eChapters

Introduction

The Integrated Watershed Development has come to be recognized internationally as an important holistic approach to natural resources management and poverty reduction, wherein promoting the concept of sustainable development. In the Indian context, watershed development has come to be acknowledged as key and discrete units in rural development which forms an important vehicle for achieving the objectives of increased production and availability of food, fodder and fuel restoration of agro ecological balance and in improving the livelihood status of the village communities.

In line with the above, the conceptualization of Integrated Watershed Development Project Hills-II (initiated in September 1999) has been built up on the success of IWDP Hills-I project with a laudable vision to arrest environmental decline, boost agricultural growth, and ensure better management of scarce land and water resources and reducing poverty dimensions in the Siwalik & Karewas regions, which are one of the most environmentally degraded areas in India. The project area encompasses two sub-watersheds in sub-tropical belt of Siwaliks of Jammu region and two in temperate Karewas of Kashmir valley, covering an area of 1,11,080 ha. Ramnagar and Akhnoor sub-watersheds are located in Siwalik range of Jammu region whereas the sub-watersheds of Rajwar and Rambiara are located in Karewas belt of Kashmir valley.

Introduction

Food and nutritional security continues to be the main plank of India’s food policy despite its tremendous achievements on food production front during the last three decades. The Green Revolution helped India to overcome chronic food scarcity and made it self sufficient in food production. The per capita availability of cereals increased from 360 gms/day in 1966 to 422.4 gms/day in 2004. On the other hand, availability of pulses, the main source of protein for over- whelming vegetarian population of India, declined from 48 gms/day to 38 gms/day, which is attributed largely to diversion of land from pulses to cereals crops (Gopalan et al, 2004). The extra income generated due to Green Revolution has increased the access of rural population to a wide variety of foods, like milk, meat, eggs, fish, fruits and vegetables, which perhaps could offset the protein deficiency due to decline in per capita availability of pulses, therefore, resulting in the increase in per capita consumption of protein in rural areas. The trends in cereal consumption indicate that per capita cereal consumption has been declining in most of the states. This trend is more prominent in agriculturally developed states, like Punjab and Haryana. In these states, production and per capita consumption of milk have increased substantially.

The dietary pattern in India remains cereal based and the expenditure shares of foods of animal origin (meat, eggs and fish) and fruits, which are rich in nutrients, are trivial. More than 22 per cent of the population stays below poverty line and generally suffers from various nutritional disorders due to lower purchasing power. The nutrient rich foods like milk, meat eggs, fruits, etc. are highly responsive to income changes. Besides, choice of food and consequently the level of nutrient intake is also influenced by the other economic, social, cultural and climatic factors. Spurt in income growth and increasing consumerism in rural areas in recent years has heightened the need for understanding the food consumption pattern. Using the farm level data from three regions of Maharashtra this paper attempts to examine the pattern of consumption of nutrients by cultivators and sources of supply of different nutrients.

Introduction

Goats provide multiple products like chevon, milk, skin, fibre, manure and transport. Pashmina occupies a prime position among animal fibres for its firmness, warmth, durability, lightness, softness and ability to absorb dyes and moisture compared to mohair and/or wool for being free from modulation and crimps. Pashmina is highly valued fibre for manufacturing quality apparels. It has recorded its name in the Guinness Book of World Records for being costliest cloth in the world after trade ban of most precious natural fibre Shahtoosh (King of fibre) of small Tibetan Antelope known as Chiru. In India, two recognized pashmina breeds are Changthangi and Chegu. Changthangi is native to high altitude areas (3700 to 4500m) in Ladakh region of Jammu and Kashmir reared by a pastoralist nomads Changpas whose population is 1,96,000 (LADHC, 2006). The Chegu breed is distributed in cold-arid trans-Himalayan mountain ranges from Himachal Pradesh to Uttaranchal at an altitude of more than 3000 m (Thakur et al., 2006).

Introduction

The world’s population is expected to grow from 6 billion people in 2000 to 7.5 billion people in 2020. Availability of land for farming is on the decline, and water for agriculture and other uses is increasingly scarce. Together these and other forces will challenge the capacity of the world’s food production system. The world has experienced an unprecedented increase in population during the past century, with a billion people added every decade during the last three decades alone. Dramatic shifts in production and consumption of food have accompanied this population explosion, including a surge in grain production, a spectacular rise in meat production and consumption, and the emergence of an increasingly vital role for international trade (Fig. 1). High-yielding varieties of wheat and rice swept across much of Asia during the 1970s and early 1980s, easing fears of imminent famine. Cereal yields have risen more modestly in recent years, but they have still outstripped gains in other crops such as cassava, potatoes, and beans.

Introduction

Food security at the national level refers to the capacity of a country to provide sufficient food for its population, and will depend on such factors as food production in relation to the population, food aid and within-country food distribution. The ability to withstand emergencies arising from drought, floods, and such other calamities, also fall in its purview. While many definitions of household security exist, they agree on a household’s ability to get sufficient food to the household. Gillespie & Mason (1991) gave a more lucid account and defined household level food security as access to food that is adequate in terms of quality, quantity, safety and cultural acceptability, for all household members. Two main factors determining household food security are income generated by the members of the family from the avenues available and food prices in operation at the given point of time. The cost of achieving and maintaining food security is important.

