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Electrical conductivity (EC) is the ability of a material to transmit electrical current. In the soil, the EC is the ability of the soil solution to carry an electrical current and is a measure of the total amount of soluble salts present in the soil. Pure water is a poor conductor of electricity and increases in soluble salts water result in proportional increases in the conductivity.

23.1. Sources of Soluble Salts in Soil

The soluble salts in soils consist mostly of the cations sodium, calcium, and magnesium and the anions chloride and sulfate. Constituents that ordinarily occur only in minor amounts are the cation potassium and the anions bicarbonate, carbonate, and nitrate. The original and, to some extent, the direct source of all the salt constituents are the primary minerals found in soils and in the exposed rocks of the earth’s crust.

While the mean chlorine and sulfur content of the earth’s crust is 0.05 and 0.06 percent, respectively, sodium, calcium, and magnesium each occur in the range of 2 or 3 percent. During the process of chemical weathering, which involves hydrolysis, hydration, solution, oxidation, and carbonation, these constituents are gradually released and made soluble. When carbon-di-oxide, of atmospheric or biological origin, dissolves in water, bicarbonate ions are formed. Water containing carbon-di-oxide is an active chemical weathering agent that releases appreciable quantities of the cation constituents as the bicarbonates. The concentrations of carbonate and bicarbonate ions are a function of the pH of the solution. Appreciable amounts of carbonate ions can be present only at pH values of 9.5 or higher.

Although plants can be grown to maturity in aerated nutrient solutions and other media, virtually all land plants, including those on which we depend for food, fibre and fuel, grow in soil. The soil has three-fold function to perform with respect to crop growth: physical, chemical and biological.

1. Raw Materials

Culture of Bacillus subtilis

Talc powder - 300 mesh

Shelf life for Pseudomonas fluorescens (TNAU Pf-1)

Aim: To find out the shelf life of P. fluorescens (TNAU Pf-1) using different carrier materials

Product: The talc based P. fluorescens (TNAU Pf-1) product is used for the study on shelf life.

Selective medium (King’B medium) for Pseudomonads

Deoxyribonucleic acid (DNA) carries the genetic instruction for the biological development and functioning of all cellular forms of life. It is the blue print which contains the instructions to construct other cell components. Molecular biology experiments often require isolation of DNA for a variety of purposes like construction of DNA libraries, gene cloning, PCR and other marker technology, etc. The extraction of DNA from actively growing tissue is relatively easier yielding higher quantities of DNA.

Principle

The cell wall is ruptured and the proteins associated with DNA are removed by detergent like SDS or by interaction with phenol. Lipids are extracted with alcohol and DNA is precipitated by isopropanol.

Materials Required

Maize seed samples, Liquid nitrogen, CTAB (Cetyl trimethyl ammonium bromide), Chloroform, isoamyl alcohol, Sodium chloride, Glacial acetic acid, Isopropyl alcohol and 70% ice cold ethanol, TE buffer (5X) (24.2 g of Tris base, 5.71 ml of galcial acetic acid, 10 ml of 0.5M EDTA (pH 8.0) , dissolved in 1000 ml of distilled water). Prepare 1X TE as per the requirement.

Agarose gel electrophoresis is used for the fractionation and characterization of nucleic acids. It is a simple and highly effective method for separating, identifying and purifying DNA fragments of various sizes. DNA can be checked for size, intactness, homogeneity and purity by this technique. Agarose is a purified form of agar and forms a gel by hydrogen bonding of the agarose monomers. Increasing the Agarose concentration of a gel reduces the migration speed and enables separation of smaller DNA molecules. Shorter molecules move faster and migrate further than longer ones.

Aim: To study the size of the DNA extracted from the fungal culture.

Principle: Ethidium Bromide added to the gel interacts with the bases of DNA and fluorescence orange when irradiated with UV light.

Basically we need to mount and prepare the slide for observation of various stages of EPN as detailed below in Table.1

6.1. Humus

Fraction of organic matter.

Complex and resistant mixture of brown or dark brown amorphous and colloidal organic substance.

6.2. Humus formation

1. Decomposition: Chemicals in the plant residues are broken down by soil microbes.

Simpler chemicals are metabolized into new compounds in the body tissue of soil microbes.

New compounds are subjected to further modification and synthesis as the microbial tissue is subsequently attacked by other soil microbes.

Involved in plant metabolic functions and the plant cannot complete its life cycle without the element.

7.1. Plant nutrient concentration and plant growth

1. Deficient

Lowest concentration of an essential element that limit yield severely and cause distinct deficiency symptoms.

3.1. Conventional farming

Refers to the use of synthetic chemical fertilizers, pesticides, herbicides and other continual inputs, genetically modified organisms, heavy irrigation, intensive tillage and concentrated monoculture production.

Highly resource and energy intensive, but also highly productive.

Conventional farming typically involves monocropping, but very expensive.

4.1. Highlights of the report on number and area of operational holdings (2015-16)

Total number of operational holdings in the country has increased from 138 million ha in 2010-11 to 146 million ha 2015-16 i.e. an increase of 5.33%.

Number of operational holders in different states

Uttar Pradesh (23.82 million ha)

Bihar (16.41 million ha)

Maharashtra (14.71 million ha)

Madhya Pradesh (10.00 million ha)

Karnataka (8.68 million ha)

5.1. Types of farming

Arable: Crops.

Pastoral: Animals.

Mixed: Crops and animals.

Subsistence: Grown just for the farmer and his family

Commercial: Grown to sell.

Intensive: High inputs of labour or capital usually small.

Extensive: Low inputs of labour or capital.

Sedentary: Permanently in one place.

Nomadic: The farmers move around to find new areas to farm.

