eChapters

Tuberculosis

Tuberculosis has been recognized as one of the most important infectious diseases in the world because of its high global impact and its chronic debilitating character, particularly in the poor section of society. Milk-borne tuberculosis is directly or indirectly related to the consumption of raw milk from infected dairy herds.

Normally raw milk contains different levels of inhibitory substances, which restrict the normal development of bacteria and some times may even kill them. The degree of inhibitory activity varies considerably in milks of different species, viz, cow, buffalo, human. Maximum activity present in human milk, variations occur in the milks of individual animals and some times even at different milking or from different quarters of the udder of the same animal.
There are two groups of antimicrobial substances present in milk:
    1.    Inherent or naturally occurring substances in milk. 
    2.    Non- inherent compounds secreted into milk from other sources.

Dairy equipment and utensils with which milk and milk products come into contact are the main sources of contamination in the products. By the use of effective equipment cleaning and sterilization methods on routine basis, milk of high bacteriological quality can be consistently produced. In composite milk plant, a variety of equipment and utensils are used. The use of stainless steel for the fabrication of dairy utensils and equipment provide highly polished and hard smooth surface that can be cleaned readily, apart from showing resistance to corrosive action of detergents and bactericidal solutions. Utmost care is taken to avoid dents and scratches, which could be the possible focal points of subsequent contamination. To overcome all these problems aluminium and stainless steel vessels and equipment present an ideal situation.

Introduction

Numerous characteristics of food determine its acceptability to consumers and to regulatory officials. Before accepting a food for consumption, it must be attractively presented, must have desirable odour and flavour characteristics and other qualities and must be free from potential pathogens or their toxic products. The ultimate nutritive qualities, flavour and appearance have been preserved and no harmful organisms or substances are present to affect the consumer adversely. If the quality of the product is good, its keeping quality is also likely to be substantial. Conversely, there are more chances of spoilage of an inferior quality food product during storage.

India

Milk legislation and regulations are designed to prevent fraud and adulteration. But they now cover many factors that affect sanitation and public health. Milk generally is classified into grades according to the care with which it is produced.

In today’s times, a lot of innovation has come into agriculture. This very hard occupation requires an amalgation of farmers with the scientists. From the rural areas after education the technocrats are moving to the cities and this is creating a great loss to the agriculturists. As the population is growing so is the demand for food. Due to shortage in the storage systems the amount of wastage has increased a lot. It is an important aspect to be looked into. A lot of waste material is seen in the vegetable markets, city markets and near the slums. This causes a lot of pollution and spoils the environment. It is important to know why is it increasing and why the facilities for wastes do not exist.

After the agricultural activities a number of by-products are obtained and these are known as agricultural waste. These include residues of different crops like stalks, straws, leaves, roots, husks and shells. The animal waste is in the form of manure. All these agricultural wastes are free of cost however; they can be utilized as an important resource (Lionel and Arnold, 1931). Agrawal (1998) has mentioned India as the final dumpyard. The wastes obtained from various resources can be converted into heat, steam, charcoal, methanol, ethanol, biofuel, compost, energy, biogas, construction and high valued chemical compounds. Many times these agri-industrial wastes are not completely utilized and either they rot in open areas or are burned in the fields.

3a. Sources and problems of agricultural wastes
3b. Waste Reduction
3c. Waste Treatment
3d. Waste Disposal
3e. Clean Technology

Different Kinds of Agricultural Wastes
Table 1: Common Hazardous Wastes: Community Source

All these methods of utilization and the conversion to useful energies depend on the climate, population density of the area and the basic infrastructure. It is important to work out the market for the products which are produced.
 