Food security takes into account only the nutritional requirements of the individuals in the society, which is basic to all the living beings for keeping the body and soul intact. Our needs go beyond this and necessarily include fiber and shelter, not only to be called civilized but also to face vagaries of weather. Once we add these dimensions to the food security then it can be termed as livelihood security. In this century, many driving forces are added in the process of evolution of strategies. Loss of biodiversity, global climatic change and information dissemination are some of the major factors that drive the rate of livelihood changes and determine the direction of its evolution.

Introduction

The availability of food depends on the production and distribution while the access to food is determined by an individual’s purchasing power. Thus, the food security in the framework of economic welfare is the situation in which the lowest income strata has a near zero probability of being vulnerable to famine and in terms of calorie it requires a near zero probability of falling below the poverty line (Rentlinger and Selousky, 1978). Therefore, food security concerns every sovereign country, especially the developing and poor nations, owing to its profound implications for their socio-politico-economic stability and which co-exists with international diplomacy. According to 1998 annual report of International Food Policy Research Institute (IFPRI), about 73 million people would be added to the world’s population every year between 19952020 increasing it by 32 percent to reach at 7.5 billion. Much of the population growth is expected to occur in the developing countries mainly in India where the population is expected to increase by 36 percent to touch at 1.27 billion by 2020 and is likely to overtake China by 2035. Therefore, meeting the food and nutrition needs of growing and urbanized population with rising incomes will have profound implications for agricultural production and food security of the country and Himachal Pradesh is no exception.

Introduction

India is more an agrarian economy, wherein about 50 percent of people directly depend on agriculture for employment. Like other developing nations, however, this country is facing some of the challenges like food insecurity, agricultural backwardness and unsatisfied farming community. Though green revolution in 1970s had brought much relief in this direction, liberalized trade polices since mid 1990s created new and complex issues, especially for small and marginal farmers. Also, since recent years the contribution of agriculture to GDP is declining, indicating that there is growth is shifting away from agriculture to industrial and service sectors. The rural-urban migration, primarily due to the poor employment absorption capacity of our traditional agricultural system, lower productivity, changing life styles, etc. is increasing at alarming rate. In spite of all these, the disparity persists within the society and across the region. Such inequalities, as measured through income distribution, consumption pattern and spending of the income, pose a big challenge, as the gaps are widening with the passage of time. Inadequate purchasing power among the poorer communities leads to undernourishment, which in turn affects their productive capacity. Even though huge food grain stocks are distributed among the needy, considerable proportion of the population lack economic access to such food, and have to rely upon the cheap and insufficient food.

Introduction

Food security problem has multiple dimensions that range from ensuring the food supply at global, country and local levels to create its effective demand round the year. The ultimate goal of an effective food security policy is to provide individuals with adequate dietary requirements through availability and accessibility of food, which are necessary conditions for nutritional well being. The level of food security existing in a country, however is a complex interactions, operating at different levels from the macro to the micro level. The components of the system would include international trade and macro policies, the agricultural sector, the market economy, consumption pattern, the micro economy or household income, urban-rural differentiation and gender issues, etc.

Food insecurity is a complex issue having several dimensions such as, poverty, unemployment, famine, gender discrimination, inequity, starvation, food and nutritional practices, for human growth, natural calamities and so on. Poverty has been recognized globally both as a cause and consequence of food insecurity. In the mid 1980s, 72 per cent of the world’s poor and 66 per cent of the world’s extremely poor lived in the Asia-Pacific region. In this region, 272 million people would suffer from chronic malnutrition during the next decade i.e. in the year 2010. In Asia-Pacific region, India alone has 204 million undernourished people, which is quite alarming when compared with neighbouring countries like China, which has only 164 million undernourished people despite being much populous than India. World Health Organization (WHO) report (1998) points out that health expectancy is more important than life expectancy. The impact of poverty and malnutrition on health has widened the gap between the rich and the poor.

Introduction

Agriculture provides unique solution to various developmental issues including poverty and hunger. World Development Report (2008) reveals that the agricultural growth has significantly contributed to the decline in poverty world over (as in China and Latin America). Though the non-agriculture sector pays more dividend, and grows steeply, the capital generated, however benefits a few (mostly urban areas) thus leading to uneven distribution of income. Whereas, the development of agriculture, which employs most of the rural population, is expected to benefit a large section of the population simultaneously and uniformly. It is in this context that this report predicts agriculture as a vital development tool for achieving Millennium Development Goal that calls for halving by 2015 the share of people suffering from extreme poverty and hunger.

