eChapters

Abstract

Field experiments were conducted on integrated nutrient management in clitoria at Central Arid Zone Research Institute, Regional Research Station, Kukma-Bhuj, during 2009 and 2010 with four levels of nitrogen (0, 30, 60 and 90 kg ha^–1) and phosphorus (0, 40, 80 and 120 kg ha^–1). In another field experiment, response of clitoria to bio-fertilisers (rhizobium, phosphorus solubilising microbes (PSM) and plant growth promoting rhizobacteria (PGPR) was assessed. Other experiments on standardising micronutrient application, seed rate, spacing and intercropping with grasses were also conducted.

Abstract

Brinjal being native vegetable crop of India possesses rich variability. It is one of the important crops for arid region with limited irrigation water. The large variability in genetic resources available in this crop, provide scope for development of varieties with desirable characteristics such as earliness, high fruit quality and yield, tolerance to high temperature and fruit and shoot borer (FSB).

Abstract

A study was conducted to evaluate the nature and magnitude of genetic divergence and also to identify divergent parents in one hundred eight sorghum germplasm collected from different agro eco-geographical areas in India. Mahalanobis D² statistics revealed considerable genetic diversity among the 108 genotypes of sorghum. The genotypes grouped into 11 clusters.

Abstract

Desert or arid regions present a unique environment for microbial growth. Thar Desert of India harbours a plethora of nitrogen fixing bacteria ranging from symbiotic nitrogen fixers, free living nitrogen fixers, associative nitrogen fixers and blue green algae or cyanobacteria. But the knowledge and extent of diversity is still limited to explore their full potential. On top of that, the documentation of the available knowledge is also scattered. Nitrogen-fixing bacteria are crucial for the protection of the nitrogen supply for vegetation in the arid region. Since deserts are poor in soil nitrogen, biological nitrogen fixation plays a crucial role in maintaining soil fertility. In this article, an attempt has been made to cover the nature and extent of diversity in nitrogen fixing bacteria in Indian arid zone.

Abstract

A pot experiment was conducted to evaluate the genotypic variability with respect to agronomic and physiological traits of Bambara groundnut (Vigna subterranea L. Verdc.) landraces collected from three contrasting environments during 2010-11 in a randomized complete block design with nine replications under transparent shade house at the University of Nottingham Malaysia Campus in Semenyih, Selangor.

Abstract

Cultivated cucurbitaceous plants viz., pumpkin, Cucurbita moschata Duch ex Poir.; karingada, Citrullus lanatus (Thunb.); ridge gourd, Luffa acutangula Roxb.; sponge gourd, Luffa cylindrica Roemer and cucumber, Cucumis sativus (L.) and wild cucurbitaceous plants viz., little gourd, Coccinia grandis (L.); kan kareli, Momordica charantia (L.); Gothamada, Cucumis callosus (Rott.) Cogr.; tutar vela, Luffa acutangula (L.); tumada, Citrullus colocynthis (L.); kankoda, Momordica dioica Roxb. and ankhfooti, Trichosanthes bracteata (Lam.) were recorded as hosts of fruit flies in Banaskantha district of north Gujarat. Melon fly, Bactrocera cucurbitae and Ethiopian fruit fly, Dacus ciliatus were the major fruit fly species infesting these cucurbitaceous plant. The relative abundance of both the species were almost the same in cultivated hosts whereas, D. ciliatus was more abundant in wild hosts.

Abstract

Most of the sorghum accessions are landraces, and much of the cultivated area of sorghum is under local land races. The local land races are highly adapted to specific environmental conditions and are useful sources of genetic variation. Under the present investigation one hundred and two local land races of sorghum collected from different geographical origins were evaluated during kharif 2010 and kharif 2011 in order to assess the genetic diversity. The analysis of variances showed highly significant differences among the accessions for all the characters studied.

Abstract

Ongoing rise in human population and affluence, and socioeconomic imperatives continue to demand more efficient and productive use of global finite resources. This is particularly true with water which society has to share between its domestic, industrial, agricultural, environmental and recreational purposes. With greater concern for nature and environment, and the socioeconomic development more water must be allocated to non-agricultural uses. Increasing crop water productivity (WP) is a key response option conserves water, energy and soil while satisfying society’s increasing demand for crops for agricultural products. Improvements to crop WP help to meet rising demands for food from a growing, wealthier, and increasingly urbanized population, when at the same time there are pressures to reallocate water from agriculture to cities and to make more water available for environmental uses contribute to the urgency for achieving gains in agricultural water management. The papers in addition to the rationale and basic concept of crop WP, explore the techniques for crop WP increases.

