eChapters

Abstract

The substantial loss in the shielding ozone layer has resulted in an increase in the solar ultraviolet radiation (UVR) on the Earth’s surface, which is detrimental for all living organisms ranging from prokaryotes to eukaryotes, including humans. This has augmented the scientific concern and interest in searching for the photoprotective compounds from diverse organisms. Cyanobacteria, the primitive O2-evolving photosynthetic prokaryotes are solely dependent upon the solar radiation for their energy requirement and thereby have to always face the UV-B stress. UVR affects cyanobacteria either directly or indirectly by inducing oxidative stress. In response, they have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing compounds such as, mycosporine-like amino acids (MAAs), scytonemin, carotenoids, biopterin glucoside, as a strategy to reduce the direct and indirect damaging effects of UVR.

Abstract

Being an obligate photoautotroph, cyanobacteria must cope with a wide range of fluctuating environmental factors, including high light and ultraviolet radiation (UVR) that may lead to oxidative stress by upsetting the cellular redox status. Photo-induced oxidative stress by means of oxidizing agent such as reactive oxygen species (ROS) may damage several biological processes. In response to several adverse effects of solar UVR, cyanobacteria have developed different strategies such as heat dissipation mechanisms, synthesis of UV- absorbing/screening compounds and antioxidant systems to overcome the detrimental effects of intracellular oxidant molecules. This review deals with UV-induced oxidative stress and their counteracting mechanisms operating in cyanobacteria.

Abstract

Present implementation of mass spectrometers has allowed developing new approaches in algal research. Soft ionization techniques like atmospheric pressure chemical ionization (APCI), electrospray ionization (ESI), and matrix assisted laser desorption ionization (MALDI) extend the analytical possibilities of mass spectrometry (MS) beyond classical fatty acid analysis by gas chromatography (GC) with electron impact ionization (EI). New MS-based analytical methods have been developed over the last two decades for algal molecule research including membrane lipids, carotenoids, mycosporine-like amino acids and peptides.
 
MS-based Metabololomics approaches have also been used to gain insights into algal biochemistry and physiology. This review aims at highlighting the achievements in algal research gained by using these recent research tools and their future prospects.

Abstract

Twelve different cyanobacteria strains from different locations in Syria were collected and analyzed. They were identified as strains from Anabaena, Nostoc, Phormidium and Chroococcus. All strains produce mycosporine-like amino acids (MAAs) as UV-screens upon UV-radiation. Composition of the MAAs and amount of UV-induced MAA production differ between the strains. In order to evaluate the long-term stability of completely encapsulated cyanobacteria aliquots were transferred into hermetically closed vessels. The survival was non-invasively determined by means of pulse-amplitude modulated fluorescence and by delayed fluorescence detection. It was found that 4 strains (one Chroococcus, two Anabaena and one Nostoc species) show photosynthetic performance after 4 years of encapsulation. In addition, many cyanobacteria are desiccation tolerant and are able to fix atmospheric nitrogen. They may play an important role in biological life support systems e.g. in space research.

Abstract

Cyanobacteria have gained a lot of attention in recent years because of their novel applications in biotechnology, besides their well recognized role as inoculants for rice crop. They represent favourite model organisms for a deeper understanding of several plant and microbial metabolic processes and efficient systems for the production of recombinant compounds of pharmaceutical and commercial value. They have been identified as a rich source of biologically active compounds with antiviral, antibacterial, antifungal and anticancer activities, which illustrate their potential as biocontrol agents. The genus Anabaena assumes significance not only as a diazotroph, but also as a rich source of pharmacologically active and structurally interesting secondary metabolites with diverse applications in agriculture and industry. The present compilation aims to present an overview of the literature available globally, and studies undertaken in India illustrating the diversity and potential of Anabaena strains, besides their significance in biology and evolution.

