eChapters

ABSTRACT

Microbes are integral part of the terrestrial ecosystem. Their function ranges from nutrients mineralization, stress alleviation to bioremediation in soils .There is a great possibility of using microbial inoculants as a biological tool for sustainable forestry and agriculture. This review gives an overview on the benefits of microbial technology and their contribution in development of green technology.

Keywords: Green technology, Microbes, AMF, PGPRs, Microbial consortium, Carbon sequestration.

1.     Introduction    424

2.    Conventional Methods of Hydrogen Production    426

3.    Biological Methods of Hydrogen Production    429

    3.1.    Hydrogen production by biophotolysis of water, 430
        3.1.1. Photolysis by cyanobacteria (Blue green algae), 430
            3.1.1.1. Nitrogenase dependent hydrogen production, 434
            3.1.1.2.  Hydrogenase-dependent hydrogen production, 437
            3.1.1.3.  Factors affecting  hydrogen production by cyanobacteria, 440
            3.1.1.4.   Bioreactors for cyanobacterial hydrogen production, 443
            3.1.1.5. Future prospects for cyanobacterial hydrogen production, 446

1.    Introduction    392

2.    Landfill Gas    393

3.    Biogas    394

    3.1.    Benefits of biogas, 394
    3.2.    Potential of biogas, 395
    3.3.    Biogas production system, 396
        3.3.1.    Raw materials, 396
        3.3.2.    Biogas technology, 398
        3.3.3.    Process of anaerobic fermentation for methane generation, 400
        3.3.4.    Conditions for anaerobic fermentation, 404
        3.3.5.    Sludge-algae-methane system, 407
        3.3.6.    Biogas plant, 408

1.    Introduction    272
2.    Alcohols    273

    2.1.    Methanol, 274
    2.2.    Ethanol, 277
    2.3.        Butanol, 283

3.    Biodiesel    284
4.    P-series fuels

Microbial Based Formulations examines preparations produced through beneficial microorganisms, fermentation, and indigenous microbial resources. It covers Waste Decomposer, Effective Microorganisms, Fermented Plant Extract, EM-Bokashi, Indigenous Microorganisms, Fermented Plant Juice, Fermented Fruit Juice, Oriental Herbal Nutrient, and lactic acid bacteria. Water-soluble potassium, phosphoric acid, and calcium preparations, brown rice vinegar, loess powder, fermented seawater, and microorganism-enriched mixtures are also discussed. The chapter demonstrates how microbial activity and fermentation can transform locally available materials into agricultural inputs. Together, these formulations illustrate approaches for nutrient management, plant growth support, compost enrichment, and ecological farming using biologically mediated processes and farm-level resources. for preparation.

ABSTRACT

Biodiversity is often understood in terms of wide variety of plants, animals and micro-organisms existing on the earth. So far, about 1.75 million species have been identified, mostly small creatures such as insects. According to scientific estimates, there are actually about 13 million species, although range from 3 million to 100 millions. The present article deals with the importance and threats of biodiversity as well as tries to highlights the role of government and non-government sectors in conservation of biodiversity. The initial part of the article indicates the concept of evolution and biodiversity, wherein we have tried to identify the present scenario. We find that a wide range of microbial, plant and animal species are sources of various biological products for human use and welfare. These species are getting lost or extinct due to lack of conservation over a period of long time. Therefore, an effort has been made to highlight the conservation acts and important rules and regulations for protecting and conserving the bio-resources.

