eChapters

Water is the most important natural resource that governs and exercises control on living organisms on earth besides supporting all human activities. The demand for water is almost increasing at exponential rate due to increase in population and industrialization. All sectors of agriculture including crop production, horticulture, animal husbandry, poultry and fi sheries primarily depend upon water. Water scarcity can cause all kinds of miseries. The water exists in all 3 different forms on earth. It exists as snow or ice in glaciers and ice caps, liquid water in rivers, lakes, streams, tanks, ponds and as groundwater storage. The water exists in all three different forms in the atmosphere. The clouds may contain fi ne ice particles, tiny water droplets and as well as water vapour. The air in atmosphere also contains water vapour. It is estimated that 97% of water is salt water and remaining 3% of water is pure and fresh water. Approximately two-thirds of the fresh water is trapped in glaciers and ice caps. Most of the fresh water (30%) exists as groundwater. About 0.7% of fresh water exists as soil water and 0.3% a fresh water accounts for surface water resources and water present in the atmosphere as water vapour, water drops and ice particles. The circulation of water between oceans, earth and atmosphere forms hydrologic cycle.
2.1. Hydrological Cycle
The hydrological cycle explains the continuous recirculation and transport of water between the atmosphere, oceans and earth. It is a very complex system that has many sub cycles associated with it. For example, the water from earth surface, oceans and water bodies get evaporated due to heat energy received from the sun in the form of incident solar radiation (Fig.2.1).

Abstract

Three villages were selected randomly representing the flood affected areas of Dhemaji district of Assam. Analysed data on climatic parameters like rainfall(mm), temperature(oC), potential evapotranspiration (mm), relative humidity (%) of last 10 years collected authentic sources and depth of ground water table  was collected from the well water depth from the three villages for twelve months showed that the length of growing period was more than 300 days and during July to September the ground water table is above the soil surface i.e. there is flood in this period, but during January to March, it is very low and water becomes inadequate for growing crops. Other climatic parameters are most suitable for both Kharif and Rabi crops, but annual flooding affects the crop during July to September. From the study it was concluded that short duration varieties of different crops like that of paddy, pulses, oilseeds etc. may be grown at pre and post flood condition.

Mosaic is the combination of two or more raster images into single image. Sometimes, single image captured by remote sensing satellite doesn’t completely covers the desired study area mostly. Therefore, users resort for mosaicking two or more images captured by satellite sensors from different paths so that the whole study area is merged into a single raster image to facilitate the image processing and analysis. The pixel size of the raster images should be same for mosaicking.

In most of the cases, there is spatial overlapping among the raster images from which we want to create mosaic. These overlapping areas are handled in multiple ways which is being discussed further using R – code example. For mosaicking raster images in R, mosaic function of the raster package is used.

Abstract

Climate change and variability can adversely affect the poultry production in India, because birds can only tolerate narrow temperature ranges. Thermal stress on poultry is major concern. Heat and clod stress can cause immunosuppression and make birds more prone to infectious diseases. Climate change affects the occurrence, distribution and prevalence of poultry diseases.  Nutritional strategies aimed to alleviate the negative effects of heat stress by maintaining feed intake, electrolyte and water balance or supplementation of micronutrients such as vitamins and minerals to satisfy the special needs during heat stress have been proven advantageous. Ventilation and cooling methods are essential for birds to survive high summertime temperatures. Tunnel ventilation coupled with evaporative cooling is very effective in keeping birds cool during hot weather. The increasing proportion of poultry production in tropic and subtropical region makes it necessary to reconsider the selection strategy and potential use of naked neck and frizzle genes for improving heat tolerance in chicken.

Soil pH

 Soil reaction is measured by pH (Puissance de Hydrogen) of a suspension of

soil in water. The word “pH” has originated from the French word “pouvoir

hydrogen” which means powers of hydrogen. The acidity, neutrality or

alkalinity of a soil is measured in terms of hydrogen ion activity (active

concentration) of the soil water system. Most of the agricultural soils have

a pH varying from 4.5 to 8.5. The active concentration of hydrogen ion is

termed as ‘active acidity’ which is 1/50,000 or 1/1,00,000 times lesser than the

exchange acidity or exchangeable hydrogen.

 Soil pH is a measure of the activity of ionised H (H+) in the soil solution. The

pH of a solution can be defined as the negative logarithm to base 10 of the H+

ion activity or the logarithm of the reciprocal of the H+ ion activity.

pH = -log10

 a[H

 +] = log10

 1/[H

 +]

 There is difference between activity and concentration. Activity and

concentration are related by the mathematical expression

 a

 c

 F

 = where a = activity of a species (moles L-1)

 c = concentration of that species (moles L-1), f = activity coefficient

 a = c for dilute solutions, f = 1

 Activity coefficient of an ionic species is the degrees of freedom of that species

to participate in an equilibrium reaction or to maintain its charge under an

ionic environment.

