eChapters

Introduction

The creation of first humane life forms has been evidenced since 4 million years ago. They were reportedly called hunter gathers and hunted animals and collected seeds and fruits from wild plants for their livelihood maintenance as food stuff. These nomadic people moved from one place to another place as they depleted the resources of an area. The trial-and-error experimentation and manipulation of species, the scene was set for domestication of plants and animals. In addition, these hunter-gatherer societies probably paved the way for domestication by developing the social structures (later on promoted to village organizations and cooperation) as well as knowledge of cultivation techniques (later on institutes and knowledge centre).

Early Farming (1650 & Before)

Around 12-10,000 years ago human being started farmingin search of food stuff for maintain their livelihood.

It was reported that the roots of farming began within the gift day of Turkey and Middle East the geographical region, referred to as Fertile Crescent of the geographical region. Cultivation and replantation involves the deliberate sowing or alternative management of plants, that don’t essentially take issue from wild populations. The beginning of farming is primarily associated with the domestications of several species; it involves genetic change of wild varieties through conscious or unconscious human selection, the start of farming is primarily related to the domestications of many species; it involves genetic amendment of untamed varieties through aware or unconscious human choice. 2 of the earliest settlements area unit referred to as Cata Huyuk and Jericho, as reported. Folks began to taking regarding wild grasses and mistreatment the seeds for food and planting for following year’s food. These seeds area unit currently referred to as cereals and compose an outsized proportion of the world’s food provide. Water was 1st primary demand of existence of life whereby Jericho, like several early cities was set around a uniform water supply, a spring that created over a thousand gallons each minute. Reportedly, around 2 to 3 thousand folks lived there. Farming of wheat, barley, peas, and lentils supported these folks were found there.

Introduction

An ecosystem is a community of living organisms (plants, animals and microbes) in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are defined by the network of interactions amongst organisms and between organisms and their environment. India exhibits a spread of landscape and climate that are mirrored within the evolution of various soils and vegetation. These also exists a significant relationship among the soils, land form climate and vegetation. These additionally exists a big relationship amongst the soils, land type climate and vegetation. Regions are diagrammatic such everyone is as uniform as potential with relevancy physiographic, climate, length of growing amount (LGP) and soils for macro level and land use designing and effective transfer of agro-technology varied Agro environmental condition Zones diagrammatic in line with the design commission which are explained together with the classification by Indian Council of Agricultural Research (ICAR).

State of Jammu and Kashmir is located almost in the middle of three climatic regimes of Asia. The chapter introduces the agro-climatic zones of Jammu and Kashmir based on physiography. Each province of the state of Jammu and Kashmir has been further delineated into micro agro-climatic zones.

Conservation Agriculture

The agronomic measures for water conservation helps to control the evapotranspiration loss from soil and plant surface, reduces the splash effect of raindrops, checks topsoil erosion and runoff losses, permits a better intake of rainwater by improving the better soil physical environment and thereby conserves higher soil moisture for better plant growth and yield.

1. Mulching : It protects the top soil from erosion loss by controlling runoff, facilitates rainwater absorption by soil, increases the consumptive use of water by crops and hence the water use efficiency, regulates the hydrothermal regime of soil, reduces the evaporation component of the evapotranspiration, prevents soil crusting and plant nutritional losses and keep down the weed infestation. Dry soil mulch as created by stirring the soil surface with the inter-culturing implements helps to minimize evaporation loss from soil surface. Use of cover mulches like black polythene sheets or organic residues or crop stubbles on soil surface will act as barrier to reduce the evaporation losses. Post-rainy season crops (rabi crops) which live primarily on soil stored moisture derive more benefit from mulching.
2. Anti-evaporants : These are used to reduce the evaporation from the soil surface. Straw, sawdust, paddy husk, wood bark etc are used to arrest the evaporation from soil surface. Hexadecanol, a long-chain alcohol, is also used to retard the evaporation from soil surface. This chemical is resistant to microbial activity and degradation and remains active in the soil for more than a year. The main limitation in soil surface mulching is high cost involvement.

Introduction

Farming system is complicated inter-related with soil, plants, animals, implements, power, labour, capital and alternative inputs controlled partly by farming families and influenced to varied degrees by political, economic, institutional and social forces that operate at several levels. The farm is viewed during a holistic manner. The farmers are subjected to several socio-economic, biophysical, institutional, body and technological constraints. Farming system conceptually may be a set of components or parts that are reticulate that act amongst themselves. At the centre of the interaction is that the farmer exercise management and selection concerning the sort and results of interaction. It’s the human setting that gives ample condition for development and utilization of a specific system. A farming system clearly is incredibly complicated system. Therefore, any agricultural technology compatible to a specific agroecological state of affairs and socio-economic environment might not be adopted by alternative farmers. Unless each natural and human environment is thought-about, agricultural analysis won’t end in relevant agricultural technology. The income from cropping alone in tiny and marginal farms is hardly ample to sustain the farmers’ family. With the decline in farm size (0.15 ha) because of explosion of population, it’d be more and more tough to provide enough food for the family by the tip of the century. Therefore, the farmer, to be assured of an everyday income for a good living (above the poverty line), a considered mixture of anybody or additional of those enterprises with agronomic crops ought to complement the farm income and facilitate in usage the farm residue/waste. The choice of enterprises should be supported the cardinal principle of minimizing the competition and maximizing the complementarily between the enterprises.