Summary

Reaching large-scale implementation should be the overriding objective of all projects that have successfully ISFM practices to share provide markets support them. All too often ISFM results are only reported in peer-reviewed journals that are not accessible outside the research community.
 
Funding agencies often fail to make the production of extension materials an integral and mandatory requirement of research projects.
Unfortunately, in the past, adoption of economically proven technology has often been poor. Some of the reasons include:

Summary

Food production starts with a good soil. No matter the kind of seed and good agronomic practices that are put in place without a good soil yields will be low and hence income. ISFM is a technology that helps to solve the problem of soil infertility and production.
 
Farmers only accept and adopt a technology if they see it to be superior to what they have been doing and it makes business sense. Farmers will not worry about the bigger picture of food security or increased production – they need to make a profit to support their household.

Summary

ISFM is important, cost-effective and has the potential of improving farming efficiency and crop productivity. This is only possible when farmers understand the concept and follow recommended practices in the ISFM approach.
 
The challenge is how to effectively disseminate ISFM practices to farmers for sustainable crop production.

Summary

Fertilizers are materials when applied replenish lost soil nutrients on farmer’s field. Without the use of fertilizers farmers would find it extremely difficult to increase their production to meet the ever-growing mouths. The purpose of this session is to discuss what a fertilizer is, and the different terminologies used in fertilizer technology.

Summary

The use of organic resources in modern agriculture implies the production of crops through organic farming without doing any damage to the environment. Synthetic chemicals are never used in organic farming. This avoids having much pressure on nature’s non-renewable resources used in farming activities. In this unit, we shall discuss many organic resources, their quality and management within ISFM.

Sources of plant nutrients include residual soil nutrients, crop residues, green manures, animal manures and biosolids, biologically-fixed nitrogen and manufactured fertilizers. Crops use plant nutrient from all sources but the nutrient elements must be transformed into the ionic forms before being taken by plants. The amount of nutrients provided by different sources varies between and within agro-ecosystems. Integrated plant nutrient management identifies and uses all available sources of plant nutrients

Summary
 
ISFM has been defined in a number of ways – but here an emphasis is placed on finding a way to explain ISFM that makes sense to the intended audience. When combined with general good agronomic practices the combination of improved planting material, chemical fertilizer along with the addition of organic mater, increases productivity.  There are, however, constraints at the smallholder level – in terms of access to farm inputs e.g. seed, credit &labour.This section looks at short and long-term approaches to the application of basic nutrients. The issues of recycling nutrients and the impact of erosion on the nutrients in the soil. There is a review of the pros and cons of ISFM – it does increase yield (4 -6 times more production).  There is a brief outline of the role of cover crops, mulching and conservation tillage as forms of agriculture that can help reduce soil erosion.The section locates the idea of ISFM along side integrated pest management and explores the impact of biological control agents in Ghana and the role of micro-organisms.

Summary

This chapter looks at the various approaches available to the farmer for the management of soil fertility. In general there are four approaches, namely, physical, biological and chemical approaches as well as the cropping systems or agronomic approach.This chapter discusses three approaches, physical, biological and cropping system or agronomic approaches. Chemical approach has been treated in chapter 7 of this book. Inoculation is an important technique in legume production. This chapter also looks at inoculation and how it is done.

Summary
 
This chapter explores different approaches to manage water in rain-fed and irrigated agricultural systems. The first methods support the retention of water and reduce soil erosion. These methods include mulching – the application of a surface coating over the soil – which is usually organic mater. This reduces the damage to soil caused by rain and wind and reduces water loss to evaporation and helps with infiltration. The other methods explored are bunding and terracing.  These approaches are about stopping the flow of water across land to increase the amount of water infiltration into the soil and to reduce or prevent soil run off.  These approaches are labour intensive. A less labour -intensive approach is contour ploughing. This approach is about encouraging farmers and tractor drivers to plough across sloping fields not up and down them. The second group of technologies refers to the introduction of water through irrigation methods.

