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Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA)

Rationale of the Programme

A vast majority of the poor people in rural areas of the country depend mainly on the wages they earn through unskilled labour. They are often on threshold levels of subsistence and are vulnerable to the possibility of sinking from transient to chronic poverty, in the event of inadequate labour demand or in the face of unpredictable crises that may be general in nature like natural disaster or personal like ill-health, all of which adversely impact their employment opportunities. In a context of poverty & unemployment, wage employment programmes provide unskilled manual workers with short-term employment. The wage employment programmes provide income transfers to poor households during critical times and so also enable consumption smoothing specially during slack agricultural seasons or years. Durable assets created under these programmes have the potential to generate sustainable livelihood.

Mould growth in raw materials or finished feeds result in production of mycotoxins. Mycotoxins are a large group of toxic chemicals causing wide range of pathological and physiological effects in animals. Symptoms depend on the amount of toxin present in the feed, the period for which the feed is ingested, the nutritional status of the feed and the susceptibility of the animal. Feed efficiency, growth rate and production are affected in animals consuming sub-acute doses.

Ruminants are generally considered less susceptible to mycotoxins than monogastric animals because of degradation of mycotoxin in rumen by rumen microorganism. However, certain mycotoxins resist rumen degradation and cause clinical mycotoxicosis. In high yielding dairy animals, during transition period, animals who are in negative energy balance (NEB), low body condition score and decreased resistance to infectious agents cause adverse effects in animal health with exposure of mycotoxins present in animal diet.

Effect of mycotoxin in ruminants

In cattle during metabolism, mycotoxin present in stored or ensiled feeds produce microbial volatile organic compounds (MVOCs) which are responsible for mouldy odour, reduced feed intake and increased feeding times. This insufficient feed intake further produces negative energy balance (NEB).

1.1. Agriculture

Derived from Latin word; Ager-soil and culture-Cultivation.

An art: Governs the knowledge to perform the operations of the farm in a skillful ways.

A science: Uses technologies including breeding, production technologies, crop protection, economics etc., to maximize the yield and profitability of the farmer.

A business: Way of life for a rural population.

Involves management of labour, water and capital, and employing technologies for production of food, fibre, feed and fuel through mechanization to achieve maximum returns.

As per Agricultural act 1947, agriculture includes horticulture, fruit growing, seed growing, dairy farming, livestock breeding, grazing land, meadow land, market gardens and nursery gardens.

During the 19^th century various hypotheses were advanced about the origin of earth. These hypotheses can be grouped into two general classes:

1. Monistic hypotheses: The pioneers of this hypotheses believed that only one mass or body was responsible for the creation of the solar system. The representative of this theory is Nebular hypothesis. The advocates of this hypothesis were Kant and Laplace.

2. Dualistic hypotheses: The advocates of this hypothesis believed that two separate masses or bodies were responsible for the creation of the solar system. The representatives of this hypothesis are Planetesimal hypothesis and Tidal hypothesis. The pioneer of Planetesimal hypothesis was the great English scientist T. C. Chamberlain. The Tidal hypothesis was advocated by another English geographer named James Jeans.

Soil formation takes place in two consecutive stages:

1. The weathering of rocks into regolith

2. The formation of true soil from regolith

The evolution of true soil from regolith takes place by the combined action of soil forming factors and processes. The first step is accomplished by weathering (disintegration and decomposition) and the second is associated with the action of soil forming factors which are known as pedogenic factors.

The pedogenic processes are dynamic and extremely complex involving several chemical and biological reactions, usually operating simultaneously in a given area. One process may counteract another, or two different processes may work in tandem to achieve the same result. Different processes or combination of processes operate under varying natural environments. The combined interaction of various soil forming factors under different environmental conditions set a furtherance to certain recognized soil forming processes. Pedogenic processes include:

Soil colour is the most obvious characteristic of soil. It has no direct effect on plant growth; however, it has indirect effect through temperature, moisture. Soil colour can indicate the climatic conditions under which it has developed and can be related to its parent material. It can also reflect upon its age, and the temperature and moisture characteristics of the climate. Thus, cooler regions tend to have grayish to black topsoils, due to the accumulation of humus. In moist warm regions, soils tend to be more yellowish-brown to red. Arid soils tend to be light in color (due to low organic content) and primarily express the color of their mineral content. Practically all colours occur in soils - white, red, brown, gray, yellow, black, etc. Predominantly soil colours are not pure, but mixtures. Frequently two or three colours occur, called as “mottling”.

