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Antibiotics have been used since their discovery to cure illness at therapeutic levels and to boost animal feed production at subtherapeutic levels by promoting animal development. Antibiotics have been regarded as necessary additives or supplements for improved growth and preservation of a healthy intestinal ecology in the production of chicken for more than 50 years (Huyghebaert et al., 2011). The Indian government outlawed the use of antibiotics in poultry feed in 2019. (Colistin, for example, is no longer allowed in poultry feed.) As a result, a lot of effort is being put into creating antibiotic substitutes. Alternatives to antibiotics should ideally possess the same advantageous qualities.

 Family: Argasidae
 •The family includes fowl ticks and tampans.
 •The integument is leather like, frequently mammillated and without dorsal shield.
 •Capitulum and mouth parts are situated anteriorly and on ventral side, thus invisible from dorsal side.
 •In general eyes are absent, if present these are two pairs and situated on lateral sides of supracoxal folds.
 •Spiracles are one pair and situated posteriolaterally to the third coxae.
 •Sexual dimorphism is not evident.
 •The important genera are Argas, Otobius and Ornithodoros.

Introduction

For many years it has been an elusive task to provide a precise definition as to what constitutes quality in wheat. Each country has its own traditions in bread and other bakery products. Quality will mean different things to a miller, a baker, a grain handler or a plant breeder. As the baking industry becomes increasingly specialized, specific qualities are sought. Even among those wheat varieties generally recognized as having desirable quality traits, the influence of environment can be substantial, and this necessitates a high level of skill on the part of grain buyers to survey the current year’s crop and blend the wheat for a specific end-use. This genotype X environment effect on quality also limits the capacity of end-users to source identity-preserved wheat from a narrow geographic area. Those of us engaged in the field of plant breeding are concerned primarily with those traits that can be manipulated genetically, and we study their stability under a range of climatic conditions. Constraints in time, cost, and sample availability usually necessitate the use of predictive tests during early generations, followed by milling and baking tests on advanced lines that have met a number of agronomic, disease and predictive quality criteria.

The pressure of population on land is increasing and the average size of a farm holding is reducing, to below one hectare. Farmers are increasingly getting indebted and the temptation to sell prime land for non farm purposes is growing. If there are other opportunities, about 40 per cent of farmers want to quit farming, says a survey conducted by National Sample Survey Organization. We hear deplorable stories of farmers ending their life not being able to cope with the loss and indebtedness from agriculture.
 
On the closer examination, we find that agricultural land is still a great source of income. But it is the practice of unsustainable methods, improper resource management leading to successive crop failure that makes agriculture non-profitable and risky. As a result, many young farmers are leaving agriculture and migrating to cities. Under these conditions, how are we going to persuade educated youth, including farm graduates, to stay  in villages and take to agriculture as a profession? How can youth earn a decent living in villages and help shape the future of our agriculture? At the same time, we also hear the stories of highly educated persons wanting to move into agriculture as their profession.
 
It is a well known fact that the recession had hit the Information Technology sector and the professionals across the globe in a big way. Some of them were ‘sacked’ and even thrown to streets as ‘loss cutting’ measures by the companies. Many qualified software professionals were forced to find an alternative job. But software professional, Sri. Kondana Chandrashekara Gatty, who was in the Information Technology field for nearly 10 years, did not feel the pinch of recession since he had switched over his carrier field from IT to agriculture. 

Introduction

In this computer age software plays a vital role in speeding up the research activity. Software and databases help in storage, processing and accessing large volumes of information. Software helps to retrieve right information at the right time at the right place for the right purpose. The time of researchers is very precious. Instead of spending it in monotonous and tedious tasks, it could be used more effectively for new findings. With the advent of computer and its softwares, this problem could be overcome to a considerable extent.

Software is a set of instructions given to the computer to perform certain tasks. In this era of information technology, its essential to apply different softwares to speed up the research activity. It is therefore, utmost importance to have information about the different software already developed in the area of fisheries/aquaculture worldwide. Almost all the routine tasks which the scientists or the farmers are doing, could be automated in the areas like financial & economic analysis, development planning and project appraisal, facility design, management planning and production forecasting, facility construction, management decision support and record keeping, disease diagnosis and treatment, environmental regulation and aquaculture databases. FAO, World Fish Centre and other International Research Organisations have contributed software and database development in the area of aquaculture (Anon, 1999; ICLARM, 1998; FAO, 1999; Erist, 1998). In India also initiative to develop software and database has been taken up. Preliminary report on the availability of fishery related software and databases are available (Roy, 2000). In this communication, an attempt has been made to list softwares and databases that may be used in fisheries and aquaculture research and development/activities.