Introduction

The diversifi cation and modernization of the present agricultural and other related activities supported by efficient on and off farm processing of the commodities for the purpose of value-addition is expected to increase food production and create employment and income generation. Adding value to food commodities after harvest is also aimed at minimizing the losses during storage and to maintain the quality of product. Efficient post-production practices, particularly the preservation and processing of agricultural and allied produces may bring a wide range of benefits to the people in this country, generating job opportunities by opening up village-level processing units. The goals of post-harvest and food processing technology are loss prevention as well as adding value to the harvested biomass, which result in more income to the farmers/processors and better quality produce provided to the consumers. Post-harvest and food processing technology are commodity-and location-specific and it is done at home, village and/or cottage levels at small and large industrial scale. On-farm post-harvest storage and primary processing integrated with production technology help to generate more employment opportunities and additional income for rural people. Minimization of the post-harvest losses is an important means to increase per capita food availability. It also helps to generate more employment and income. Investment in post-harvest measures is more economical and time saving than in productivity to obtain the same amount of a particular commodity. Furthermore, post-harvest measures automatically add value to the raw commodities as they pass on their marketing channels. Adoption of postharvest technologies and value additive measures are very strong tools for rural and social development through employment and income generation. Development and adoption of efficient value addition practices will enhance national food supply and sustain food security even at the household level. Fruits and vegetables processing industries have a good deal of potential in serving the rural economy. First, it helps in generating more employment for rural people. It will also check mobility of rural masses towards urban areas in search of employment. Employment opportunities offered by agroprocessing industries are plenty to the farm population and entrepreneur seeking self-employment. Cottage scale units particularly offer self-employment opportunities. Traditionally women handle food and are familiar with skills of food processing. In order to improve the status of living of woman and rural food processing, low cost appropriate fruit and vegetable processing technologies offer excellent opportunities for production of processed foods. The improvement of status of socially backward and landless labor classes will be possible only through providing non-farm employment at their doorsteps. This will generate a sense of security and confidence amongst rural people for overcoming uncertainty in agricultural income and providing self-employment to the land-less labor. The locally available untapped resources should be used effectively.

Introduction

The concept of food security having relevance at global, national, regional, state, household and individual level is well understood as a core issue over the last three decades in the world. The World Food Conference of 1974, organized in the wake of the world food crisis of 1972-74, was largely concerned with global food security. It was felt as the common responsibility of all nations that international approaches were needed to achieve the goal of improved world food security. The food security at national level means arrangements for providing physical supply of a minimum level of food during all periods including those having harvest failures. FAO (1983) had formulated that the basic concept of food security implied that all people at all times have physical and economic access to the basic food they need. The World Bank (1986) has modified this formulation to indicate that food security is access by all people at all times to enough food for an active healthy life.

In this direction, the conference on Environment and Development held in Rio (1992), the Joint FAO/WHO Conference on Nutrition held in Rome (1992), the World Conference on Human Rights held in Vienna (1993), the International Conference on Population and Development held in Cairo (1994), the World Summit on Social Development held in Copenhagen (1995), the Fourth World Conference on Women held in Beijing (1995), the Habitat II Conference held at Istanbul (1996), the World Food Summit held in Rome (1996), etc. deliberated on various facets of food security like food security and sustainable development, right for nutritionally fit and safe food, population growth and food production, global measures to satisfy the food needs, campaign against hunger, women in food production, rural-urban linkages and so on.

Introduction

Poverty has been described as a situation of “pronounced deprivation in well being” and being poor as “to be hungry, to lack shelter and clothing, to be sick and not cared for, to be illiterate and not schooled. Poor people are particularly vulnerable to adverse events outside their control. They are often treated badly by institutions of the state and society and excluded from voice and power in those institutions.” Lack of access to resources is a unifying characteristic of poverty in all its manifestations. The poor lack ownership of or access to assets such as land, water, forest, dwelling units, credit, literacy, longevity, voice and capital-both physical and social. Those who are severely below the poverty line are largely involved in subsistence type activities for which they get exploitatively poor returns despite suffering extreme physical hardship and undertaking grave risks so as to earn a meager income. Since earnings are below even the margins of existence, expenditure and survival needs exceed income. This often results in the need to borrow small amounts of money at usurious interest rates of as much as 120 per cent per annum (Mehta, 1996) when borrowing is not possible, hunger is suffered. Their inability to change the power relationships results in scarcely available common resources (such as even drinking water) or public funds meant for poverty alleviation being misappropriated and diverted through manipulation by the locally powerful or corrupt. Since there are no mechanisms for grievance redressal this could result in social tension, despair or a combination thereof.

Introduction

Food security means access by all people at all times to enough food for an active healthy life (Reuntlinger, 1985; World bank, 1986; FAO, 1989). But now-a-days, food security is used differently at national, regional and household level. At regional and national levels, it is related to regional and national balances between availability and need whereas at household level, it is related with food production resources, income available for purchases and assistance sufficient to meet the aggregate needs of all household members.

Availability of food alone may not guarantee access due to poor distribution or lack of purchasing power as co-existence of aggregate food self sufficiency and widespread malnutrition and hunger do exist. As per Chen and Kates, 1994, food security includes combination of criteria as:

Introduction

Food is the most important requirement of every section of the society. But, mere availability of food sometimes is not enough and it does not mean that everybody is having access to a fair share of it or that every one has an adequate diet (Oshaug et al., 1994). Therefore, affordable food prices and adequate purchasing power with the people are equally important.

The need of food security was felt due to the gaps in food production and availability of sufficient food from domestic resources. Large proportion of the underfed population starves not because of general food shortage but due to the insufficient access to food supplies or insufficient income to purchase food.FAO (1999) estimated that there were 20.4 million undernourished people in India only).

