is a complex aggregate of dark brown colored amorphous substances, which have originated during the decomposition of plant and animal residues by microorganisms, under aerobic and anaerobic conditions. Humus and living microorganisms are connected by numerous ways which must be appreciated in order to understand the origin and nature of humus. Our attempt is to narrate the role of organic matter and vital role of microbes in humification process.

ABSTRACT
Methanogenesis is a ubiquitous process primarily encountered in anaerobic environments. Methanogens are a group of diverse obligate anaerobic bacteria that produce methane from complex organic matter. Despite their differences in morphological characters and habitat, they show coherence in terms of methane-producing metabolic activity. Being distinctive from all other classical prokaryotes, these are grouped under another kingdom of Archea. Other distinctions of the members are based on their unique cell wall structures and membrane components, as well as differences in their highly conserved gene sequences. Methanogens likely owe their cosmopolitan status to their unique mode of energy metabolism of methane generation. They are active in various ecological niches, from rumens of animals to submarine volcanic vents, sewage digestors and landfills. Methanogenic bacteria are abundant in habitats where high affinity electron acceptors are negligible. Methane fermentation involves bacteria that obtain energy by catalysing anaerobically degradable organic matter to CH₄ and CO₂ by consuming H₂, CO₂, and low-carbon organic acids as their substrates. The gaseous products of methanogenesis are greenhouse gases, thus are major contributors to global warming. Methanogens could be used to produce renewable carbon-neutral energy substitute, biogas. Methane cycling archaea play a major role in global methane production as energy for the future.

Key Facts
    
·    The United Nations Framework Convention on Climate Change (UNFCCC) defines ‘climate change’ as a ‘Change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over the comparable time periods’.
    
·    The main green house gases (GHGs) that have caused the global climate change or global warming are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O).
    
·    CO₂ is the principal anthropogenic GHG that affects the earth’s radiative balance. It is the reference gas against which other GHGs are measured and therefore has a Global Warming Potential (GWP) of 1. CH₄ and N₂O have a GWP of 21 and 310 respectively.
    
·    CO₂ is responsible for most of the enhanced green house effect of more than 50%, CH₄ for about 10-15% and N₂O for about 8%.
    
·    The global atmospheric concentrations of CO₂, CH₄ and N₂O have increased since 1750. While CO₂ increased from a pre-industrial value of 280 ppm to 379 ppm in 2005, CH₄ increased from 715 ppb to 1774 ppb and N₂O increased from 270 ppb to 319 ppb during the same period.

Food security is one of the most important issues during this century under the projected climate change scenario. The world is facing severe food crisis due to weather vagaries as a part of global warming and climate change. Many countries are under severe food crisis during the crisis of weather abnormalities since 75 per cent of world’s population is dependent on agricultural activities for their livelihood. Therefore, there is an urgent need to produce more and more foodgrains at the global as well as national levels to meet the food requirement of growing population under the projected climate change scenario. There has been a major decline in world rice production since late 2007 due to various reasons including global warming and climate change in top rice producing countries. 

Key Facts

    •    The heavy metals (HM) or trace metals in an aquatic environment can come from natural (e.g. geological minerals, wind blown silicate dust, volcanic emissions, sea spray and combustion) and anthropogenic sources (e.g. mining, industry and sewage treatment discharges as well as electronic waste and agriculture fertilisers). In aquatic systems, the heavy metals of greatest concerns are cadmium, copper, lead, mercury and zinc.
    •    Metals may exist in a number of physico-chemical states in aqueous systems such as particulate matter and dissolved forms. Metal speciation in freshwater is strongly influenced by hardness, alkalinity, pH, natural dissolved organic matter (DOM) and redox potential. 
    •    Water hardness is quantitatively related to metal toxicity in freshwater (i.e. toxicity of heavy metals decrease with increasing hardness and alkalinity; on the other hand, toxicity increases with decreasing salinity, dissolved organic matter and chelators). The uptake and toxicity of heavy metals of most metals in marine waters is low as compared to freshwater because metals are easily complexed with chloride ions.
    •    The toxicity of HMs is related to the dissolved ionic form of the metal rather than total concentration of the metal. Each different physico-chemical forms of an element has a different toxicity, for example, if the element (e.g. Cu) is absorbed on a colloidal particles it is expected to be of little or no effect on aquatic organisms, however,  if the copper is available as free Cu (II) ion, few aquatic organisms may survive.

13.1 Introduction

Greenhouse gas (GHG) emissions have become an increasingly important topic worldwide due to their effects on global warming and climate change. The effects of GHG emissions on the ecological and socioeconomic vulnerability have already been noticed and will continue to grow regionally and globally in the years to come (IPCC 2007). Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons, perflourocarbons, and sulfur hexafluoride are the important GHGs that are monitored by the United Nations Framework Convention on Climate Change (UNFCCC 2008). Global GHG emissions due to human activities (anthropogenic) have grown since the beginning of the industrial revolution with an increase of 70% between 1970 and 2004 (IPCC, 2007).