Abstract

Recycling of organic wastes by chemical amendments and bio-inoculants are the recent developments in the technology for composting to manage voluminous wastes with economic advantages as well as environmental and social perspectives. Various composting technologies such as vermicomposting, P-enriched vermicompost, phospho-sulpho-nitro compost, phosphocompost and microbial enriched compost have been developed utilizing agro-industrial wastes, municipal solid wastes, distillery effluents and press mud, amended with certain mining waste materials such as rock phosphate and pyrites for increasing the nutrient supplying potential of the compost. It was observed that matured enriched compost (after 110 days of composting) contains 3.2 to 4.2% P and 1.5 to 2.3% N. In vermicomposting, earth worms helps in accelerating the decomposition processes and bringing down the composting period from six to eight months to around 2-3 months. Thus, enriched compost helps to produce higher yields of crops and also improve soil physical, chemical and biological conditions, thereby, enhancing productivity and sustainability of agriculture.

Abstract

The present study was conducted in Jhunjhunun district of Indian Thar desert to evaluate the soil fertility status and impact of different land uses on soil physico-chemical properties. Surface soil samples (0-30 cm depth) from rainfed crop lands, irrigated croplands, Orans (traditional grazing lands) and sand dunes were collected and analyzed for fertility. The pH and EC values of the soils ranged from 7.2- 9.7 and 0.02 – 2.5 dSm,^-1 respectively. The soil organic carbon (SOC) content in the soils varied from 0.03-0.62%, with the lowest average content (0.07%) in sand dunes, whereas average SOC under rainfed crop lands and Orans was 0.13 and 0.15%, respectively. Soils under irrigated crop lands recorded highest values for SOC (0.22%). Phosphorus deficiency was spread in the district across the land uses. However, soils under irrigated crop land showed phosphorus buildup due to carry over effect of continuous use of P fertilizers over a period of time.

Abstract

Soils of various depth ranges were identified at the experimental farm of Central Arid Zone Research Institute, Regional Research Station, Kukma-Bhuj, Gujarat. Different depth range of soils included in this study were shallow soil (effective soil depth <15 cm), moderately deep soil (effective soil depth15- 25 cm), deep (effective soil depth 25-70 cm), and very deep (effective soil depth 70 to >1m). The soils are developed from calcareous and ferruginous sand stone and mud stone. A field experiment was carried out to study the performance of different crops and grasses under variable soil depths. Crops namely, clusterbean (Maruguar), greengram (K 851), sesame (GT2), groundnut (GG2) and pearl millet (Pusa 23) and grasses C .ciliaris (CAZRI-75) and L. sindicus (CAZRI 30-5) were grown in these four different soil depths.

Abstract

Water scarcity and soil erosion are the two most severe problems in arid region of Gujarat, particularly in Kachchh district being entirely under hot arid climate. Present study examines need of soil and water conservation measures in Kachchh district utilizing topographical details and 34-year (1980-2013) annual rainfall data for ten rainfall gauging stations. The impact of three factors, i.e. rainfall, topography and drainage pattern, on the water scarcity and soil erosion was studied. The rainfall characteristics in the study area were explored by computing basic statistical properties, plotting rainfall bar charts and drawing box-whisker plots. Furthermore, topographic features are examined by using Google Earth image and available topographical details. Drainage characteristics and pattern are explained and usefulness of farm pond for water conservation is demonstrated.

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.

1. Introduction

Cold-Arid areas are unique eco-systems lying in the north-western Himalaya. The Himalayan mountain ranges can broadly be grouped in two categories 1) the Himalayan ranges extending to the south of the main range including the greater Himalaya and 2) the trans-Himalayan ranges to the north of it. The cold-arid areas are situated in the Trans-Himalayan ranges which comprise of the Zanskar Range, the Ladakh Range and the Karakoram Range. The Ladakh region is situated in the rain shadow of the Himalaya and is dry and arid. To its south lie the Himalayan mountains, in west lies the Kashmir, in east lies the Tibet and the northern boundaries are flanked by the Karakoram ranges.

Large parts of the country perennially reel under recurring drought. Over 68% of India is vulnerable to drought. The ‘chronically drought-prone areas’ – around 33%, receive less than 750 mm of rainfall, while 35%, classified as ‘drought-prone’ receive rainfall of 750-1,125 mm. The drought-prone areas of the country are confined to peninsular and western India – primarily arid, semi-arid and sub-humid regions. Approximately 218.1 thousand square kilometers of land in India under sub-tropical semi-arid and arid conditions are spread over the states of Rajasthan, Gujarat, Haryana and Madhya Pradesh (Anonymous, 1974). Agriculture is predominantly rainfed and the region is drought-prone. Less than 23% of land is irrigated. Forest cover is <5% and waste and fallow areas occupy 42% of the land.

The arid regions of India, spread over 3,17,090 sq. km account for 12% area of the country. The western Rajasthan carries the onus of nearly 62% of arid area. Dryland farming is the main occupation of the people in Indian arid zone. More than 70% of the population in the region is engaged in dryland farming on more than 90% of cultivable lands. The average farm family in Indian arid zone consists of 6-8 members possessing 4-6 hectares of land. The over-exploited fragile natural resources are predominantly under mixed farming - pastoral as well as arable. Farming is almost entirely rainfed in this zone with low and unstable yields.