Importance of maintaining food security over the world has been abundantly recognized since long. However, during 1974, FAO was called by the World Food Conference to establish a Committee on World Food Security so as to keep the world food situation under constant review and to suggest the strategies for rectifying the problems in problematic areas. Later, an International Undertaking on World Food Security was set up wherein member nations committed themselves to maintain food stocks for ensuring uninterrupted supply of foodgrains and to cope up with the problems of shortage in case of crop failure due to the natural calamities etc. Since then, the Committee on World Food Security monitors the implementation of the undertaking.

Introduction

Food being the foremost basic need gets the priority in expenditure of people, especially poor class. Access to food demands affordability, which depends upon the twin factors namely, income of the people and prices prevailing in the country. Slower growth in income than prices would undermine the purchasing power, resulting in inadequate access to food and calorie consumption. Foodgrains account for about four-fifth of the calorie intake of the poor and an increase in cereal prices could significantly reduce the calorie intake of the poor, as it is sensitive to cereal prices.

Introduction

The importance of food security and its management world over has been recognized long back. The World Food Summit in 1974, called in response to the persistent and widespread under-nutrition and the future role of agriculture, stressed upon establishment of committee to review and recommend location specific action plan in sensitive areas. Asserting that every man, woman and child has the inalienable right to be free from hunger and malnutrition in order to develop their physical and mental faculties, an international undertaking on world food security was set up in which member nations committed to maintain food stocks to ensure routine and emergency food supplies (in case of crop failure, natural disaster, etc.). Monitoring the implementation of such undertaking has since then become the responsibility of the Committee on World Food Security.

Introduction

India has made impressive strides on the agricultural front during the past three decades. Much of the credit for this success should go to the several million small farming families that form the backbone of Indian agriculture and Indian economy. Policy support, production strategies, public investment in infrastructure, research and extension for crop, livestock and fisheries have significantly helped in increasing the agricultural productivity, food production and its availability. Notwithstanding these achievements, producing additional food with limited land, and providing economic access to food at the household level for ensuring food security would continue to be a major challenge for the nation. India has experienced considerable changes in the crop mix, yield and production since the inception of the Green Revolution. The Green Revolution phase displayed a high yield growth per unit of input. The first post-Green Revolution phase (from late-1960s to mid-1980s) was marked by the continued growth in returns from land through the intensification in use of chemical inputs and machine labour. The second post-Green Revolution phase (beginning the mid-1980s) was characterized by high input-use and decelerating productivity growth. It calls for an examination of the issues related to the trends in agricultural productivity, particularly with reference to individual crops in recent years. In the present paper, the temporal and spatial variations in the productivity status of major crops in India have been analyzed using the TFPG estimates. Some policy measures have also been suggested for sustaining TFP of the crops.

Role of Agriculture in Livelihood Systems

For the developing countries like India, where a majority of families, in both the farm and non-farm sectors, derive their livelihoods from agriculture, sustainability of agriculture cannot be discussed or even defined in isolation of the issue of livelihoods. Livelihood is defined as adequate stock and flow of food and cash with an individual or a family to meet its basic needs. Livelihood security then means secured ownership of, or access to, resources and income-earning activities, including reserves and assets to offset risks, ease shocks and meet contingencies. There are four principal ways of acquiring livelihoods by the rural households. First is the production-based livelihood. A large proportion of the small and marginal farmers gain livelihoods through production on small pieces of land. For these households, availability or access to inputs and improved methods of production are quite critical for their livelihoods. Second is the labour-based livelihood. Most of the small landholders and landless rural households derive livelihoods by selling their labour. For their livelihoods, demand for labour, wage rates and prices of food are the critical factors. Third is the exchange- or market- based livelihood. Those rural households which produce surplus food and non-food agricultural products or non-farm goods earn their livelihoods by selling these surpluses in the market. The marketing system for these products and relative prices of what they sell and what they buy, affect their livelihoods. The fourth set of livelihoods is transfer-based entitlements. The households without any income-earning asset or able-bodied person to work depend for their livelihoods on transfers from the government or other social organizations. Government’s social security and food assistance programmes are relevant for this group of rural households in fulfilling their livelihood requirements. The rural livelihood systems in the developing countries thus encompass a broad range of factors and depend on several macro sub- systems of the economy.

Introduction

India accounts for 16.7 per cent of the world’s food consumers. India’s size in terms of food consumers is many times larger than the average size of the rest of the countries, except China. At the time of independence in 1947, India was in the grip of a serious food crisis, which was accentuated by the partition of the country. The demand for food far exceeded supply, food prices were ruling at high levels and more than half of the populations were living below the poverty line with inadequate purchasing power. With high rates of population growth, the dependence on imported food increased further. However, the situation improved considerably after the mid-1960s, when new agricultural development strategy and food policies were adopted in the country. The production of staple cereals increased substantially, mainly contributed by productivity improvements. The dependence on food imports reduced and the country became a marginal net exporter of cereals. There was also an improvement in physical and economic access of households to cereals and other nutritive food products. The proportion of households reporting hunger went down and the incidence of economic poverty was reduced. The objective of this paper is to review the Indian approach to tackling the severe problem of food insecurity, which it faced immediately after independence. It reviews the evolution of food policy, the major policy instruments deployed, intervention in food marketing system, and the current status of food security/insecurity. The paper also identifies the lessons emerging from the experience of India. The paper has been divided into eight sections. The second section briefly presents the evolution of the food policy in India and the approaches to food security. The current status of food security and insecurity is analyzed in section 3. The next three sections detail the three major instruments of the food security policy. Price support policies pursued in the country are described in section 4. Section 5 examines the magnitude of input subsidies in Indian agriculture. Direct food and other assistance programs for improving household food and nutrition security and magnitude of food subsidy are presented in section 6, while some salient features of food marketing system that affect food security are given in section 7. Lessons emerging from the Indian experience are presented in the last section.

