eChapters

Agriculture is very intensely influenced by weather and climate. While farmers are often compliant in managing weather and annual variability, there is however a high degree of adaptation to the local climate. This may be in the form of conventional infrastructure, native agricultural practices or personal experience. Climate change an in this way be relied upon to affect the agriculture, possibly threatening established characteristics of farming systems and provide chances for improvements. The role of climate change in influencing human activities and the natural environment is all around acknowledged. This may go from an extreme event enduring just a couple of hours (i.e. hurricane, thunderstorm and showers) through to the multi-year dry spells (Maracchi et al., 2005). Increase in concentration of greenhouse gases in the atmosphere further contribute to climate change. This results in a strong impact on human activities and natural environments. Essential areas, for example agriculture and forestry, will be more susceptible than auxiliary and tertiary segments, for example manufacturing and retailing (Parry et al., 1998).

The State of Himachal Pradesh encompasses a geographical area of 55.7 lakh ha and is situated between 31°22’40" and 33°12’40"N latitude and 75°45’55" and 77°10’20"E longitude. The state is bordered by Jammu and Kashmir on the north, Punjab on the west, and Haryana on the south-west (Fig. 19.1). About 12 per cent of the state area is under agriculture which is mostly (80 per cent) rain fed. Wheat, maize, rice, and barley are the principal crops. In state, there are 12 districts, viz., Bilaspur, Chamba, Hamirpur, Kangra, Kinnaur, Kullu, Lahaul & Spiti, Mandi, Shimla, Solan, Sirmaur and Una. About 20 per cent of the area is under forest cover. It is rich in biodiversity of flora and fauna. Nearly 27 per cent of the area of the state is covered under permanent pastures. The state is endowed with a wide range of physiography/landform, climate, vegetation and geology which have influence on genesis of soils. The soils are mostly shallow, medium deep to deep, well/excessively drained, sandy, sandy-skeletal, loamy-skeletal, coarse-loamy and fine-loamy, calcareous as well as non-calcareous with low available water capacity. The State is the biggest montane ecosystem in India situated in northern part of the country. It is seventeenth largest state in terms of area and twentieth in population of which 65 per cent people are dependent on agriculture and 60 per cent of GDP comes from agriculture sector. Increasing temperature and reducing rainfall affecting the crop growth and crop production is a major issue everywhere in the world nowadays and this state has also not remained untouched by these prime issues of climate change. For sustainable development of agriculture in state, there was/is a need to identify and quantify climatic change where agriculture has a significant influence on both the economy and livelihood.

Bihar’s economy is highly dominated by agriculture and allied sectors. Around 85 to 90 percent of the population still lives in rural areas, where agriculture along with animal husbandry, is the main source of their livelihood. In Bihar, the gross and net sown area is estimated at 8.26 and 5.64 million hectares, respectively. Nearly 60 per cent area under cultivation in the state is rainfed (Anon, 2008). The region comes under sub-humid subtropical monsoon climate. Most of the annual rainfall (almost 85 per cent) received from south-west monsoon, occurs during June to September (Sattar, 2010). There are three crop growing seasons in the state commonly known as kharif, rabi and zaid. The important kharif season crops, which are planted in May-June and harvested in September–October, are rice, maize, sesame, sorghum and bajra. Pigeon pea is an important long duration pulse crop sown during kharif season as sole crop or intercropped with maize. The important rabi crops which are sown in October–November and harvested in February–March are wheat, rabi maize, potato, chickpea, lentil, rapeseed, mustard, barley.

Climate change and its variability imposed a great threat to agriculture production and ultimately on food security. Understanding of anomalies in climatic variables is essential to make agriculture sector resilient. Jharkhand state, geographically located at 220 28’ N – 250 30’ N latitude and 830 22’ – 870 40’ E longitude with an altitude up to 1142 m above msl and having humid to sub-humid tropical monsoon type of climate, has a number of agro-climatic/physiographic constraints. The state has 3 agroclimatic sub-zones viz; Central and North Eastern Plateau sub zone (zone IV), Western Plateau sub-zone (zone V) and South Eastern Plateau sub-zone (zone VI) falling under agroecological regions XI, XII and XIII. Zone IV is having 15 districts; Zone V has 6 and Zone VI have 3 districts. Agriculture in Jharkhand is very tedious due to topographical, physiographic and climatic constraints. Vagaries of climate put greatest limitation before the agricultural production system in the State.

The Northeast Region (NER) of India consists of Assam, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, covering an area of 255168 km2. The area is characterized by rich biodiversity, heavy precipitation and high seismicity. Although the contribution from agricultural sector towards gross domestic product has declined, yet it remains the predominant sector for Indian Economy. Over 75% of the people of NE India directly depend on agriculture for their livelihood. Therefore, better performance of agriculture has a direct and multiplier effect across the economy of the region. Because of climate change the rain fed agriculture is facing a greater risk as it is resource poor and having limited flexibility for adaptation. Under changing scenarios there is increase in demand for fresh water and nutrient requirement, increase in soil erosion and nutrient losses affecting soil health, intensification of pest, disease and weed problems, reduction in nutritional quality and low input use efficiency. Continuous mono-cropping and the associated excessive tillage, inadequate erosion control measures and large scale slash and burn cultivation (Jhum) resulted in significant environmental damage and a non-sustainable crop production system in the region.