ABSTRACT

Soil borne fungal pathogen causing root diseases of vegetables are difficult to control by chemical methods. The existing biocontrol bacteria are not very effective in control of soil borne fungal pathogens. As such very less number of bacterial biopesticide is available commercially to control the fungal pathogens. Increasing concerns in recent years about human health and environmental problems due to chemical pesticides, couple with increasing pest resistant to chemical, have led to a reappraisal of our approach to control pest and disease in crops. The trends now are towards a management concept in which the best combination of tools is used to manage plant diseases below economic thresholds with minimal risk to human health and environment. The modern management concept includes extensive use of biocontrol agents which are harmless to non-target organisms. Development of effective technology for control of pest and disease by using microbial resources of a region to enhance the quality of ecosystem is a potential alternative approach to chemical control of plant diseases. In such strategy, search for microorganisms and biological system is an important prerequisite prior to development and practical exploitation of biocontrol. Rhizosphere microorganisms are shown to be perspective candidate for biocontrol agent as they provide the front line of defense for plant roots against the attack by various plant pathogens causing the most diseases of vegetables and crops. Chemical control of soil-borne fungal pathogen had been the subject of growing concern because of their adverse effect on the environment and emergence of chemical pesticide resistant to plant pathogen, moreover, soil borne pathogens are very difficult to control. Crop rotation, breeding for resistant plant varieties and application of pesticides are insufficient to control root diseases of important plants because they survive as sclerotia and has got wide host range.

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.

Soil microbial biomass is an important parameter linking the plants to soil. It comprises about 2-3% of the total organic carbon in the soil and recognized as an important source of nutrients to plants. It is also a dynamic component of the soil associated with several functional properties of the terrestrial ecosystem. It represents the fraction of the soil responsible for the energy and nutrient cycling and the regulation of organic matter transformation.

Microbial biomass is a small but labile and living component of soil organic matter that is involved in most bio-geo-chemical processes in the terrestrial ecosystem. It interacts with crop productivity by regulating nutrient availability as a source; determining soil carbon storage- sink; and contributing to the atmospheric CO₂ from respiration. Thus it is the main agent that controls the flow of carbon and cycling of nutrient elements.

There is a close relationship between soil microbial biomass, decomposition rate, and nitrogen mineralization. It is also positively correlated with grain yield in organic farming and also contributes to soil structure and stabilization. Thus, there is the immense importance of microbial biomass in soil fertility as well as in agriculture.

1. Introduction
Pharmaceutical pollution has emerged as a significant global concern, raising alarms about its potential impacts on ecosystems and human health. The journey of pharmaceutical compounds from their point of use to contamination of water bodies reveals a complex and interconnected web of anthropogenic activities. From manufacturing plants to individual households, these pollutants persistently infiltrate aquatic systems, creating a growing

Abstract

Now a days, the public has become more sensitive towards the protection of the environment and general awareness has increased about the adverse effects of industrial effluents contaminate with various pollutants, including dyes on the environment. Dyes are an important class of synthetic organic compounds used in many industries, especially textiles. Consequently, they have become common industrial environmental pollutants during their synthesis and later during fiber dyeing. Textile industries are facing a challenge in the field of quality and productivity due to the globalization of the world market. The dyes, which are widely used in textile industries when left in water bodies without any treatment cause environmental pollution and in turn are toxic, carcinogenic and mutagenic. The efficient treatment of the sludge from the industries is not economical and a challenging task. Currently, a number of different technologies and methods such as biological, physical and chemical are widely used for the removal of dyes. The treatment technologies for the removal of textile dyes from the textile wastewater found that over the past two decades interestingly focused on biodegradation methods such as microbial decolourization, enzymatic decolourization, adsorption by microbial biomass (living or dead) and bioremediation systems as a better alternative as the available physico-chemical methods.

Biodiversity is the variety of life in different microbes, animals, plants and their genes present in the ecosystem. Soil provides a vital habitat and environment primarily for microflora such as bactria, actinomycetes, fungi as well as microfauna viz. protozoa and nematodes, mesofauna such as microarthopods, enchytraeids, macrofauna such as earthworms, beetles, termites and millipedes (Gaur 2006a).

Biodiversity and soil are interlinked which interact closely with wider biosphere. Conversely, biological activity is ofprime importance in influencing the physical and chemical conditions of soil (Bardgett 2005). The level of soil biological activity is, therefore, affected by soil type and also depends on the use of management practices which contribute to crop productivity.

