eChapters

Introduction

Soil algae are not as numerous as bacteria, actinomycetes and fungi. Furthermore, these are photosynthetic microorganisms. Recent work has led to a more complete knowledge of the ecology and importance of terrestrial algae. These algae are found abundant in the habitats in which moisture is adequate and light is accessible.

Classification

Soil algae are classified into four major classes:

1. Cyanophyceae (Blue green algae)
2. Chlorophyceae (Green algae)

Fungi are a diverse group of multicellular eukaryotic organisms with wide variation in vegetative and reproductive morphologies and diverse life cycles. They are more abundant, on a mass basis, in soils than any other group of microorganisms; their biomass ranges from 500 to 5000 wet kg ha^-1 (Metting, 1993). Fungi inhabit almost any niche containing organic substrates, so that they are active participants in ecosystems as -

• degraders of organic matter
• agents of disease as well as beneficial symbionts - lichen (algae and fungi), mycorrhizal association

Introduction

The microorganisms exist as single cell or cluster of cells capable of orderly growth, metabolism and reproduction in two identical daughter cells. These includes cellular organisms {protozoa, algae and fungi (Eukaryotes), bacteria and archaea (Prokaryotes)} and viruses (non cellular entities). The study of microorganisms contribute to understanding of :

1. Basic biological sciences - It acts as a tool for providing the basic information for life processes. The discovery of DNA, RNA, proteins and enzyme functions all came from microbial study.
2. Applied biological sciences - Medicine, agriculture, industry, plant and animal pathology, immunology, plant and animal nutrition, biotechnology all have origin from the understanding of the cell function and metabolism of microorganisms.

ntroduction

Millions of living organisms present in soil make it a living and a dynamic system. Under a microscope, it reveals a complex array of soil particles and pore spaces filled with air and water. In these pore spaces that plant roots and millions of organisms develop, which are ranging from sub-microscopic to macroscopic in size. The physical and chemical characteristics of soil determine the nature of the environment in which vast number of soil microorganisms especially soil microorganisms are found. Living organisms in soils include both macro (earthworms, rodents, termites etc.) and microorganisms (bacteria, fungi, actinomycetes, algae and protozoa). These organisms not only help in the development of soils but also carry out a number of transformations, facilitating the availability of nutrients to the plants.

Methods and procedures for the qualitative characterization and quantitative analysis of different constituents of soil organic matter are presented in this Chapter.

20.1. Moisture

The soil sample should be in an air-dry condition after mixing, sieving and grinding. When stored in a moisture-tight container, the free H₂O content should not vary appreciably during storage. While most determinations can be done on air-dry samples, for certain purposes such as obtaining summation values, a moisture content value is required.

Managing soil organic matter is of paramount importance in sustainable crop production. Human interventions always lead to a decrease in soil organic matter content and biological activity. Therefore, even for maintaining moderate levels of organic matter in soils, sustained efforts should be in place. Such sustained efforts should include adopting high-residue crops in rotation and ensuring regular return of residues to soils.

It is all the more difficult to maintain the organic matter content in well aerated soils and soils of hot and arid regions, because in these soils added materials decompose rapidly. However, in comparison, it may not be so difficult to maintain the organic matter levels in fine-textured soils with restricted aeration and in soils of cold temperate regions.

19.1. Measures that Decrease Soil Organic Matter Content

The study of soil organic matter is becoming increasingly important by the day as world agriculture attempts to ensure sustainability of soils, while at the same time striving to enhance food production to feed an ever-burgeoning population. The use of green manures and pasture leys, the return of residues and additions of organic amendments to the soil are often resorted to in an attempt to increase soil organic matter which immensely benefit the physical, chemical and biological make-up of the soil.

The nuclear magnetic resonance spectroscopy (NMR) has led to major advances in the studies on the nature and chemical composition of soil organic matter. The technique has the potential for characterizing organic matter in the intact soil and its size fractions without the need for extraction and fractionation. Furthermore, it can provide information on the compositional changes in crop residues, peat and litter of the forest soils during biodegradation and humification.