Introduction

India, only occupies 3.29 million km² bounded geographical areas, which forms 2.4% of the world’s land acreage area; it support over 15% of the world’s population. The population of India as on 1 March 2016 stood at 1332 billion. Thus, India supports about 1/ 6th of world population, 1/50th of world’s land acreage and 1/25th of world’s water resources. The country as well has a livestock population of 500 million, which is about 20% of the world’s absolute livestock population. More than half of these are cattle, forming basic the backbone of Indian agriculture. The absolute accessible water assets of the country are adjourned as 1086 km³. Total bounded breadth of alone Eastern India occupies 28% of country’s absolute breadth of 328.73 m ha. The share of forest area to geographical area ranges from 33 to 54% for North Eastern hill states, in Assam. The per capita land availability decreased from 0.50 ha in 1981 to 0.33 ha in 2000 due to proportionate increase of land use for non-agriculture purpose and increasing population density. Rice, maize, wheat, rapeseeds, groundnut, pulses, sugarcane, potato, jute, jowar and bajra are the major crops grown in this region amongst which rice is the principle crop. India has a long history of agriculture since civilization. Then the agriculture was based on traditional practices and the local varieties were being grown without much care. Population densities usually didn’t pose much difficulty to supply food grains. Rice both under low/up land ecosystem is primarily grown under rainfed conditions having production constraints of entirely opposite in nature. Very low productivity under rainfed eco-system is mainly due to yield depressing factors caused by biotic stresses across the rice ecology, either resulted from excess or deficit water due to uneven and erratic distribution of annual rainfall. The cropping intensities in the states like Assam, Bihar, MP, Orissa, UP and West Bengal are 137.7, 137.8, 125.6, 154.6, 148.6 and 159.6 per cent, respectively. This indicated that a vast majority of lands remain fallow during dry (winter/rabi)season due to lack of proper technologies, which are under rainfed conditions, specifically lack of available moisture and or rainfall during this period. That is more than half of the arable land remains fallow during rainless period. Increasing cropping intensities in rainfed uplands is not easily achievable but there is great potential of intensification of cropping in rainfed lowland by utilizing natural resources and conserved residual moisture. Pulses like black gram, green gram, lentil, lathyrus, chick pea and oilseeds like linseed, groundnut, and rapeseed could not only increase the cropping intensities but also come forward to increase national productivity. Adoption of improved crop cultivars, cropping system, increasing cropping intensities, precision farming can hold good to get out of this situation where whole system is to be considered.

Introduction

A system is a set of inter-related, interacting and committal elements acting calm for an accepted purpose and able of reacting as an accomplished to alien stimuli. It is artless by its own achievement and it has alien boundaries based on all cogent augment backs.

Farms are systems because several activities are carefully accompanying to anniversary added by the accepted use of the Grassland labour, Grassland and capital, by accident administration and by the collective use of the farmer’s administration capacity. The assay of farms is absolutely important to the accountable of development.

Relevance of the farming systems approach: Choosing behavior for agronomical development requires the use of advice about the absolute farming situation. After-effects of farming system from a circuitous alternation of committal and committal apparatus of elements that the agronomical enterprises of the rural household. At the centermost is the agriculturalist who takes accommodation in an attack to accomplish his aspirations, goals and adapted objectives aural the banned of technologies accessible to him. Uses inputs to get outputs in acknowledgment to the abstruse elements which are the accustomed ability award in any accustomed breadth akin what the farming system can be. The human aspect provides the framework for development and appliance of an accurate farming system.

Introduction

Farming system that advised integrated the needs of the ancestors the economic factors like profitability, amusing acceptability and economically active and technically achievable enterprises in a accumulated furnishings wherein availability of acreage resources, basement and institutions such as irrigation, marketing facility business accessories including storage and transportation and credit besides the agro biological application namely interdependence. Technically achievable enterprises and the achievement of individual farmers are to be advised as above factors in farming system approach. Farming system, therefore, designates a set of agronomical activities organized while attention acreage productivity, anatomy superior and advancement adorable similar of biological assortment and ecological stability. The accent is added on a system rather than on gross output. In added words farming system is an ability administration action to accomplish bread-and-butter and sustain agronomical accumulation to be accommodated a sorted claim of the acreage domiciliary while attention the ability and advancement top quality. Farming system in its absolute faculty will advise the afterward agency to lift the abridgement of Indian farming and accepted of active of the farmers. Farming system distinctively refers to an accumulation aggregate of enterprises in which the articles and or the byproducts of one action serve as the inputs for accumulation of added enterprise. Farming systems access has appear after than that farming came into actuality getting strategically activated as breadth specific suitability. Farming systems decidedly contributed to the re-silence of farming and as able-bodied as affluence farming, organic farming and inorganic farming. Agro-climatic regions of the country are abounding adapted and differed from breadth to breadth wherein types of farming are as well different. Somewhere, the farming is based on horticulture, ley farming, agroforestry and abounding added like farming of agronomic crops. India’s bounded locations are amenable for such variations, as the assertive locations acquaintance altered climates, appropriately affecting anniversary region’s agronomical abundance differently. India is actual abased on its vagaries of cloud burst abundantly to accord satisfactory crop yields. India’s farming has all-encompassing accomplishments which go aback to at organic 10 thousand years. Reportedly, the country holds the additional position currently in agronomical accumulation in the world. In 2007, farming and affiliated industries fabricated up added than 16% of India’s GDP. Despite the abiding abatement in agriculture’s addition to the country’s GDP, now the farming is getting advised as the bigger activities antecedent of alimentation in the country and plays a key role in the socio-economic advance of the country. Now a day, India is the additional bigger ambassador of wheat, rice, cotton, sugarcane, silk, groundnuts, and of abounding more. It is as well the bigger farming of vegetables and fruit, apery 8.6% and 10.9% of all-embracing production, respectively. The above fruits produced are mangoes, papayas, sapota, and bananas. India as well has the bigger amount of livestock in the world, captivation 281 million. The country housed the additional bigger amount of animals in the tune with 175 million in the year 2008. In this accomplishments the apperception of farming system, appropriately was demography application as aggregate of agri-horti and animals, veterinary including fisheries taken into account as integrated approach.

