eChapters

While conventional agromet advisories have played a crucial role in informing agricultural practices, their inherent broad-scale nature often falls short of addressing the nuanced realities of modern farming. For instance, rainfall predictions at a district level can mask significant variations at the farm or even field level due to local topography, soil types, and microclimatic conditions. Similarly, generic recommendations for irrigation scheduling or fertilizer application may not align with the specific needs of different crop varieties, growth stages, or soil moisture retention capacities within a farm. This lack of granularity can lead to inefficient resource utilization, sub-optimal application of inputs, and increased vulnerability to localized weather events, ultimately impacting productivity and profitability.
9.1. Key Drivers for the Emergence of PAAS
Several converging factors are propelling the shift towards precision in agrometeorology:
• Escalating Climate Variability: The increasing frequency and intensity of extreme weather events, coupled with long-term shifts in climate patterns, demand more adaptive and localized strategies. Farmers need precise and timely information to make informed decisions in the face of unpredictable weather.
• The Imperative for Sustainability: Sustainable agricultural practices necessitate the efficient use of resources like water, fertilizers, and pesticides. PAAS can contribute significantly by providing targeted recommendations that minimize waste and environmental impact.
• Technological Advancements: The rapid development and increasing affordability of various technologies are making PAAS a reality. These include:
• Remote Sensing: Satellite and drone-based imagery provide highresolution spatial data on crop health, soil moisture, and other critical parameters.
• Internet of Things (IoT) Sensors: Networks of sensors deployed in fields can continuously monitor local weather conditions, soil properties, and plant physiological parameters.

Agriculture sector alone uses nearly seventy per cent of fresh water in the world. Therefore, water use economy in the agriculture sector is becoming a necessity. Increasing flood production is possible reducing water used for irrigation if we can adopt precision irrigation (Fig.11.1).
The precision irrigation has to be practiced by providing water to the crop plants in its root zone to meet the water requirements. The precise irrigation can result in-
• Water saving
• Avoid weed control
• Preventing loss of water due to infiltration
• Preventing loss of water due to surface evaporation from the soil
• Minimise salinity problems
• Improving water use efficiency of crops
Traditionally farmers were practicing flood irrigation. It is a method of watering crops delivering to a field and allowing it to flow over the ground among the crops. It is a simple and inexpensive technique followed in less developed areas. Flood irrigation is not very efficient way as nearly 50 per cent of the water applied in the field will be lost through run-off, soil evaporation and other factors. Flood irrigation is only suitable in wet climates and not effective in sandy soils. It leads to water logging in clay soils. There are several types of flood irrigation such as basin, border, furrow and contour irrigation. Although flood irrigation is not very efficient, the water wastage can be avoided to some extent using some techniques

Abstract
 
The definition of what drought is and what drought is not, has profound implications for the environment and all segments of society, yet it may be different for each. Many attempts have been made to develop a comprehensive and meaningful definition. A generic definition provides a starting point:  Drought is a persistent and abnormal moisture deficiency having adverse impacts on vegetation, animals, and people. The public perceives “drought” as a serious departure from normal water conditions, a departure that requires a public response to reduce negative impacts. About two thirds of the geographic area of India receives low rainfall (less than 1000 mm), which is also characterized by uneven and erratic distributions.

Abstract

Gastrointestinal parasitic infections particularly Haemonchus contortus infection in goats is very common and found as major nematode infections in farm condition. To chalk out the control programme and to prevent the initiation of anthelmintic resistant parasites, it is essential to know well in advance the prevalence of H. contortus infection. During the year 2009, a study was undertaken on H. contortus infection in the goat farm of ICAR Research Complex for NEH Region, Umiam, Meghalaya, which is a subtropical hill area and bioclimatograph was prepared to predict the prevalence of H. contortus infection in goats of this area. Meteorological data of this area was collected to visualize the effect of temperature, rainfall and humidity. Bioclimatographs were prepared in which total rainfall (TRF) or relative humidity (RH) is plotted against the maximum temperature (T-max) or minimum temperature (T-min) for the months and the resultant points are joined by a closed curve. The lines constituted the windows on these bioclimatographs, indicating the limit of the climatic conditions most suitable for development and survival of exogenous stages of gastrointestinal nematodes.

Principle

Standard solutions are the solutions of accurately known concentrations. There are two types of standard solutions viz., primary and secondary.