Humic substances, the natural organic materials, represent a mixture of relatively small organic components, which form supramolecular structures held together by dispersive forces such as n - n and van der Waals’ interactions. Identification of the best analytical method for complete characterization of humic substances is still being discussed. Humic substances differ in molecular weight, elemental composition, acidity and cation exchange capacity and often are classified into three major fractions according to their solubility as humic acids, fulvic acids and humins.

Humic substances are the most widely-present, natural, complexing ligands occurring in nature. They are found not only in soils, but in natural waters, sewage, compost heaps, marine and lake sediments, peat bogs, carbonaceous shales, coals and other miscellaneous deposits.

The fate of natural organic matter, especially humic substances, has over recent decades attracted increasing attention of scientists representing various disciplines. Humic substances constitute about 25% of the total organic carbon on the earth. These are a group of naturally occurring complex molecular structures into which biomolecules derived from plant and animal residues are transformed progressively through biotic and abiotic pathways, by aggregation and accumulation processes

It is well known that organic matter plays a unique role in the binding of pesticides in soil, and that this phenomenon is usually the most important cause for interaction of pesticides in the soil environment. Fulvic or humic acids are most commonly associated with the binding interactions. Binding can take place with either the original pesticide or a transformation product, the reaction being induced by abiotic or biotic agents (microbial or plant enzymes). The reactions or processes involved are apparently the same as those responsible for the formation of humic substances, i.e., for the humification process.

Organic matter is of immense importance in forming good aggregates in a wide range of soil types, particularly those representing Mollisols, Alfisols, Ultisols and Inceptisols. Organic matter is somewhat less important in the Oxisols where hydrous oxides may play apredominant role. These relationships are depicted in Fig. 13.

Fig. 13.1: Relationship between OM and the formation of soil aggregates

Aggregates do not directly influence plant growth, but they alter the physical and chemical environments in which plant roots grow through their effects on porosity, aeration, moisture retention, etc., when well-irrigated, even fine- textured soils permit adequate exchange of gases with the atmosphere. The polysaccharides of soil have received the greatest attention in producing stable aggregates, but other organic substances bonded to clay through association with Fe or Al may also be involved.

Extensive studies have shown that much of the humified material in soil is finely bound to colloidal clay. However, it is uncertain to what proportion of the clay surface in any given soil is coated by organic substances as this will depend on the organic matter content and the type and amount of clay.

The ways in which organic substances are retained in soil are as follows:

1. As insoluble polymeric complexes of humic and fulvic acids.
2. As polymeric complexes of humic and fulvic acids bound together by di- and trivalent cations such as Ca²+, Fe³+ and Al³+.

Understanding the mechanisms controlling the adsorption of organic molecules on clay minerals is of significance in many branches of science and industry. The interaction between clay minerals and organic compounds elicits interest that emanates from the prospect that the adsorption of the organic matter fraction in the soil on the mineral particles would render physical stability to soil aggregates.

Organic compounds tend to interact with clay minerals by:

• adsorption process at the external surfaces
• adsorption process at the external and internal surfaces

The chemistry of humic substances is the least comprehended in the field of Soil Science. The many important functions of humus will remain obscure if the structural chemistry of the humic and fulvic acids is not known. A variety of functional groups have been reported in humic substances. However, considerable disagreement still exists in respect of the exact amounts present and, in some cases, proof of existence is lacking.

Some important structural groups of organic molecules are given below:

Practically every aspect of the chemistry of heavy metals in soil is related to the formation of complexes with organic matter. While monovalent cations (Na+, K+, etc.) are held mainly by simple cation exchange through the formation of salts with COOH groups (RCOONa, RCOOK), multivalent cations (Cu²+, Zn²+, Mn²+, etc.) form coordinate linkages with organic molecules.

A schematic diagram showing organic matter reactions involving metal ions in soils is given in Fig. 9.1. The metals present in the solution phase as charged species and as soluble metal-organic complexes (MChe), are shown to be influenced by the activities of higher plants and microbes, both of which serve as sources of water-soluble ligands for complex formation; some metals are held in insoluble organic complexes and are non-leachable and relatively unavailable to plants.

The synthesis of humic substances is the least understood and the most intriguing aspect of humus chemistry. This has been one of the intensely- researched subjects for a long time. Formation of humic substances takes several pathways during the decay of plant and animal remains in soil and the four important ones are shown in Fig. 8.1.