19.1. Plant Available Fraction of Nickel, Cadmium, Lead and Chromium

The DTPA method was originally developed to extract Mn, Cu, Fe and Zn from slightly acidic to alkaline soils (Lindsay and Norvell, 1978), but in some cases it can be used for other metals also such as Nickel (Ni), Cadmium (Cd), Lead (Pb) and Chromium (Cr). Among them Ni is considered as an essential micronutrient. The DTPA is used to extract soil metals by forming chelates with free metals in solution, which lowers their ionic activities so that additional quantities of metal are released from the soil until equilibrium is attained. Triehanolamine (TEA) is used to buffer the extracting solution at pH 7.3 in an attempt to optimize the extraction of various metals. Calcium chloride is included in the extracting solution to minimize dissolution of CaCO₃.

18.1. Determination of Available Micronutrient Cations (Zn, Cu, Fe and Mn) in Soil

The available micronutrient cations (Zn, Cu, Fe and Mn) can be estimated in a single extraction with diethylene triamine pentaacetic acid (DTPA) as proposed by Lindsay and Norvell (1978). DTPA has the excellent property to combine with free metal ions in the solution forming soluble complexes. The stability constants of metal-DTPA complexes make DTPA as a most suitable extractant for simultaneous complex formation with Zn, Cu, Fe and Mn. In calcareous soil DTPA extractant may result overestimation due to excess dissolution of CaCO_3, thus releases occluded micronutrient cations which are not plant available. To avoid this excessive dissolution of CaCO₃, DTPA is buffered at pH 7.3 using triethanol amine (TEA). At this pH major part (3/4^th) of TEA is present as HTEA⁺ (protonation) and exchanges for Ca and Mg ion from the soil exchange site. This increases concentration of Ca and Mg in the solution phase and suppresses dissolution of CaCO₃. The DTPA has the capacity to complex each of the micronutrient cations 10 times of its atomic weight and it ranges from 550 to 650 ppm depending on the micronutrient cation.

The amount of cation in the extract is determined on an atomic absorption spectrophotometer (AAS). The experimental condition such as shaking time, DTPA concentration, pH and temperature during shaking influence the amount of Zn, Cu, Fe and Mn extracted. Increase in shaking time and temperature markedly influence the extractability of these cations.

Sulphur (S) occurs in soil in both organic and inorganic forms. Inorganic S fraction may occur as sulphate (SO₄^2-) and compounds of lower oxidation state such as sulphide (S^2-), polysulphide (S_n^2-), thiosulphate (S₂O₃^2-) and elemental sulphur (S⁰). In well drained soils inorganic S usually present as sulphate. Under anaerobic condition (reduced or waterlogged soil) inorganic S mainly occur as sulphide and under extreme condition as elemental S form. Estimation of S carried out in two steps:

16.1. Forms of Soil K

Ignoring potassium (K) in soil organism, total K in soil may be classified as (i) water soluble K, (ii) readily exchangeable K (exchangeable K), (iii) slowly exchangeable K (non- exchangeable or fixed K) and (iv) mineral or lattice K. The different forms are in dynamic equilibrium with one another.

Phosphorus in soil present both in inorganic form and organic form. The inorganic P can be divided into different pools. The major active inorganic forms are: P bound to aluminium (Al-P), iron (Fe-P), calcium (Ca-P) and silicate minerals and relatively less active forms are occluded and reductant soluble forms of P. On the other hand the principal organic P compounds present in soil are (i) inositol phosphate, (ii) phospholipids, (iii) nucleic acid and other unidentified esters and phosphoproteins.

15.1. Determination of Available Soil P

The availability of soil P to plant varies greatly depending upon the reaction, minerological composition and amount of the soil colloid. Very little P is present in the soil solution except in recently fertilized or sodic soils. The type of phosphate ions present in the soil solution depends on the soil pH. In soils of neutral to slightly alkaline pH, HPO₄^2- ion is the dominant form. In slightly or moderately acidic soils, both H₂PO₄^- and HPO₄^2- ions prevail. At strongly acidic soil H₂PO₄^- ion tends to dominate, while above pH 9.0, the PO₄^3- ion becomes more important than H₂PO₄^-.

14.1. Determination of Total Nitrogen in Soil (Modified Kjeldahl Method)

Nitrogen mostly present in soil in organic form. Relatively small amount of nitrogen usually occur in ammonium and nitrate form, the available form. The Kjeldahl method of total N determination includes both organic and ammonium form and with modification nitrate form of N can also be included.