Fermentation

The term fermentation is loosely used to denote any process in which microorganisms are involved, regards of whether or not the organism is growing in the presence of molecular oxygen. Thus, it can be defined as 'an ATP generating metabolic process in which organic compounds serve both as electron donor (becoming oxidized) and electron acceptor(becoming reduced). Energetically, fermentations are poor energy yielding process and products have lower energy content then the substrates. Since there is no net oxidation in fermentation, the number of molecules of C, H and O remain the same in products as in the substrate.

14.1 Culture from Urine

Infection of urinary tract due to microorganisms affect patient of all age group and both sex., and they vary in severity from an unsuspected infection to a condition of severe systemic disease. Urine is a ordinarily excellent culture medium for the multiplication of common pathogen of urinary tract. Most bacteria found in the urine are due to contamination of skin flora during passage and they tend to increase greatly, exceeding 10⁶/ml. When the bacterial count exceeds 10⁵ per ml of urine it indicates significant bacteriuria and is indicative of a urinary tract infection. Infection of the urinary tract may be limited to a single tissue/ organ or they may spread upward and involve the entire urinary system. Escherichia coli is the most common urinary tract pathogen. Pseudomonas aeroginosa causes another important urinary tract infection, which is characterized by blue green pus. Cystitis (inflammation of urinary bladder), Pyelonephritis (inflammation of the kidney) are permanent diseases of urinary tract.

Urinary tract infections are generally characterized by bacteriuria, bacteria in the urine. Quantitative microbiological assay of urine can identify the probable pathogen. For this purpose, calibrated loop- direct streak method and pour plate method are routinely used. Now-a-days commercially prepared special plastic device called the urine dip slide and diagnostic urine–culture called Bacturcult is being used for isolation and identification of microorganisms from genitourinary tract infections. The Bacturcult is a sterile disposable plastic tube coated with a special medium on its inner side for detection and identification of bacteriuria.

With increasing industrialization, water sources available for consumption as potable water are being adulterated with industrial, animal and human wastes. As a result water has become a formidable factor in disease transmission. Polluted water usually contains large amount of organic matter which forms nutritional base for growth and multiplication of microorganisms. Usually the water with non-pathogenic organisms, like autotrophs and saprophytic heterotrophs, are not of major concern, but presence of intestinal contaminants of fecal origin are of great concern. These pathogens are responsible for intestinal infection such as bacillary dysentery, typhoid fever, cholera and paratyphoid fever.

The detection of all the intestinal pathogens on a routine basis would be a tedious and difficult task, however, it would be easy to demonstrate the presence of some of the nonpathogenic intestinal organisms like Escherichia coli and Streptococcus faecalis. These are always found in intestine but their detection confirms the contamination of water with fecal material. Such organisms are also called pollution indicator.

Viruses are smaller than bacteria and require living cell for their growth. They can be detected through the bacteria to which they parasitise. Viruses are associated with both eukaryotes as well as prokaryotes and contain either DNA or RNA; only few have both DNA and RNA.

Viruses that infect bacteria are called bacteriophage. They consist of head or capsid and a tail. The head may be round, oval, polyhedral and is made up of proteins while tail is hollow and provides an exit for nucleic acid to enter in bacterial cell. The tail also helps in attachment to the cell wall surface of bacteria. After injection of the nucleic acid into bacteria they multiply and form large number of bacteriophage particles which cause lysis of the bacterial cell wall releasing many bacteriophages. Phages that cause lysis are known as lytic phages and that do not cause lysis are called temperate phage. The most common lytic phage is E.coli – a coliphage.

Identification of enteric bacilli is of prime importance for controlling intestinal infections. This can be achieved by preventing contamination of food and water by a group of bacteria belonging to family – Enterobacteriaceae which are found in the intestinal tract of human beings and lower mammals. The microorganisms of this family are short, gram negative, non spore forming bacilli. Such common enteric bacteria are a) pathogens such as species of Salmonella and Shigella b) occasional pathogens like species of Proteus and Klebsiella and c) normal intestinal flora like species of Escherichia and Enterobactor.

10.1 Transformation of E. coli by electroporation Principle

Preparation of electro-competent bacteria is considerably easier than preparing cells for transformation by chemical methods. Bacteria are simply grown to mid –log phase, chilled, centrifuged, washed extensively with ice cold buffer containing 10% glycerol. DNA may be introduced immediately into the bacteria by exposing them to a short high voltage electrical discharge. Alternatively, the cell suspension may be snap frozen and stored at-70^oC for 6 months before electroporation, without loss of transforming efficiency.

Since E.coli cells are small, they require very high strengths (12.5- 15KV cm^-1) for electroporation as compared to those used to introduce DNA into eukaryotic cells. Electroporation is temperature dependent and is best carried out at 0-4°C.

The highest efficiency of transformation is obtained when the concentration of input DNA is high (1-10 μg/ml) and when the length and intensity of the electrical pulse are such that only 30-50% of the cells survive in the procedure. Under these conditions, as many as 80% of the surviving cells may be transformed. Higher frequencies of transformation (colonies/ molecules input DNA) are obtained when the DNA concentration is low (?10pg/ml).

The method outlined in this protocol is followed with most strains of E.coli and with plasmids <15kb in size. However, substantial variation in the efficiency of transformation between the strains of E. coli. has been reported. As in case with chemical transformation, linear plasmid DNAs introduced into E.coli by a pulsed electrical discharge transform very efficiently from 10 to 1000 fold but less efficiently than the corresponding closed circular DNA – perhaps because the exposed terminal of linear DNA are susceptible to attack by intracellular nucleases.

Antibiotics are produced by some true bacteria, actinomycetes and fungi that destroy or inhibit the growth of other microorganisms. Some antibiotics are synthesized or modified in the laboratory; however, their origins are always in living cells.