Water can move in the liquid and gaseous phases:

1. Liquid water

i) Saturated flow: Most pores are filled with water; water in this condition is tension free

ii) Unsaturated flow: Pores are partially filled with air; the water is under tension.

2. Water vapour

i) Diffusion: Water vapour moves by diffusion as a result of vapour pressure differences (partial pressure)

ii) Mass flow: Water vapour flows in a mass with other gases of the system in response to differences in total pressure.

Soil Colloids

A colloidal system is a two-phase heterogenous system in which one material in a very finely divided state is dispersed through the second phase. Solid in liquid (dispersion of clay in water) and liquid in gas (fog or clouds in atmosphere) are examples. The clay fraction of the soil contains particles less than 0.002 mm in size. Particles less than 0.001 mm size possess colloidal properties and are known as soil colloids.

Structure of Crystalline Clays

Soil clay minerals are of two types: crystalline and amorphous. Crystalline clays are made up of sheets of octahedra and tetrahedra of O and OH. Clays with alternating sheets of aluminium octahedra and silicon tetrahedra, are called, “1:1 clays” or “diphormic clays”. A sheet of octahedra is sandwiched between two sheets of tetrahedra in 2:1 clays which are called as, “triphormic clays”.

The building blocks of clay crystals are called “unit cells”. The geometry of octahedra has 3 voids in each half unit cell, equivalent to 6 negative valences. In order to nullify these 6 negative valences, 6 positive valences are needed. The 6 negative valences can be nullified by 3 divalent cations, one each in the three voids, or by 2 trivalent cations, leaving the third void empty. When trivalent cations such as Fe³+ and Al³+ fill two of the three voids, the clays are called, “dioctahedral clays”. When three divalent cations such as Fe , Mg and Mn fill up all the three voids, such clays are called, “trioctahedral clays”.

Ion Exchange Defined

By ion exchange is meant “the reversible process by which cations and anions are exchanged between solid and liquid phases, and between solid phases, if in close contact with each other”. For exchange of cations the term “base exchange” is exclusively used.

To millions of different organisms around the world, soil is the habitat. A handful of soil can contain billions of soil micro-organisms. One gram of a fertile soil can harbour up to one billion bacteria. Only 5% of what is produced by green plants is consumed by animals, but 95% is consumed by microorganisms. Soil organisms are generally grouped into microfauna/microorganisms and macrofauna. The main soil microorganisms are bacteria, fungi, and protozoa. The macro-fauna includes oligochaeta, arthropods, mollusks and nematodes. These organisms play an essential role in soil formation and soil environment.

27.1. Bacteria

Bacteria are the major single-celled microorganisms in the soil ecosystem that are responsible for many important processes. There are many different types of bacteria and most of them are aerobic, requiring oxygen from the soil atmosphere. However, there are bacteria that live without oxygen and other types can live both with and without oxygen. The growth of these bacteria is limited by the food that is available in the soil. They decompose plant materials as well as other organisms’ wastes that contain plant nutrients in an unusable form and convert them into a form that can be used by plants. One such essential nutrient that is converted by bacteria is nitrogen. Nitrogen-fixing bacteria are able to use the nitrogen (N₂) that exists in the atmosphere and convert it through cellular processes into ammonia (NH₃). Nitrifying bacteria mix ammonia with water to create ammonium ion (NH₄+) and nitrate (NO₃^-), which can be used by other organisms.

Soil quality is the capacity of the soil to function, within its natural or managed ecosystems, to sustain plant and animal productivity, maintain or enhance water and air quality, support human and animal health and habitation. This is not limited to agriculture, though most work and evaluation has occurred on agricultural lands.

Soil health refers to the condition of the soil and its potential to sustain biological functions, maintain environmental quality and promote plant and animal health. Healthy soils are the key to food security and sustainable future. They support sustainable food production, mitigate and adapt to climate changes, filter water, enhance resilience to floods and droughts and so much more.

India is endowed with varied types of soils and this could be attributed varied relief features, landforms, climatic realms and vegetation types in the subcontinent. In ancient times, soils used to be classified in India into fertile and sterile soils. Later, the inherent characteristics and external features of soils such as texture and colour, were used to classify the soils. Based on texture, soil types were identified as sandy, clayey, loam, etc. In terms of colour, they were red, yellow, black, etc.