Soils vary greatly in their organic matter content. For all practical purposes the organic matter content of the soil parallels the soil N content. The C/N ratio of soil organic matter generally falls in the range of 10 to 12. Because of the ease with which Kjeldahl determination can be made, N is often used as an index of soil organic matter content.

3.1. Composition of Organic Matter in Soil

Organic matter constitutes 1 to 6% of the topsoil weight of most upland soils. In a typical grassland soil, 5 to 6% of organic matter may be present in the top 15 cm. Top soils with less than 1% organic matter are mostly limited to desert regions. On the contrary, the organic matter content of soils in low, wet areas may be as high as 90% or even more. Soils with more than 12 - 18% organic carbon (approximately 20 - 30% organic matter) are called organic soils.

Soil is the product of various soil forming factors acting on the parent material over a period of time. The parent material is usually devoid of organic matter and consists of variable quantities of sand, silt, clay and carbonates. High temperatures and adequate moisture promote mineral transformations, but these effects are magnified by living organisms and the organic substances they produce. The biosphere and the organic substances they produce are directly or indirectly responsible for the following:

1. Decay of organic matter by microbes leads to the formation of CO₂ which is quantitatively the most important “aggressive” weathering agent because of its tendency to form carbonic acid with water [CO₂ + H₂O → H₂CO₃].

Climate change is one of the most pressing issues of our time, with far-reaching consequences for the environment, human health, and the economy. One of the most significant impacts of climate change is on the world’s water resources. Rising temperatures, changing precipitation patterns, and increased frequency of extreme weather events are all taking a toll on the availability, quality, and management of water resources. Water is essential for human survival, and its availability and quality are crucial for human health, food security, and economic development. However, climate change is altering the hydrological cycle, leading to changes in precipitation patterns, increased evaporation, and altered water flows. These changes have significant implications on demand for water resources, including reduced water availability, decreased water quality, and increased risk of waterrelated disasters which will ultimately impact agricultural production and food security.
15.1. Changes in Precipitation Patterns
One of the most significant impacts of climate change on water resources is the alteration of precipitation patterns and projected per cent changes in average annual precipitation over 1850-1900 period at 2.00C increase in temperature are depicted here (Fig.15.1).

The synthesis of humic substances is the least understood and the most intriguing aspect of humus chemistry. This has been one of the intensely- researched subjects for a long time. Formation of humic substances takes several pathways during the decay of plant and animal remains in soil and the four important ones are shown in Fig. 8.1.

Fig. 8.1: Mechanisms for the formation of soil humic substances

The classical theory by Waksman advocated humic substances as modified lignins (Pathway 1), but a vast majority of current crop of investigators favour a mechanism involving quinones (Pathways 2 and 3). Including sugar-amine condensation pathway (Pathway 4), all the four pathways must be considered as likely mechanisms for the synthesis of humic and fulvic acids in nature. It is absolutely possible that these four pathways may operate in all soils, though not to the same extent or in the same order of importance. 

Abstract

The anomalies observed in the reverine systems have been demonstrated to be the potential tool in deciphering the tectonically active zones. Such various drainage anomalies viz: radial drainages, anomalous compressed meanders, eyed drainage and the youthful floodplains observed in Annamali – Palani - Varushanad hill ranges of the Western Ghats of Tamil Nadu show that the N-S and NE-SW trending faults are tectonically active in the recent years.

Much has been talked about the mighty river systems and their migratory histories, since Purana and Vedic times. In Mahabharata the places where the Lord Krishna is said to have played with Gopis in the banks of River Yamuna are now forming flat lands many kilometers away from the present day Yamuna. In the same way, there is a mention in ancient literature about the ‘Indo-Brahm’ river which was originated from the Himalayas and flown through Brahmaputra valley, Indo-Gangetic plains, Rajasthan desert and met the Arabian Sea in Rann of Kutch. Such a mighty river is said to have fragmented into Brahmaputra, Ganges and the Indus rivers due to Tectonic activity in Himalayan regions. Similarly there are many evidences in the Tamil literature. For example in ‘Kalingathuparani’ it is mentioned that the river ‘Palar’ was flowing north of Kanchipuram but the same river is now flowing south of it.

All these facts show that the rivers have the tendency to frequently change their courses. The advent of modern Remote Sensing Technology has opened up new vistas in studying such migratory rhythms of the rivers, as such old and buried rivers exhibit spectacular ribbon like, linear, curvilinear and contorted features with typical darker tone in black and white images and reddish tone in false color composites (FCC) and other color coded images.

7.1 Summary

Climate change is a complex global phenomenon that poses significant challenges for agriculture including uncertainty about future weather patterns, soil conditions, and other environmental factors. Farmers are facing the difficult task of interpreting and responding to these changes in order to maintain their livelihoods and ensure food security for growing populations. In this context, mental modelling has emerged as a useful approach for understanding how farmers interpret and respond to climate change. Mental models are cognitive representations of how individuals understand and make decisions about complex systems, and can be used to identify key drivers of behaviour and decision-making.