9.1 Assay of Antibiotics

Soil serves as the major repository of microorganisms some of which produces antibiotics. Four groups of soil microorganisms viz; Streptomyces, Bacillus, Penicillium and Cephalosporium represent three microbial types, namely, actinomycetes, true bacteria and molds respectively.

Following procedure may be applied to isolate antibiotic-producing microorganisms from soil:

Our exposure to wide variety of chemicals has increased markedly in the recent past. Most of these compounds are mutagenic as well as potential carcinogens. Emphasis is being laid to develop method for detection of environmental carcinogens so that their use can be avoided.

Despite the fact that mammalian cell structure and human enzymatic pathways differ from those in bacteria, the chemical nature of DNA is common to all organisms; this permits the use of bacterial test systems for rapid detection of possible mutagens.

The Ames test which was developed by Bruce Ames in 1970, at the University of California, U.S.A. is a mutational reversion assay employing several special strains of Salmonella typhimurium, each of which has a different mutation in the amino acid histidine biosynthesis operon.

S. typhimurium, the indicator organism, used in this test is the mutant strain that cannot synthesize histidine (His^-), lack the enzyme to repair DNA so that mutation shows up readily and has leaky cell wall that permit the rapid entry of chemicals. In addition, this S. typhimurium strain carries mutation enhanced plasmid, the combined effect of these characters increase the sensitivity of the organism to mutagenic treatments.

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

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

1)By colony counting or cell counting

2)By weighing the cells

3)By cell activity (turbidity method)

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

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

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

Generally microorganisms are so small and colourless in their natural state that it becomes difficult to observe them clearly under microscope. Stains and dyes, which are colouring agents, are used by biologist for better understanding of the morphological and anatomical structures of the organisms under study. Stains are prepared with great care and specification to get satisfactory result, while dyes are not as exacting in their characteristics.

Dyes are of two types, natural and synthetic. The natural dyes are used for histological purposes, whereas the synthetic dyes for bacterial stain. Usually dyes which are derivatives of cyclic compound benzene of benzole, are prepared from one or more substances found in coal-tar, and so are called coal-tar dyes. Chemically dyes are organic compounds containing both chromophore and auxochrome groups linked to benzene rings. Chromophore group provides the compounds the property of colour and thus benzene containing chromophores are called chromogens. It has no affinity to combine with fibres or tissue and as such not called dye. For being a dye, compound should contain an auxillary group which provides the compounds the properties of electrolytic dissociation.

The dyes may be acidic, basic or neutral. The acidic dyes are eosin, acid fuchsine and picric acid whereas the basic dyes are safranin, methylene blue, crystal violet etc. The acidic dyes ionize to give the dye portion of molecule a negative electrical charge. They are salts of sodium, potassium, calcium, magnesium etc. The basic dyes ionize to give the dye portion of molecule a positive electrical charge and are salts of chlorides, sulphates or acetates.

4.1 From Soil

Soil contains varied group of microorganisms such as fungi, bacteria, actinomycetes, algae and protozoa. The type of nutrients available, moisture, temperature and pH of the soil determine the nature of microbial population in soil. Different laboratory techniques for isolation of microorganisms have been detailed in chapter-III. These are used in particular for the isolation of specific type of microorganisms. All the techniques adopted are just to segregate the pathogens/ microorganisms from the mixture of microbial population present in nature.

(a) Isolation of Fungi

Soil contains large number of fungi and constitutes a major place of microbial population. They can be isolated in pure form by following the methods given below:

Under natural habitats microorganisms usually grow in mixed populations containing several species. This is really a problem for microbiologists because a single type of microorganism can not be studied adequately in a mixed culture. In laboratories these populations can be separated into pure cultures. The pure cultures contain only one type of organism and are thus suitable for studying the cultural, morphological and biochemical characters of an individual species. In the present days there are several ways of developing pure cultures in laboratories. Some of which are as follows:

Microorganisms, being ubiquitous, are found in soil, air, water, food, sewage, on body surfaces as well as on degrading and decomposing substances. Their survival and continued growth mostly depend on an adequate supply of nutrients and favourable growth environments. The culture media (nutrients) consisting of chemicals support the growth of microorganisms in a given condition. They are devised in such a way that the organism should get all the nutritional requirements. These are usually prepared in laboratory by weighing and dispensing the individual ingredients. Generally, the common media contain both inorganic and organic nutrients; however, for the cultivation of large number of microorganisms, specialized media are required.

Basically the culture media are of three types: (1) Natural, (2) Semi synthetic and (3) Synthetic.

Microbiology is a branch of science dealing with the study of organisms which are too small to be seen clearly by unaided eye. Roughly the organisms with a diameter of 0.1mm or less, which can not be seen by the human eyes unaided, come under the domain of microorganisms.

Thus, the laboratory work dealing with the microorganisms needs special care to avoid infection and infusion for maintaining good health. In fact all microorganisms should be treated as potential pathogens. Thus, for working with microorganisms aseptic techniques must be followed by students as well as by the laboratory assistants and teachers.

Fill in the Blanks

1.The highest amount of rain is received in India by _______ Monsoon

2.Country with largest irrigated area in the world is _______

3.The major source of irrigation water in Andhra Pradesh is _______

4.The annual water budget of India is about _______ million ha meters

5.Ultimate irrigation potential in India is _______ m. ha.

6.The portion of the total rainfall that is retained in the soil directly for evapotranspiration is _______ M ha m

7.The first irrigation commission was constituted in the year _______

17.1 Rice

Rice culture at present dominates irrigated agriculture. About 64% of the irrigation water resources in Andhra Pradesh are used for cultivation of rice. An adequate water supply is one of the most important factors in rice production. In many parts of India including Andhra Pradesh rice plants suffer from either too much or too little water because of irregular rainfall and land topography.