Summary

The soil is the basis of agriculture as the productivity of the farm enterprise is strongly linked to the fertility status of the soil. The soil acts as a reservoir for the essential nutrients that crops need for growth. When these nutrients are in sufficient quantities and balance, agricultural productivity is greatly enhanced. On the other hand if the nutrients are in short supply and imbalanced, crop growth is hampered. When crops grow and produce harvest, they remove nutrients from the soil. These nutrients are exported when the grains or edible parts are eaten and the stover removed. Consequently with time, a soil that is considered fertility will also lose its fertility if no nutrients are added periodically. It is important to assess the fertility status of the soil before planting and all necessary ameliorations effected in time to ensure a good harvest. Various methods exist for evaluating soil fertility. The best indicator of a fertile soil is good growth of crops growing on it.

Summary

Soil fertility is the ability of the soil to support plant growth. The productive capacity of the soil depends on complex interactions between biological, chemical and physical properties of the soil. In essence, soil fertility does not refer only to plant nutrients but also soil organic matter, structure and maintenance of thriving soil organisms. Good farm practices aim at managing the various factors that make up each of these three properties to optimize yields of crops in an environmentally friendly manner. The debate on soil fertility is often erroneously limited to issues relating to plant nutrients.

Introduction

Engineered nanoparticles are a group of products that are defined by their size, ranging from 1 to 100 nm. Due to the smaller size, the physio-chemical properties of nano particles become very different from those of the same material in a larger form. Total production of nano-materials is expected to increase considerably in the near future. Nanotoxicology is yet another emerging field of science dealing with the effects of nano-devices and engineered nano-particles on living organisms. It has been observed that the materials in nano-dimensions react totally different in comparison to their existence in micro or macro sizes.

Introduction

The characterization of the potential health impact of engineered materials produced through nanotechnology is an emerging issue of considerable discussion and debate. The current focus on nanotoxicity fails to assess the risk in different local environments and populations. People in developing countries may be more prone to adverse effects of nanoparticles because of underlying health conditions and malnutrition. Moreover, genetic susceptibility to toxic effects varies in diverse ethnic groups and geographical areas. The scientific community needs to identify these information gaps before developing regulations and standard methodologies for nanotoxicity assessment.

Introduction
 
Nanotoxicity is a serious concern to be addressed sooner than later as nano-based processes and products in various fields are being extensively exploited. Nanotoxicology is the science of engineered nanodevices and nanostructures that deals with their effects in living organisms (Oberdorster et al., 2005). The unique property of nanoparticles is in its very large surface area to mass ratio, which is considered to be a boon to create novel products. But this distinctive property also challenges the way we identify, understand and address potential risks caused by nanoparticles (Rajkishore et al., 2011). It is sufficient to alert us to the fact that some engineered nanoparticles do indeed behave differently to their more conventional counterparts and may present new and unusual risks. Kahru and Dubourguier (2010) assessed the existing literature on nanotoxicity to main food chain levels (bacteria, algae, crustaceans, ciliates, fish, yeasts and nematodes) and classified the NPs of Ag and ZnO as “extremely toxic”, C60 fullerenes and CuO NP as “very toxic”, SWCNTs and MWCNTs as “toxic” and TiO₂ NP as “harmful”. 

Introduction
 
Maintaining and restoring the quality of air, water and soil is one of the great challenges of our time. Most countries face serious environmental problems, such as the availability of drinking water, the treatment of waste and wastewater, air pollution and the contamination of soil and groundwater. There are two main approaches to these problems: the first is to control pollution at source to minimize or eliminate waste production or harmful emissions; the second is to remedy the pollutants that accumulate in the environment. Considering the enormous scale of soil and groundwater contamination, the complexity of the task seems intractable. In many cases, conventional remediation and treatment technologies have shown only limited effectiveness in reducing the levels of pollutants, especially in soil and water (Rickerby and Morrison, 2007).