Fig. 8.1: Mechanisms for the formation of soil humic substances

The classical theory by Waksman advocated humic substances as modified lignins (Pathway 1), but a vast majority of current crop of investigators favour a mechanism involving quinones (Pathways 2 and 3). Including sugar-amine condensation pathway (Pathway 4), all the four pathways must be considered as likely mechanisms for the synthesis of humic and fulvic acids in nature. It is absolutely possible that these four pathways may operate in all soils, though not to the same extent or in the same order of importance. 

Soil is the fundamental resource in the agricultural production systems and monitoring its fertility is critical to the sustainability of agriculture. Plant nutrients undergo different transformation processes through which they are converted from unavailable to available forms. Nutrient cycling thus involves the transformation and availability of nutrients and is mediated by microbial action. Understanding the dynamics of nutrient and soil organic matter transformations requires an understanding of the biological, chemical, and physical processes involved.

7.1. Soil Nitrogen

Soil organic matter is among the most complex materials existing in nature. In addition to the organic constituents present in undecayed plant and animal tissues, soil organic matter contains living and dead microbial cells, microbially synthesized compounds and an endless array of derivatives of these materials produced as the result of microbial activity. Soil organic matter probably contains most of the naturally occurring organic compounds. Some components of soil organic matter are no doubt distinctive to the soil environment, particularly those involving inorganic-organic complexes.

6.1. Composition of Soil Organic Matter

The composition of soil organic fraction is as follows:

1. Components of organic residues undergoing decomposition

Soil is the product of various soil forming factors acting on the parent material over a period of time. The parent material is usually devoid of organic matter and consists of variable quantities of sand, silt, clay and carbonates. High temperatures and adequate moisture promote mineral transformations, but these effects are magnified by living organisms and the organic substances they produce. The biosphere and the organic substances they produce are directly or indirectly responsible for the following:

1. Decay of organic matter by microbes leads to the formation of CO₂ which is quantitatively the most important “aggressive” weathering agent because of its tendency to form carbonic acid with water [CO₂ + H₂O → H₂CO₃].

Carbon is the cornerstone of all life on Earth. Plant tissues and microbial cells contain approximately 40 to 50% of carbon on dry weight basis. Yet, the ultimate source is the CO₂ of the atmosphere. The CO₂ is converted into organic carbon by the action of photoautotrophic organisms (higher plants and green algae). It has been estimated that the vegetation on earth’s surface consume some 1.3 x 10¹⁴ kg of CO₂ per annum which is about V₂₀ of the total CO₂ supply of the atmosphere or ¹/₁₀₀₀ of that in the ocean.

Soils vary greatly in their organic matter content. For all practical purposes the organic matter content of the soil parallels the soil N content. The C/N ratio of soil organic matter generally falls in the range of 10 to 12. Because of the ease with which Kjeldahl determination can be made, N is often used as an index of soil organic matter content.

3.1. Composition of Organic Matter in Soil

Organic matter constitutes 1 to 6% of the topsoil weight of most upland soils. In a typical grassland soil, 5 to 6% of organic matter may be present in the top 15 cm. Top soils with less than 1% organic matter are mostly limited to desert regions. On the contrary, the organic matter content of soils in low, wet areas may be as high as 90% or even more. Soils with more than 12 - 18% organic carbon (approximately 20 - 30% organic matter) are called organic soils.

Soil organic matter makes up only a few per cent of most soils, but it has a great deal of influence on soil properties and on agricultural productivity.

2.1. Quantity of Organic Matter

Based on the content of organic matter, soils are identified as mineral or organic. Mineral soils dominate most of the world’s cultivated land and may contain anything from a trace to 30 per cent of organic matter. Organic soils are naturally rich in organic matter, chiefly due to climatic reasons. Although they contain more than 30 per cent organic matter, it is precisely for this reason that they are not vital cropping soils.

The term soil organic matter (SOM) includes any material that is produced originally by soil organisms (plant or animal) that is returned to the soil and undergoes decomposition process. At any point in time, it consists of an array of materials, ranging from the intact original tissues of plants and animals to the substantially decomposed mixture of materials known as humus (Fig.1.1). Most soil organic matter originates from plant tissues. Plant residues contain 60 - 90 per cent of moisture and the remaining dry matter consists mostly of carbon, oxygen, hydrogen, with smaller amounts of sulphur, nitrogen, phosphorus, potassium, calcium and magnesium. Though present in small amounts, these nutrients are of great significance from the standpoint of soil fertility.