Percolation losses in rice fields

Percolation losses are a function of the local soil and topographic conditions. Therefore, at any time the amount of rainfall or irrigation water entering the soil becomes greater than its water holding capacity, losses by downward movement of free water (vertical percolation) will occur. Percolation is often defined as the movement of water through saturated soils due to gravity, hydrostatic pressure or both.

Thus where the soil is heavy and the water table is close to the soil surface, percolation losses are low, about 1 – 2 mm/day. On the other hand, where the soil is light and the water table is deep, percolation losses may be high, about 8 – 15 mm/day, or more. About 50 to 60% of applied water to rice is lost by deep percolation. The percolation losses can be reduced by adopting following agronomic practices:

16.1 Water logging

For optimum growth and yield of field crops, proper balance between soil air and soil moisture is quite essential. Except rice many of the cultivated plants cannot withstand excess water in the soil. The ideal condition is that moisture and air occupy the pore spaces in equal proportions. When the soil contains excess water than that can be accommodated in the pore spaces it is said the field is water logged.

Causes of water logging

1. Excessive use of water when the water is available in abundance or cheaply due to the belief that more water contributes better yield.

2. Improper selection of irrigation methods

3. Percolation and seepage from lands canals and reservoir located at nearby elevated places

4. Improper lay out and lack of outlets

5. Presence of impervious layer with profile impeding percolation

6. Upward rise of water from shallow ground water table or aquifer.

When rocks and minerals under go weathering process large quantities of soluble salts are formed. In humid regions these salts are washed down to the ground water and to the sea. But in arid and semi arid regions they accumulate in the soil. Excessive irrigation and poor water management are the two chief causes of water logging and salt accumulation. An accumulation of salts in soil leads to unfavourable soil water-air relationship and effect the crop production.

The following are the main causes which leads to development of salty soils (salinity or alkalinity)

Whatever may be the source of irrigation water viz., river, canal, tank, open well or tube well, some soluble salts are always dissolved in it. The main soluble constituent in water are Ca, Mg, Na and K as cations and chloride, sulphate bicarbonate and carbonate as anions. However ions of other elements such as lithium, silicon, bromine, iodine, copper, cobalt, fluorine, boron, titanium, vanadium, barium, arsenic, antimony, beryllium, chromium, manganese, lead, selenium phosphate and organic matter are also present. Among the soluble constituents, calcium, sodium, sulphate, bicarbonate and boron are important in determining the quality of irrigation water and its suitability for irrigation purposes. However other factors such as soil texture, permeability, drainage, type of crop etc., are equally important in determining the suitability of irrigation water.

The following are the most common problems that result from using poor quality water.

An efficient irrigation system implies effective transfer of water from the source to the filled with minimum possible loss. The objective of the efficiency concept is to identify the nature of water loss and to decide the type of improvements in the system.

Evaluation of performance in terms of efficiency is prerequisite for proper use of irrigation water.

Irrigation Methods

Surface

Sub-surface

Pressurized irrigation

12.1 Surface Irrigation

Surface irrigation method refers to the manner or plan of water application by gravity flow to the cultivated land wetting either the entire field (uncontrolled flooding) or part of the field (furrows, basins, border strips). Most irrigated areas have characteristic land features and differ from those in other areas. Hence, for efficient application of water it is important to select such method of irrigation, which fits one’s own land.

The adoption of a certain method need not be necessarily based on convention or that followed in the adjoining farm. The factors, which determine the suitable method of irrigation are local conditions (soil type - its permeability & water storage capacity; land topography, climate, water availability & water quality), crop type, type of technology, previous experience with irrigation, required labour inputs etc. Good yield of crops can be obtained from irrigated land only if the water is applied judiciously to meet the needs of the plant, but not to cause waste and damage. Irrigation water is applied to cultivated land by the following surface methods of irrigation:

Allocation of the water receipt including anticipated within the crop period and its detailed account of expenditure for efficient and profitable farm management is called as water budgeting.

Water budgeting may be for an irrigation system planned by irrigation engineers; may be for a canal or for an area (block) or may be for a farm according to the need and plan by responsible persons who plan the irrigation efficiency.

10.1 Evapotranspiration (ET = Evaporation + Transpiration)

Evaporation is a diffusive process by which water from natural surfaces, such as free water surface, bare soil, from live or dead vegetation foliage (intercepted water, dewfall, guttation etc) is lost in the form of vapour to the atmosphere. It is one of the basic components of hydrologic cycle.

Likewise transpiration is a process by which water is lost in the form of vapour through plant surfaces, particularly leaves. In this process water is essentially absorbed by the plant roots due to water potential gradients and it moves upward through the stem and is ultimately lost into the atmosphere through numerous minute stomata in the plant leaves. It is basically an evaporation process. However, unlike evaporation from a water or soil surface, plant structure and stomatal behaviour operating in conjunction with the physical principles governing evaporation modify transpiration.

Thus, evapotranspiration is a combined loss of water from the soil (evaporation) and plant (transpiration) surfaces to the atmosphere through vaporization of liquid water, and is expressed in depth per unit time (for example mm/ day). Quantification of evapotranspiration is required in the context of many issues:

Crop water requirement is the water required by the plants for its survival, growth, development and to produce economic parts. This requirement is applied either naturally by precipitation or artificially by irrigation. Hence the crop water requirement includes all losses like:

• Transpiration loss through leaves (T)

• Evaporation loss through soil surface in cropped area (E)

• Amount of weather used by plants (WP) for its metabolic activities which is estimated as less than 1% of the total water absorption. These three components cannot be separated so easily. Hence the ET loss is taken as crop water use or crop water consumptive use.

• Other application losses are conveyance loss, percolation loss, runoff loss, etc., (WL).

• The water required for special purposes (WSP) like puddling operation, ploughing operation, land preparation, leaching, requirement, for the purpose of weeding, for dissolving fertilizer and chemical, etc.