Introduction

Climate change is an important determinant of abundance and distribution of species. It is concerned with everyone since it posess potential threat to environment, and agricultural productivity and production throughout the world. It has implications for livelihood and survival of human beings. According to Intergovernmental Panel on Climate Change (IPCC, 2001), it is defined as “Change in climate over time, either due to natural variability or as a result of human activity.” As described by IPCC, the most of global warming observed over last 50 years is attributed to the human activities.

Over the past decades climate change and climate related disaster risks have become more important than ever. The effects of climate change are unprecedented today and thus pose serious risks for human wellbeing, livelihoods and life-supporting systems. They also present serious challenges to society, in addition, increased climate variability significantly undermine the socio-economic development and environment. The consequences of climatic change, such as increase in frequency and extent of droughts, floods, cyclones, mudslides and avalanches have impacts on all sectors of economy including water, agriculture, fisheries, health, forestry, transport, tourism and energy sectors. Amongst these sectors, the agricultural sector is one of the most vulnerable sectors to impacts of climate change, which can have multiplicative effects on other sectors, as well as the economy and overall human being. The projected climate change towards warming may affect not only the crop cultivation but also on agro-climatic conditions for growing pasture vegetation, forming of feed stocks in pastures and conditions for grazing livestock. Favourable conditions for grazing livestock are determined, on the one hand, by sufficient amount of forage in pastures and on the other, by the extreme weather conditions that restrict the use of these fodders.

Abstract

The balance between resources and population constitute the solid base for drawing the future map of sustainable development in the study area in all developmental sectors such as agriculture, industry, tourism, and commercial sectors. Geoenvironmental hazards such as erosion, sea level changes, sand dune encroachment, siltation of the navigation channel of the Damietta harbor, salinization of the soils, the negative effects of the protective structures and bad management of the coastal areas must be studied in details before making the future planning for any area. The main geomorphologic units in this area are: beaches, sand dunes, wetlands, urban areas, reclamation lands and lagoons.

The rate of erosion from 1984 to 2000 in the Rosetta beach is -117.6 m/yr, while it is -17.6 m/yr in the Damietta beach. On the other hand, the rate of erosion in the period from 1984 to 2005 is -104.6 m/yr and -11.4 m/yr in Rosetta and Damietta beaches, respectively. Since, Nile Delta is a typical wave dominated delta (Coleman et al., 1981) and Tide is a semi-diurnal microtidal regime with a maximum tidal range of 50 cm (UNESCO/UNDP, 1978), the erosion and accretion are very dangerous hazard in the area.

Due to the reclamation of vast areas of the coastal dunes, the lagoons and wetlands, the new reclaimed lands are added to the agricultural deltaic land. Thus, the coastal sand dunes, lagoons and wetlands are decreased. The main urban centers have expanded, and new urban centers (Damietta harbor, the New Damietta city and Mansoura city in near future) have been constructed at the expense of vast areas of lagoons, coastal dunes, and backshore flats. The siltation of the navigation canal of the Damietta harbor, salting of the soil (new and old) and sand dune encroachment are very important hazards in the study area. All the previous geoenvironmental hazards and others threaten the sustainable development in the study area.

Introduction

Groundwater investigation has a long history. In the past a waterman in the village would walk around the investigation area with a Y shaped wooden fork and identify the location for digging the wells. Certain trees and organic landforms like termite mounds were considered as indicators. The native intelligence of local topography should have played a role in identifying potential location. Successful or otherwise the method can be said to lack scientific objectivity. The optimal groundwater surveying method is no doubt drilling. This method ensures that all necessary information is being brought up from the geological formations. However, in order to obtain a desired degree of information from the subsurface of an area, drilling alone is normally not a feasible alternative.

There are a number of efficient and inexpensive geophysical surveying methods available to the hydrogeologist. It is worth noting at this point that these are, without exception, indirect methods. This implies that no method measures directly what we are actually looking for. With geophysical surveys, the target features are therefore invariably associated features. This implies that unless we understand the water context of these features, our geophysical surveys will be less than meaningful.

Objective methods of investigating groundwater are discussed in this chapter.

Introduction

All models are but approximations of reality. When we approximate there is always room for uncertainty. The preference of a particular model over the other is the relative degree of uncertainty acceptable to the objective and budget of the study. With the advent of computers, hosts of modeling software promising a lot to the researcher have arrived on the horizon. It is not in the scope of the book to enumerate all the techniques of hydrogeological modeling. Physical modeling using sand tanks was the earliest attempted modeling technique, about 107 years ago. Most recent and significant modeling technique practiced by many in groundwater potential identification is Geographic Information System (GIS) based modeling. After a brief treatment of physical models, concepts of mathematical models and GIS modeling are elaborated. The modeling techniques have involved mathematics and or software specific instructions. Hence it is recommended that relevant text books for individual techniques be referred. This chapter deals more on modeling concepts.