Soil biodiversity and soil processes

A majority of soil organisms participate in various processes which are essential for the biosphere. The main ecological function is to decompose organic matter largely derived from the plant and animals residues Which consist of celluloses, hemicelluloses and lignin, and to supply plant nutrients to support growth. These organisms participate in various nutrient cycles and processes such as nitrogen mineralization, nitrification, nitrogen fixation, transformations ofphosphorus, potassium, sulphur, calcium, magnesium, iron and micronutrients (Pankhurst et al 1997). They participate in bioremediation of harmful compounds such as heavy metals and pesticide residues (Gaur 2006 b). They not only maintain physical and chemical conditions of soil, but also regulate emissions / assimilations of green house gases and suppress soil borne diseases and pests

1.    Introduction    129
2.    Soil Microbiology    129

    2.1.    Bacteria, 130
    2.2.    Fungi, 132
    2.3.    Algae and Cyanobacteria, 132
    2.4.    Protozoa, 132
    2.5.    Viruses, 135

3.    Water Microbiology    133
4.    Microbial Associations    133

    4.1.    Neutral interactions, 133
    4.2.    Positive interactions, 133
    4.3.    Negative interactions, 133

The study of soil microorganisms involves various complicacies when compared with those of plants or animals aboveground. The complicated heterogeneous environment existing in soil and the varied growth behaviour of microbial populations in soil have necessitated the development of special techniques to study the microbes and their metabolic diversity, individually and holistically without disturbing their natural habitat. With the gradual improvement in microscopy since its discovery in 1667 and also with the greater understanding of the nature of soil microbes and their properties in relation to total ecosystem function, the concept of studying microbes in isolation has enormously changed. Microscopes have helped in magnifying these, otherwise invisible, minute creatures within the limits of naked eyes.

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.

Genetics is the study of what genes are, how they carry information, how their information is expressed, and how they are replicated and passed to subsequent generations or other organisms.

DNA in cells exists as a double-stranded helix; the two strands are held together by hydrogen bonds between specific nitrogenous base pairs: A-T and C-G.

A gene is a segment of DNA, a sequence of nucleotides, that code for a functional product, usually a protein.

When a gene is expressed, DNA is transcribed to produce RNA; mRNA is then translated into proteins. This is also referred as Central Dogma of Life. The DNA in a cell is replicated before the cell divides, so each daughter cell receives the same genetic information.

The term growth for bacteria and other microorganism usually refers to changes in the total population rather than an increase in size or mass of an individual organism. As the mechanism of conservation and dissipation of heat generated during metabolism lacks in bacteria, the enzyme system in bacteria gets directly influenced by temperature. The purpose of studying the bacterial growth curve is a) to become familiar with the population growth dynamics of bacterial culture and b) to plot a growth curve and determine the generation time of bacterial culture.

A number of methods are now available for measuring bacterial growth. Some important ones are

1)By colony counting or cell counting

2)By weighing the cells

3)By cell activity (turbidity method)

Introduction

The increasing concern about the long-term productivity of agro ecosystems has emphasized the need to develop a management strategy that maintains and protects the soil resources. This is directly related to the maintenance of the level of soil organic matter and nitrogen status, which are the critical components of soil productivity. These parameters can change over time due to crop management practices such as cultivation, crop rotation, residue management or fertilization which, in turn, can influence the long-term sustainability of ecosystem. Application of chemical fertilizer is one of the most expensive inputs in agriculture. About 65% of the applied nitrogenous fertilizer is lost from the plant–soil system through gaseous emissions, runoff, erosion and leaching which causes greenhouse effects and nitrate pollution of surface and ground water (Rejesus and Hornbaker 1999). Similarly, P applied in soil is rapidly fixed and results in low P availability for plant production. In this context, the deployment of microbial biofertilizers promise increasing soil nutrient availability in integrated nutrient management system.

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. 

1.    Introduction    174
2.    The Thermodynamic and Mechanistic basis of Cellular Metabolism    174

    2.1.      Adenosine triphosphate, 175
    2.2.    Coenzyme A, 176
    2.3.    Modes of ATP synthesis, 177

3.      Components of Electron Transport Chain    181

    3.1.    Electron carriers in ETC, 182
    3.2.    Complex I - NADH dehydrogenase (NADH coenzyme Q reductase), 185
    3.3.    Complex II - Succinate - coenzyme Q reductase, 187
    3.4.    Complex III - Coenzyme Q - cytochrome c reductase, 187
    3.5.    Complex IV - Cytochrome c oxidase, 188
    3.6.    ATP synthese, 188