• Hence the water requirement is symbolically represented as:

8.1 Moisture extraction pattern

The moisture extraction pattern reveals about how the moisture is extracted and how much quantity is extracted at different depth level in the root zone. The moisture extraction patter shows the relative amount of moisture extracted from different depths within the crop root zone. The moisture extraction pattern of plant growing in a uniform soil without a restrictive layer and with adequate supply of available soil moisture throughout the zone is shown in Figure. 8.1.

The measurement of soil moisture is needed to determine when to irrigate and the amount of water needed when irrigating, to evaluate evapotranspiration, and to monitor soil matric potential. The soil moisture is measured in two ways- direct and indirect methods as follows:

The water contents expressed under certain standard conditions are commonly referred to as soil moisture constants. They are used as reference points for practical irrigation water management. The usage of these constants together with the energy status of soil water gives useful knowledge. These constants are briefly explained below:

6.1 Saturation Capacity

Saturation capacity refers to the condition of soil at which all the macro and micro pores are filled with water and the soil is at maximum water retention capacity”. The matric suction at this condition is essentially zero as the water is in equilibrium with free water. Excess water above saturation capacity of soil is lost from root zone as gravitational water.

5.1 Kinds of Soil Water

The following re the three main classes of soil water:

(i)  Hygroscopic water. Water held tightly to the surface of soil particles by adsorption forces.

(ii) Capillary water. Water held by forces of surface tension and continuous films around soil particles and in the capillary spaces.

(iii) Gravitational water. Water that moves freely in response to gravity and drains out of the soil.

4.1 Soil Moisture Tension

Soil moisture tension is a measure of the tenacity with which water is retained in the soil and shows the force per unit area that must be exerted to remove water from soil. The tenacity is measured in terms of the potential energy of water in the soil measured, usually with respect to free water. It is usually expressed in atmospheres, the average air pressure at sea level. Other pressure units like cm of water or cm or mm of mercury are also often used (1 atmosphere = 1036 cm of water or 76.39 cm of mercury). It is also sometimes expressed in bars (1 bar = 106 dynes / cm² = 1023 cm of water column. 1 millibar = 1/1000- bar).

Soil moisture tension is brought about at the smaller dimensions by surface tension (capillarity) and at the higher dimensions by adhesion. Buckingham (1907) introduced the concept of ‘capillary potential’ to define the energy with which water is held by soil. This term, however, does not apply over the entire moisture range. In a wet soil, as long as there is a continuous column of water, it might be called ‘hydrostatic potential’, in the intermediate range the term ‘capillary potential’ is appropriate. In the dry range the term ‘hygroscopic potential’ would be suitable. However, the term ‘soil moisture potential’, ‘soil moisture suction’ and ‘soil moisture tension’ are often used synonymously to cover the entire range of moisture (Khonke, 1968).

The soil is a heterogeneous, polyphasic viz., solid, liquid and gaseous, particulate, disperse and porous system (Fig. 3.1). The solid phase constitutes the soil matrix, the liquid phase consists of soil water, which always contains dissolved substances so that it should properly be called as soil solution and the gaseous phase is the soil atmosphere.

Plants and any from of living organisms cannot live without water, since water is the most important constituent about 80 to 90% of most plant cell.

2.1 Role of water in crop and crop production

(A) Physiological importance

•The plant system itself contains about 90% of water

•Amount of water varies in different parts of plant as follows

•Apical portion of root and shoot >90%

•Stem, leaves and fruits - 70 - 90%

•Woods - 50 - 60%

•Matured parts - 15 - 20%

•Freshly harvested grains - 15 - 20%

Sustainable development and efficient management of water is an increasingly complex challenge in India. Increasing population, growing urbanization, and rapid industrialization combined with the need for raising agricultural production generates competing claims for water. There is a growing perception of a sense of an impending water crisis in the country. Some manifestations of this crisis are:

(a) Increasing costs of developing new water resource – Many major and medium irrigation projects seem to remain under execution forever as they slip from one plan to the other with escalating cost and time overruns.

(b) Siltation of reservoirs and owing to lack of maintenance, the capacity of the older irrigation systems seems to be going down.

(c) Declining groundwater table due to over-exploitation imposing an increasing financial burden on farmers who need to deepen their wells and replace their pump sets and on State Governments whose subsidy burden for electricity supplies rises.

(d) Water pollution and degradation of water-related ecosystems - Water in most parts of rivers is not fit for bathing, let alone drinking. Untreated or partially treated sewage from towns and cities is being dumped into the rivers. Untreated or inadequately treated industrial effluents pollute water bodies and also contaminate groundwater,

(e) Wasteful use of already developed water supplies, often encouraged by the subsidies and distorted incentives that influence water use,

(f) Besides in many rural habitations there are pockets where arsenic, nitrate, and fluoride concentration in drinking water are posing a serious health hazard

(g) Rise in water-logging and salinity resulting in degradation of soils in irrigated areas,

(h) Increasing water conflicts about water rights between upper and lower riparian states in a river, conflicts about quality of water, people’s right for rainwater harvesting in a watershed against downstream users, industrial use of groundwater and its impact on water tables and conflicts between urban and rural users etc

(i) The gross irrigated area does not seem to be rising in a manner that it should be, given the investment in irrigation. The difference between potential created and area actually irrigated remains large. Unless we bridge the gap, significant increase in agricultural production will be difficult to realize.

In addition to farm ponds, irrigation to crops can be met from other sources. The main sources can be broadly classified as: (i) Canal irrigation, (ii) Well Irrigation and (iii) Lift irrigation. In arid and semi arid areas, where availability of water is scarce, pitcher irrigation is practiced. These sources of irrigation are briefly mentioned as follows.