The present study has explored the social, ecological, and economic factors that influence farmers’ mental models on perception of climate change, level of uncertainty and trend of agricultural change in the selected study area. It argues that farmers’ mental models are shaped by a range of factors, including their own experiences and observations, social networks and interactions, access to information and resources, and broader economic and political contexts. The present study has also highlighted the role of uncertainty in shaping farmers’ mental models and decision-making. Uncertainty about the future impacts of climate change can create significant challenges for farmers, as they must make decisions based on incomplete information and uncertain predictions.

Abiotic Environment

The physical or abiotic environment includes all those physical and non-living chemical aspects, which exert an influence on living organisms. The abiotic components are soil, water, air and energy from various sources. These provide both habitation and raw material for the synthesis of organic food.

Instrumental methods of chemical analysis are the quantitative methods of analysis that use, as principal measuring devices, instruments other than those employed in conventional gravimetric and volumetric determinations.

The main basis for this method of analysis is the physical property of any particular element or compound being analyzed. These properties include:

6.1 Biodiversity

Biodiversity means biological diversity. It measures the variety of the earth’s animal, plant and microbial species; of genetic difference within species and of the ecosystems that support the species in its widest. Biodiversity is virtually synonymous with “life on earth”, this word was coined in 1985. Biodiversity is the degree of variety in nature and not nature itself.

To a layman, wasteland is a piece of land, which is lying uninhabited or uncultivated. These lands are also commonly perceived to produce much less than their potential. Depleted of the green cover and productivity, such lands are often in a critical condition. Broadly, wastelands may be defined as land where the production of biomass is less than its optimum ‘productivity. Wasteland also refers to lands, which are economically unproductive, ecologically unstable and subject to environmental deterioration.

Introduction

India was a self-sufficient nation in its food production before independence but after the occurrence of various famines, the government in late 1960s started focusing more on the crop production i.e.,green revolution (NAAS 2019). Use of hybrids, fertilizers and plant protection chemicals increased and major investments were made on irrigation structures which led to a massive jump in the production of crops. But with time, the negative externalities caused by green revolution were vividly noticeable. The indiscriminate use of chemicals has debilitated the environment by causing soil depletion, pollution, deforestation, climate change etc. thus affecting the health of human kind. The lofty prices of inputs led the farmers to resort to debt thus falling into debt trap and suicides. In order to address this problem an alternative to the conventional farming is required which is more sustainable and climate resilient. In the mid-1990s, natural farming viz., Zero Budget Natural Farming (ZBNF) was demonstrated by Sh. Subhash Palekar also known Subash Palekar Natural Farming (SPNF). It is an agroecology based diversified farming system which involves no financial outlay to purchase essential from outside and makes farming profitable. Mishra (2018) studied on Zero Budget Natural Farming (ZBNF) and found that crops grown under ZBNF evinced higher yield than the crops grown under non-ZBNF.

In November 1992 a document entitled Warning to Humanity was released, signed by 1500 scientists from around the world, including 99 Nobel laureates, and the Director General of the United Nations Educational, Scientific and Cultural Organization (UNESCO). The document stated that “human beings and the natural world are on a collision course,” which “may so alter the living world that it will be unable to sustain life in the manner that we know.”

ABSTRACT

The carbonatites are genetically and geochemically distinct and contain several rare earth minerals that are unknown or are very rare in other types of rocks. A useful review of the REE’s in carbonatites is given by Cullers and Graf (1984), who point out that carbonatite contains the highest concentration of REE’s and highest LREE: HREE (La:Lu) ratio of any igneous rock. High REE abundances are considered as the diagnostic character of carbonatites to discriminate them against recrystallized limestone. Rare earth mineralization in carbonatities can be classified into three categories. The first is primary magmatic crystallization (bastnaesite). The second is hydrothermal mineralization and the third is supergene mineralization produced by weathering of carbonatitie bodies. The only economic Nb mineral in carbonatite is pyrochlore. Apatite deposits constitute the largest bulk mining in carbonatites and have higher phosphate content than marine phosphorites. Pyrochlore, cubic fergusonite, eschynite, Fe-Nb rutile, monazite apatite, bastnaesite and allanite are the rare earth minerals that are enriched in Tamil Nadu carbonatites. Such enrichment of above rare earths is typical of undersaturated alkaline complexes. The lanthanides are seen associated with these minerals, mainly the light lanthanides are predominant than heavier ones. Thus the carbonatite complexes provide the locus for several metal deposits that are presently of strategic importance, containing elements, which are otherwise largely dispersed in earth crust.

Historical Development of Soil Science/Agriculture

Francis Bacon (1561-1624 A.D.): Found the water as nutrient of plants.

Van Helmont (1577-1644): Give the ideas about the role of soil as a simple source of water and minerals for the plants.