13.1 Exchange Capacity

Soil colloidal particles carry both negative and positive charges on their surface which attract and hold equivalent amount of oppositely charged ions to their surface. The total number of negative charges present on a given mass of soil or capacity of a given mass of soil to exchange cations or total number of cation held by a given mass of soil is termed as cation exchange capacity (CEC). Similarly, the capacity of a soil to retain anions is known as anion exchange capacity (AEC). The ion exchange capacity of a soil depends upon the type and amount of colloidal particle (clay and organic matter) present in the soil. Ion exchange capacity (CEC / AEC) is expressed as milliequivalent ion (cation / anion, respectively) per 100 g of soil (meq / 100g). It is also expressed as centimoles of charge (positive / negative) per kg of soil [cmol (±) / kg]. Meq / 100g = cmol (±) / kg of soil.

Carbon may present in soil in four different forms:

1. Carbonates: Mainly as CaCO₃ and MgCO₃, active CO₃^2- and HCO₃^- ions and gaseous CO₂.
2. Highly condensed elemental organic form: Charcoal, graphite.
3. Completely decomposed resistant organic residues: Humus.
4. Undecomposed and partially decomposed organic residues.

11.1. Determination of Electrical Conductivity of Soil Solution

The conductivity or more precisely the specific conductance of a soil at a given soil-water ratio is the reciprocal of the specific resistance offered by the solution at 25ºC between the electrodes of 1 sq cm cross section kept 1 cm apart. Thus, the electrical conductivity of any solution depends on the amount of soluble salt present in it. Knowledge on the extent of salinity is important for management of saline soil including the choice of the crop suitable for that soil. Soluble salt content in saturation extract is more reliable index of salinity level than in soil: water ratio of 1: 2 or 1: 2.5 because it simulates the extent of salinity experienced by crop in field moisture condition.

Salinity class of soil is based on the electrical conductivity (EC) of saturation extract at 25ºC. However, EC of water extract from 1:2 soil-water suspension can be transformed into the EC of saturation extract following the formula (except for soil containing gypsum).

10.1. Determination of Soil pH

The soil pH value is the measure of hydrogen or hydroxyl ion activity in the soil solution and it indicates whether the soil is acidic, neutral or alkaline in reaction. The pH is the most important property of soil as it controls the availability of plant nutrients, microbial activity and physical condition of soil. Since crop growth is affected both under very low (strongly acidic) and very high (strongly alkaline) soil pH, reclamation of these soils are necessary. Soil pH in fact indicates the extent of active acidity (activity of hydrogen ion in soil solution) of soil. Depending upon the purpose of measurement and soil condition, soil pH is measured in several soil-water or soil-salt solution ratios. The saturated paste is used for identifying specific soil problems like degree of acidity or alkalinity. For making fertilizer recommendation, 1: 2 soil-water suspension is generally adopted. To mask the variability in salt content of the soil, the pH is measured in soil-CaCl₂ suspension (1:2 soil-0.1 M CaCl₂ solution). The soil pH value is independent of dilution over a wide range of soil-salt solution ratio, thus more reproducible than those obtained with soil-water suspension.

9.1. Balance and Weighing

9.1.1. Principle of Functioning of a Balance

It is one of the important tools used in the laboratory and one should have thorough knowledge about its assembly, use and care, otherwise it may be the initial step for introducing error in any physical or chemical analysis. Every balance has its maximum load limit and sensitivity depending upon its construction.

Essentially balance may be regarded as a rigid beam, BC having a central fulcrum, O and two arms of equal length, d₁, d₂ (Fig.9.1). The both ends of beam have prism edges upon which the balance pans are suspended by means of suitable suspension.

8.1. Law of Mass Action

Gulberg and Waage, the two Norwegian chemists in the year 1864 stated the law of mass action in this form: ‘The velocity of any chemical reaction at any instant at a given temperature is proportional to the active mass of each of the reactants at that instant present in the system, the active mass in a homogeneous system is defined as the number of gram molecule of the substance present per unit volume i.e., the molar volume’.

Mathematical Formulation of the Law of Mass Action

Let us take a simple case of a reversible reaction at constant temperature represented by the equation:

Soil consistency is a term used to designate the manifestation of different physical forces acting within the soil at various moisture levels. The consistency limits, also known as ‘Atterberg Limits’ (Atterberg, 1911; 12) are defined by the water content of the soil to create specified degree of consistency. These limits are – (i) Liquid limit or upper plastic limit, (ii) Plastic limit or lower plastic limit and (iii) Sticky limit.

7.1. Determination of Liquid Limit or Upper Plastic Limit

Equipments and Materials

Liquid limit device (Casagrande, 1932) and accessories, spatula, dish, oven, moisture box, balance, desiccator

6.1. Determination of Hydraulic Conductivity of Saturated Soil: Laboratory Methods

Hydraulic conductivity of a saturated soil indicates the ease with which water is transmitted through the soil pores. If a constant water head (h) is maintained on a saturated soil column of length (L) and the volume of water (V) percolating per unit time (t) through per unit cross sectional area (A) to the other end, then according to Darcy’s Law the rate of flow of liquid or flux (q) is proportional to the hydraulic gradient (ΔH/L) across the length of soil column.

5.1. Determination of Soil Moisture

5.1.1. Determination of Soil Moisture Content by Gravimetric Method (Direct method)

Traditionally water content in soil is expressed as the ratio of the weight of water present in the soil to the weight of dry soil. When this ratio is multiplied by 100, it becomes the percentage of water in the soil sample on dry weight basis.

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.