Organic manures

Anand Swarup (1992) stated that application of green manures along with rice husk increased the concentrations of N, P, Zn, Mn and Fe and decreased the Na concentration of rice in a reclaimed sodic soil. Kolambe and Patel (1994) reported that application of organic amendments along with phosphorus increased the uptake of phosphorus at different growth stages of rice.

Talashilkar and Chavan (1997) reported that incorporation of 10 t of Glyricidia ha^-1 and application of 100 per cent RDF recorded the highest total N uptake by rice over three successive years. Mishra and Sharma (1997) found that application of 100 per cent NPK + 10 t FYM ha^-1 resulted in highest total uptake of NPK by rice. Mahapatra etal. (1997) revealed that application of 80 kg N ha^-1 through green manure alone or through combined use of green manure and urea increased the total uptake of N by rice over application of fertilizers alone.

The uptake of Mg by rice plant was highest when fertilizer was applied in combination with vermicompost (Jadhav etal, 1997). Pattanayak etal. (2001) also reported the highest Ca uptake in the treatments that received green manuring of dhaincha. Sriramachandrasekharan (2001) who reported the highest Fe uptake of rice with green manuring of Sesbania aculeata.

Debele et al. (2001) reported that the application of FYM enriched with 10% rock phosphate + gypsum with PSB and PSF @ 500 g inoculums t^-1 of FYM increased the nutrient uptake of maize. The higher nutrient uptake of 227 kg N ha^-1, 59.5 kg P ha^-1 and 227 kg K ha^-1 recorded with the application of enriched FYM @ 2 t ha^-1.

In the global scenario, the increasing energy crisis and consequent escalation of chemical fertilizer prices along with increasing risk associated with soil degradation have reviewed interest in bio-resources for attaining soil health and sustainable crop production. The use of organic manures, bio-fertilizers and chemical fertilizers will augment the efficiency of combined application of nutrients to maintain a high level of soil productivity and rice production (Thakuria et al., 1991; Prasad et al., 1995). Several experimental evidences showed that the combination of various bio-resources with chemical fertilizers improved the rice production in sustainable way (Roy and Jha, 1987; Subba Rao, 1995; Mahapatra et al., 1997; Suresh et al., 2001).

The bio-resources application in the soil is known to improve the biological properties of the soil. Several earlier reports show a spur in microbial populations or increased microbial biomass carbon and the enhanced enzymatic activities with the incorporation of bio-resources in soil (Perucci, 1990; Goyal et al., 1993; Bonde et al., 2004).

Microbial populations

Indigenous microbial populations in soil are of fundamental importance for an eco system functioning, through determining nutrient cycling, organic matter decomposition and energy flow (Doran and Zeiss, 2000).

Secondary nutrients

Secondary nutrients includes Calcium, magnesium, and sulfur. Crop plants requires secondary nutrients in moderate quantity for crop growth and yield. Their requirement by plant is less than the macro nutrients. Sulphur and Magnesium requirement of crops are very similar to the Phosphorus needs. Calcium is required in higher amount than Phosphorus. Calcium and magnesium are mostly deficient in acid and alkali soils. In India S deficiencies are found in almost 40 per cent of the cultivated soil. Under intensive cropping system, the use of higher amount of nitrogenous fertilizer without secondary and micro nutrients and lesser use of organic manures are the major reason for the secondary and micro nutrient deficiency in soil.

Potassium availability in most of the coastal salt affected soils of India is rich except when the soils are low in clay content (Bandyopadhyay et al., 1985). Plants grown under high salinity may show K deficiency due to the antagonistic effect of Na on K absorption and / or disturbed Na / K ratio. Under such conditions application of K is also known to reduce the adverse effect of salinity and sodicity on crop growth (Qadar, 1995). Singh et al. (1980) reported that the addition of FYM increased the K concentration in the soil. Swarup (1987) reported that the incorporation of green manure increased the available N, P and K status of the soil. Available P and K remarkably increased to a tune of 30 and 44 per cent respectively by the application of coir waste (Santhi et al., 1991).