The essential nutrients and their function in microbial cells

Abstract
 
Opencast mining destroys the original land ecosystem and microbial community due to mining and stockpiling of mine rejects on adjoining land, which is a matter of great environmental concern. Mining creates formation of wastelands, formation of gullies, ravines, overburdens, reduced water infiltration and increased runoff. Reclamation of mined out areas is often difficult due to its chemical, physical and biological traits. Absence of topsoil is the most common feature of the mine spoils dumps. Arbuscular mycorrhizal fungi (AMF), the synonym of VAM fungi, are important microbes of soil that form symbiotic association with most of the terrestrial plants on the earth. Observations led to use of legume microsymbionts as biological substitutes for fertilizers. AMF diversity increases with species diversity of plants as the potential number of association increases. Dominant arbuscular mycorrhizal fungi can prevent the invasion of non-mycorrhizal plants on land where they have established symbiosis and promote their mycorrhizal host.

Abstract

Anaerobic sulfur compound reduction processes make use of sulfur, thiosulfate, trithionate, tetrathionate, and sulfite during the reduction process. Complete reduction of these sulfur compounds leads to production of H₂S. Isolation of sulfur compound reducers requires a suitable electron donor and one of the sulfur compound as a sole electron acceptor during the reduction process carried out in anaerobic conditions. Anaerobic sulfur, thiosulfate and tetrathionate reductases identified to date are molybdopterin binding oxidoreductases that extract out electron during the reduction process. The electron transport chain during the reduction process involves cytochromes and menaquinones. Dissimilatory sulfite reductases include conventional siroheme dissimilatory sulfite reductase and the nonconventional sulfite reductases including ASR sulfite reductase, F₄₂₀ dependent sulfite reductase and the MccA sulfite reductase. Anaerobic sulfur compound reduction process are almost ubiquitous in nature and are important part of the biogeochemical cycle. They occurs in aquatic systems, are found in extreme environments such as hydrothermal vents, acid mine drainage sites and are also found in important human and animal pathogens.

Abstract

Microbiological synthesis of nanoparticles has emerged as rapidly developing research area in nanotechnology across the globe with various biological entities being employed in production of nanoparticles constantly forming an impute alternative for conventional methods. Simple prokaryotes to complex eukaryotic organisms including higher plants are used for the fabrication of nanoparticles. In the present article, the synthesis of important plant nutrients like Mg, Zn, Ag, Au, Ti, P and Fe nanoparticles from different fungal species, their characterization and application potential of nanonutrients in agriculture is elaborately discussed.

Soil microorganisms immobilize and mineralize various elements to satisfy their growth requirements. The subsequent turnover of microbial biomass also releases several mineral elements. The elements may be released as a result of organic matter decomposition (e.g. during the process of mineralization, ammonification, etc.) or through biological weathering. Other transformations may involve oxidation and reduction of various inorganic ions and compounds which are mostly catalyzed by chemoautotrophic bacteria during oxidation of ammonium, nitrite, sulphur, iron, etc. Such oxidations may also release energy for microbial growth.

Introduction

Phosphorus is only second to nitrogen as a mineral nutrient required for plants, animals and microorganisms. It is a major constituent of nucleic acids in all living systems essential in the accumulation and release of energy during cellular metabolism. Phosphorus is found in soil, plants and microorganisms in number of organic and inorganic compounds. It is the second major inorganic nutrient after nitrogen in term of quantitative requirement for both crop plants and microorganisms. This element may be added to soil in the form of chemical fertilizers, or it may be incorporated as leaf litter, plant residues or animal remains. In cultivated soils it is present in abundance (i.e. 1100 kg/ha), but most of which is not available to plants, only 15% of total soil phosphorus is in available form. Thus, phosphorus occupies a critical position both in plant growth and in the biology of soil.

Introduction

In soil, microorganisms influence not only the availability of carbon and nitrogen, which are important constituents of plants, but also of sulfur (S), phosphorus and many other trace elements for plant absorption. Sulphur is found widely distributed and considered as tenth most abundant element in the nature. Sulfur is considered as an essential element for survival of plant and animals and found as gypsum (CaSO₄.2H₂O), pyrite (FeS₂) and other combined form and also in elemental form (S⁰) in the nature. The requirement of sulphur by plant is comparatively less than the primary nutrients, hence sulfur is recognised as ‘secondary’ nutrient. 