Bio-waste management: It needs to take from small actions to the ambitious ones. European Commission proposes to use wastes which could make up to 25% of total energy consumption by 2020. They propose to have directives for the promotion of renewable electricity (Directive 2001/77/EC) and biofuels (Directive 2003/30/EC). The waste production in Europe has gone upto 2 kg per capita per day. Recycling rates are also rising (European Commission, 2017). The Member states must develop a national action plan and outline the national policies to develop existing biomass resources and mobilise new biomass resources for different uses. A European project has studied the amount of renewable energy to be used in 2020. According to them it will be around 195 million tons of oil equivalents (Mton) of biomass which is biodegradable part of MSW. This will be 20% of renewable energy target. It has also been estimated that the amount of bio-energy from the MSW will be 20 Mton, which would account for around 7% of all renewable energy in 2020. This may be available after composting and anaerobic digestion (Atanasiu, 2010).

The possibility of making genetic changes in the laboratory in plants, animals and microbes used in food started almost 10,000 years ago. Along with natural changes taken place during the evolution totally different species have come into existence. This has helped in increased food production with better taste and nutrition. The losses caused by biotic and abiotic stresses from fungi and bacterial pathogens have reduced.

In the Asian and Pacific ‘region, it is China alone which produces the largest quantities of agricultural waste and also crop residues. This is followed by India. From the production of rice, corn and wheat alone 587 million tons of residues are generated per year in China. Maheshwari (2014) has surveyed the proportions of waste that Malaysia generates from the production of rice, palm oil, rubber, coconut and forest products. In Myanmar the crop waste and residues constitute about 4 million tons per year out of which more than half constitutes rice husk.

The livestock sector is one of the fastest growing agriculture sub sector in India, which accounted for about 17% of the value of agriculture output in 1981-83, has gradually increased by to 25% in 2011-2012 (CSO 2011, GOI). India possesses one of the largest livestock populations in the world with 218 million cattle, 115.4 million buffalos, 160 million goat, 75 million sheep, 9.4 million pigs, 947 million poultry (FAO, 2012) which provide excellent opportunities and boost rural income and alleviation of poverty. The country has 16.5% cattle, 56.8% buffalo, 5.78% sheep and 14.76% goat population of the world. India stands first in milk production likely to be touch142.6 MT in 2014 with 4.5% annual growth rate of milk.

In recent years, there has been a considerable interest in the new technological interventions for enhanced livestock productivity in the Indian sub-continent, because of the increased demand for livestock products for human consumption. Bypass nutrients defined as a nutrients fed in such a form that provides an increase in the flow of the nutrient (s) unchanged to the abomasum, yet is available to the more important nutrient (high BV) should escape from the rumen or face minimum ruminal fermentation. The reasons for protecting different nutrients are based on their mode of utilization in the rumen. The literature on the effect of the bypass fat and protein on nutrient utilization, milk production and reproductive performance has been reviewed and presented in following subheads

The present experiment entitled, “Protected Nutrient Technology for Crossbred Cattle” was conducted at Research Cum Development Project on Cattle, Department of Animal Husbandry and Dairy Science, Mahatma Phule Krishi Vidyapeeth, Rahuri Dist. Ahmednagar, India located at 19o 23’ 0" N and 74o 39’ 0" E at an altitude of 511 mtr. Minimum and maximum ambient temperature range from 10 to 20^ºC in winter and 30 to 40°C in summer with annual rainfall of 561.6 mm

4.1 Composition of Concentrate Mixture
 
The ingredient composition of experimental concentrate mixture is presented in Table 3. Groundnut cake in T1 and T3 were treated with formaldehyde as a tool of protein protection while protected fat at the rate of 10g per liter milk production per animal in T2 and T3 was added in concentrate mixture before feeding every day.

Twenty four crossbred cows in second to fourth lactation with most probable production ability (MPPA) of average approximately 2300 liter milk production per lactation for each group were selected from the herd maintained at RCDP on Cattle. The experimental animals were randomly divided into four treatment groups of 6 in each. Control group (T₀) was fed with 2/3 DM through roughages (2/3 from dry roughages and 1/3 from green roughages) + 1/3 DM from concentrate mixture (Conc. Mix includes 20% GNC (untreated). T₁ group was feed with 2/3 DM through roughages (2/3 from dry roughages and 1/3 from green roughages) + 1/3 DM from concentrate mixture (Conc. Mix includes 20% GNC treated with formaldehyde (FA) @ 1.0 g FA/100g CP).