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.

Soil pH

Danish scientist Sorensen (1909) first used the term pH. The H+ concentration is usually small and is expressed in terms of pH, defined as the logarithm of the reciprocal of the H+ concentration, in moles per litre. The pH scale ranges from 0 to 14, with 7 being neutral. Soil acidity is the concentration of H+ in the soil solution. This is active acidity. Besides, there is a potential acidity, that includes the H+ adsorbed on the colloidal fraction of soil. The pH scale is derived from the dissociation constant of water, Kw:

The soil acidity and alkalinity are major driving forces in regard to the mobility of plant nutrients from soil to plants. The extreme acidity or alkalinity cause damage to the crops and thus yield is affected. Correction of soil acidity or alkalinity depend upon the pH of the soil and its previous management options. Application of fertilizer in soil may be one of the factors affecting soil conditions. Exchangeable and soluble iron and aluminium ions and their hydroxy ion species may contribute hydrolysis to release H+ ions to the soil solution. The soluble salts of carbonate and bicarbonates also develop salinity in soils.

7.0 Soil reactions

Soil reaction is an indication of the acidity or alkalinity of soil and is measured in pH . The pH scale ranges from 0 to 14 with pH 7 as the neutral point. When the amount of active hydrogen ions in the soil solution increases the soil pH decreases and thus becoming more acidic in reaction. One of the outstanding physiological characteristics of the soil solution is its reaction. Soil reaction can influence the physico-chemical properties of soil which can regulate the growth and activity of plant and soil organisms associated with it.

Soil acidity is most conveniently measured by pH of soil suspension with water. Pure water undergoes dissociation into hydrogen and hydroxyl ions and are in equilibrium with undissiociated water molecules Thus, H2 O ??? ??? H+ + OH- (1) and in presence of another H2 O molecule, H+ converts to H3 O+ H+ + H2 O ??? ??? H3 O+ (2) Since water is a weak electrolyte and dissociates as per Eqn. 1, the ionic product of water can be written as – KW = aH+ x aOH- = (CH+ x COH– ) x ( fH+ x fOH-) (3) where, a, C, and f represents the activities, concentrations and activity coefficients of respective ions. In pure water and in dilute solutions the activity coefficients are approximately unity thus the product of concentrations of H+ and OH-1 is the ionic product of water and at ordinary temperature (250 C) this has a constant value of 10-14 gm ions per litre so, Kw =(CH+ x COH–1) = 10-14 gm ion per litre (4) such that, CH+ = COH–1 = 107 gm ion per litre Therefore, if hydrogen ion concentration of an aqueous solution exceeds this value, (10-7gm ion per litre), the solution is said to be acidic then there will be a proportionate decrease of OH- concentration to maintain the constant value of ionic product.

Aggregation is a direct indicator of soil structure. Ahealthy soil is considered to have well aggregated structure. Though not routinely followed during soil testing and chemical analysis, aggregation is one of the major indicators of soil physical health. Wet sieve method (Yoder, 1936) is usually followed for soil aggregate analysis. This involves gently raising and lowering a nest of sieves in water to assess the stability of aggregates to rapid wetting. However, the Yoder’s wet sieving method has been modified to make it simpler and currently, the method of Kemper and Rosenau, 1986 is being commonly used in research laboratories. One of the pre-requisites in these methods is the availability of wet sieving apparatus and further, these methods are laborious and time consuming. On the other hand, the method described by Cambardella and Elliott (1993) is considered very ideal because of its simplicity and is being widely used for aggregate bound soil carbon fraction study. The soil sample is wet sieved with a series of three sieves (2000, 250 and 53 micron size).

Aggregation is one of the basic physical characteristics of soil. Under natural conditions, primary soil particles, particularly clays, tend to join together to form secondary units called aggregates. Size distribution of soil aggregates is important because the size of the aggregates determines their susceptibility to water and wind erosion. Also, their size is important in determining the pore size distribution and regulating pore space in cultivated soils.

There are a variety of procedures being in use to test the stability of aggregates and aggregate size distribution. However, choice of the method for analysis of aggregate size distribution is determined by the purpose of analysis. The developed measures are relative and purpose specific. This chapter discusses dry aggregate analysis.