The green revolution enhanced the food grain production by increasing  productivity of the arable crops as the only means of expanding output. The impact of this ‘revolution’ was first realized especially in the north Indian states of Punjab, Haryana, and western Uttar Pradesh. Since the new technology was based on use of seeds of high yielding varieties, increased use of irrigation and chemical fertilizers, pesticides and farm mechanization; the incremental gains in productivity of late began to end and food production started stagnating, and in many places it even acquired a decreasing trend. It is well accepted fact that ‘success always has its costs and green revolution has been no exception’. Critics of green revolution point to the environmental and health hazards due to increased use of agro-chemicals and the vulnerabilities that is there due to the spread of monocultures in which indigenous land races have been ignored and least emphasis was given on cropping systems based on crop diversification.

Climate change impacts on agriculture are being witnessed all over the world, but countries like India are more vulnerable in view of the high population that depends on agriculture and excessive pressure on natural resources. The warming trend in India over the past 100 years (1901 to 2007) was observed to be 0.51°C with accelerated warming of 0.21oC per every 10 years since 1970 (Kumar, 2009). The projected impacts are likely to further aggravate the yield fluctuations of many crops with impact on food security and prices. Climate change impacts are likely to vary in different parts of the country. Parts of western Rajasthan, Southern Gujarat, Madhya Pradesh, Maharashtra, Northern Karnataka, Northern Andhra Pradesh and Southern Bihar are likely to be more vulnerable in terms of extreme events (Mall et al., 2006).

The global economy has adversely been affected to a considerable extent due to weather related disasters which are not uncommon in the recent past due to global warming and climate change. It is true in the case of the Indian economy too. The year 2010 was the warmest year ever recorded, followed by 2009 in India. The year 2015 was the warmest year globally. Model simulations indicate that a marked increase in rainfall and temperature over India would be seen during the current century. The maximum expected increase in rainfall is likely to be 10–30% over the Central India. Temperatures are likely to increase between 2 and 3^oC by the end of 2100 A.D. Greater number of high surges and increased occurrence of cyclones in post monsoon period along with increased maximum wind speed are also expected along the East Coast of the Country. As a result, the occurrence of floods and droughts, cold and heat waves adversely affected the foodgrains production to a large extent across the Country in one or other region as seen in 2014, 2012, 2009, 2004, 2002 and 1987. It is true in the case of plantation crops also, which are predominantly grown in the Humid Tropics like Kerala (8°15` N and 12°50`N latitudes and between 74°50`E and 77°30`E longitudes). As seen in previous chapters, summer drought and heavy rains including waterlogging during monsoon period is a threat to plantation crops production in the Humid Tropics to a considerable extent. Waterlogging and floods due to excess rains could be minimised by providing surface and subsurface drainage facilities in plantation gardens which will improve the soil health and nutritional status, in turn yields can be increased in plantation crops.

Coffee is grown at higher elevation across the Western Ghats between 750 and 1200 m amsl. It requires a certain degree of shade for its better performance. The annual rainfall over the coffee growing tracts varies between 1400 and 2600mm, having uni/bi-model rainfall with prolonged dryspell from November to May. It is more so over North of the Western Ghats. The mean annual maximum temperature varies between 24 and 30⁰C while the minimum between 15 and 18⁰C. The difference between maximum and minimum temperatures (temperature range) varies between 5 and 16⁰C across the coffee tract. The ‘Monsooned Malabar Coffee’ is a specialty coffee produced from the erstwhile ‘Malabar Region’. It undergoes certain changes in physical and biochemical characters when the coffee beans are processed during the summer monsoon (June to September). It is processed at Mangalore, located in Coastal Karnataka. The processing location experiences heavy rainfall of more than 1000 mm in July, followed by 950 mm in June and 600 mm in August. Out of 3264 mm of annual rainfall, 2852 mm is received during the monsoon period. It accounts more than 80 per cent of annual rainfall. The maximum temperature during the monsooning varies between 28 and 30°C while night temperature revolves between 22 and 24°C. Being located in the tropics along the West Coast, the crop processing environment in terms of surface air temperature is relatively uniform and moderate with a characteristic feature of heavy clouds and continuous rainfall during the monsoon period.

The State of Kerala under the Humid Tropics is one of the wettest places in the Humid Tropics where annual rainfall is of the order of 3000 mm, ranging from less than 1000 mm to greater than 5000 mm. About 68 per cent of the rainfall is obtained during southwest monsoon while 16 per cent in post monsoon and the rest from summer (14 per cent) and winter rainfall (2 per cent). Bi-model rainfall pattern is noticed towards southern districts due to influence of both southwest and northeast monsoons while uni-model rainfall pattern towards northern districts of Kerala. Coconut productivity is better towards south despite dreaded disease of root-wilt when compared to that of northern districts due to less dryspells during summer. Floods during monsoon adversely affect paddy production in the State while prolonged droughts during summer in the absence of post monsoon rainfall adversely affect plantation crops’ production to a considerable extent. The wetlands in Kerala are rich sources of water during summer and act as sink during monsoon season. Such wetlands are fast declining in Kerala and converted as garden lands. Decreasing wetlands might be one of the reasons for frequent floods and droughts in Kerala in recent years. The forest cover of Kerala also declined from 70 per cent to 24 per cent over a period of one- hundred- and - fifty years due to deforestation and forest fires.