Eastern India is frequently affected by weather hazards, such as drought, flood and heat wave. The region consists of Orissa, West Bengal, and Bihar. The coastal states of Orissa and West Bengal frequently face cyclones, while Bihar and eastern U.P. face cold wave. Due to unfavorable seasonal weather, crop productivity is poor. However, the recent change in climate induced by global warming has further threatened the agricultural productivity in the region. Rice is the principal crop of Eastern India and rice based cropping systems has long been practiced in the region. While rice-rice is the most dominant cropping system in Orissa and West Bengal, rice-wheat is in Bihar and eastern U.P. Besides, rice-groundnut occupies a considerable area in the region. It is now doubtful whether the resilience of these cropping systems would continue sustaining the productivity under the climate change. The major aim of the proposal was to identify suitable adaptation measures of crop production under projected climate change. Climate change is expected to alter precipitation pattern, increase temperature, change in humidity level and decrease sunshine. As a result it is like to influence right from land preparation to the harvest and post harvest process. Thus the project aim was to revisiting the existing package of practices of selected cropping systems by simulation modelling, deduce suitable adaptation measures and validate these by OTC experiments.

Climate change is a multifaceted alteration of climate which is perceptibly subtle and yet continuous, nevertheless it is extremely important due its consequences on whole biome that thrives under constant or relatively unchanged climates. The effects of climate change have reached such an extent that irreversible changes in the functioning of the planet are feared. Some of the main effects of climate change with specific reference to agriculture and food production especially during the last decade are: increased occurrence of storms and floods; increased incidence and severity of droughts and forest fires; steady spreading out of frost-free intervals and potential growing season; increased frequency of diseases and insect pest attacks; and vanishing habitats of plants and animals. Currently, the world is facing a challenge of producing sufficient food from dwindling natural resource base for the constantly increasing population.

Agricultural production in India is still vulnerable to vagaries of monsoon rainfall in spite of rapid technological advancements like 1) Availability of high yielding varieties 2) Improved crop management practices and increased irrigation availability and effective control of pests and diseases and etc, over last few decades. Majority of Indian farming community which broadly comprising of small and medium farmers are often subject to climate extremes such as droughts, floods, heavy rainfall events, heat and cold waves, frost, hail storms during the crop growing season. The probabilities of occurrence of such climate extremes and associated crop damages and production losses are common in tropical countries like India. Compensation to the resource crunched farmers in the form of crop insurance seems to be the best option for speedy recovery from the losses incurred during the season. It provides security and stability to farm income by protecting the farmers’ investment in crop production and then improves their risk bearing capacities. Crop insurance scheme is based on the fundamental principle of insurance business in which risk is distributed across space and time. For successful implementation of any crop insurance scheme operating presently in the country, proper monitoring of accurate weather parameters at the identified locations throughout the crop life cycle is important.

Increasing evidences over the past few decades indicate that significant changes in climate are occurring across various regions of the globe in the form of increased occurrence of extreme weather events. The significant cause to this sustained increase in climate variability, known as climate change has been a resultant of increased level of greenhouse gases (GHGs) in the atmosphere. The reason for this increase is mainly ascribed to enhanced human activities such as industrialization, uncontrolled burning of fossil fuels, increased use of refrigerants and changed land use patterns and practices. Most significantly, the concentrations of GHGs like CO₂ has already crossed the 400 ppm mark, while other potential contributors like methane and nitrous oxide also show significant rise. As a result of the heat absorbing capacity of these gases, there has been a considerable rise in global mean temperatures, more so in the recent decade and more. The increase in mean air temperatures of the globe was 0.76^ºC during the past 100 years. This rate of increase has been higher during the past two decades and the recent period recorded the warmest years in sequence, the latest being the 2017.

The District-wise weekly agroadvisory service based on medium range weather forecasting (3 to 10 days) has been made operational by the State Agricultural Universities in collaboration with National Centre for Medium Range Weather Forecasting (NCMRWF), India Meteorological Department. The Agroadvisory Bulletin (AAB) contains three parts. The first part of AAB consists of weather events occurred during the past week and weather forecast for three days ahead. These forecasts provide expected weather on cloud amount, rainfall, average wind speed, wind direction, maximum and minimum temperatures and cumulative rainfall. The second part contains the factual information on the varieties of crops, their state and stage, ongoing agricultural operations and occurrence of insect pest and diseases of crops.