3.1. Determination of Bulk Density of Soil

3.1.1. Determination of Bulk Density of an Undisturbed Soil

Bulk density of soil is expressed as the ratio of the mass (weight) of soil particle to their total volume including the pore space between the soil particles. Alternately, it is the weight of unit volume of dry soil. It is usually expressed in the unit of gram per cubic centimeter (g/cc) or mega gram per cubic meter (Mg/m³). In fine textured soil bulk density varies from 1.00 to 1.60 g/cc, whereas in coarse textured soil from 1.20 to 1.80 g/cc.

2.1. Particle Size Distribution Analysis

Soil is composed of particles of varying size and shape. The expression of the proportion of the different size particles is termed as ‘soil texture’. It is one of the most important basic characters being little changed by cultivation or other practices. Particles are arbitrarily distinguished into following groups on the basis of their diameters.

Soil is a mass of large variability and thus its sampling is the most challenging problem for any soil analyst. Practically, soil sampling is a two step process which includes (i) collection of soil from homogeneous unit and (ii) processing which in turn includes drying, grinding, sieving, mixing, partitioning and storing.

1.1. Sources of Error in Soil Chemical Analysis

Different sources of error involved starting from soil sampling to chemical analysis of a sample can be divided into three main groups:

1. Sampling error : This error results from variability among the different samples drawn from same soil unit with respect to the objective of sampling.
2. Sub-sampling error : This error is due to variability introduced among sub samples of the same soil sample.
3. Analytical error : This error introduced due to variability from one chemical determination to another on same sub sample.

Abstract

The landslides of the hill ecosystems are either due to the natural morphotectonic and morphodynamics processes of the planet earth or due to the anthropogenic effects or due to the combinations of the both. In the Indian subcontinent, the landslides are reported from three major provinces viz: Himalayas, Westernghats and The Nilgiris. While the landslides of the Himalayas are demonstrated to be predominantly due to active tectonics, the landslides of the Westernghats are attributed to excessive weathering and rock fall. On the contrary the landslides of the Nilgiris have been thought to be due to extensive deforestation and the related increase in the pore pressure during rainy seasons. But the studies carried out in the recent years show that not only in the Nilgiris but also in other hill systems of Tamil Nadu, the landslides seem to be related to the recent earth movements. This is very significant in the context of fastly recurring seismicities in South India and hence this aspect warrants detailed studies for landslide mitigation.

Abstract

The analysis of IRS - 1A satellite imagery has indicated the existence of two NE - SW trending sub parallel faults along which the coast is undergoing land subsidence as revealed by the concavity in the shore line, preferential migration of the river systems and the drainage congestion, absence of beach ridges, occurrence of off shore shoal etc. The study has further indicated chains of tectonically induced environmental problems such as ground water logging, coastal zone flooding, storm surges, harbour sedimentation etc.

INTRODUCTION

Coastal zones are always dynamic and active, because of the multivariate morpho tectonic and morpho dynamic processes, viz: tectonic, fluvial, marine and aeolian which act in varying degrees and duration along the coasts. As these geomorphic / morpho dynamic processes act in varying permutations and combinations in different segments of the coasts, the land - ocean interactive phenomenon vary greatly in time and space, which in turn frequently and dynamically alter the coastal environment, and cause fragility to the coastal ecosystems. Further, as the coastal zones act as the junction between the Continents and the oceans, even mild earth movements exhibit exemplified expressions in land - water distribution pattern along the coasts. The green house effect and the much apprehended sea level rise and the disasters like cyclones also contribute in their own way in accelerating such land - water distribution / land - ocean interactive phenomenon.

OBSERVATION

The examination of the IRS - 1A imagery under raw and the digitally enhanced modes vividly display heavy concentration of suspended sediments in certain sectors along the east coast of Tamil Nadu. Such pockets of suspended sediments are seen as long and linear bodies trending parallel to the coast to the strike length of 20 - 30 km and width of 5 - 10 km. Such Phenomenon of suspended sediments concentration are strikingly observed in two sectors. One in between Tuticorin harbour and Vaippar river mouth and the other just at the mouth of Ponnaiyar river along Cuddalore-Pondicherry coast. Both of them are observed along conspicuous (Fig.1& 2) concave coasts.

The resources on the land have started showing sign of faster depletion owing to the population explosion, over exploitation of mineral and water resources and also the improper exploitation and the related wasting of the natural resources. Hence a time has come to search for more and more newer natural resources amongst which the ocean resources gain supreme importance as this treasure is yet to be hunted due to the non - availability of suitable technology for the same.

Such ocean resources mainly include the mineralogical and biological resources. The ocean biological resources, their birth, growth, population and migration greatly depend as chlorophyll content, total dissolved oxygen, total suspended solids, salinity etc. These parameters which constitute the marine environment drastically change in a quick span of time owing to the dynamically changing marine forces.

Abstract

The present study has revealed that the NE-SW and WNW-ESE trending sinistral faults are very active along the Tamil Nadu coast and the same have caused considerable slope modifications along the Coleroon and Karungalar rivers which are well-manifested in the land, water and mudflat distribution pattern. Similarly, the progradation of the land in Vedaranniam nose is due to the rise of Pattukottai-Mannargudi area and the time transgressive modifications of the Vedaranniam backwater indicates the opening up of the N-S trending Pleistocene-Holocene faults.