Tea (Camellia sinensis) is one of the most important beverage crops in the World and the second most commonly drank liquid on earth after water. It has numerous medicinal benefits mainly due to its antibacterial and antioxidant properties. The major tea growing regions of the world are South-East Asia (India and Sri Lanka), Eastern and South Africa consisting of Kenya, Malawi, Tanzania, Uganda and Mozambique. All these countries are producers of black tea. China and Japan are the major producers of green tea.

Black pepper (Piper nigrum L.), famous as “Black Gold” and also known the “King of Spices” is the most important agricultural commodities of commerce and trade in India. It is the most important, most popular and most widely used spice in the World. Of the total spices traded internationally, black pepper accounts for 34 per cent. South West India is the traditional home of this important spice, particularly the Malabar Coast. Black pepper is also grown in tropical zones such as the Asia Pacific Region, mainly India, Indonesia, Malaysia, Sri Lanka, Thailand, China, Vietnam and Cambodia. Outside the Asia Pacific region, the crop is distributed in Brazil, Mexico, Guatemala, etc., totaling about 26 countries. It is grown successfully between 20°N and 20°S latitude and from mean sea level to 1500 meters above sea level. World’s black pepper production varies in the range of 2.7 to 3.35 tonnes annually.

The natural habitat of rubber (Heavea brasiliensis) is rain forests of the Amazon basin, situated within 5° North and South at altitudes below 200m. The climate of this region is equatorial monsoon type characterized by mean monthly temperature by 25 to 28°C, well distributed rainfall and no marked dry weather. Though it is originated in the Amazon basin, it is now predominantly grown in the tropics where an equatorial monsoon type climate prevails. Regions between 8°N and 10°S which includes Indonesian archipelago, Malaysia, southern part of Sri Lanka and some other Islands, are better suited to rubber cultivation. The production of natural rubber in the country was 8.65 lakh MT in 2008–09, registering a 4.74 per cent growth compared to the previous year.

Small cardamom (Elettaria cardamomum Maton), popularly known as the “Queen of spices”, occupies an important position among the foreign exchange earning commodities. Cardamom is cultivated on a commercial scale in Sri Lanka, Guatemala, Tanzania and Papua New Guinea. Guatemala is the largest producer of cardamom in the World. In India, it is confined to the States of Kerala, Karnataka and Tamil Nadu, accounting for an area of 41588 ha, 25021 ha and 4561 ha, respectively (Spices Board, 2009). Among these States, Kerala accounts for the major portion of production (58.4 %), followed by Karnataka (35.2 %) and Tamil Nadu (6.4 %). In Kerala, Cardamom is mainly grown in the erstwhile Travancore area in the present Idukki district and it is known as the Cardamom Hill Reserve (CHR), which was specially reserved, denotified and removed from the control of forest development by the orders of the Travancore Government. By a Royal Proclamation in Medam 997(ME) 334 square miles (86,506 ha) area in Devikulam, Udumbanchola and Peermedu taluks of the present Idukki District was declared as CHR for the promotion of cardamom cultivation (Miniraj and Nybe, 2007). Cardamom is a native of the moist evergreen rain forests of the Western Ghats of South India and is grown extensively in the hilly regions at elevations of 700 to 1300 metres as an under crop in forest lands. Cardamom thrives well within certain thermal regimes. It is believed that diurnal symmetries in temperature trends, if any, have close links with the changes in cloudiness, humidity, atmospheric circulation pattern, winds and soil moisture (Kumar et al., 2002).

The global production of cocoa is around 36.49 lakh tonnes against the demand of 37.37 lakh tonnes. Ivory Coast leads in cocoa production in the world with a contribution of 38 per cent, followed by Ghana and Indonesia. Unlike in other crops, it appears that the production and demand of cocoa at the global level match each other to a large extent. However, the recent trends in the world production of cocoa beans indicated that there was a drop of nine per cent in 2006–07, declining from 3.8 million tonnes in 2005–06 to 3.4 million tonnes in 2006–07 (Table 9.1). It was attributed to unfavourable conditions in many cocoa producing areas. West Africa, the main cocoa producing region, was hit by a severe harmattan (dusty dry wind from November to March) and its inherent dry weather, which lasted from the end of 2006 to February 2007, had a strong negative impact on global cocoa production. In Asia and South America, El Nino- related weather conditions developed in September 2006 and continued until the beginning of 2007. It led to relatively low cocoa production in 2007–07. However, it was rebounced in 2007– 08 to some extent though it was low (36.49 lakh tonnes) when compared to that of 2005–06. The favourable weather which prevailed over most of the cocoa growing regions during 2002–03 and 2003–04 helped to achieve better production during the above years while dip in the global production in 2006–07 due to unfavourable weather. It reveals that the weather abnormalities like floods, droughts, cold and heat waves across the cocoa growing regions of the world adversely affect the Coca production and the cocoa industry is likely to suffer.