13.1 Canal Irrigation

To feed the world population of 8 billion in 2025 AD, it is necessary to bring more area under irrigation because irrigated farms typically get higher yield under provision of irrigation. The food production will have to increase by about 50 percent to feed some two billion more people by 2025 AD, and a large part of that increase needs to come from irrigated agriculture. It is reported that the yield of different crops are generally 2-3 times higher than the crops grown under rainfed conditions. Furthermore, it is possible to raise 2-3 crops round the year under irrigated agriculture whereas hardly a single crop is successfully grown in a year under rainfed condition. It is reported that about 40% of the world’s food production comes from only 17% of the irrigated land of the world (Sivanappan, 2000). Everybody is aware of the fact how the irrigation played a crucial role to make the Green Revolution in India successful. A major part of irrigation is achieved by canal irrigation through different irrigation schemes.

A project that makes use of weir or a barrage for providing irrigation to fields is called as direct irrigation scheme. On the other hand, a storage irrigation scheme makes use of storage reservoir by construction of dams. In order to provide irrigation by both the schemes, it is necessary to have a network of canal systems including main canals, branch canals, distributaries, minors and watercourses. It is imperative to design the canal systems properly for a certain realistic value of peak discharge that must pass through them so as to provide sufficient irrigation to the command areas. These canals have to be aligned and excavated either in alluvial soils or non-alluvial soils; depending upon which they are called alluvial canal or non-alluvial canal.

12.1 Introduction

Farm ponds are used for multipurpose including as a viable source for supplemental irrigation to rainfed crops, a good place of entertainment, a vital place for wild life habitats, livestock and fish and aquatic plants. Like any other structure, the farm pond needs regular repair and maintenance for effective operation. The purpose of construction of the pond will be fruitful and the life span of the pond will be enhanced if proper care and maintenance are taken. In this chapter some salient discussions on care and maintenance of the pond are mentioned.

12.2 Maintenance Against Silting

The farm ponds constructed in medium to deep black soils are subjected to getting silted up. Hence, periodic desilting to restore the original storage capacity is required. If the pond is used for supplemental irrigation to crops, then desilting may be done once in every 5 to 10 years depending on the amount of silt getting deposited in the pond.

The breaches and rill formed in the spoil bank and shoulder bunds should be immediately repaired. The inlet and outlet structures should be maintained periodically. The silt deposited in the silt trap should be removed periodically. In areas where silt carried by the runoff is more, a vegetative filter near the inlet structure may be used. The pond may be desilted manually if it is small in size otherwise mechanical measures may be used to desilt. It is easy to desilt the pond when it is dry. A Simple and inexpensive method to desilt the pond is to stir the water of the pond and then allow the desilted water move away from the pond through the outlet (Belgaumi, et. al., 1997). Fig. 12.1shows a badly maintained pond with excess silting and weed infestation causing severe reduction of its storage capacity.

11.1 Introduction

Economic analysis is the most important parameter for determining the optimum size of farm pond. It is, no doubt that a big size farm pond can meet the irrigation demand of the crops grown in the command areas in addition to meeting the other demand in the command areas. But a big size farm pond is an oversize structure which necessitates large investment to be incurred which may not be economically viable. On the other hand, a small size structure may not be able to meet the crop water demand and also other demands in the command areas and so is called as under-designed structure. It has been observed that as the size of the farm pond gradually increases from a certain minimum size, the total investment cost increases. At the same time, the benefits from the increasing storage capacity of the farm pond also get increased. In such cases, from a purely business point of view, the most economical capacity is that which provides the highest rate of return on investment. As the size of the farm pond increases, the proportion of the benefit/profit to the cost also increases from certain minimum size, attains maximum value at a particular size and then declines as the size further increases. This particular size of the farm pond at which the net profit is maximum, is called as the optimum size. It is to be noted that at the optimum size, the other economic indicators like the benefit-cost ratio and internal rate of return are also high. The variation of net profit with size of the farm pond is a concave curve. The size of the farm pond corresponding to the peak of the curve which represents the highest net profit is the optimum size of the pond.

The principle of obtaining the optimum size of farm pond is to first assume a certain minimum size say five percent of the farm area and conduct the economic analysis by studying the costs and net profits of the assumed size. Then the size is gradually increased and the economic analysis is conducted for each increased size. Then a curve relating the size of the farm pond and net profit is drawn. Such a curve is generally concave shaped. The size of the structure corresponding to the maximum net profit gives the optimum size. It is to be noted that any size chosen more or less than the optimum size would give less net profit and benefit-cost ratio than that of the optimum size.

10.1 Introduction

Rainwater is the main source of water for agriculture but its current use efficiency for the crop production is low ranging between 30-45%. The rising demand for water for non-agricultural uses is proportionately decreasing its share for agricultural uses. Efficient methods of water harvesting in the farm reservoirs including farm ponds and its management for subsequent uses in agriculture with improved water use technologies are vital for increasing the productivity and reducing poverty in rainfed ecosystems. It is not to be forgotten that the harvested water in the pond is a very valuable commodity. It may be used for industrial use or for irrigation in agriculture. The harvested water is also a good source to meet the water demand of domestic animals and for human beings (Fig. 10.1). The stored water of the pond can be used for fish farming, tree plantation, intensive irrigation to small area and extensive supplemental irrigation to rainfed crops. Stored water in a pond is developed resource and is, therefore, more expensive than the natural resource. Hence, there is a need to utilize it judiciously and efficiently.

9.1 Introduction

The water harvested in the farm pond is a very valuable commodity. Every care should be taken so that not a single drop is wasted. The two major forms of losses in farm pond are (i) evaporation losses and (ii) seepage losses. Evaporative water loss (E_loss) and losses due to seepage are the two vital natural outflow components of unlined farm ponds. Studies conducted byGuerra et al. (1990) and Pal et al. (1994) indicated that the seepage loss from unlined ponds amounts to 45-67 per cent whereas the E_loss constitutes 30 per cent of the total out flow from the system. Water losses by evaporation and seepage were 5.3 and 9 mm day^-1, respectively amounting to 70% of total storage in the ponds (Syamsiah et al.1994).