Abstract

The art of remote sensing has opened up many vistas in the study of river migration as satellite photographs, both in their normal and digitally enhanced modes, vividly show the rivers and their migratory signatures. The rivers migrate for various reasons amongst which tectonic movement is one of the main causes. In the present study an attempt has been made to exhibit the palaeochannel network of the rivers of Western India and integrate them with lineament fabric, so as to understand the Quaternary tectonics of the region. The study has shown that Western India shows considerable signs of Quaternary tectonics.

The great Indian epic ‘Ramayana’ says that ‘Lord Rama’ has tried to cross over the Bay of Bengal so as to reach Sri Lanka from India from three points along the southeastern fringe of the Indian coast. Firstly, he is said to have tried to cross from Vedaranniyam which is mythologically called as ‘Kodiyakkarai’ Secondly from Manamelkudi and finally crossed over to Sri Lanka from Rameswaram Island (Fig.1), as the former two coastal locations were widely separated from Sri Lanka by Bay of Bengal and the Rameswaram Island was nearer to Sri Lanka during that period. But, the recently acquired satellite data shows the huge accretion of sediments and rapid land building activity off Vedaranniyam coast (Fig. 2 and 3). The geomorphic interpretations carried out using IRS 1A imagery and 14^C archaeological dating of such geomorphic features have shown that such ongoing sediment accretion phenomena off vedaranniyam nose might in future connect the Vedaranniyam part of Indian Peninsula with Jaffna Peninsula of Sri Lanka if the sediment accumulation continues unabated. The sediment accretion in this area, therefore, requires detailed studies particularly in the context of the coastal ecosystem (Fig. 1).

Abstract

The Remote Sensing and the followed up field based investigations show that the Tamil Nadu coast, India, is facing series of geoenvironmental problems due to tectonic movements and morphodynamic processes. Such problems pose a challenge to the engineering geologists. The paper discusses such challenging engineering geological problems and plausible remedial measures.

Abstract

The tectonic and the geomorphic features observed along the west coast of the area between Mangalore and Cape Comorin show that the NNW-SSE trending west coast has been carved out by the Western Ghats orogeny and the related NNW-SSE trending release fractures. The sinuosity of the otherwise straight coast line is due to Quaternary cymatogenic arching caused by the thrust related to the northerly movement of the Indian plate. The coast line has further attained peaks, projections and serrations due to the ENE-WSW trending series of Precambrian extension fractures which were reactivated gaining the northeasterly directed forces from the rising Carlsberg ridge. Overall, the west coast is being tectonically evolved even today due to the rise of Carlsberg ridge and the Indian plate movement.

Abstract

There is a consensus amongst the geoscientists that overall there has been progradation along the east and west coasts of peninsular India. However, the present day configuration of the coasts and some of the geomorphologic features such as absence of spit and delta along west coast and absence of major estuaries and petroliferous structures along east coast still remain controversial. The present study, based on the appreciation of certain geomorphological and tectonic features on Landsat imagery and aerial photographs of southern part of Indian Peninsula, suggests that the evolution of the coastline has been mainly controlled by tectonism.

The tapering nature of the coastline is attributed to the Precambrian orographic axis. The serrated nature of the post Precambrian coast line is due to the Precambrian transverse faults, whereas the serrated margin of the post Gondwana, Post cretaceous and post Tertiary coast lines are attributed once again to the Precambrian faults reactivated time and again. During the Quaternary period the coast line has undergone many modifications. The coast line attained sinuosity due to Pleistocene folding which is well manifested by river migration. The coast line was subsequently faulted and shifted with en echelon pattern due to N-S regional compression which is referable to the collision of Indian Plate with Tibetan plate.

Remote sensing has proved its credibility beyond doubt in natural resources survey and environmental monitoring owing to its synoptivity, multispectral photographic capability and repetitive coverage. While its synoptivity gives unbiased information on the regional panorama of the earth surface, its multispectral possibility aids precise interpretation of various objects, as different terrestrial objects exhibit various spectral responses in different bands of the electromagnetic spectrum. Amongst various terrestrial objects, water has a characteristic spectral response of its own, i.e. it permits the blue / red part of EMR (electromagnetic radiation, 0.4-0.8 µm) to penetrate inside. On the contrary, it totally absorbs the infrared part of EMR (0.8-1.5 µm). As such blue/red part of EMR penetrates the water bodies, the impurities and suspended sediments are seen very clearly in various shades of gray as and when the water bodies are shallow. Many workers, therefore, have used blue / red band of the satellite data in such water-quality studies^l-3. Hardy⁴ has observed that the infrared light in the spectral regions of 0.6-1.4 µm has the potential to map the turbidity in the ocean water, whereas Kritakos et al ⁵ have used the rationed data of visible and near infrared bands (0.4-1.1 µm) and obtained better results for water quality monitoring. Keeping such facts in mind, the blue/red band (band 2) of the IRS 1A satellite data was used to configurate the bathymetry along Madras coast in Bay of Bengal (Figure 1 a).

In the present study, the IRS lA band 2 data (0.52-0.59 µm) of March 1991 was used and subjected to edge enhancement studies for the coastal zone of Madras (Figure 1 a). Such edge enhancement normally sharpens the edges of two contrasting objects or sharpens the edges of objects of contrasting relief. In such edge enhanced data, few