Key words : GPS, GIS, DSS, SDSS, RS, Digital Elevation Model (DEM), Ground Water Exploration, Conjunctive Use of Surface and Ground Water, Digital Terrain Modeling (DTM).

Introduction

Water is one of the most precious gifts of nature to living beings and particularly to the mankind. On account of erratic distribution of rainfall both in time and space, the country is subjected to cycles of floods and droughts. With the increase in demand for water for various purposes and to mitigate the twin problems of floods and droughts faced by the country, a coordinated approach for optimum utilization and proper management of this precious resource is of prime importance. In addition, proper development and management of both irrigation and drainage systems are essential. This would require integrated management of surface water as well as gorund water. All the water related problems whether mitigating droughts or floods or better irrigation management practices, dictate for adoption of state of the art water management practices. Water management deals with the control, distribution and allocation of water flows and the treatment of rivers and catchments, consequently, solutions to many of the problems in water management require the knowledge and expertise from diverse sources.

9.1. Balance and Weighing

9.1.1. Principle of Functioning of a Balance

It is one of the important tools used in the laboratory and one should have thorough knowledge about its assembly, use and care, otherwise it may be the initial step for introducing error in any physical or chemical analysis. Every balance has its maximum load limit and sensitivity depending upon its construction.

Essentially balance may be regarded as a rigid beam, BC having a central fulcrum, O and two arms of equal length, d₁, d₂ (Fig.9.1). The both ends of beam have prism edges upon which the balance pans are suspended by means of suitable suspension.

The measurement of greenhouse gases (GHGs) has been started during middle of the last century. Initially, CO₂ and water vapour were measured with other common meteorological variables like temperature, sunshine hours, rainfall, humidity etc., for monitoring the weather condition and pollution. The absolute or relative concentrations of gasses in atmosphere are used to measure basically for monitoring purpose. However, limited studies were dealt with actual gaseous exchanges of fluxes. The concern about gaseous flux measurement and GHGs-exchanges started after 1900s when people got concerned about anthropogenic pollution, environmental sustainability and climate change issues. The GHGs-exchanges in earth-atmosphere systems primarily occur due to change in meteorological variables, soil responses and physiological activities of crops. If we are interested for environmental data inventories, then absolute GHGs concentrations of atmosphere at a specific time is required. However, presently researchers, students, environmentalists, climate scientists are primarily interested for quantitative data on GHGs fluxes and or GHGs-exchanges. They want to know what and how much quantity of a particular GHG is emitting from unit area at unit time.

Flux refers to the amount of any gas emitted per unit area per unit time. The dimension of that is M A^-11 T^-1. (Where, M= Mass/ Quantity; A= Area; T= Time). The SI unit of flux is g m²s^-1. Therefore, flux is a vector. It has magnitude as well as direction. As for example positive flux of CO₂ from earth surface means, CO₂ is moving out from earth surface to atmosphere. If it moves in opposite direction then the flux would be negative. In that case CO₂ gas may be absorbed by the soil surface from adjacent atmosphere. Similarly, GHGs fluxes of earth surface are either positive or negative. Generally, positive GHGs flux refers to emission of GHGs from earth to atmosphere and vice versa.

Introduction

The Indian hot arid zone occupies an area of 0.32 million km to forming a continuous stretch in the north western states of Rajasthan, Gujarat, Punjab, Haryana and scattered land masses in the states of Maharashtra, Karnataka and Andhra Pradesh, 70 per cent of it falls in western Rajasthan. Low and erratic rainfall, extreme temperatures, long sunshine duration (6.6-10 hours), low relative humidity (30-80 per cent), high wind velocity (9-13 km/h) and high evapo transpiration (1600-1800 mm) and characteristic features of the region. Moreover the soils are poor in nutrients and scarcity of water and recurring droughts are perennial constraints. Despite hostile conditions, the western arid Rajasthan supports a large human and livestock population and a variety of flora and fauna. However, the ever increasing human and livestock population and development activities exert enormous pressure on the natural resource in the region. These areas experience an annual rainfall between 100 and 500 mm with a coefficient of variation varying from 40 to 70%. The region is characterized by low and erratic rainfall with extremes of temperature (1–48 °C), high wind velocity and sandy soils. In dry and arid region, wind erosion affects 13.5% in India (Sehgal et al., 1994, Kar et al.,1959). Wind erosion is very active in the Indian Thar Desert and poses severe multifaceted problems (Dey et al., 2016). Loss of nutrient-rich particles from agricultural fields has been occurring due to suspension of fine particles in air and deposition of eroded soil. Among terrain properties, soil aggregate distribution, surface roughness, soil moisture and vegetation cover are important factors influencing wind erosion. Indiscriminate grazing in the region also further destroys vegetation and exposes the land surface, thus making it more vulnerable to wind erosion.