To achieve maximum possible irrigation efficiencies, there are two approaches.

Modernization of conveyance system down below the reservoirs upto government controlled outlet. Involves mainly the construction and maintenance of head sluices, main canals, branch canals, and distributaries (Modernization of supplier’s side or system level development works)

Modernization below the government controlled outlets upto the drains (Modernization of user’s side or farm level development works). Also known as On-Farm Development Works (OFD).

3.1. Integrated nutrient management

Maintenance of soil fertility and plant nutrient supply at an optimum level for sustaining the desired productivity through optimization of all possible sources of organic, inorganic and biological components in an integrated manner.

3.2. Concepts

Regulated nutrient supply for optimum crop growth and higher productivity.

Improvement and maintenance of soil fertility.

Zero adverse impact on agro – ecosystem quality by balanced fertilization of organic manures, inorganic fertilizers and bioinoculants in an integrated manner.

3.1. Concept of farm mechanization

To apply the principles of engineering and technology to do the agricultural operations in a better way to increase crop yield.

Development, application and management of all mechanical aids for field operation, water control, material handling, storage and processing.

Mechanical aids include hand tools, animal drawn implements, power tillers, tractors, engines, electric motors, grain processing and hauling equipments.

2. 1. Plant domestication

Process of bringing wild species under human management.

2.1.1. Changes in plant species under domestication

Elimination or reduction in shattering of pods, spikes, etc.

Elimination of dormancy

Decrease in toxins of other undesirable substances. Eg. Bitter principle of cucurbits.

Cultivated plants show altered tillering, branching, leaf characters.

Decrease in plant height. Eg. Cereals and millets.

5.1. Characteristics of asexually propagated crops

Majority of them are perennials

Many of them show reduced flowering and seed set.

Invariably cross pollinated.

Mostly polyploids.

Many species are inter specific hybrids.

Agriculture is the science and art of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization. The history of agriculture began thousands of years ago. After gathering wild grains began 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs, sheep and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture. This chapter discusses about the agriculture and robotics in agricultural field.

1.1 Introduction to Agriculture

The word agriculture is derived from a Latin word- “agri” means soil, and “culture” means cultivation of the soil. In modern terms, agriculture comprises “the art and science of cultivating the soil, growing crops and rearing livestock.”

Farming is a complete system which includes inputs, processing, and outputs. The inputs are seeds, fertilizers, machinery, which undergoes operations like ploughing, sowing, irrigation, weeding, and harvesting. The final outputs are like crops, dairy and poultry products.

Theory

The volume of food material play an important role in design of storage bins, conveying equipments, separation equipments, etc. Volume of larger products such as fruits and root crops can be determined using the platform scale or water displacement method.

Aim

To determine the water solubility and absorption index of given food powder.

Materials required

Digital centrifuge machine

Graduated measuring cylinder

Beaker and distilled water

Aim

To determine the angle of repose of the given biological materials.

Materials required

Angle of repose apparatus
Grains
Scale

Theory

This type of moisture measurement is called brown-duvel fractional distillation method. The method is recognized as an official method for determination of moisture content. In this method, directly measures the volume of moisture in cubic centimeter. This apparatus consists of flask, burner, thermometer, condenser, graduated cylinder. This apparatus consists of flask in which grain sample is boiled with mineral oil.

Aim

To determine the effectiveness of the spiral separator.

Materials required

Spiral separator

Weighing balance

Sample divider

Stopwatch

Grain mixture (round and others)

Aim

To determine the contours by cross-section method using dumpy level.

Materials required

Dumpy level

Leveling staff

Measuring tape

Wooden pegs/chain pins

Field book

Aim

To determine the contours by radial line method using dumpy level.

Materials required

Dumpy level
Leveling staff
Measuring tape
Wooden pegs/chain pins
Field book

Aim

To measure irrigation water by volumetric method

Apparatus required

Siphon tube

Stop watch

Measuring bucket

Refers to entire operation of the induction and isolation of mutants.

Term mutation was introduced by Hugo de vries in 1900 in connection with sudden heritable changes observed by him in Oenothera.

Refers to induced chromosome manipulation

Aneuploidy-One or few chromosomes extra or missing from 2n.

Autoploidy-Genomes identical with each other.

Crop production is challenged by abiotic and biotic stresses results in low yield and high production costs.

Magnitude and intensity of stresses are increasing dramatically due to climate change causing recurrent droughts, increased temperature (heat) and emergence of new diseases and pests.

Methods for plant diseases control were first classified by Whetzel (1929) into exclusion, eradication, protection and immunization.

Two more principles - avoidance and therapy were created (NAS, 1968).

11.1. Storage fungi

Store fungi include all species of Aspergillus, Fusarium and Penicillium.

Aspergillus flavus, A. candidus, A. niger, A. parasiticus, A. repens, A. rubber, A. versicolor, etc. Penicillia etc

Penicillia are more prevalent in cooler climate.

1.1. Above ground feeders

1.1.1. Feeding on flower buds, leaves and bulbs.

Seed gall nematode: Anguina tritici

Leaf and bud neamtode: Aphelenchoides

Stem and bulb nematode: Ditylenchus

3.1. Definition

Systems approach to reduce nematode to tolerable levels through predators and parasites, genetically resistant hosts, natural environmental modifications and appropriate nematicides.

Bioagents like insects, pathogens etc., and other animals are used either to reduce growth or kill weeds.

But, not possible to eradicate weeds.

9.1. Agriculture Insurance Company of India Limited (AIC)

Formed 1 April 2003 took over implementation of National Agricultural Insurance Scheme (NAIS) from General Insurance Corporation of India.

Also transacts other insurance businesses directly or indirectly concerning agriculture and its allied activities.