Scientific surveys of soils in India have been conducted by various agencies since independence. All India Soil Survey Organization, established in 1956, carried out detailed soil surveys in the catchment areas of major river valley projects like the Damodar Valley. Later, the National Bureau of Soil Survey and the Land Use Planning (NBSSLUP) ofthe Indian Council of Agricultural Research, established in 1976, made extensive studies on Indian soils and classified them as per the USDA SoilTaxonomy

The Horticultural crops show wider adaptation and therefore exact delineation of the agro-climatic areas specific to each crops is not possible, except for the typical temperate and tropical species. However, our country can be broadly divided into seven zones for horticultural crops as indicated below:

1. Temperate Northern Region

Comprising of states of Jammu & Kashmir, Himachal Pradesh, Hilly areas of Uttar Pradesh and West Bengal. Temperate fruits, cool season vegetables are the important horticultural crops in the zone.

2. North Western Arid Region

Comprising ofthe entire Rajasthan state, Gujarat and parts ofPunjab & Haryana. Arid fruit crops like ber, pomegranate, amla, date palm, wood apple and seed spices like coriander, cumin, fennel occupy major area in this zone.

3. North Eastern Sub-tropical Humid Region

Comprising of states and union territories like Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland and Tripura. Fruit crops like banana, pineapple, citrus, jack besides plantation crops like tea and large cardamom are also grown here.

The Government of India has established boards for important crops. The boards are statutory bodies which help in guiding the production and export. The main objectives for setting up the boards are -

To monitor and promote the export of primary items.

To empower the producers by providing trainings and close guidance.

To conduct research to improve the commodity, e.g. Central Coffee Research Institute, Coir Research Institute etc.

To advise the government on policy matters such as price fixing, fixing quota for export and signing trade agreements.

To promote the commodity by opening offices and outlets in India and abroad.

To showcase the commodity by participating in trade fairs and exhibitions.

A number of tools, implements and machineries are used in cultivation of horticultural crops to make every operation easy and efficient. There are a number of operations involved in cultivation of horticultural crops, like making of nursery, propagation of plant material, field ploughing, breaking of clods, levelling, making bunds, sowing and planting, plant protection, training, pruning, harvesting, lawn mowing etc. All these operations are physically taxing and cannot be carried out efficiently without proper tools, implements and machineries. Following are some important tools -

1. Bill hook: To cut and remove big sized unwanted branches of trees.

2. Buckets and plastic pots: used in the orchard for spraying, transport water, carry harvested produce etc.

3. Budding and grafting knife: The budding and grafting operations in propagation of many horticultural plants are carried out using budding and grafting knife.

4. Country plough: Used in field preparation for ploughing the soil, incorporation of organic manures into the soil at the time of last ploughing, summer ploughing in conserving of soil moisture.

5. Crow bar: Used to loosen the soil, digging and deepening the pits and channels.

6. Dibbler: Used to make holes and sow the seeds in the nursery as well as in the main field.

7. Digging fork: It is of a great use in harvesting the tuber crops without damaging the produce.

Water is an extremely essential component in plant growth and development. It is of utmost importance for photosynthesis, cell division, cell growth / elongation, respiration, nutrient uptake, mineral utilization and much other metabolic process, which directly affect the quantity and quality of the produce. Hence quantity and quality of water play a vital role in performance of a crop. A well distributed water supply, throughout the growth of plant is essential. Rainfall is the major source of water for the crops. Rainfall recharges the surface water resources such as rivers, streams and ponds and also the ground water resources like wells.

Introduction

A sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks. The objective for IPM practitioners is to minimize risks to human health and the environment from the pest management actions implemented. IPM is a holistic approach that seeks to manage pests by using methods that are effective, economically sound, and ecologically compatible. IPM practitioners base decisions on information that is collected systematically as they integrate economic, environmental, and social goals. IPM promotes the use and integration of biological control agent as one of the strategies for pest and disease management. Because, biological control of plant pathogen is a potential alternative to the use of environment harming chemical pesticides in agriculture.