A known quantity of the substances is dissolved in a volumetric flask and the volume is made upto the mark. Standard solutions prepared in this way are known as primary standard. This method can be used for preparation of standard solutions of substances which satisfy the following conditions.

Principle

Equal volumes of all acids / bases containing their gram equivalent weights per litre of the solution react completely with each other.

More often, if the reagent is not a primary standard, a secondary standard solution must be prepared. The chemical is dissolved and made up or diluted to the desired concentration and then it is standardized against a primary standard or against another reliably known secondary standard solution. Such solutions are called as secondary standard solutions.

    In recent years, the global demand for renewable and sustainable energy sources has led to increased interest in biogas production from agricultural residues and lignocellulosic biomass. Among these, paddy straw an abundant agricultural by-product—has gained attention as a potential substrate for anaerobic digestion and biofuel generation.
However, the biochemical conversion of paddy straw into biogas is limited by its complex lignocellulosic structure, which makes it resistant to microbial degradation. Therefore, pretreatment of biomass is a critical step to enhance its digestibility and improve the overall efficiency of biogas production.
Objective
The primary objective of pretreatment is to break down the structural and compositional barriers within lignocellulosic biomass that hinder microbial degradation and enzymatic hydrolysis. Specifically, pretreatment aims to:
1. Disrupt lignin structure and reduce cellulose crystallinity.
2. Increase surface area and porosity of the biomass for microbial access.
3. Improve enzymatic hydrolysis efficiency for higher sugar and methane yields.
4. Minimize sugar loss and avoid the formation of inhibitory byproducts.
5. Enhance biogas yield and the rate of biodegradation.
6. Achieve these improvements in a cost-effective and scalable manner

Soil Erosion As a Process
 
Soil erosion is a three stage process, namely (1) detachment, (2) transport, and (3) deposition of soil. Different energy source agents determine different types of erosion. There are four principal sources of energy: physical, such as wind and water, gravity, chemical reactions and anthropogenic, such as tillage. Soil erosion begins with detachment, which is caused by break down of aggregates by raindrop impact, sheering or drag force of water and wind. Detached particles are transported by flowing water (over-land flow and inter-flow) and wind, and deposited when the velocity of water or wind decreases by the effect of slope or ground cover. Processes like dispersion, compaction and crusting, accelerate the natural rate of soil erosion. These processes decrease structural stability, reduce soil strength, exacerbate erodibility and accentuate susceptibility to transport by overland flow, interflow, wind or gravity. These processes are accentuated by soil disturbance (by tillage, vehicular traffic), lack of ground cover (bare fallow, residue removal or burning) and harsh climate (high rainfall intensity and wind velocity).

ABSTRACT

The chemical characteristics of the groundwater in and around the Valapadi taluk of Salem district have been studied to evaluate the suitability of water for domestic and irrigation uses. Twenty three groundwater samples representing the shallow and deep aquifer of the area were collected and analyzed for pH, TDS, Ca, Mg, Na, K, HCO3, CO3, SO4 and Cl. It is observed that the quality of the groundwater is suitable for domestic use with some exception. The observed high quantity of Cl, SO4 and Mg at some places require immediate attention and detailed study. The value of EC and SAR indicate good to medium q of water for irrigation.

Probability analysis measures the likelihood of uncertain climatic and agricultural events. It is particularly useful for assessing rainfall occurrence, drought, floods, heatwaves, cold events and other risks that cannot be predicted with complete certainty. This chapter introduces classical, empirical, subjective and conditional probability, probability distributions, return periods and recurrence analysis. It explains how historical climatic records can estimate the likelihood and severity of future events. These methods assist in crop selection, sowing decisions, irrigation planning, infrastructure design and weather-risk management. By converting uncertainty into measurable probabilities, the chapter provides a scientific basis for climate-informed agricultural planning, disaster preparedness and development of resilient farming systems.

Abstract

An attempt has been made in this paper to study probability model for modeling of spell distribution & Weather Cycles during the monsoon period (June to September) at Cochbehar, West Bengal. The daily rainfall data of 31 years (1970 to 2000), recorded at Cochbehar have been analyzed. In this study, it was found that daily rainfall during monsoon period follows Markov Chain model. Markov dependent truncated geometric distribution model is best fitted for studying the Dry spells, Wet spells & Weather Cycles during the monsoon period.