The basic methods for wastewater sewerage (collection, treatment, and disposal) are as follows:

• Off-site sewerage
• Separate sewerage system
• Combined sewerage system
• On-site sewerage

Many nations have implemented separate sewage systems that transmit sewage and storm water through separate pipelines in order to separate the two. Storm water often does not contribute to a wastewater treatment facility (WWTP). Domestic sewage contains 99.9% or more water. The remaining portion is made up of bacteria

Life on Earth is dependent on microorganisms for many essential services. Microbes are intimate partners in global agriculture by way of mobilization of nutrients, antagonism against pathogens and exploitation of plant- microbe interactions and optimization of plant microbiome allows farmers to apply less chemical fertilizers and pesticides, and improving plant growth and yield for sustainable development.

India has 2.4% of land area of world and 8.1% global species diversity. India has 7500 km long coast line in nine states and three union territories. About 14% of Indian population (17 crores) lives in coastal area. In 10.78 million ha of coastal ecosystem, rice is the major coastal crop. Coastal rice accounts for 15% of total area and production of India. Coconut, cashew, areca nut, spices, plantation and fruit crops are the other important coastal crops. The east coast in four states (Tamil nadu, Andhra Pradesh, Orissa, West Bengal) and one union territory (Pondicherry) has sandy coast and plains with medium to high rainfall (100-250 cm), and hot humid climate. It has marshy lands and mangroves. The west coast in five states (Kerala, Karnataka, Goa, Maharashtra, Gujarat) and two union territories (Diu and Daman, Dadar and Nagarhaeli) has fertile sandy plains with high rainfall (250-300 cm) and hot humid climate suitable for horticulture and plantation crops. Western Ghats near west coast is a hot spot with high biodiversity. ICAR established the Central Coastal Agriculture Research Institute (CCARI) at Goa in 2015 to carry out research on coastal agricultural crops.

Soil salinity in coastal regions is not only a soil type character, but also due to low quality irrigation water. The plant associated microorganisms “Plant microbiome” play a significant role in conferring resistance to soil salinity. The endophytic bacteria- rhizobium, rhizobacteria- azospirillum, azotobacter, phosphobacteria, PGPR bacteria, cyanobacteria, symbiotic fungi- ecto and endo mycorrhiza, alleviate the impact of soil salinity. Minimal microbiome for plants is the key determinant of plant health and productivity. The plant- microbe interactions are of three types: (i) Positive: Beneficial organisms- nitrogen fixers, phosphobacteria, mycorrhiza; (ii) Negative: Harmful organisms - plant pathogens; (iii) Neutral: Transient organisms. Millions of microbes inhabit plants, form complex ecological communities to improve plant growth, crop quality and productivity.

A farm microclimate refers to the specific climatic conditions of a small, localized area within a farm. These conditions can differ significantly from the broader regional climate due to various natural and man-made factors. Understanding and managing microclimates is crucial for optimizing crop growth, animal welfare, and overall farm productivity. Modern commercial dairy production requires a special approach to the microclimate on the farm. High quality milk and animal health depend on the conditions of their keeping. At the same time, farm for dairy production for the most part do not have the means to control and manage the microclimate, in contrast to poultry farm. When organizing the correct process of controlling the microclimate, a prerequisite is the presence of an automated system for collecting data. Generally animals adapt to a wide range of weather conditions although their growth and productivity varies with weather conditions. Buffaloes and cows form the main component in dairy industry. The extent to which these animals can adapt to different weather conditions is given below: Successful management of buffalo rearing will be incomplete without wellplanned and adequate housing facilities (Fig.10.1).
Improper planning in the arrangement of animal housing may result in management problems, increase in disease incidence, additional labour charges and hence decrease in the profit of the farmer. During erection of a house for dairy buffaloes, care should be taken to provide comfortable accommodation for individual animals. It is important to ensure:
• Proper sanitation
• Durability
• Abundant supply of clean water
• Arrangements for the production of clean milk under convenient and
economic conditions.
Buffaloes may be successfully housed under a wide variety of conditions, ranging from close confinement to little restrictions except at milking time. However, two types of farms are in general use.