Estimate of evaporation across the country indicates that it is as high as 2000 mm in the semi-arid tropics. Annual average value of the evaporation loss varies from 1400 to 1800 mm across major parts of the country: the value being highest in west Rajasthan, parts of Saurasthtra and Tamilnadu and lowest in coastal Mysore, Bihar plateau and east M.P. Reliable statistics reveal that about 70 M ha m of water evaporates from the water bodies and land surfaces out of the total annual precipitation of about 400 M ha m received by the country. The total evaporation losses from the water surfaces are about 5 M ha m from the total storage of 15 M ha m in the reservoirs including ponds, lakes spread all over the country (Belgaumi et al.,1997). In this section, the methods to estimate the losses like seepage and evaporation and various techniques to control them are discussed.

8.1 Introduction

After deciding the optimum size of farm pond and its dimensions, the next step begins the construction of farm pond. Further the site selection and location of the pond in the selected site to be finished before the construction of pond starts. The selection of site and location of farm pond areas have been discussed in Chapter 3. In this chapter, discussion on methodologies for construction of farm pond including spillways, inlet and outlet structures, design of grassed waterways and embankment have been presented. As a guiding principle, the construction of farm pond involves the following steps:

8.2 Site Clearing

The area where the pond is to be constructed has to be inspected first. The site where pond has to be dug out should be cleared to an extent of about 10 m from all sides of top dimensions of the pond. All bushes, shrubs, stumps and other unwanted materials should be dug out and removed. If there are roots of plants, they should be uprooted. The land may be ploughed and harrowed, if necessary, to get a more or less even topography.

7.1 Introduction

The practice of rainwater storage in the pond is quite common but still there is a need to improve its design. Most of the ponds used for rainwater storage are designed on thumb rule: either they are under or over designed. An over designed farm pond can meet the supplemental irrigation needs of the crop but it may not be economical. On the other hand, an under designed pond though economical, may not be able to meet the irrigation needs of the crops at all times. It is reported that in some case up to 20% of the farm area is used for construction of farm pond. These farm ponds are found not to be optimal. Although these ponds are able to meet the crop water demand at most of the stress periods, but considering the economics, they are observed not to be optimal. The big size farm ponds need large areas to be wasted for the digging of the structures. They need huge investment for their construction and lining. Hence, proper scientific studies are needed so that its storage becomes adequate to save the crops from the adverse effects of the drought in monsoon and to assure the possibility of growing a second crop in the winter and at the same time, it is economical also. Simulation studies by daily water balance models of both the crop field and the pond help to understand the availability of water in the pond to meet the supplemental irrigation demand of the crops.

6.1 Introduction

Farm ponds used in farmers’ fields are generally square shaped or rectangular shaped pyramidal structures. It has a regular side slope, depth, and top and bottom dimensions. It may be excavated/dugout pond or embankment pond. In excavated pond, the pond is constructed below the ground level. Water is collected in the pond by gravity from the adjacent catchment. In embankment type, the pond is partly above the ground and partly below. This type of pond has higher storage capacity than the dugout type pond. This type of pond has a berm and dyke/embankment around the pond. The embankment has some side slope. The pond has bottom dimensions, dimensions at the ground level as well as some dimensions at the top above the embankment. In this chapter, various dimensions of pond like depth, side slope of the pond, as well as the various dimensions at bottom, ground and top level will be discussed.

5.1 Introduction

A farm pond that collects and harvests in-situ rainfall as well as runoff from the catchment area can be used for many purposes: the most important of which is the supply of water to crops as supplemental irrigation. It is no doubt a viable source for integrated farming system. In addition, the water of the pond can be used for domestic and to some extent for the industrial uses. It is also a good source for recreational use. Total water demand of the pond including irrigation to different crops in different seasons, domestic and other non agricultural uses are to be assessed. While estimating the crop water requirement and irrigation requirement, various crops to be grown in the service area of the pond, their water requirements, crop duration, extent of coverage and water management practices followed are to be taken into consideration. Multiplying the irrigation requirement with crop coverage area, volumetric irrigation water requirement of crop can be found out. Summation of irrigation requirement of all crops grown in service area of the pond, gives total irrigation demand of the pond.

Farm ponds are normally used for irrigation to crops as well as to meet the live stock water demand. Normally the large live stocks like horse, cattle require 20 thousand litres of water per head per year whereas the small live stocks like sheep, goat, pigs require 2 thousand litres of water per head per year. Adding the irrigation demand to the livestock demand, total water requirement of the pond is calculated. In addition to this, if the pond water is used for industrial, domestic and other sectoral purposes, then water used in all such sectors are to be added to irrigation and livestock demand to estimate the total water demand of the pond.

4.1 Introduction

A farm pond is basically small scale water harvesting and water recycling structure. It harvests water mainly in the rainy season when there is abundant rainfall producing sufficient runoff and the harvested water may be used for single or multiple cropping. When there is deficient supply of water to the crops it may supplement as supplemental irrigation. The leftover water in the pond can be used for growing another crop in winter when there is no or less rainfall. Ij addition, the stored water in the pond can be used for domestic and other uses and rearing fish. Thus it serves as viable medium for integrated farming system in rainfed farming ecosystem. Before designing a pond in a given location, it is very important to estimate the total quantity of water supply to the pond. The two main sources of water supply to pond are (i) in situ rainfall and (ii) runoff (some times called as discharge) generated from the catchment and conveyed to the pond. Some times there is groundwater contribution to the pond when the pond is unlined and the underlying groundwater table with reference to the ground level is at lower elevation than the depth of water in the pond such that there is a hydraulic gradient in the direction of underlying groundwater level to the water level in the pond.