Soil survey is essentially a study and mapping of soils in their natural environment. It is the systematic examination, description, classification and mapping of soils of an area.

2.1. History of Soil Survey in India

The original investigations on Indian soils were carried out by Voelcker dates back to 1893 and by Leather to 1898.They classified the soils of the country into four major groups, namely the Indo-Gangetic alluvium, the black cotton soil or regur, red soil and laterite soil. Schokalskaya (1932) has published a soil map of India based on the Russian concept which describes 16 soil groups such as climate,vegetation, soil-forming materials, salinity, alkalinity, swamps and peats (Bhattacharyya et al. 2013). In 1935,Wadia and his co-workers collected a soil map of India with significance on geological formations and classified the soils as red, black (regur), laterite and lateritic soils of Peninsular India and also Indo-Gangetic Plains (IGP) which includes delta, desert, bhabar, terai and alkali soils. Vishwanath and Ukil (1943) published a soil map of India by placing the soils in different climatic zones for the first time. This was prepared by Imperial Agricultural Research Institute, New Delhi, and published in the year 1943. There were 17 kinds of soils identified, viz., deep black soils, black clay soils, black loamy soils, black sandy soils, red sandy soils, brown sandy soils, red and yellow soils, dark reddish brown soils, mixed soils (white and yellow), alluvium (Indus, Gangetic, Brahmaputra), coarse alluvium, soils of swamp lands, calcareous soils, usar soils, kallar soils, coastal alluvium soils and soils of Great Himalayan Ranges.

Soil survey works were started in 1954, in most of the states as a part of their agricultural development programme, and Bihar (Soil Survey and Land use Planning Scheme, Sabour) was pioneer. In 1954, the soil survey work was started under the leadership of Dr. P. P. Jha following the conventional procedures in Bihar (including Jharkhand) to delineate the soil associations based on geology, relief, physical and chemical characteristics of soils for the first time in India by the then Soil Survey Scheme at Sabour (Mishra et al. 2001; Mishra 2015, 2016). Meanwhile, the National Atlas Organization, Kolkata, prepared a soil map of India in 1957 classifying Indian soils into six major groups and 11 broad types. Murthy and Pandey (1983) applied the working principles of the USDA 7^th Approximation in classifying the Indian soils with available data on soil classes and thus used the US system for the first time at great soil group level, which was transformed into a soil map of India on 1:6.3 million scale. Mishra et al. (1994) attempted to propose “Fluvisols” as the 13th Order in USDA Soil Taxonomy for active floodplain soils frequently occurring in different parts of India and elsewhere. Mishra (2015, 2016) proposed a framework of Indian system of soil classification mainly based on land use options.

Soil fertility is the resultant of several factors, not the least important of which is the soil itself. Theoretically, the soil only plays the part of a support and could be very easily dispensed with and replaced by sand and even that can be replaced by a wire framework to support the plant mechanically and it will grow quite well if the right amount of nutrient materials have been added to water. ‘Where does the soil come in?” you will ask. The importance of the soil is two-fold: (1) It provides vast reserves of plant food which is slowly made available. (2) It provides limiting factors which restrict plant growth; these limiting factors must be neutralized. We have already discussed these reserve food materials and limiting factors in Chapter II.

It has been shown that if we treat a soil with dilute acid exhaustively we can remove everything from it except the mineral framework. If we try to grow anything in this mineral framework nothing will grow. Yet it is not like sand, for whereas in sand by adding appropriate amounts of nutrient materials in water solution you could grow a crop, nothing will grow if you added the same solution of nutrient materials to the soil. This mineral framework, therefore, is not inert like sand, but it is active and can react with the nutrient salts in such a way that either they are rendered unavailable or something else which is toxic is produced by the interaction between the soil and the nutrient salts. This mineral framework is not acted upon by dilute acids, but it reacts with alkalies in such a way that the alkalies are neutralized. In this respect, therefore, the mineral frame work behaves like an acid. With alkalies it forms salts and different alkalies are required in equivalent amounts for the formation of these salts. Thus we can have salts of a number of bases and if we use sodium hydroxide for neutralizing we shall have sodium soil, similarly we can have a calcium, magnesium or potassium soil. Now in nature, all the various bases principally, calcium, magnesium, sodium, and potassium, are associated with it in different proportions. The nature and amount of these bases determines the physico-chemical properties of the soil affecting crop yield and leading to soil infertility. We have already indicated the method of bringing the soiil to the normal state when it suffers from any of the defects associated with the soil framework.