Ambasankar, K. and Balakrishnan, V. 2011. Influence of protected sardine oil on in vitro rumen fermentation and nutrient digestibility of complete diet. Indian J.  Anim. Sci., 81(1): 
84-86.
Amrutkar, S.A., Thakur, S.S. and Pawar, S.P. 2014. Economics of supplementing rumen protected methionine and lysine in the ration of lactating crossbred cows. Indian J. Anim. Nutr., 31 (1) : 14-19.
AOAC, 2005. Association of Official Analytical Chemists. Official Methods of Analysis. Washington, DC.
Arewad, G. R., Thube, H. A., Pandya, P. R., Parnerkar S. and Shankhpal S. 2011. Effect of feeding bypass protein based total mixed ration on performance of growing crossbred calves. Indian J. Anim. Nutr. 2011.28 (3) : 303-308.

In Vedas the cow has been regarded as the mother of Rudras, the daughter of Vashu and the sister of Aditayas and also the use of cow ghee in religious ceremonies had been mentioned in Rig Veda and there is mention of the cow as “Kam Dhenu” in ancient writings. In Shiva temples are found the references of sculpture of “Nandi Bulls”. In Hindu mythology, the male buffalo thought to be the vehicle of the God of death “Yama” and also regarded as physical form of the demon Mahishasur, a symbol of inertia-”Tamas”.

Animal husbandry is an integral component of Indian agriculture supporting livelihood of more than two-third of the rural population. The livestock sector plays a significant role in supplementing family incomes and generating gainful employment in the rural sector, besides providing cheap nutritional food to millions of people. Livestock provides milk, egg, meat as nutritious food, draught power for agriculture, wool, fibre, manure and domestic fuel, hides & skin. In 2010-11, this sector contributed 121.84 million tonnes of milk, 63.02 billion eggs, 42.99 million kg wool, and 4.83 million tonnes of meat. Milk is the main output of livestock sector accounting around two third (67%) of the total output by livestock sector. Meat and egg share 17.5% and 3.6% of the value of livestock output. Livestock contributed 4% to the total GDP and 26% to the agricultural GDP in 2010-11. Livestock are the best insurance against the vagaries of nature like drought, famine and other natural calamities.

Dairy farming has been the backbone of the agriculture and rearing of livestock for milk/milk products and draft power has been the tradition of ancient rural India. Whenever the crops have failed miserably attributed to natural calamities, the livestock has emerged the savior of farmers providing livelihood security in rural India. India is a country of villages (640930 villages) and 68.84% population of India is living in villages as per the All India Census, 2011. Further, 41.8% rural population is below poverty line as compared to 25.7% urban population (Basic Animal Husbandry Statistics, 2012). The marginal and small farmers are rearing 71.7% of total livestock revealing that livestock has been the source of sustainable livelihood security for rural poor majority of which falling under the category of population below poverty line.

India produced 121.8 MT milk during the year 2011-12 and continued to rank first in world milk production. India contributed 16 % of world milk production. As per 2010 statistic, India with 12.5 % of world cattle population contributed 8.4 % in world cow milk and  with 56.7 % of world buffalo population contributed  67.45 % in world buffalo milk. In total milk production of India, contribution of crossbreds, indigenous cattle and buffalo were 23 %, 20% and 53%, respectively.

Introduction

India ranks third in sheep population and accounts for 6.13 % of world population (FAO, 2009) with 71.56 million sheep to its record as of Livestock Census 2007 (DAHD, 2012). Out of 71.56 million sheep, 3.73 million are crossbred and 67.83 are indigenous. Sheep husbandry is backbone of rural economy in India. It is important as it helps in sustaining the livelihood of rural poor in difficult terrains characterized by sparse vegetation, marginal land and a high incidence of poverty. These breeds were developed following domestication and natural and artificial selection over the past 12,000 years.