ACID SOILS: Acid soils with pH below 6.5 are widespread. Main limitations of these acid soils are low pH, low CEC, low status of bases, especially Ca, Mg, and K along with toxicity of Al and Mn. Use of acidifying fertilizers aggravates this situation.

Introduction

Problem soils are those that impede agricultural productivity owing to mineral stress, dryness, acidity, sodicity, waterlogging, etc. Vertisol, acid sulphate soils, saline-sodic soils, peat soil, and fine textured alluvial soils were the categories Beek et al., (1980) used to group the problematic soils. In addition to vast areas where deficiencies of zinc, phosphate, and iron, or excesses of iron, aluminium, and manganese limit rice yields, Ikehashi and Ponnamperuma (1978) observed that approximately 100 million hectares of land that are physiographical and climatically suitable for rice lie idle due to the soil toxicities caused by salt, alkali, acid, or organic matter. Problem soils can be broadly defined as those that have unfavourable conditions whether natural or artificially created that severely restrict the successful development of crops. Soil profiles with high groundwater levels and a less permeable argillic layer, degraded soils, sandy soils with low fertility, coastal soils that frequently flood, and laterites could all be categorised as problem soils. Without taking into account related soil functions, soil health is evaluated independently. It is also based on the f indings from a few soil tests for different criteria. 2015 has been recognized the International Year of Soils by the 68th UN General Assembly in recognition of the importance of soil health in all dimensions.

Let‘s dive deeper into the processes of condensation and explore each in more detail:
• Adiabatic Processes: Adiabatic cooling occurs when air rises and expands, reducing its temperature (Fig. 9.1). This process can lead to condensation and cloud formation. There are several ways air can rise and cool adiabatically:
• Orographic Lift: When air is forced to rise over a mountain or hill, it cools, and condensation occurs, resulting in clouds and precipitation. This is why mountainous regions often experience more rainfall than surrounding are as.
• Frontal Lift: When two air masses with different temperatures and humidity levels meet, the warmer air is forced to rise, cool,
and condense, forming clouds and precipitation. This can lead to significant weather changes, such as the formation of fronts and lowpressure systems.
• Convection: When the sun heats the ground, it warms the air closest to the surface, causing it to rise and cool, leading to condensation and cloud formation. This process can lead to the development of cumulus clouds, thunderstorms, and other types of convective weather.

Introduction

GIS (Geographical Information System) based mapping takes cogence of three major geometrical dimensions, point, line and polygons and in GIS these three features correlate their relationship through a concept called Topology. Among the various applications where covariate processing requires specific attention, the landuse/ land cover and Digital Elevation Models/surfaces or terrains are the major area of interest. Use and processing of data for these covariates carries importance as accuracy of both these aspects would influence the derivatives extracted out of them further. For example, if landuse is improperly defined, the site for which planning is proposed may not sustain, similarly, point data/elevation data in case of DEMs would decide the exact topography of any landforms for their further utilization. For their use in GIS, while DEMs depend upon point data, the landuse/ land cover will be taken care by polygons. For the purpose of the study, we are going to discuss about these two covariates in the following paragraphs.

Generally, Covariate (covariable) (koh-vair-iãt) in statistics is defined as a continuous variable that is not part of the main experimental manipulation but has an effect on the dependent variable. In other words, as per ANCOVA (Analysis of covariance) definition: a covariate is a control variable.

Introduction
The sun is the primary source of energy for all life on Earth. The primary energy source for the majority of ecosystems is limited to this one. Photosynthesis is performed by green plants, certain types of algae, and microorganisms. They utilize solar energy to fuel chemical reactions that combine basic inorganic components to create intricate organic chemicals. Elements undergo a cyclical process as they move through the different compartments of an ecosystem.
Photosynthesis is the process by which solar energy is captured and transformed into food in the form of chemical energy. Food comprises fundamental elements such as carbon, hydrogen, nitrogen, and other necessary elements, along with stored energy. The components present in the food undergo recycling. The flow of energy and nutrients begins with the producers, then moves to the consumers, and ultimately returns to the producers through the activity of decomposers. Energy, in contrast to materials, is not subject to recycling. Food traverses the food web, resulting in energy dissipation. Typically, just a mere 10% of the energy accumulated in a certain trophic
level, such as the producers, is effectively passed on to the subsequent trophic level, such as the herbivores. This is referred to as the energy pyramid. Ultimately, the energy available in the trophic level becomes so depleted that it cannot sustain any higher trophic levels. Consequently, the presence of fourth order consumers in any ecosystem is extremely rare.
The biotic component, often known as the life component of the environment, encompasses a diverse array of plants, animals, and bacteria, which form interconnected communities.