Change in weather affects growth and development of plants. The extent of these effects depends upon the range or severity of change of weather. It is very much possible to change the weather in relatively small area to reap better harvest. Micro weather modification is defined as, “The manipulation of weather elements at increasing or decreasing the duration, intensity, quality etc., for desired effects at microlevel of crop under investigation”.

The climate near the ground can be managed partly by influencing the moisture status and temperature of the upper soil layers, e.g. by mulching and partly by action above the ground e.g. by shading or use of wind breaks.

There is an increased use of Glass houses and poly houses in commercial agriculture. The glass houses and poly houses provide a controlled environment for plants throughout the year. Some of the aspects of related to the advantages of Glass houses and poly houses are highlighted in the following text:
9.1. Glass houses
Glass houses are also referred as greenhouses. The glass prevents harmful ultraviolet radiations. The glass is transparent to solar radiations of wavelengths up to 300 nm and does not allow long-wave radiations to pass through it (Fig.9.1). Therefore, the Glass houses maintain higher temperature and high relative humidity during daytime as well as nighttime and offer the following advantages:
9.1.1. Controlled Environment: Glass houses facilitate regulation of temperature,
humidity, and light intensity, creating optimum environment for growing various plant species. This is especially beneficial for tropical and sub-tropical plants that require specific conditions to grow and survive.
9.1.2. Protection from Pests and Diseases: The enclosed glass house protects
plants from pests and diseases. The glass house also protects the plants from harsh weather conditions thereby minimizing risk of infestations and environmental stresses. Fig. 9.1: Microclimate management in Glass house
9.1.3. Extended Growing Season: By maintaining stable climate, glass houses
enable cultivation of plants that may not survive outdoors in certain climates thereby extending the growing season for sensitive species.
9.1.4. Research and Conservation: Botanical gardens often use glass houses for
research purposes, studying plant growth, genetics and breeding. The glass houses will also serve as a means for conserving rare or endangered plant species by providing stable environment for propagation. The advantage of glass houses is that the structure has long life span.
9.2. Poly houses
The poly houses are constructed using polythene material. The poly houses protect the plants from wind, cold weather, hail storms, extreme temperatures, insects and pests. The polythene house farming is a popular greenhouse technology due to its low cost of construction and maintenance. Generally, heat accumulation (70 to 75 per cent of solar energy) takes place inside the polyhouse. Solar radiation is allowed to pass through the polythene material and the long wave radiation cannot escape through polythene. The benefits of poly houses are:

There is growing demand for increasing fruit production as fruits are considered to be healthy, nutritious and easy to digest. Fruits are natural foods and have export potential as well as provide opportunities for increasing employment by establishing fruit processing industries. Some of the fruits can be grown around the year where as some fruits are of seasonal in nature. Usually, the fruit cultivation is undertaken by establishing orchards. In case of orchards, wrong decisions in planting may result in huge loss and therefore right method of planting is the key factor for establishing orchards.
The fruit crops are of three types depending on the adoptability to the climate of the region and are grouped as
• tropical fruits
• sub-tropical fruits
• temperate fruits
The microclimate of the orchards depends upon
• height of the plants/trees
• horizontal spread
• canopy architecture
• spacing/plant density
• age of plantation
• seasonal weather
15.1. Tropical Fruits
The tropical fruits require higher temperature throughout the year. The crops do not require low temperature for breaking dormancy and for flowering. The plants are ever green and grow throughout the year. There plants are well adopted to regions where the minimum temperatures are more than 10°C and very sensitive to frost. There are grown in tropical regions between 23°N to 23°S latitudes. The optimum maximum temperature for growth and development ranges from 30 to 37°C.
15.2. Sub-Tropical Fruits
The sub-tropical fruits perform better between temperate and tropical climates as the plant requires both high and low temperatures. Some of the fruit crops are green and some of those are deciduous. The temperate fruit crops are very sensitive to frost. The sub-tropical fruit plants break dormancy of flower buds