Hill cattle in Uttarakhand are multipurpose animals. They are used for milk, draft, manures and ceremonial purposes. Improvement for these attributes depends on definition and subsequent selection for various traits. Based on the criteria for improvement and detailed literature analysis, it is believed that the hill cattle of Uttarakhand is one of the potential population for milk in the state specially in the remote and high altitude areas.. Hill cattle have also been used for dairy improvement as a dam breed for crossbreeding in some cases in the state. It has been observed that hill cattle in the state mostly reared as dual purpose animal i.e milk and draft. Therefore, the hill cattle could be improved for both milk and draft. The aim of the present study is to know the status, characterstics and performance  and to suggest the possible options for improvement in milk productivity of hill cattle in the state.

India’s livestock sector is one of the largest in the world and dairy farming is the single largest contributor to country’s GDP, apart from being the biggest source of employment. India has 56.7 per cent of world’s buffaloes. Buffalo genetic resource greatly helps the countries to assess their strengths and potential to harness the nature’s gift and India is fortunate in terms of having largest buffalo population, huge buffalo germplasm diversity (13 recognized plus 14 distinct population groups) and the world renowned buffalo breeds: Murrah, Banni, Jaffrabadi and Nili-Ravi.

The prospects of Farm Animal Genetic Resources (FAnGR) are exceedingly uncertain. The FAnGR characterize the genetic makeup of the thousands of local breeds worldwide which are well-adapted for producing in harsh environments, and which for millennia have been essential in nourishing human communities. Currently, the genetic diversity in numerous livestock breeds across the world is threatened. Decades of consistent selection intended mainly for production increase has caused irreversible loss of genetic diversity (FAO, 2009).

Introduction

India is a vast country comprised of different agro-ecological regions with diverse climate, natural vegetation resources, topography, possesses almost all domesticated animal species, landraces and crops with different production systems. Domestic animals provide a considerable amount of   food requirements for mankind. India ranks first in milk production with 112.5 million tonnes milk produced in 2010-11. As India is a tropical country, in summer the temperature hikes about 40-48°C in various parts of the country. Such a temperature is certainly not within the comfort range of animals and thus the animals respond to the stress imposed by temperature on them in various ways to combat the stress and to maintain the homeostasis.

Livestock is an important source of income for the rural poor and marginal farmers which enables earn income and food security using common resources.It is a best option to utilize such waste resources in proper way to earn income. About 65-69% of Indian population consisting of small and marginal farmers and land less laborers reared animal as supplementary occupation by feeding their animals agriculture by products. Indian agriculture is very difficult to sustain without dairy animals. Per capita availability of milk comes out to 281gm per day, which is below than the average of 300gm recommended by Nutrition Council of ICMR. Thus, there is a further need to increase the milk production of the country in view of minimizing difference between per capita availability and requirement. Milk production in India has increased from a modest 22 million tons during 1970-1971 to about 122 million tons in 2011—2012 (Deptt. of Animal Husbandry and Dairying).

Dairy buffalo production has been a tradition in Asian region and some other parts of the world where fresh  buffalo milk, dahi (cultured sour milk), ghee (butter oil) and yoghurt are very popular. In Italy, the dairy buffalo industry is flourishing; thanks to the popularity of buffalo mozzarella cheese. Because of the market for Mozzarella, buffalo farming is a profitable enterprise and is carried out in an organized manner with modern equipment.

Introduction

In India 70 to 75 per cent of the indigenous cattle and buffaloes are designated as non-descript that is they do not come under any well defined breed. Among the animals of defined breed also, less than 5-10 per cent of the population can be considered as elite and used for the production of breeding stock. Average productivity of cross-bred and desi cows is 2141 kg/lactation & 634 kg /lactation, respectively, which is still very low. The average productivity of buffaloes is 1355 kg/lactation only.

Breeds are the result of the hundreds of years of natural selection and evolution. They are adapted to tropical climate and diseases and perform reasonably well even with low quality of feed and fodder. India has agrarian economy, with majority of population dependent on agriculture. India is a mega diversity hub of different livestock breeds. There are 10 buffalo breeds, 30 cattle breeds, 42 sheep breeds, 20 goat breeds, and 18 poultry breeds contributing significantly to GDP of the country. Despite our vast population of different species, there is a need for conservation of breeds. Conservation is the management of human use of the biosphere, so that it may yield the maximum sustainable benefits to the present generation, as well as maintaining its potential to meet the needs and aspirations of future generation.