Introduction

Food packaging is a critical technology addressing the ever-increasing demands for convenience, freshness, ease, shelf-life, safety and security of food products.
 
The main purpose of food packaging is to protect the food from microbial and chemical contamination, oxygen, water vapor and light. The type of packaging used therefore has an important role in determining the shelf-life of the food. Nanotechnology can be intervened to achieve the purpose of food packaging and it will become one of the most powerful forces for innovation in the food packaging industry.

Introduction

Fruits are important sources of vitamins, carbohydrates, fiber and sugar. A large variety of fruits are grown in India, of which mango, banana, citrus, guava, grape, pineapple and apple are the major ones. In India, grapes occupies fifth position amongst fruit crops with a production of 16.77 million tonnes from an area of 0.64 million ha (FAO, 2009). The total grape export from India during the year 2007-08 was 96,723 tonnes worth Rs 317.84 crores. (APEDA, 2009). Grape is an excellent source of many nutrients and phytochemicals, able to contribute to a healthy diet. Grapefruit is a good source of vitamin C and pectin fiber. The major varieties of grapes grown in India are Thomson seedless, Sonaka, Anab-e-Shahi, Perlette, Banglore blue, Pusa seedless, Beauty seedless etc. (NRCG, 2009). Red grapes are grown in large quantities, especially for wine and juice production. Grapes are used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, grape seed oil and some kinds of candy.

Introduction

Fungicides are biocidal chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. An insecticide is a pesticide used against insects. Pyrethroids are widely used insecticides in agriculture as they control pests and diseases effectively in plants. Because of their low biodegradability and high persistence, they are extensively found in environmental samples such as air, water, soil, sediments, food and biological tissues [1-4]. Moreover, these chemicals induce cancer and act as endocrine disrupters in several organisms due to their high degree of toxicity. Although the use of most pyrethroids has been prohibited or limited in developed countries, they are used in many developing and under developed countries for controlling of pests and insecticides [5-8].

Introduction

Spoilage in agricultural products due to mould growth can occur at various stages of production and storage and is significant in terms of trade economics, food safety and public health (Shephard, 2008). It has been reported that 5–10 % of agricultural products in the world are spoiled by mould contamination to the extent that they cannot be consumed by humans or animals. Mould growth decreases the quality of food and also creates a potential risk for human health because of the production of toxic secondary metabolites known as “mycotoxins”. Foods contaminated by mycotoxins, when consumed by humans and animals causes a disease called “mycotoxicosis”, resulting in death (Wagacha and Muthomi, 2008).

Introduction

Plant diseases are one of the causes of concern in agriculture and horticulture industry. Estimated global crop loss due to plant diseases exceeds hundred billion US$ worldwide (Orke et al. 1994; Narayanasamy, 2010). Plant diseases are caused by microorganism such as fungi, bacteria, viral, viroids and phytoplasma. Most of the plant pathogens are transmitted through seed or planting material, which can spread secondarily through vectors and lead to severe loss to the crop. Among plant diseases, viral diseases cause serious crop losses and affect the quality of products, while the use of virus- free seeds and planting stocks results in a substantial increase in agricultural crop production (Waterworth & Hadidi, 1998; Strange& Scott, 2005).

Introduction

Crops diseases are caused by bacteria, virus, fungi and phytoplasmas. The detection of pathogenic bacteria and viruses in plants, planting material, vectors or natural reservoirs is essential to ensure safe and sustainable agriculture. The molecular based techniques, have evolved significantly during recent past that  allows the rapid and reliable detection of pathogens. The detection and diagnosis of plant pathogens is essential to take control measures and subsequently for eradication of the disease that causes.  Molecular detection is largely based on PCR or RT-PCR amplification following purification of nucleic acids from the samples, with the extraction of the target DNA.