Microclimate under irrigated conditions and dryland conditions can differ significantly due to variations in water availability, which influences several environmental parameters such as temperature, humidity, soil moisture, and vegetation cover. The crops are grown both under irrigated and dryland / rainfed situations. The major difference between irrigated and dryland conditions is availability of water. In irrigated areas, the crops are regularly provided with water through irrigation at regular intervals. Under dryland situations, the water availability to the crops depends upon the rainfall and/or stored soil moisture. Under irrigated situations, there are two different possibilities as indicated below:
• vast stretch of irrigated areas
• isolated pockets of irrigated areas in predominantly dry areas. In dryland areas the following possibilities exist:
• humid and moist sub-humid areas where predominantly rice based cropping systems are adopted during rainy season
• per-humid areas where plantation crops and rice grown during rainy season.
• dry sub-humid areas with rice based cropping systems in low lands and finger millet, maize based cropping systems in upland areas
• semi-arid regions where kharif crops are grown during rainy season.
• rabi-crops grown under conserved moisture conditions during post rainy season.
• arid regions where pearl millet based cropping system are practiced during rainy season.
• hill agriculture
The microclimatic conditions are likely to vary between irrigated and rainfed conditions due to different agro-ecological settings. The comparative analyses of microclimatic variation under both conditions are given below:

Modifying microclimates in agriculture involves altering the local climate conditions surrounding crops or plants to create a more favorable environment for growth. This can be achieved through various techniques when the crops are subjected to weather related stresses.
14.1. To Mitigate Moisture Stress during Droughts
When the crops are under moisture stress, the principles involved are conservation of soil moisture and reduce the evapotranspiration from crops. The moisture conservation can be achieved by suppressing soil evaporation using mulches (Fig. 14.1). The evapotranspiration can be reduced using antitranspirants. Some antitranspirents close the stomata of the leaves to reduce evapotranspiration. Some anti-transpirants increase the reflectance of radiation from the crops, thereby reducing heat load on crops. When crops are grown under irrigation in isolated patches, micro shelter belts can be provided across the predominant wind direction to reduce the increased evapotranspiration from advection. Advection is phenomena of horizontal transport of heat due to strong hot and dry winds.

Modifying microclimates in agriculture involves altering the local climate conditions surrounding crops or plants to create a more favorable environment for growth. This can be achieved through various techniques when the crops are subjected to weather related stresses.
14.1. To Mitigate Moisture Stress during Droughts
When the crops are under moisture stress, the principles involved are conservation of soil moisture and reduce the evapotranspiration from crops. The moisture conservation can be achieved by suppressing soil evaporation using mulches (Fig. 14.1). The evapotranspiration can be reduced using anti transpirants. These are chemicals sprayed on crops. Some antitranspirents close the stomata of the leaves to reduce evapotranspiration. Some chemicals increase the reflectance of radiation from the crops, thereby reducing heat load on crops. When crops are grown under irrigation in isolated patches, micro shelter belts can be provided across the predominant wind direction to reduce the increased evapotranspiration from advection. Advection is phenomena of horizontal transport of heat due to strong hot and dry winds.

The science dealing with the measurement of size of any microscopically visible microorganism is known as micrometry which is based on the principle of physics. Before measuring a cell, the diameter of the microscopic field must be established by means of optic devices, namely an ocular micrometer and a stage micrometer.

a)Ocular micrometer : It is a circular disc that is placed in the eyepiece. The disc is graduated in to several small divisions marked from 0 to 100.It is placed inside the eyepiece of the microscope. The distance varies according to the objective of the microscope which can be easily determined by using a stage micrometer.

b)Stage micrometer : It is a glass slide graduated in 1 mm. Again 1mm is divided into 10 large divisions and 100 small divisions (10 x 10 = 100 divisions). These divisions are equally placed therefore 1 small division is equal to 0.01 mm or 10 μm.

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.