Introduction

Over decades, improvement of domestic animal species has been done by selecting superior animals, mainly based on individual performance and their subsequent breeding to get progenies with higher production potential. Within the 20th century, understanding of inheritance of economic traits, factors influencing genetic potential and their interactions provided better criteria for selection and this has resulted into faster genetic gains. Several selection criteria which were composite ones based on the individuals as well as its relative performances were being used.

Bioinformatics is a branch of biological science which deals with the study of methods for storing, retrieving and analyzing biological data, such as nucleic acid (DNA/RNA) and protein sequence, structure, function, pathways and genetic interactions. It generates new knowledge that is useful in such fields as drug design and development of new software tools to create that knowledge. Bioinformatics also deals with algorithms, databases and information systems, web technologies, artificial intelligence and soft computing, information and computation theory, structural biology, software engineering, data mining, image processing, modeling and simulation, discrete mathematics, control and system theory, circuit theory, and statistics.

Introduction

Agricultural biodiversity must be an integrated part of climate change adaptation and mitigation efforts. Climate change adaptation, biodiversity conservation and poverty alleviation should complement each other (FAO, 2007, 2008). Climate affects vectors, pathogens, hosts and host-pathogen interactions from the level of cellular defence to that of the habitat. Hoberg et al. (2008) provide an overview of predicted responses of complex host-pathogen systems to climate change. Climate change may affect the spatial distribution of disease outbreaks, and their timing and intensity (Epstein 2001). Outbreaks of African horse sickness, peste des petits ruminants, Rift Valley fever, bluetongue virus, facial eczema and anthrax are triggered by specific weather conditions and changes in seasonal rainfall profiles.

Poultry industry in India has a strong standing globally, being third highest egg producer with more than 50000 million eggs and fifth highest broiler producer with 2.25 million tones of broiler meat. Largely, Indian poultry industry is chicken dominated and the rearing of high yielding varieties under intensive rearing system is the backbone of its present face. Analysis of trend of egg production in last five years i.e. 2001-2006 revealed that annual growth rate in egg production is about 5-6 %, except a much lower rate of 3 % during 2003.

Poultry has been extensively used for various biological experiments and its contributions to science are impressive. Among poultry species, chickens have made fundamental contributions to our current understanding of many immunological processes and it ranks high in the biological world. It still serves as an animal model to investigate immunogenetic aspects of disease resistance and tumor regression. Among the major contribution from poultry, the first evidence for viral induced tumor came from chicken (Rous, 1911; Nobel prize, 1966), reverse transcriptase enzyme was isolated from Avian Leukosis virus (Tamin and Baltimore, 1963; Nobel Prize, 1975), oncogenes in virus are from host cells (Bishop & Harold Varmus; Nobel Prize, 1989) and major two arms of immune response i.e. the T and B cells were first discovered in chicken.

Rural poultry production constitutes vital component of agricultural economy in India. The organized sector of poultry industry is contributing nearly 70% of the total output and the rest 30% by the unorganized sector. In unorganised sector, poultry are reared in free range extensive system with very little input in the form of grain or farm by-products, birds have to scavenge from limited amount of feed resource. The productive out put of these birds are very low (60-70 eggs per bird per annum; 2.0 kg. and 1.5 kg. body weight per bird in males and females, respectively). Moreover, still more than 50 % population of poultry in India comprises of non-descript / deshi birds.

India, the progenitor of the present day chicken, is a vast country having varying climatic zones such as the high altitude Himalayan regions, the Indo-Gangatic plains, the Deccan plateau in the south and hot and humid coastal areas. Although, no exact data is available, factual information suggest that poultry raising in this sub continent is as old as its civilization. Owing to the long widespread chicken raising in the vast territory of this country and manifold ecological niches at different places, many native breeds were evolved over the years some of the documented breeds and ecotypes are Aseel, Ankaleshwar, Busra, Brown Desi, Chittagong, Daothigir, Denki,  Ghagus,  Haringhatta black, Kadakanath,  Kalasthi, Kashamir faverolla,  Miri,  Naked neck, Frizzle, Punjab brown, Tellichery, Titri, Teni and Nicobari.