Cashew (Anacardium occidentale L.) is a very important horticultural crop which fetches considerable foreign exchange to India. The crop is a native of Brazil and was introduced in India by the Portuguese during 16^th Century. It is grown in India, Brazil, Vietnam, Tanzania, Mozambique, Indonesia, Sri Lanka and other tropical Asian and African countries. The crop is grown within the latitudinal belt of 27°N and 28°S of the equator experiencing a tropical temperature for its growth and development (Rao and Gopakumar, 1994). The trend in productivity has a phenomenal bearing to the distance from the equator. The world production of cashew is estimated to be around 20.8 lakh tonnes. The global productivity level of cashew is 690 kg/ha. Since 2000, the world raw cashewnut production registered an increase of 40 per cent. India’s share in the world raw cashewnut production accounts to about 25 per cent. In recent times, India is facing tight competition from Vietnam and Indonesia in international cashew trade. Since its introduction in the Country, cashew has well adapted to the Indian climatic conditions and is grown in the East and West Coasts of India. Now, India is the largest producer, processor, consumer and exporter of cashew in the world (Bhat, 2009 a). In India, cashew is grown mainly in Maharashtra, Goa, Karnataka and Kerala along the West Coast and Tamil Nadu, Andhra Pradesh, Orissa and West Bengal along the East Coast.

The Coconut palm, also known as the Cocos Nucifera L., is one of the most fascinating and beautiful palms in the world. Epigraphical, literary and sculptural evidence provide proof that coconut has served humanity for more than three millennia. The palm is looked upon with reverence and affection and is referred to by such eulogistic epithets as “Kalpavriksha”, tree of heaven, the tree of abundance, nature’s super market, king of palms and the tree of life. The coconut is believed to have originated in Southeast Asia (Indonesia, Malaysia, Philippines) or Micronesia (Harries, 1977; Purseglove, 1968 and 1972). Coconut has been cultivated in India since ages and plays an important role in social, economic and cultural activities of the people. The palm is amenable to both plantation and homestead management and it can be either a major crop or a minor one in a homestead garden of mixed crops. While responding favourably to scientific management, the palm also tolerates negligent farming to a certain extent. Thus, it can adapt to the divergent farming situations and management practices that are prevalent in different agro-climatic regions. The coconut palm is usually found near the sea on sandy beaches where it can tolerate salt spray and brackish soils. It is also grown under different soil types such as loamy, laterite, coastal sandy, alluvial, clayey and reclaimed soils of the marshy low lands. The ideal soil conditions for better growth and performance of the palm are proper drainage, good water-holding capacity, and presence of water table within three metres and absence of rock or any hard substratum within two meters of the surface. The coconut palm can also grow well inland, within altitudinal limit of 600 m to 1752 m in the Tropics. It requires an equatorial climate with high humidity. A year-round warm and humid climate favours the growth of coconut. The ideal mean annual temperature, which can be tolerated by coconut palm, is around 27ºC with 5–7ºC diurnal variation. The palm does not withstand prolonged spells of extreme weather/climate variations under rainfed conditions. A well-distributed rainfall of 1300–2300 mm per annum is preferred. It is known as a coastal tree since it is grown along the Coasts and Islands and does not tolerate high temperature range, that is the difference between the maximum and minimum temperatures.

Of the various weather elements affecting crops, temperature and rainfall are perhaps the most important. It is the reason for the development of special flora and fauna in different climatic zones of the world as seen in the tropical, temperate and frigid zones. The tropical regions get abundant solar heat and the vegetation is high while it is low in the temperate regions. The vegetation is very little in the frigid zones. Similarly, natural vegetation is at its poor growth in the Arid Climates and better in the Humid Tropics. Xerophytes are confined to the Arid Climates where low rainfall is seen, while hydrophytes are confined to the Humid Tropics. Mesophytes are intermediate in their water requirement. Most of the crops are included in this group. If the crops are selected for cultivation on the basis of the optimum climatic requirements, it is likely that crop production can be maximised under rainfed as well as irrigated conditions. For example, coconut is grown in vast areas across the East and West Coasts of the Country in different agroclimatic zones and known as a coastal tree. It gives reasonably better yield in terms of quantity and quality in the Humid Tropics under rainfed conditions. However, the coconut yield scenario is totally different when the crop is cultivated in Semi-arid Tropics under irrigation. Therefore, it is a complex phenomenon to understand the influence of weather and climate on crops under rainfed and irrigated conditions in various climatic zones. The production potential of crops under field conditions could be explained through crop-wise agroclimatic zonation, whether the crop is well-suited with minimum inputs for maximising yields under rainfed conditions, but not under irrigated conditions due to crop manipulation. Many attempts were made to explain the climatic boundaries for various crops based on agroclimatic indices under rainfed conditions.

Rice is one of the major staple food of the world’s population. About 114 countries grow rice and more than 50 have an annual production of 100,000 tonnes or more. Asian farmers produce about 90 per cent of the total, with two countries, China and India, growing more than half of the total crop. For most rice producing countries where annual production exceeds one million tonne, rice is the staple food. In Bangaldesh, Cambodia, Indonesia, Lao PDR, Myanmer, Thailand and Vietnam, rice provides 50–80 per cent of the total calories consumed.