Experiments at Central Soil Salinity Research Institute (CSSRI), Kamal, India showed that alkali soils are not always high in available P and rice and wheat significantly responded to addition of P (Pathak et al., 1975).

The availability of phosphorus in soil either native or added is limited by fixation and precipitation mechanisms. The organic acids released during decomposition of organic matter influences the soil pH, form stable complexes with cations responsible for P fixation and thus increases the availability (Tiwari et al., 1980).

The use of bulky organic manures (Maurya and Ghosh, 1972; Chaudhary et al., 1981) and green manures (Prabhakar et al., 1972; Sharma et al., 2000) has been found very beneficial for P management of saline and alkali soils as these improve the soil physical condition and the availability of soil phosphates.

It is generally observed that N, P and Zn content in soil decreases with increasing soil salinity. Nutrient imbalances created by continuous use of chemical fertilizers, particularly nitrogenous fertilizer alone, combined with sub optimal rates of other nutrients or total omission of other nutrients are the primary causes for unsustainable yields of crops in saline soil. A sustainable approach for nutrient management in salt affected soils should therefore include balanced use of organic, inorganic and biological sources of nutrients (Bandyopadhyay and Rao, 2001). Organic amendments are known to facilitate the reclamation of sodic soils and better nutrition of crops (Anand swarup, 1992).

The coastal salt affected soils are low in productivity due to various soil fertility constraints that affect the crop growth and yield. The high salt content &/or high pH cause changes in solubility, availability and efficiency of plant nutrients, besides deteriorating the physical condition of soil. The soil biology (microbial population and enzymatic activities) also severely affected in these salt affected soils. The bio-resources are known to improve soil physical, chemical & biological properties of the soil. The maximization of rice production and considerable improvement in quality and composition of rice in coastal salt affected soil with the use of bio-resources have been reported by several research workers.

Around the world, nearly one billion people live along the 3,12,000 Km long coastline. The Indian coastline runs around 8,129 Km distributed along nine coastal states, two groups of islands and two union territories. The coastal ecosystem of India forms a very valuable resource community, supporting the livelihood security of several million rural poor and also contributing the national economy in a large measure. The latest estimates by National Bureau of Soil Survey and Land Use Planning (NBSS & LUP), Nagpur, India, using Global Assessment of Soil Degradation (GLASOD) guidelines indicate that the coastal area in the country is spread over an area of 11.8 million hectares (Mishra, 2005). Yadav et al. (1983) have reported about 3.1 M ha and 2.1 lakh ha of coastal salinity in India and Tamilnadu respectively.

Potato is an important crop of the world and grown in almost all the states in India. Apart from India, potato is grown in more than 100 countries but the intensity of cultivation varies considerably. For example in the Netherlands 19.6% of the total arable land is cultivated with potatoes. The figures for Germany, Peru and USA are 10.1%, 5.6% and less than 1% respectively. India ranks fourth in area (1.29 m ha) and third in production (25.23 m ton) in the world. The productivity of potato depends mainly on the quality and quantity of planting materials and the agronomic management practices adopted. Most of developing countries including India experience release of high yielding varieties, development of adequate agronomic and pest control measures but the gap between supply and demand of good quality adequate quantity seed has to be the major constraint in increasing its productivity. 

5.1 Jute Seed Production

Jute ranks secand next to cotton as the most important natural fibre and it recognized as the ‘golden fibre’. Its products being biodegradable and environment friendly in contrast to synthetic substitutes, a renewed interest in this natural fibre has been generated in the recent past throughout the world. Important characteristics of jute fibre are its silky lustures, high tensile strength, low extensibility, considerable heat resistance. Because of its great abundance and shortage of cotton, jute is blended with cotton and jute/cotton blended yarns are produced mainly to take advantage of the lower price of jute fibre (Doraiswamy et al, 1998). Several diversified product is also made from jute. Since currently the paper industry has been using it as a raw material for paper. It is also being used in geotextile. The jute sticks are largely used as fuel and also for making gun powder.