Camels across the world are reared for milk, meat, draught, race and tourism. They are distributed in the African, Arabian and south Asian countries.  Apart from this, a feral population exists in Australia and recent reports indicate that a few animals of the species are also being reared in Europe. The world camel population shows an increasing trend with 12.92 m in 1961 to  24.68 m in 2010 producing 0.38 m tonnes of meat and 2.36 m tonnes of milk per annum.  The top 20 camel rearing countries produce both milk and meat with the exception of India and Pakistan as per FAO. Contrary to this, the research articles and news reports indicate that the species in the two south Asian countries too produce both milk and meat.

Biodiversity, coined by W. G. Rosen in 1985, is the variety of life on Earth. It is the occurrence of different kinds of organisms and the complete range of varieties adapted to different climates, environments and areas being constituents of food chains and food web of biotic interrelationship. Biodiversity refers to totality of genes species and ecosystems of a region. Biodiversity differs from place to place. Biodiversity is the biological wealth of world.

There is continuous depletion of biodiversity due to increasing population resources consumption, urbanization and pollution. The basic reason for concern is that biodiversity is being lost even before it attains its size. Loss of biodiversity would check evolutionary capability of biota to cope up with environmental loss.

Livestock sector may be considered as a driving force for nutritional security and an important component of sustainable agriculture in India. Livestock sector besides providing milk and meat also provides a diverse range of output for agriculture (manure, draught power and transport) and for manufacturing sector (fiber and leather). According to estimates of the Central Statistics Office (CSO), the value of output from livestock sector at current prices was about 4,59,051 crore during 2011-12 which is about 24.8% of the value of output from total agricultural and allied sector at current price and 25.6% at constant prices (2004-05). The value of output of milk is 3,05,484 crore in 2011-12, which is higher than the value of output of paddy and wheat. The value of output from eggs and wool group is 17,803 crore and 318 crore respectively for 2011-12. Livestock agriculture is the only way to produce food in many of the world’s harshest environments. Locally adapted breeds enable these vast areas to be used in a sustainable manner.

India has vast animal genetic resources with a wide variety of indigenous farm animal breeds. These breeds have evolved over generations to adapt to specific agro-climatic and socio-economic needs of the people. Many number of these breeds are now subjected to fast genetic degradation and dilution because of unplanned and indiscriminate breeding and introduction of exotic germplasm.

Domestic animal diversity in developing countries is embedded in traditional farming and pastoral communities who manage their livestock according to their Indigenous Technological Knowledge (ITK) and in tune with local ecological constraints.

Stress is described as the cumulative detrimental effect of a variety of factors on the health and performance of living beings (Rosales, 1994). Heat stress arises when there is an imbalance between heat production within the body and its dissipation. Homeotherms can maintain their body temperature within a relatively narrow range and both physiological and behavioural responses help in thermoregulation. Stress occurs when an animal suddenly faces a change in its environment. Heat stress during summer and post summer months in tropical countries is a problem of great concern among farmers and livestock producers as it costs both production and reproduction of animals.

Plants require altogether 17 essential elements to nourish themselves and to complete their reproduction and life cycle. Among them nine elements are required in large amounts for their growth, the so called macro nutrients like C, H, O, N, P, K, Ca Mg and S.  The former three elements (C, H and O) are available to the plants through air and water over which we have relatively little control either in their application rates or uptake into plant system.

Soil is a major source of nutrients needed by plants for growth. The three main nutrients are nitrogen (N), phosphorus (P) and potassium (K). Together they make up the trio known as NPK. Other important nutrients are calcium, magnesium and sulfur. Plants also need small quantities of iron, manganese, zinc, copper, nickel, chlorine, boron and molybdenum, known as trace elements because only traces are needed by the plant. The primary nutrients are nitrogen, phosphorus and potassium, because they are required in larger quantities than other nutrients. These three elements form the basis of the N-P-K label on commercial fertilizer bags. As a result, the management of these nutrients is very important. However, the primary nutrients are no more important than the other essential elements since all essential elements are required for plant growth. Remember that the ‘Law of the Minimum’ tells us that if deficient, any essential nutrient can become the controlling force in crop yield.