Kerala, popularly known as the God’s own country, is situated at the southern tip of India between latitude range 8°15‘ N to 12°50’ N and 74°50’ E to 77°30’ E longitude. The State is graced with 44 rivers and numbers of streams and has rich biodiversity and tropical rain forests spread in 13 agro-ecological zones under humid tropics. Kerala is the Gateway of monsoon in India. Though Kerala is identified as Plantation State, the major staple food is rice. The annual rainfall in Kerala is about 2.7 times the national average. More or less assured amount of rainfall is being received in almost every year over the State, though inter-annual variability is felt more in recent decades. Uncertainties in rainfall are also felt much in the recent decades. Droughts during summer and floods during rainy season are frequent. Natural disasters like landslides/mud slips during rainy season are common across the mid and high lands of Kerala as the intensity of rainfall is high. Atmospheric temperature across the State is increasing. 1983 was a disastrous drought year in Kerala. The severe summer affected the State’s plantation crops economy to a considerable extent. Insignificant rainfall led to the severe summer drought during 1982–83.

Food security is one of the most important issues during this century under the projected climate change scenario. The world is facing severe food crisis due to weather vagaries as a part of global warming and climate change. One sixth of world’s population is under starvation. It is estimated that 300 million people in the world do not get food three times a day. About 18,000 children die every day due to malnutrition. Many Asian-African countries are under severe food crisis. It is also estimated that out of the World’s most hungry people, 29 per cent is in India. 47 per cent of children below three years of age are suffering from malnutrition problem. 75 per cent of world’s population is dependant on agricultural activities for their livelihood. Therefore, there is an urgent need to produce more and more foodgrains at the global as well as national levels to meet the food requirement of growing population under the projected climate change scenario. There has been a major decline in world rice production since late 2007 due to various reasons including global warming and climate change in top rice producing countries. Deficit monsoon over India during 2009 resulted to poor foodgrains production including rice as the area under rice cultivation was less. There were also devastating floods in southern States of India viz., Andhra Pradesh and Karnataka. Andhra Pradesh, one of the major rice producing states of India, was affected first by drought and then by floods. Thus rice production decline in India was a real set back in 2009. Similar was the case in 2010 due to excess rain during monsoon and floods during NE monsoon across the rice growing regions. At the same time, Philippines got hit by two major typhoons in September-October, 2009 causing damage to rice crop on ground. Approximately one million tonnes of rice in storage also got damaged. These events resulted to low world rice production over the country in 2009. The immediate impacts of global warming and climate change on rice production systems and food security will be felt in the form of adverse effects of extreme weather events such as floods, droughts, heat and cold waves, hailstorms and cyclones on rice production. Less immediate but significant impacts are anticipated due to changes in mean temperatures, increasing weather extremes and sea level rising.

India is the seventh largest country in the world with 17 per cent of the world’s population and with a total geographical area of 329 Mha, extending from 8°4’ to 37°6’ in the North and 68°7’ to 97°25’ in the East. It is bounded by the World’s highest mountains- the Himalayas in the North and surrounded by the Arabian Sea, the Indian Ocean and the Bay of Bengal in the South. The Indian Coastline along the southern part of the Country is over 7500 km long. The Country includes vast plains like the Indo-Gangetic Plains, and the Central Deccan Plateau, bordered by the Western Ghats on either side in the West and the South. The biodiversity in the terrain leads to a wide variety of climatic conditions, ranging from tropical to temperate climates across the Western Ghats. These range from permanent snowfields to tropical coastlands; areas of virtual desert in the northwest to fertile intensively cultivated rice fields in the northeast. A large proportion of India’s population continues to live in rural areas and depends heavily on climate-sensitive sectors such as agriculture, fisheries, animal agriculture and forestry for its livelihood. Agriculture is the mainstay of Indian economy. The Indian climate is dominated by the great wind system called the Monsoons, on which the Indian agriculture is dependant. The southwest monsoon is critical to the kharif crop (first crop), which accounts for more than 50% of the foodgrains production and 65% of the oilseeds production in the Country. The inter-annual monsoon rainfall variability in India leads to large-scale droughts and floods, resulting in a major effect on Indian foodgrain production (Parthasarathy and Pant, 1985; Parthasarathy et al., 1992; Selvaraju, 2003; Kumar et al., 2004) and on the economy of the Country (Gadgil et al., 1999a; Kumar and Parikh, 2001). Climatic variability and occurrence of extreme events are major concerns for the Indian subcontinent as they are inbuilt features under the projected climate change scenario. All the projections on climate change are based up on the General Circulation Models (GCMs). All the models project increase in temperature over the Country under different GHG emission scenarios. Rainfall variability is felt in different sub-meteorological divisions across the Country. Though the GCMs have been successful in depicting the gross features of the observed large scale climatological features, there is large uncertainty associated with these projections on regional scale, since the GCMs are yet to realistically reproduce the observed features at regional scale, particularly over the monsoon region (Kumar, et al., 2002). Several downscaling approaches are being used to derive the regional features from large scale model simulations. Under the projected climate change scenario, India will be one of the Countries facing the adverse impacts of climate change as agriculture is the mainstay of people of India. Hence, understanding of rainfall and temperature variability across the Country deserves attention in the projected climate change scenario.