3.1 Redgram or Pigeon Pea

In any production programme, the importance of quality seed needs hardly be emphasized. In fact, the major bottleneck in the pigeon pea cultivation programme is the restricted or poor availability of quality seeds of the desirable varieties. The seed has been considered as the ‘vehicle of change’. With better attention paid to their interaction among water, fertilizer and seed of improved varieties, the production can be maximized. Although a numbers of improved varieties of pigeon pea have been released since 1970, organized seed production programmes have been rather limited. Most of our national efforts in this direction continue to be centralized on cereal crops like wheat, rice and hybrid millets. Moreover, the benefits of the current research will not reach the farmers unless large-scale seed multiplication programmes are organized.

4.1 Mustard

The principle oil yielding rape seed and mustard sp. cultivated in India are

4.1.1 Land Requirement

Select seed field on which the Brassica sp. was not grown in the previous season unless the crop in the previous season was of the same variety and was grown from certified seed. To avoid disease control it is necessary to fallow a 3-4 year crop rotation so that a given field is selected one in every 3-4 years. In addition select field should be well drained, leveled and suitable for Brassica cultivation.

2.1 Rice

Rice is the staple food for the largest number of people on the Earth. According to an estimate, the global rice production must reach 800 million tonne from the present 91.04 million tonne in 2005-06 to meet the demand in 2025. It’s area is 37% of the total area under food grains as against 20% under wheat, another important food crop. But globally it stands next to wheat in harvested area. As the irrigated rice contributes more than 75 per cent of the total rice production, enhancing its yield potential would be key to meeting the global rice requirement for an additional 215 million tonne. To achieve the target yield, rice varieties with a yield advantage of about 20 per cent over popular and widely adapted rice varieties under tropical conditions must be developed. Experience in China, India, Vietnam, Philippines, Bangladesh and several other countries clearly indicates that hybrid rice technology offers readily available option to meet this challenge. 

Current Status of Seed Production

Organized seed production in India became possible with the formation of National Seed Corporation (NSC) during 1963, which paved the way for a sound seed industry to come as a consequence of the introduction of hybrid technology during 1961-65. The release of high yielding dwarf varieties of wheat and rice by the 1960’s gave further impetus to the growth of the seed industry in the country. For the total area under cultivation of 26.7 m ha and 65 per cent of the area) insect, disease and weeds (10-40 per cent loss) and also poor shelf-life. Hybrid technology have defined solution in several crop plants specially vegetables, cotton, rice etc. with the development of appropriate hybridization and seed production. In 1990-91, the area planted to ‘bought seed’ was about 10.35 per cent. The total ‘bought seed’ was estimated at around 5.91 lakh tonnes valued at Rs 679.80 crores. 

7.1 Introduction

The occurrence of extreme weather events like drought and flood is increasing in Bihar due to climate change. Bihar receives nearly 80% of annual rainfall during June to September which is quantitatively enough for growing most of the crops. However, aberration in temporal and spatial distribution of rainfall makes the crops vulnerable to drought as well as flood. Rainfall is the most important factor for planning of crop production in rainfed areas. The information on annual, seasonal and weekly rainfall of a region is helpful to design different agricultural operations like field preparation, sowing, irrigation, fertilizer application as well as overall crop planning (Singh et al., 2008). Zone I and zone II of Bihar are receiving too much rainfall which causes flood in this region whereas zone III B is identified as rainfed region which has low, erratic and uncertain rainfall pattern with frequent dry spells during the monsoon season. Hence kharif cropping is tricky operation in this region and sudden crop failures is a common phenomenon due to frequent dry spell or early withdrawal of monsoon. In India many scientists studied on rainfall probability pattern (Suchit et al., 2012) and they concluded that rainfall occurrence is certain at greater than or equal to 80 % probability, while 50% probability is the medium limit of certainty and may involve dry spell risk. Based on these climatic and probability factors, the study was carried out for four different locations situated in different agro climatic zones of Bihar for interlinking the rainfall probability pattern with the crop planning pattern in those regions.

6.1 Introduction

One of the key challenges in the 21^st century is that Agromet Advisory Services (AAS) have to respond to an unpredictable and changing climate. In India Gramin Krishi Mausam Sewa (GKMS) is the umbrella project for Agromet Advisory Services (AAS) and it intends to link AAS to different sources of knowledge and innovations to respond to the climate change at root level farmers. The main aim of GKMS is to create effective, efficient and synergistic linkages to improve the delivery of these AAS to the farmers. GKMS works under the frame work of India Meteorological Department (IMD) which seeks to enhance the livelihood of every Indian farmer. 