Introduction

Biosensor technology is a powerful alternative to conventional analytical techniques, harnessing the specificity and sensitivity of biological systems in small, low cost devices. Despite the promising biosensors developed in research laboratories, there are not many reports of applications in agricultural monitoring. The authors review biosensor technology and discuss the different bio-receptor systems and methods of transduction. The difference between a biosensor and a truly integrated biosensor system are defined and the main reasons for the slow technology transfer of biosensors to the market place are reported. Biosensor research and development has been directed mainly towards health care, environmental applications and the food industry. The most commercially important application is the hand-held glucose meter used by diabetics. The agricultural / veterinary testing market has seen a number of diagnostic tests but no true biosensor systems have made an impact.

Introduction

Since past decades, the application of nanotechnology in the areas of medicine, materials science and electronics have been widely accepted and appreciated due to its potential and benefits.  However, only during the recent years, researchers from other disciplines have started to see the potential applications of nanoscience in the field of agriculture (Robinson and Morrison, 2009). Recently, a generalized and process based framework to enable identification and characterization of the outputs (publications, patents etc.), and map them to the different agricultural research theme areas through the filter of links in the agri-value chain were developed by Kalpana Shastri et al., (2010) from National Academy of Agricultural Research Management (NAARM), Hyderabad, India. The frame work also permits assessing the implications for technology transfer, and impacts on society and environment. This frame work mainly relies on the identification of nano research and relating them agri-food thematic areas (Fig.1).

In recent years application of nanotechnology in various fields including agriculture has received increased attention. Nanotechnology offers an important role in improving the existing crop management techniques especially in plant disease management by controlled and targeted release of agrochemicals to enhance their efficiency. The nano-based delivery systems are beneficial because of improvement in efficacy due to their higher surface area, higher solubility, induction of systemic activity, higher mobility and lower toxicity (Sasson et al., 2007). The pharmacokinetic parameters of nano particles may be altered according to size, shape and surface functionalization. They can also be used to alter the kinetic profiles of drug release leading to more sustained release of drug there by reducing the frequent application (Sharon et al., 2010). The successful use of metal nanoparticles in medical streams as antimicrobial agents has also led to their applications in controlling phyto pathogens (Nair et al., 2010).

Background

The demand for development of Integrated Pest Management (IPM) strategies is increasing, since many problems have appeared with the use of synthetic pesticides and semiochemicals – informative molecules used in insect-insect or plant-insect interaction – are being considered as an alternative or complementary approach within IPM strategies. (Heuskin et al., 2011). Indeed, such communication molecules like para-pheromones do not present any related adverse effects on beneficial organisms in the ecosystem.

For fruitflies management, several eco-friendly control options  have been developed and recommended across the globe which  include trapping, safe disposal of infested fruits, repulsion with botanical products and physical covering of the developing fruits, besides area-based control through mass trapping and sterile-insect technique. Nevertheless, the use of para-pheromones-based lures in trap systems appears to have greater potential to be among the more widely adopted practices (Verghese, 2009).

Nanotechnology offers unique opportunities for the development of novel materials and applications. It is set to offer a platform to revolutionize agriculture sector from production, protection, processing and storage (Kuzma and Verhage, 2006). Bulk of nanomaterials produced is used in other sectors; only ten per cent is of use in food, beverages and packaging sector. Studies have projected the opportunities that nanotechnologies might bring to developing countries in the fields of water, energy, food and agriculture and health (Salamanca- Buentello et al., 2005) The key contributions due to application of nanotechnology in agriculture are delivery systems that aid in slow release and efficient delivery of agroinputs.

Nanofibres are an exciting new class of material used for several value added applications in the field of such as medical, filtration as barrier in composites, garments, wipes, insulation, and energy storage. Special properties of nanofibres make them suitable for a wide range of applications from medicine to consumer products and industrial to high-tech applications. The US - National Science Foundation (NSF) defines nanofibres as having at least one dimension of 100 nm or less (Hegde, 2005). Amongst the various nanostructures that have recently been developed for use in practical applications, nanofibres produced from synthetic and natural polymershave received increased attention due to their ease of fabrication and the ability to control their compositional, structural and functional properties (Burgeretal.,2006).