Climate Change has emerged as one of the most serious environmental concerns of recent times. The most imminent climate change is increase in atmospheric temperature due to increased levels of greenhouse gases such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) and hydrochlorofluoro carbons (HCFCs). Because of increasing concentrations of the greenhouse gases in atmosphere, there is much concern about future changes in the climate system viz., Atmosphere, Lithosphere, Biosphere, Hydrosphere and Cryosphere. Direct or indirect effects on the society linked sectors like water, forestry, agriculture, animal agriculture, fisheries, land and marine biodiversity and health due to climate change/variability are many-fold and economic impact of climate change is enormous. The recurrent drought and desertification threaten seriously the livelihood of over 1.2 billion people who depend on land for most of their needs.

9.1 Introduction

Flood water which is in the form of a hydrograph when passes down a river section undergoes several changes in its form. There may be some addition of water to the river section when the flood wave passes down the river section. There may be some diversion of water from the section. Thus, depending on the addition or abstraction of water to the incoming flood water, shape of the flood hydrograph in the downstream section may change. Sometimes channel storage and resistance to flow of water in the channel section also affects the shape of the flood hydrograph.

8.1 Introduction

The knowledge of statistics and probability is very helpful for correct prediction of hydrological data and correct prediction of hydrological data is useful in giving good performance in all water resources projects. Since hydrological data are highly stochastic varying both in space and time, it is essential to predict them as correct as possible. The hydrologic evens do not depend on physical and chemical laws but depend entirely on nature. They cannot be predicted exactly by using any relationship but can be predicted at different probability levels by fitting suitable probability distribution functions. Application of statistics and probability in the field of hydrology can help to predict the hydrologic events in a better way. In hydrology, objectives of statistics are as follows (Suresh, 2008):

7.1 Introduction

Flood is an unusually high stage in a river resulted due to high rainfall or snow melt which causes large flow of runoff in it. During flood, the river overflows the banks and inundates the adjoining areas. Flood causes heavy damages to buildings and hydraulic structures besides causing catastrophic loss to human life and property. It causes great economic loss due to disruption of many structures and damage to agricultural fields. Many forest and aquatic lives are affected by the flood. Hundreds of crores of rupees are spent every year to control, forecast and manage the flood.

6.1 Introduction

When rainfall strikes a ground surface, some losses like initial and infiltration will occur. After these losses are fulfilled, runoff will begin. The runoff will ultimately reach a stream. The main routes through which runoff flows are (i) overland flow, (ii) interflow and (iii) groundwater flow. Overland flow which is also called as surface flow flows over the land mass and reaches a stream. Overland flow soon reaches a stream and if it occurs in sufficient quantity, it forms an important element in the formation of flood peaks. In small and moderate storms, there may have predominant initial and infiltration losses resulting minimum amount of surface runoff and this is especially true in case of permeable soils. If the soil is impermeable, then there may have reasonable runoff. However, surface runoff is an important factor in streamflow only for heavy or high intensity rainfall.

5.1 Introduction

A steam can be defined as a flow channel in to which the surface runoff flowing over the land surfaces and base flow/ground flow flowing below the ground surfaces meet. It receives the total flow from a specified basin. Streamflow representing the runoff phase of the hydrologic cycle is the most important basic data for hydrologic studies. Interestingly, stream flow is the only part of the hydrologic cycle that can be measured accurately. Stream flow is a historical data and like rainfall and runoff, it is a stochastic hydrologic variable. It is also called as discharge or rate of flow. Discharge is defined as the volume of water flowing through a cross section in a unit time.

4.1 Introduction

Precipitation is a major component of hydrological cycle. It occurs because of condensation of water vapour molecules in the atmosphere. When the precipitation falls on the grounds, it undergoes several phases before it appears as runoff in the streams. Certain amount of precipitations is intercepted by the foliage of plants and roofs and other parts of the building and other hydraulic structures. This intercepted water is called as interception loss which is evaporated to the atmosphere. Sometimes the dried surface of the buildings and other structures soak certain amount of precipitation while falling on them which also adds to interception loss. After striking the land masses, certain amount of the precipitated water gets infiltrated into the soil surface which then moves both in lateral as well as in vertical direction. This loss is called as infiltration loss. For the study of groundwater, infiltration loss is not a loss but rather it is a gain in terms of groundwater recharge. However for a surface water hydrologist, it is a loss since it decreases the amount of runoff contributing to the stream or any other water bodies.