To meet the food needs of the burgeoning population, India will need to produce 300 million tonnes of food grains by 2020. At present more than 75% of the total food grains produced in the country are of rice and wheat. Use of nitrogenous fertilizers has contributed much to the remarkable increase in production of rice and wheat in India that has occurred during the past three decades. During the last half-decade or so while fertilizer N consumption is touching new heights, the production of both rice and wheat is showing a trend of plateauing. In fact, fertilizer N efficiency of food grain production expressed as partial factor productivity of N (PFPN) has been decreasing exponentially since 1965. The PFPN is an aggregate efficiency index that includes contributions to crop yield derived from uptake of indigenous soil N. fertilizer N uptake efficiency, and the efficiency with which N acquired by the plant is converted to grain yield. A decrease in PFPN occurs as farmers move yields higher along a fixed N response function, unless other factors shift the response function up. In other words, an initial decline in PFPN is an expected consequence of the adoption of N fertilizers by farmers and not necessarily bad within a system’s context

Introduction

Agricultural lands in India have mostly low native soil fertility. On these soils there must be a regular application of nutrient inputs through chemical fertilizers and/or organic manures for a successful and sustained crop production to replenish soil nutrient reserves depleted by crop removal and other losses. It is essential to recognize that even in agricultural production systems with relatively low productivity level, the quantity of nutrients available for recycling through plant and animal residues is not enough to compensate the amount being removed by crops. Under these circumstances mineral fertilizers play a key role in those areas having low fertile soils by increasing agricultural production to meet out growing food demand. Chemical fertilizers are the major contributors as source of plant nutrients to enhance crop production and also to maintain soil productivity.

Phosphorus (P) is a critical nutrient in crop production, due to its low bioavailability in soils (Feng et al., 2004). Phosphorus is the vital component of DNA, RNA, ATP and photosynthetic system and catalyses a number of biochemical reactions from the beginning of seedling growth through to the formation of grain and maturity. Many factors influence soil P availability like type of parent material from which the soil is derived, degree of weathering and climatic conditions. In addition to this, erosion, crop removal and phosphorus fertilization and soil phosphorus levels also affect P availability in soil. Rock phosphate is the key raw material used for manufacturing phosphatic fertilizers on which the food production depend.

For efficient nutrient use, most important factors are the timely supply/recycling of adequate amount of nutrients to the production system and its retention and release by soil for timely and ready availability in the root zone for its mobility to the plant in the presence of optimum moisture content in the soil. For keeping the applied nutrients retained in the root zone one has to reduce the soil erosion and leaching losses through technologies available in hand which include direct measures of soil and water conservation and maintain the soil aggregation and porosity through suitable tillage and organic residue recycling. For movement of nutrients into plant system we need to ensure optimum soil moisture content through water management.

Meeting food demand and escalating food prices are serious issues, as current food scenario indicate that crop demand will increase by 100 to 110% from 2005 to 2050 at global level (Tilman et al., 2011). Precision use of fertilizer is the crucial for achieving sufficient food production for growing population. It is costly input to produce and apply, both financially and environmentally. Fertilizer consumption measures the quantity of plant nutrients used per unit of arable land.

Preamble

Crop nutrient management in the climate change scenario is carried out with the basic understanding of nutrient concentrations in soils, plants and their transformations but these strategies might not apply under changed climate conditions where there is an overall change in the environment. It is understood that nutrient acquisition by plants from the soil is closely associated with overall biomass and strongly influenced by root foraging area. It is speculated that change in soil factors due to climate change could restrict root growth and nutrient stress would also occur. Plant size may also change but nutrient concentration may not change; therefore, nutrient removal will scale with growth. The interaction of mineral behavior in the soil with global climate change variables is poorly understood.