Nanotechnology is an emerging of field of science which is being highly exploited in the sphere of medicine where “nano” plays a vital role in delivery of drugs or chemical molecules to the point it is required in précised quantities in right proportions. Nanoscience infuses intelligence to the truck load of chemical constituents that are to be delivered at appropriate locations and cleave from the site after the task is complete. Such process will likely to reduce the cost besides ensuring environmental safety. Nanoscale devices with its unique properties make the agricultural system more smart and effective; such devices are capable of responding to different situations by themselves, thus taking appropriate remedial action with the need of external directions from humans. In short, these devices act as a detectors and if need arises serve as a solution/remedy for the particular issue. These smart delivery systems of chemicals in controlled and targeted manner can be considered synonymous to the proposed nano-drug delivery system in human (Patolsky et al., 2006).

Introduction

Weeds are unwanted plants in agricultural production causing huge losses in crop production system particularly rainfed agriculture. Of the total estimated losses caused in crop production by pests, diseases and weeds in the world, the weeds alone are responsible for one-third of it. Weeds interfere with crop growth and cause an yield loss to the tune of 10% of crop production which amounts to a total loss of about 20 million MT of food grains, valued at over Rs.10,000 crores, at current prices in India. Besides, losses of similar magnitude are experienced in vegetable, fruit and plantation crops. The losses inflicted on biodiversity, environment and health are considerable and have not been quantified scientifically.

Introduction

Fertilizers play an important role in improving soil fertility and productivity of crops regardless of nature of cropping sequence or environmental conditions. It has been unequivocally demonstrated that one third of crop productivity is dictated by fertilizers besides influencing use efficiencies of other agri-inputs. In the past four decades, nutrient use efficiency (NUE) of crops had hardly exceeded 35-50%, 18-20% and 30-35 % for N, P and K, respectively, despite our relentless efforts. The remaining nutrients stay in soil or enter into the aquatic environment causing eutrophication. In addition to the low nutrient efficiencies, Indian agriculture facing a problem of low organic matter, imbalanced fertilization and low fertilizer response that eventually caused crop yield stagnation (Biswas and sharma, 2008).

Introduction

Seed is the key input in agriculture deciding the fate of productivity of any crops. Indeed, seed is referred as a nature’s “nano-gift” for agriculture. Seed is a smart delivery system where we shall make manipulation to achieve the desirable goals. The seed technologists in the country were trying to find a second or third generation technologies to address the issues of seed science. Nanotechnology is one of the cutting edge research areas that has enormous potentials to solve the unresolved field problems. The application of nanotechnology to the agricultural and food industries was first addressed by a United States Department of Agriculture roadmap published in September 2000. Nanotechnology in the agricultural front has been more useful in improving the existing crop management techniques. Most of the applications of nanotechnology spearhead around nano encapsulated agrochemicals, herbicides, nano coated gene delivery and nano fertilizers (Nair et al., 2010).

Introduction

Gas chromatography–mass spectrometry (GC-MS) is equipment that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, environmental analysis include pesticides residue in soil, water and plant crop produce, greenhouse gas quantification, food toxicants, assessment of antibiotic compounds, estimation of volatile organic compounds from biological systems besides identification of unknown compounds.

Introduction

Biological systems are complex and are full of mysteries. Understanding function in relation to structure is crucial in many biological systems. A microscope is used to magnify, resolve and visualize a substance that is impossible to see by naked eyes and plays a vital role in various biological studies. We can visualize macroscopic organisms like animals, plants, and insects by the unaided eye but not bacteria, viruses or individual proteins. Biological structures have sizes variable over such a wide range that is not possible for a single microscopic technique to analyze all of them. Therefore, different types of microscopes with varying magnification and resolving abilities were developed to unveil the structural complexities of biomolecules (Fig. 1). Over the last 100 years, several types of microscopes have been designed and used in various fields. The microscopes work on different principles, and have a broad range of applications.

