eChapters

Field capacity may be defined as the amount of water held in soil after excess water has drained away and the rate of downward movement of water was materially decreased which usually taken place within two to three days after heavy rain or irrigation. In this condition water was moved out of the macropores and air has moved into take its place. 

The soil water plays an important role in the physical, chemical and biological activities taken place in the soil which directly or indirectly affects the crop growth. The water content of the soil can be measured by different methods. These methods are gravimetric method, neutron scattering method and electrical resistance method.

Primary particles tend to adhere under natural condition so as to form secondary unit called aggregates. It is very difficult to determine the diameter of the individual aggregated particle. So the mean weight diameter is calculated as a single value constant, which indicate the wetted average value for a group of aggregates.

Pore space or porosity : Porosity is an index of the relative pore volume in the soil or volume fraction of pores. Its value generally lies in the range of 0.3-0.36 (30-60%). Coarse textured soils tend to be less porus than fine textured soil, though the mean size of individual pores is greater in the former than in the latter. The total porosity, in any case, reveals nothing about the pore size distribution which itself is an important property.

Soil texture is the relative proportion of sand, silt and clay in soil by weight. As per the classification of the inorganic soil particle by the International Society of Soil Science, diameters of the sand, silt and clay particles vary from 2 to 0.02 mm, 0.02 to 0.002 mm and less than 0.002 mm, respectively. There are 3 broad textural groups i.e sand, loam and clay and each broad textural group is subdivided into different textural classes depending upon the proportion of sand, silt and clay.

Aim of the Experiment: The composite soil samples, collected, are air-dried and processed before analysis in the laboratory.

Soil testing identifies various constraints in soil that limit crop production. Fertilizer recommendation and soil management practices to be adopted are based on the soil test report. Soil testing starts with collection of soil samples from the field
and ends with interpretation of soil test results leading to necessary recommendations for increasing crop production.

A pH meter is very commonly used for the measurement of the reaction of a solution or a medium. The pH determination with the help of a pH meter is based on the measurement of the electromotive force (e.m.f) of a pH cell consisting of an electrode sensitive to W ions and a reference electrode.

The quality of irrigation water is a crucial factor for long-term soil productivity. Poor quality water if used for a long time can make the soil less productive or even barren, depending on the amount and type of constituents present in it and the texture of the soil in question. Low or marginally saline waters sometimes appear to stimulate crop growth because of the higher amounts of nutrient ions present.

Accumulation of nutrient elements in plant tissues indicates the accessibility of the concerned elements from the soil to the plant. Although different plant species and even different varieties of the same species may vary in their nutrient requirements, composition of a part or of the whole plant may well be adopted as a guideline to support the soil-test results for factual assessment of soil’s nutrient supplying power.

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.

10.1 Introduction

The consistent process of rapid urbanization and expeditious developmental activities have severely impacted the environmental components and thereby the quality of life. With limited natural resources, individuals and societies have to learn to bring in attitudinal changes in order to accomplish environment sustainability (UNESCO). From the Book “Our Common Future” (Brundtland Report), the concept of Sustainable Development can be understood as the “development that meets the needs of the present, but does not threaten the ability of future generations to meet their own needs”. 

Introduction

With ever-increasing population growth, waste management has become a major challenge threatening environmental sustainability. The total solid waste generation was recorded to be 1.3 billion tonnes per year by the world’s cities in 2012, with an ecological footprint of 1.2 kilograms per person/day. With the intensity with which the population growth is happening coupled with urbanization, predictions are made that by the end of the year 2025, 2.2 billion tonnes of municipal waste will be generated (The World Bank, 2018). 

8. Introduction

The idea of sustainable development stands on the concept of maintaining the best possible environment within the availability of minimal resources and for the convenience of the society. Now-a-day the term “sustainability” gained a lot of attention due to challenges and problems faced in tackling the current situation of global pollution. One of the vital areas of research needs to be addressed in concern with sustainable development is the new innovations to enhance sustainability (Silvestre and Silva, 2014). 

7.1. Developing Sector in Scientific and Technological Approach of Waste Management

From the very past, many traditional practices have been put into use for waste management like landfilling, composting, and recycling, which are practiced even today. However, the boundless upsurging waste compels the modern world to modify the traditional methods or to introduce innovative techniques with the grace of technology

6.1 Introduction

Urbanization is now a global phenomenon, but in developing countries the implications are more pronounced. Natural growth of population, reclassifications of habitation and migration trends are important in urban population in India. The population of India, which accounts for 27 per cent of the total population, was 285 million according to 2001 census. International experience shows that the pace of urban development accelerates when a country’s urban population crosses close to 25 percent of the total population (like in India).(Kumar and Chakrabarti, 2010). 

Definitions: Before starting the chapter, it is better to understand the basic definitions of the terms commonly used in this chapter.

Waste: Waste is any material or object which is discarded after its primary use by its holder. A holder means the person who produces and keeps the waste. 

4.1. Introduction

Presently, in the world, there are 195 countries according to the United Nations, and the number would even go up to 247 if we consider the disputed territories like Isle of Man, Hong Kong, etc. (United Nations, 2016) (Kershner, 2020). But the majority of the countries are still struggling to provide basic life-supporting amenities like nutrition, shelter, and employment. Conjointly, termed as emerging and developing countries such as India, Vietnam, Venezuela, Utopia, etc. (Ahmed and Shimada, 2019). Most of the developing countries are situated mainly in the continent of Africa, Asia and South America. They have got independence for the European countries like England, France, Portugal and Spain in the mid and late 20th century. 

3.1 Introduction

A Massive increase in population, urbanization and industrialization have led to an increase in the quantity and composition of waste. The waste is increasing day by day and is estimated to reach up to 2.2 billion tonnes by 2025, according to the reports by World Bank. It becomes a necessity for every nation to fore look upon the waste management system for their respective countries. From the collection, segregation, transportation, disposal all have become an important criterion to deal with. Among the available disposal options; the easiest and environment friendly is “Recycling”. 

1.1 Introduction

Increased emission of greenhouse gases results in climate change which becomes one of the most prominent environmental issues to the world today. Carbon dioxide (CO2) is the major greenhouse gas whereas nitrous oxide (N2O) and methane (CH4) are other substantial contributors to climate change (IPCC, 2014, Tongwane et al., 2016). However, these gases are emitted in minimal quantities in comparison to carbon dioxide but impart more global warming effect by absorbing more infrared radiations (Oertel et al., 2016). The warming potential of one kg of CH4 is 23 times more than one kg of CO2 while  in the case of N2O, it was nearly 300 times more than CO2 (Ramaswamy et al., 2001, Bharti et al., 2019; Biswas et al., 2010). Around one-third of methane and two –thirds of nitrous oxide come from soil (Prather et al., 1995, Tubiello et al., 2015, Smith, 2016).