Abstract

Micronutrient (vitamin and mineral) deficiencies affect more than 2 billion people worldwide and are especially prevalent in developing countries including India. Conditions due to vitamin mineral deficiencies account for 7.3 percent of the global disease burden.Iron deficiency (anemia), vitamin A and iodine deficiency disorders continue to be a grim public health problem. Thus, elimination of vitamin and mineral deficiencies is essential to improve the overall health of the masses as well as to sustain economic growth and national development. Food fortification is an effective intervention to deliver vitamin and mineral rich foods to large populations. In addition to the prevention of vitamin and mineral deficiencies, food fortification is an effective measure to raise vitamin and mineral levels by moving the population towards consuming recommended dietary allowances for most micronutrients-making it a long–term and a sustainable strategy. India is the largest producer of milk in the world with 146.3 million tonnes and the consumption rate of milk and milk products by all age groups of people are high.Therefore, fortification of milk with mineral and vitamins could be a safe and effective strategy to fight these micronutrient deficiencies.

Micronutrients are required in small quantities but are essential for normal plant growth and crop productivity. Their availability in irrigated soils can vary considerably because of changes in soil pH, moisture conditions, organic matter, texture and interactions with other nutrients. This chapter introduces the concepts of micronutrient deficiency and toxicity and discusses critical limits used for evaluating micronutrient status. Particular emphasis is placed on boron and zinc. Boron content, deficiency in Indian soils, availability and leaching are examined, together with the influence of soil texture, pH and moisture. Boron indicator plants, correction of deficiency, sources, crop response and frequency of application are also discussed. Interactions between boron and other nutrients receive attention. The chapter then considers zinc content and zinc deficiency in soils and examines the influence of pH, phosphate level, organic matter and adsorption by clay minerals on zinc availability. Methods, timing and rates of zinc application and crop responses are presented to support effective micronutrient management.

ZINC (Zn)

Chandler et al., (1932) deduced the requirement of zinc by plants while working solution for little leaf or “rosette” on peach. Zinc plays significant role in assimilation of NO₃ and for synthesis of tryptophan. Involved in biosynthesis of indole acetic acid which is responsible for f lowering and fruiting, it is an activator of several enzymes (triphosphate dehydrogenase and tryptophan synthetase), involved in photosynthesis and nitrogen metabolism.

Deficiency results in poor growth of the terminal bud. Decrease in stem length resulting in resetting and whorling of leaves. Zinc deficiency disorder in rice is called khaira. Common when zinc availability is < 0.7 ppm. White bud in maize and malformation of fruits, reduction in water uptake. Interveinal chlorosis often with necrosis and pigmentation and reduced leaf size in broad leaved crops known as little leaf and malformation of leaves.

The crops which are known to respond for zinc application are maize, rice, soyabean, castor, onion, barley, wheat, potato, sorghum and cotton

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

25.1 Determination of Available Micronutrient cations (Zn, Cu, Fe and Mn) in Soil

The available micronutrient cations (Zn, Cu, Fe and Mn) can be estimated in a single extraction with diethylene triamine pentaacetic acid (DTPA) as proposed by Lindsay and Norvell (1978). DTPA has the excellent property to combine with free metal ions in the solution forming soluble complexes. The stability constants of metal-DTPA complexes make DTPA as a most suitable extractant for simultaneous complex formation with Zn, Cu, Fe and Mn. In calcareous soil DTPAextractant may result overestimation due to excess dissolution of CaCO₃, causingrelease of occluded micronutrient cations which are not plant available. To avoid this excessive dissolution of CaCO₃, DTPA is buffered at pH 7.3 using triethanol amine (TEA). At this pH major part (3/4^th) of TEA is present as HTEA⁺ (protonation) and exchanges for Ca and Mg ion from the soil exchange site. This increases concentration of Ca and Mg in the solution phase and suppresses dissolution of CaCO₃. The DTPA has the capacity to form complex with each of the micronutrient cations 10 times of its atomic weight and it ranges from 550 to 650 ppm depending on the micronutrient cation.

The amount of cation in the extract is determined on an atomic absorption spectrophotometer (AAS). The experimental condition such as shaking time, DTPA concentration, pH and temperature during shaking influence the amount of Zn, Cu, Fe and Mn extracted. Increase in shaking time and temperature markedly influence the extractability of these cations.