Transmission electron microscope (TEM)

The transmission electron microscope (TEM) operates on the same basic principles as the light microscope but uses electrons instead of light. What you can see with a light microscope is limited by the wavelength of light. TEMs use electrons as “light source” and their much lower wavelength makes it possible to get a resolution a thousand times better than with a light microscope.

We can see objects to the order of a few angstrom (10^-10 m). For example, we can study small details in the cell or different materials down to near atomic levels. The possibility for high magnifications has made the TEM a valuable tool in both medical, biological and materials research.

Electron Microscopes are scientific instruments that use a beam of highly energetic electrons to examine objects on a very fine scale. This examination can yield information about the topography (surface features of an object), morphology (shape and size of the particles making up the object), composition (the elements and compounds that the object is composed of and the relative amounts of them) and crystallographic information (how the atoms are arranged in the object).

Electron Microscopes were developed due to the limitations of Light Microscopes which are limited by the physics of light to 500x or 1000x magnification and a resolution of 0.2 micrometers. In the early 1930’s this theoretical limit had been reached and there was a scientific desire to see the fine details of the interior structures of organic cells (nucleus, mitochondria...etc.). This required 10,000x plus magnification which was just not possible using Light Microscopes.

Electron microscopy is a specialized branch of science, which uses the electron microscope as a tool. The electron microscope is an instrument which magnify smallest object thousands times. The magnification is not only requirement to see the smallest otherwise invisible object but the details of the object are most important. The details of the object are depending upon the resolving power of the microscope, which is known as the resolution of the microscope. This resolution or power of the microscope is depends upon the wavelength of the illuminating source. The smallest the wavelength of the illuminating sources is the best resolution of the microscope. Electron microscopes use electrons as an illumination source to take advantage of the very short wavelengths attainable in electron beam, which permit a considerable improvement in resolution over the light microscope.

Wilhelm Conrad Roentgen, German physicist, born on November 8, 1895 discovered X-rays and was awarded the first ever Nobel Prize in Physics in 1901 in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him. These short-wave electromagnetic radiations have the wavelengths that are matching with both the atomic sizes and shortest interatomic distances. But, the index of refraction of X-rays is near unity for all materials and hence they could not be focused by a lens in order to observe small objects such as atoms, as it is done by glass lenses in a visible light microscope or by magnetic lenses in an electron microscope. Thus, in general, X-rays cannot be used to image individual atoms directly. As an alternative to this difficulty, Max von Laue in 1912 proved that the periodicity of the crystal lattice allows atoms in a crystal to be observed with exceptionally high resolution and precision by means of X-ray diffraction for the first time by using a single crystal of hydrated copper sulfate (CuSO₄ 5H₂O).

Raman Spectroscopy

It is a spectroscopic technique based on inelastic scattering of monochromatic light, usually from a laser source. Inelastic scattering means that the frequency of photons in monochromatic light changes upon interaction with a sample. Photons of the laser light are absorbed by the sample and then reemitted. Frequency of the reemitted photons is shifted up or down in comparison with original monochromatic frequency, which is called the Raman effect. This shift provides information about vibrational, rotational and other low frequency transitions in molecules. Raman spectroscopy can be used to study solid, liquid and gaseous samples.

Nano-materials are to be extensively studied and characterized prior to their application in material science, biological science, electrical and electronics. In addition to the basic physical properties of the nano-materials, other characteristics such as paramagnetism, ferromagnetism, supermagnetism, optical properties, quantum size effects and electrical properties have to be studied. With a view to provide the fundamental information on these aspects this chapter is dedicated.