In natural condition primary soil particles cohere to each other to form a cluster or an aggregate through the cementing action of various agents like organic matter, oxides of iron and aluminium, carbonates, etc. Aggregate analysis tells one about the structural status, pore geometry which in turn influences the movement of air and water in soil, amount of water stable secondary particles (aggregate) as well as the extent of finer particles aggregated to the coarser particles and the erodibility status of surface soil against wind and water.

Methods of Analysis

Among the several methods of aggregate analysis the commonly used methods practiced in agriculture and related fields are wet sieving and dry sieving method of aggregate analysis.

In natural condition primary soil particles cohere to each other to form a cluster or an aggregate through the cementing action of various agents like organic matter, carbonates, oxides of iron and aluminium, etc. Aggregate analysis tells one about the structural status, pore geometry which in turn influences the movement of air and water in soil, amount of water stable secondary particles (aggregate) as well as the extent of finer particles aggregated to the coarser particles and the erodibility status of surface soil against wind and water.

9.1 Determination of Oxygen Diffusion rate (ODR) of Soil

The rate of movement of oxygen from atmosphere to respiring plant root cells is important for root respiration and thereby the growth and development of plant. While diffusion through the air-filled pores maintains the exchange of gases between the atmosphere and soil, diffusion through water films maintain the supply of oxygen and disposal of carbon dioxide from active root tissues which are typically hydrated.

Principle

Lemon and Erickson (1952) introduced a method for measuring oxygen diffusion in soil with the help of platinum electrode. The process measures the extent of chemical reduction of oxygen by the platinum electrode maintaining a constant potential of 0.65V with a reference electrode.

Soil amendments and organic matter play critical roles in enhancing soil fertility, improving crop productivity, and promoting sustainable agriculture. This abstract provides an overview of the importance of soil amendments and organic matter in soil management practices, highlighting their impacts on soil structure, nutrient availability, and microbial activity. By incorporating organic amendments such as compost, manure, and green manures into soil, farmers can replenish essential nutrients, improve soil structure, and enhance water retention capacity. Additionally, soil amendments can mitigate soil degradation, erosion, and nutrient runoff, contributing to long term soil health and ecosystem resilience. Understanding the benefits of soil amendments and organic matter is essential for promoting sustainable soil management practices and ensuring food security in a changing climate.

3.1 Important Soil Physical Properties

3.1.1 Analysis of Soil Texture

Soil texture refers to the relative proportions of sand, silt, and clay on weight basis. Soil texture was recognized from very early times by experienced farmers from the feel of moist soil placed between the thumb and forefinger. The size groups arbitrarily classified by the International Society of Soil Science (ISSS) into clay (< 0.002 mm), silt (0.002 0.02 mm), fine sand (0.02-0.2 mm), and coarse sand (0.2 2.0 mm). Each soil textural name specifies the weight percent of each fraction falls within certain defined limits. The determination of the percentage of the soil separate present in a sample is called particle-size analysis.

Each type of particle present makes its contribution to the nature of the soil as a whole. Sandy soils are usually quite permeable to air, water, and roots, but they have two important limitations. One is their relatively low water-holding capacity; the second is that they are poor storehouses for plant nutrients. These limitations of sandy soils can, of course, be overcome if both fertilizer and irrigation water are available, but the costs are large.

Clay not only have a large surface area per gram, it also has electrically charged particles. These charges give clay the capacity to attract plant nutrient ions to its surface in forms available to plants, but sand lacks this capacity. Clay holds much more water than sands because they have a large surface area to be coated with water. One important problem with clay soils is their stickiness. When wet, they stick to ploughs, boots, or whatever they contact. Loam and silt loam soils are highly desirable for most uses. They have enough clay to store adequate amount of water and plant nutrients for optimum plant growth but not so much clay as to cause poor aeration or to make working with them difficult.

Soil sampling is the first step of soil analysis. As very small fraction of the huge soil mass is used for analysis, it becomes extremely important to get a true representative soil sample of the field.

A. Soil Sampling

Soil is a store house of several nutrients. These are present in available and reserve forms and a dynamic equilibrium always exists between these forms of nutrients in soil. If the available form of a given nutrient element is depleted by crop uptake or by any other means, there will be immediate replenishment from the reserve source. In this context, it is also appropriate to note that soil is not an eternal source of plant nutrients. In a bid to produce more, soils are exploited very badly and they are gradually becoming deficient in several nutrients. There are several soil related constraints coming in the way of achieving sustainability in crop production.