Buffaloes have been classified in two main categories namely riverine and swamp buffaloes depending upon variation in their habitat and genome structure. Riverine buffaloes are generally large in size mostly with curled horns and are mainly found in India, Pakistan and some of the west Asian countries, prefer to enter clear water and have 50 (2n) numbers of chromosomes and are primarily used for milk production and also used for meat production and draught power. Swamp buffaloes are stocky animals with marshy land habitats and have 48 (2n) numbers of chromosomes. They were primarily developed for draught power in paddy fields and haulage and are also used for meat and milk production. Swamp buffaloes are mostly found in south east Asian countries and also in north eastern states of India.

Introduction
Fossil fuels are finite and as population growth drives energy demands, the need for renewable energy solutions has become paramount. Among the many ways of producing biofuels, the use of algae has emerged as a promising source. Algae particularly, microalgae are photosynthetic organisms that can convert CO2 into fuel compounds. This innovative way of using microalgae to produce biofuels can address both sustainability as well as the depletion of fossil fuels.
1.1 Microalgae as energy source
Microalgae can be used over conventional biomass as they have several advantages. One of the biggest advantages is their rapid growth rate. They are easy to grow and multiply very quickly. Other benefits include high oil yield and their adaptability to different growth conditions. They also use CO2 to grow making them carbon neutral. Conventional biomass obtained from sugar bagasse or corn needs a lot of resources for a small yield, such as land, water, and electricity whereas microalgae do not require these high investment costs or land. However, the advantages of microalgae do not stop with biofuel production. Researchers have established the use of microalgae across various industries. Commonly, spirulina has been used as a source of protein surpassing protein content per 100 g compared to other protein-rich sources. Similarly, various other microalgae have been used for extracting vitamins, and essential fatty acids, and some are also used as feed for livestock. In recent years, microalgae have also been used in cosmetics for their antioxidant, collagen-boosting properties that can lead to anti-aging benefits. In the supplement industry, microalgae have been used in research as alternatives to mainstream ingredients. Microalgae also have other environmental benefits as they can be used to treat wastewater due to their ability to degrade pollutants and excess nutrients that concentrate in water bodies. With these benefits at hand, they can also be used as an excellent input for the production of biofuels (Razzak et al, 2022; Ramaraj et al, 2015). The figure below shows the various applications of microalgae such as the production of proteins, carbohydrates, biofuels, materials production, etc.

Introduction

Under arid and semi-arid regions of the world, major problems are salinity, alkalinity and calcareousness, which seems further aggravate with changing climate scenario. Besides that most of the developing countries lies in this zone with flanging population resultant shrinking down of land resource and good quality of irrigation water. Globally area under saline/sodic soils is about 953mha covering 8% of the land surface. Resent estimates indicate that 6.7 mha area in India is affected by soil salinity and alkalinity and about 25% of ground waters are sodic and/or saline in the country. There are two important approaches for utilizing saline, alkali or calcareous environment. The first one is to modify the environment so as to suit the plant or modifying the plant or substitute the plant species so as to suit the environment. First approach has been used more extensively because it enables the plants to respond better not only to water but also to other production inputs and also not far sustainable. However, second option is cost effective and most sustainable.

Accumulation of excessive salt in root zone leaves adverse effect on general agricultural crops and or crop failures sometimes, while crop diversification using seed spices are the option for such conditions. Most of the seed spices particularly cumin, fennel, dill, fenugreek, ajwain, celery, anise, caraway and coriander (and their cultivars) have some degree of salinity and alkalinity tolerance. However, among the seed spices, cumin is having high degree of salinity tolerance. In case of sodic or calcareous environment, fennel is most tolerant followed by dill as well as these crops are the remedy for such degraded environment by bringing down the sodicity and calcareousness. In some cases, germination, growth, yield and quality of seed spices improved by saline sodic environment. Besides eco-friendly use of these soils, phytoremediation of saline, sodic and calcareous soils by seed spices seems most sustainable.