Nano-material possess unique properties such as dimension, shape, specific surface area, surface mass ratio etc., that are highly influenced by the mechanical and physical properties. It is pertinent to understand the basic physical properties of nano-materials in order to apply them in a wide array of functions. In this context, this chapter is devoted to provide basic information on physical, mechanical and photo-luminescence properties of nano-materials.

The history of nanotechnology in the modern world dates back to 1959 when American physicist Richard Feynman inspired the scientific community in his lecture “There is a plenty of rooms at the bottom”. Research on nanosized particles dramatically developed into an important field of modern research with potential effects in electronics to medicine and recently in agriculture and food industry.

Nanoparticles exhibit unique properties in terms of chemical, physical, photoelectrochemical and electronic properties when compared to their respective bulk materials. The applications of these nanosized particles are defined in a bigger ways in the field of Biotechnology. All these applications require custom based synthesis methods for specific applications.

Introduction

The metal particles in nanometer scale shows exciting optical and electronic characteristics when compared with respective bulk metals. Because of the inherent electronic properties of the metal and metal oxide nanoparticles these nanostructure materials are applied in various disciplines in recent days. Mostly these nanoparticles can be synthesized either top down or bottom up approaches. The conversion of bigger size particle or matter into tiny particles is called top down approach where as smaller particles or atoms joined together forming particles in regular shape within nanometer scale dimension is called bottom up approach. The formation of nanoparticles by chemical reduction is an example for the later one and the reduction size with the help of mechanical crusing leads to the formation of fine nanoparticles is named as top down approach. Mostly nanoparticles can be synthesized by chemical method because of its easiness to synthesis particles with uniform size and high purity.

Introduction to Nano-materials

Nano-sized materials are naturally present from forest fires and volcanoes, but are also generated unintentionally from anthropogenic sources as a by-product of combustion and deliberately as manufactured nanomaterials. Nanoparticles have been used for centuries. The coloured glass that we see in many old cathedrals from the middle age was made of gold nanosized clusters that created different colour depending on the size of the nanoparticles. The most prominent example of engineered nanoparticulate material is carbon black which has been around us for decades in applications like printing inks, toners, coatings, plastics, paper, tires and building products.
 
Two of the major factors why nanoparticles have different properties (optical, electrical, magnetic, chemical and mechanical) than bulk material are because in this size-range, the quantum effects start to predominate and the surface area to volume ratio is increased.

Introduction

Nature has been performing wonderful feats for millions of years. All organisms from microbes to humans are powered by highly evolved molecular and cellular machines that operate at nano scale. The capability to manipulate, control, assemble, functionalise, produce and manufacture things at atomic precision provides an opportunity to understand this new and exciting field of science. Nanotechnology is application of science to control the properties and structure of matter at nanometric scale.

Indian Agriculture is facing a wide spectrum of constraints such as burgeoning population, shrinking farm land, restricted water availability, imbalanced fertilization, low soil organic carbon, besides experiencing the fatigue of green revolution and vagaries of climate change. To address all the challenges ahead, we should think of an alternate technology such as “nanotechnology” to precisely detect and deliver the correct quantity of nutrients or other inputs required by crops that promote productivity while ensuring environmental safety. The word “nano” refers to the size of one-billionth of a metre or one-millionth of a millimeter in any one of the dimension. We are aware that all materials are made up of atoms which are the smallest units and for example, ten hydrogen atoms put together will measure one nanometer. As the size gets reduced, the surface area gets increased by several folds.

Till twentieth century information technology was restricted to European and American countries but entering in twenty first century witnessed passage of this technology with a vast speed in all other countries making a spectrum of changes in communication and transmission of knowledge that has altogether changed scenario of whole world. Earlier communication to international scientists was costly, time consuming while now its only a click away. So is of transmitting reprints of research papers – earlier they were dispatched by mail, now these reprints and other matters are available in soft copy and are attached with e-mail that is transmitted instantly.