3.1 Runoff

Runoff is one of the important parameter of hydrologic cycle. It is defined as that portion of precipitation which is not absorbed by the deep soil strata but finds its way into the stream after meeting the demands of evapotranspiration, interception, infiltration, surface storage, and surface as well as channel detention. It includes surface runoff received into the channels after precipitation occurs, delayed runoff that enters the stream after passing through the land surface, and other delayed runoff from the temporarily detained pits, depressions, swamps or detained as snow fall. It is thus the flow collected from the drainage basin and appearing at the outlet of the basin. The runoff process is demonstrated in Fig. 3.1 as flow chart. Details of the runoff process are discussed as below.

2.1 Introduction

Precipitation is the general term for all forms of moisture emanating from clouds and then ultimately falling on the land surface. It is the total supply of water derived from the atmosphere in the forms of rain, snow, hail, mist, dew, sleet, fog etc. The liquid form of precipitation is called as rainfall whereas the frozen forms of precipitations are snow, hail and sleet. Of all the different forms of precipitation, rain and snow are the two dominant factors that contribute maximum amount of water. In Indian condition, rainfall is the most important form of precipitation that contributes the highest amount of water causing stream flow. Unless otherwise stated, the term rainfall will be used in this book synonymously with precipitation. It is the primary input vector of the hydrologic cycle. Generally it is expressed as the depth water on a horizontal surface over any specified time interval. If the specified time interval is day, then the amount of precipitation is called as daily precipitation. Similarly, the precipitation being contributed over time interval of a month, season and year is termed as monthly, seasonal or annual precipitation. Its form and quantity are influenced by the action of different climatic factors such as wind, temperature and atmospheric pressure. The study of precipitation forms a major portion of the subject of the hydrometeorology.

1.1 Water and its Importance

Water has played a crucial role in sustainace of lives of all living beings including animals, plants and human beings in this earth since time immemorial. It is there since the creation of the nature and will probably remain till the destruction of the nature. It is used in multifarious uses including domestic, industrial, agricultural, recreational and many other uses. It occurs in the nature in practically three forms i.e. solid, liquid and gaseous forms. All the three forms are important to living beings; but the liquid form of water is more beneficial. The weight of the water helps in running hydroelectric turbines, the density of water helps in floating the ships, the steam energy produced by heating the water helps to run the locomotives and thus is beneficial in many ways. It is considered as the most important resource of the society. It has become part and partial in our life so that we cannot live without water. That is why water is called as life.

Tools of Public Awareness

The public awareness and awakening can be created among people through various means and ways. In this age of computers and communication, science and technology, information and advertisements there are several quick and effective means of spreading news. The electronic media, the press, education institution, religious, adult education, moral education, spiritual education, religious discourse etc. all are essentially complementary to each other. The governments and the policy makers can only work forwards environmental preservation on political basis. The media, if work passively on pro environmental issues, awareness can be effectively generated among people.

16.1 What is Sustainable Development?

Sustainable development (SD) is a pattern of resource use that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for generations to come (sometimes taught as ELF-Environment, Local people, Future). The term was first  coined by the Brundtland Commission and defined sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (UN, 1987; Smith and Rees, 1998)

The acts for Environment Protection are :

        The Air (Prevention and Control of Pollution) Act
        The Water (Prevention and Control of Pollution) Act
        The Wildlife Protection Act
        Forest Conservation Act
        Environment Impact Assessment (EIA)
        Citizens Actions and Action Groups
        Public Awareness and Awakening

14.1 What is Education

Education is a systematic attempt towards human learning. All learning is subjective and self related. It is neither literacy nor information. Knowledge can never be learned. Knowledge is the fruit of experience and experience is the sensation of the individual. Individual experience is the internal function and is the function of awareness and understanding. And, one of the processes of knowledge and raising awareness is to be able to identify and clarify our values. Now values in education are essential to help each one of us directly so that we may order our relationships to the environment that lies outside us. Once we are clear about values, we shall be better able to shift and control information of the natural world, make wise choices and decisions, and be creative in our mental processes.

India is home of 16.7 % of the world population living in just 2.4 % of the worlds total land area. The decennial increase in population (1991-2001) has been 18.1 equivalents to the total population of Canada, France and Germany. The population in this century has 1.6 billion by 1960.

12.1 What is Climate Change?
 
The earth receives short-wave radiation from the sun, one-third of which is absorbed by the atmosphere, ocean, ice-land and living organisms. The energy absorbed from solar radiation is balanced, in the long-term, by the outgoing radiation from the earth and atmosphere. While short-wave radiation from the sun can easily pass through the atmosphere, the long-wave radiation emitted by the warm surface of the earth is partially absorbed by trace gases in the atmosphere called greenhouse gases’ (GHGs).

11.1 Global Warming

Definition : Global warming is defined as an increase in the earth’s temperature due to the use of fossil fuels and other industrial processes leading to a build-up of green house gases (CO2, methane, ozone, nitrous oxide, and chlorofluorocarbons) in the atmosphere.

11.2 Who Coined the Term Global Warming?

The principle of global warming was first put fourth by S. Arrhenius in his paper on “the influence of carbonic acid in the air upon the temperature of the ground” in 1869. This concept gained ground in the late 1980s and early 1990s when it was found that the earth’s temperature had warmed over the past century, because of increased carbon dioxide emission.