Bacteria are by far the common type of soil microorganisms, possibly because they can grow rapidly and have the ability to utilize a wide range of substances as either carbon or nitrogen sources. The bacteria that provide some benefit to plants are found near, on (or) even within the roots of plants (Kloepper et al., 1980) to protect the plants from pathogen attack called as antagonistic organism. Among the many potential bacterial antagonists associated with the plant roots the fluorescent pseudomonads have received prominent attention due to their abundance in plant rhizosphere and their ability to colonize roots of a wide range of crop plants. Pseudomonas fluorescens is a Gram negative, non spore forming, rod shaped bacteria producing pigments which are greenish, fluorescent and water soluble. It is found to be effective against the following fungal pathogens viz., Rhizoctonia solani, Macrophomina phaseolina, Fusarium udum, Pyricularia grisea, Fusarium oxysporum fsp. cubense. It is capable of surviving in the spermosphere, rhizosphere and phyllosphere of plants. The mechanisms of biological action exhibited inovles antibiosis, competition, lysis and induced resistance. Pseudomonas have an exceptional capacity to produce a wide variety of metabolites, including antibiotics, that are toxic to plant pathogens.

Many Bacillus species are capable of producing a wide variety of secondary metabolites that are diverse in structure and function. The production of metabolites with antimicrobial activity is one determinant of their ability to control plant diseases. The activity is determined using PCR. PCR consists of an exponential amplification of a DNA fragment, and its principle is based on the mechanism of DNA replication in vivo. dsDNA is denatured to ssDNA, duplicated, and this process is repeated along the reaction according to the following formula

Although the Rhabditids have been studied from last one century, the field level use of Entomopathogenic nematodes the members of Rhabditids for the management of insect pest was followed only after Dutky who practically used EPNs in 1937 on Apple Codling moth.

The taxonomy of Entomopathogenic nematodes of the order Rhabditidae is discussed in this lecture.

I. In vivo culturing technique

In vivo culturing means culturing of entomopathogenic nematodes (EPN) in the host. Generally rice meal moth, Corcyra cephalonica and greater wax moth, Galleria mellonella are used as insect hosts for rearing EPNs.Insect hosts such as Spodoptera, Helicoverpa and Bombyx mori are also used for culturing Steinernema and Heterorhabditis but these insects need plant host especially leaves for culturing. Corcyra can be grown in broken cumbu grains and Galleria in honey comb or artificial diet.

Introduction

Entomopathogenic nematodes (EPNs) viz., Heterorhabditis, Neosteinernema and Steinernema have been recovered from many regions of the world and have been used commercially as biocontrol agents of insect pests. They are associated with mutualistic bacteria in the genus Xenorhabdus for Steinernematidae and Photorhabdus for Heterorhabditidae. The infective juvenile nematodes enter their host insect through natural openings (mouth, anus or spiracles), they release bacteria into the insect and cause rapid death of insect host (24-48 h). EPNs were used against many insect pests viz., rice leaf folder, Cnaphalocrocis medinalis (Srinivas and Prasad, 1991); tobacco cutworm, Spodoptera litura (Rajkumar et al., 2003); brinjal fruit borer, Leucinodes orbonalis (Hussaini et al., 2002) diamond back moth, Plutella xylostella (Singh and Shinde, 2002); Diaprepes abbreviates (Jenkins et al., 2007); Bemesia tabaci (QiuBaoli et al., 2008) and sugar beet beetle (Saleh et al. 2009).

4.1. Role of soil microorganisms

Soil N utilization by plants.

Dead organic matters decomposed.

Nutrient transformation.

Physical and chemical properties of soil.

CO₂ content.

Soil formation.

5.1. Organic matter

In sandy soil, the sticky and slimy organic materials cement the sand particles together to form aggregates.

In clayey soil, it modifies the properties of clay by reducing its cohesiveness and making clay more crumby.

8.1. Classification of essential nutrients

8.1.1. Based on the amount required by the plant

Major nutrients-Required in large quantities eg. N, P, K.

Secondary nutrients-Required in lesser quantities compared to major nutrients eg. Ca, Mg, S.

Micronutrients-Required in trace quantities eg. Fe, Mn, Zn, Cu, B, Mo.

9.1. Nutrient deficiency of corrective measures

9.1.1. Major and secondary nutrients

14.1. Soil fertility

Ability of the soil to supply essential plant nutrients during growth period of the plants

Crop producing capacity of the soil

2.1. Definition

Land which is presently lying unused or which is not being used to its optimum potential due to some constraints

1.1. Cropping pattern

Yearly sequence and spatial arrangement of crops or crops and fallow on a given area.