5.1 Introduction

Weather is one of the most important factors which determine success or failure of agricultural production. It effects every growth phases and development of plant. During the growing period of the crop, any variability in the weather condition such as delay in monsoon, excessive rainfall, drought, flood, heat or cold wave affects the crop growth and finally reduces the quality and quantity of crop yield. These losses due to weather hazards can be reduced by taking proper crop management in time and by applying accurate weather forecast. Weather forecast also provides guidance for selection of crops and varieties best suited to the local climatic condition. 

4.1 Introduction

The livestock/poultry have great capability for climatic adaptation and acclimatization. However in an open environmental condition their overall well-being and efficiency depends on day-to- day weather conditions. While certain breeds of livestock and poultry are considerably flexible to adjust themselves with the varying weather conditions, the others may have little adjustability. This has led to the development of weather/climate based livestock/ poultry management practices which include the general care. Nutrition and health managements for optimizing conditions for best yield in respect of milk, meat, eggs, wool, load carrying capacity etc. have been properly documented. 

3.1 Introduction

One of the most important functions to the AAS units is to widely disseminate the advisory bulletins among the user community. A unit cannot be considered operational unless its bulletins are reaching the target masses. The dissemination is one way communication which is broadly speaking the process by which human beings share information, knowledge, experience, ideas and motivation. 

2.1 Introduction

Agro-meteorological advisories relate the past, current and predicted future weather to agricultural activities. Behaviour of weather both in space and time, considerably affect the agricultural production. Year to year variations in crop production are generally depended to the abnormalities in the behaviours of weather. The mission of the Agromet Advisory Services (AAS) of NCMRWF is to maximise farmers’ profits by decreasing losses due to weather calamities and also by increasing the timeliness of operations in the crop field. An ideal AAS bulletin helps to reduce environmental pollution through the optimum use of chemicals in the crop filed. An ideal AAS bulletin should contain farm management information to weather based agricultural operations and available to the farmers in real time.

1.1 Introduction

Climate change is evident from the observation of increase in global average air and ocean temperatures, precipitation and extreme rainfall, widespread melting of ice, storms / storm surges flooding and rising global mean sea level, as recorded in the Fourth Assessment Report of IPCC. Eleven of the last twelve years (1995-2006) rank among the twelve warmest years in the instrumental record of global surface temperature (since 1850). 

10.1 Introduction

As one ofthe oldest and most widely used renewable energy sources, hydropower generates electricity by using the natural flow of flowing water. Streams and rivers have been used for producing mechanical energy for thousands of years. Hydroelectric power plants are located near or on water sources since they derive their power from flowing water. The amount of energy that can be released in moving water depends on the volume of the water flowing and the elevation change from one point to another, often called head. Generally, hydropower plants can produce more electricity when there is more water flow and a higher head. 

13.1 Introduction

At a national level, the agricultural sector is one of the major potential users of energy in the Indian context. Further, it is often highly dependent on the supply of electricity and fuel in order to function properly. The term “agriculture” refers to all on-farm activities required for farming, raising animals, and associated activities associated with farmers, growers, and entrepreneurs. Fuels such as petroleum and electricity are primarily used for the operation of pump sets and other operations. In the future, this may result in problems with supply and price. Moreover, India has relatively small reserves of crude oil and will eventually be forced to import more crude oil to make up for the lack of reserves. In order to save energy and money on the farm, farmers must identify opportunities for energy conservation on the farm in order to maximize energy efficiency. 

12.1 Introduction

A magneto hydrodynamic energy conversion system or MHD system converts heat energy directly into electricity. An MHD generator produces electricity via the interaction of a moving fluid with a magnetic field and ionized gas. MHD conversion does not involve any mechanical conversion intermediary. As a result, this process offers substantial fuel savings because the process of producing mechanical energy and then converting it to electrical energy is eliminated. It is possible to generate electricity in large quantities using MHD power plants while reducing the impact on the environment. During his Bakerian lecture in 1832 to the Royal Society, Michael Faraday presented the concept of MHD power generation for the very first time.