1.2. Cropping seasons in India

1.2.1. Kharif season: Southwest monsoon

Crops - Rice, cotton, jute, jowar (sorghum), bajra (pearl millet) and redgram (Pigeon pea).

5.1. Irrigation requirement of field crops

The subject on micrometeorology deals with small scale meteorology of near ground surface with its related elements of both physical and biological processes. When this micrometeorology is integrated for crop production purposes, then it becomes crop micrometeorology, which is very important in the science of agricultural climatology. This crop micrometeorology gets varied with the architecture of the crops grown, available soil moisture, agronomical practices followed, soil texture, topography of the area, the nature of climate and weather that prevails etc. The soil surface heat, exerts a profound frictional effect on wind movements and hence it is different from the air layers at higher levels. These special features constitute the microclimate, which is modified compared to a flat bare surface by factors like topography, nature of soil surface, presence of vegetation and type of vegetative cover. The presence of crop canopy leads to distinct differences in the thermal and humidity regimes of the soil, the air layers immediately above it and the distribution of radiation and wind profiles inside the canopy. The study on the physical exchanges of the transfer of heat, momentum and moisture in the microclimatic region is called as micrometeorology (Venkataraman and Krishnan, 1992).

Radha Krishna Murthy (2002) reported that the micrometeorology is the micro scale of both the physical and meteorological factors that are taking place within the ecosphere. The ecosphere means the area between just above the crop canopy and just below the root zone of a crop. Further he was on the opinion that the microclimate of valley is important as compared to the entire climate of the mountain for the bio-life of valley. For the crops purpose, the microclimate is the climate of the ground surface to top of the crop canopy or otherwise it can be called as crop’s climate, a modified one from the Stevenson’s Screen climate/weather observation.

Potentiometry

Potentiometry is based on measurement of potential of an electrode system

Principle

When a metal electrode is immersed in a solution containing its own ions, the metal atom pass into the solution in the form of metal ions and a potential difference is established between the metal and the solution. This potential is called as electrode potential.

Potential on an electrode depends on the ions present in solution and their concentration which can be determined by using electrochemical cells and expressed by Nernst equation

Determination of size of the food materials

Size is an important physical attribute of foods used in screening solids to separate foreign materials, grading of fruits and vegetables, and evaluating the quality of food materials. Various types of cleaning, grading and separation equipment are designed on the basis of size. The size and shape of the grains are used to determine the size of screen openings, angle of inclination, vibration amplitude and frequency of screen in designing an air screen grain cleaner and conveying characteristics of the solid materials.

Theory

Texture testing is a well-established technique for evaluating the mechanical properties of raw materials, food structure, pre- and post- harvest quality control checks. The texture testing has many applications across wide range of foods including cereals, fruits, vegetables, meat, poultry, fish, baked foods, confectionaries, snacks, dairy, gelatins, pasta, etc. Food texture analysis of foods can highlight the quality improvement throughout the supply chain. At research and development stage, new or alternative ingredients can be compared with existing ingredients.

Texture profile parameters

The texture profile parameters including hardness, firmness, crispiness, rupture strength springiness, chewiness, cohesiveness, gumminess, gel strength, adhesiveness, consistency, crunchiness, elasticity, extensibility, fracturability, stiffness, stringiness, toughness, work to cut, penetrate and shear can be measured by the mechanical food texture analyzer.

Aim

To study the numerical problems on grain moisture content and equilibrium moisture content.

Problem 1

Five hundred kilograms of paddy at 22% moisture content (wb) is dried to 14% moisture content (wb) for milling. Calculate the amount of moisture removed in drying.

Aim

To study the determination of drying rate of agricultural products

Problem

In a drying experiment on paddy at an air temperature of 60ºC, the following data were obtained. Prepare a drying rate curve for the experiment. Initial weight of the sample is 1250 gm and initial moisture content is 35% (d.b).

Aim

To draw the drying characteristic curve for given grain by thin layer drying.

To determine the drying constant, heat utilization factor and coefficient of performance.

Aim

To design a bucket elevator

Theory

The bucket elevator’s capacity mainly depends on bucket size, conveying speed, bucket design and spacing, the way of loading and unloading, the bucket and the characteristic of bulk material.

Bucket elevators with a belt carrier can be used at fairly speeds of 2.5 to 4 m/s. The speed of the belt depends on the head pulley.

If the belt speed is too low, the discharge of the grains become more difficult, with too high speed the buckets are not fed well.