Natural disasters are extreme events within the earth’s system (lithosphere, hydrosphere, biosphere or atmosphere) which differs substantially from the mean, resulting in death or injury to humans, and damage or loss of valuable good, such as buildings, communication systems, agricultural land, forest, natural environment. They are a profound impact of the natural environment upon the socio-economic system (Alexander, 1993). This impact may be rapid, as in the case of earthquakes, or slow as in the case of drought. It is important to distinguish between the terms disaster and hazard. A potentially damaging phenomenon (hazard), such as an earthquake by itself is not considered a disaster when it occurs in uninhabited areas. It is called a disaster when it occurs in a populated area, and brings damage, loss or destruction. Natural disasters occur in many parts of the world, although each type of disaster is restricted to certain regions. Natural disasters are events which are caused by purely natural phenomena and bring damage to human societies (such as earthquakes, volcanic eruptions, hurricanes). Mitigation of natural disasters can be successful only when detailed knowledge is obtained about the expected frequency, character, and magnitude of hazardous events in an area. Many types of information that are needed in natural disaster management have an important spatial component.

The United Nations Framework Convention on Climate Change (UNFCCC) defines Climate Change as a change the weather parameters attributed directly or indirectly to human activity, altering the composition of the global atmosphere. Human activity includes the pollution that arises from industrial activity and other sources that produce greenhouse gases. These gases, such as carbon dioxide, have the ability to absorb the spectrum of infrared light and contribute to the warming of our atmosphere. Once produced, these gases can remain trapped in the atmosphere for tens or hundreds of years.

Climate change has become real and tangible affecting people. It is a major challenge for agriculture, food security and rural livelihoods. Climate change impacts on vulnerable groups have social, economic, political, and environmental implications. The impacts of climate change are global. India is more vulnerable in view of the high population depending on agriculture, which in turn is dependent on the seasonal monsoons. India is confronted with the challenge of sustaining rapid economic growth amidst the increasing global threat of climate change. Government of India has accorded top priority for addressing climate change related concerns.

Sorghum (Sorghum bicolour (L.) Moench) is one of the most nutritional and fifth most important cereal crop after maize, wheat, rice and barley as well as a major dietary staple food crop of more than 500 million people in various countries (Ashok Kumar et al., 2011). It is considered as the “King of Millets” that extensively grown in Semi-Arid Tropics (SAT). As a coarse grain, it is used not only for human food, but also for fodder and feed for animals, and building material etc. Its grain is used to make bread, biscuits, sugar, starch, syrups, and alcohol, beer and malt products. It is a good source of energy, protein, vitamin, minerals, and trace elements. Sorghum cultivation in India probably started in the first millennium BC (Dogget, 1988). In India, sorghum is commonly known as jowar and accounts 14% of total world’s sorghum cultivated area and 8% production. India stands first in area of cultivation and second major producer until the end of 20th century. Currently (2012-16). India stands second in cultivated area after Sudan and fourth in production after USA, Nigeria and Mexico. It is the fifth major cereal crop in India after rice, wheat, maize, and pearl millet (bajra), and accounts 6% of total cereal cultivated area and 3% of total cereal production (DES, 2016). Sorghum is cultivated in India majorly during kharif (rainy) season as a rainfed crop and in rabi (post-rainy) season under residual soil moisture/limited-irrigated conditions. Sorghum is gaining importance along the coastal belt of Andhra Pradesh as rice fallows during rabi season in place of maize due to water scarcity in recent years. Maize requires 4 to 6 irrigations while 2 to 3 irrigations in case of sorghum during the crop season for potential yields under field conditions. In this chapter,a glimpse of sorghum growing regions in India, interrelationship between climatic changes and yield of sorghum and adaptation strategies to sustain sorghum productivity in India during future climatic periods are discussed in detail.

Wheat (T. aestivum) is a staple food of the vast majority of the human population in most part of the world; Europe, West Asia, South East Asia, Americas and North Africa. It provides more nourishment than any other food crop and leads all other food crops-rice, maize and potato on a global basis. The wide varieties of food products prepared from it make the crop popular and also a reason for its expansion even to non-traditional wheat cultivated areas. As a leading cereal crop, it is cultivated widely under varied agro-ecological regions and cropping systems throughout the world. It is one of the first plants domesticated and cultivated by humans, which played a critical role in the transition from hunter–gatherer groups to stabilized societies with an agrarian foundation. Wheat is harvested every month of the year somewhere in the world, from as far south as Argentina and as far north as Finland, and it is grown over a substantial area in almost every country of North and South America, Europe, and Asia (Fig. 32.1). Even though, the normal planting period of wheat falls in the same month across different countries, the harvesting period is different (Fig. 32.2).

Introduction

The major environmental issue of global nature is increasing green house effect, which is warming earth. Enhanced green house effect is mainly due to increased emission of carbon dioxide, methane, nitrous oxide and CFCs. Because of the increasing concentrations of these greenhouse gases, there is much concern about future changes in our climate and direct or indirect effect on agriculture (Arora et al. 2011). Increases in atmospheric concentrations of green house gases and additional anthropogenic perturbations of the climate system affect the spatial and temporal distribution of weather regimes which contribute to shaping the diversity of agricultural activities throughout the world (Havlik et al. 2015). Consequences of changing climatic attributes such as rainfall, moisture regimes, temperature etc. affect qualitative and quantitative production of agricultural crops as well as livestock population by altering pasture quality and yield (Thornton et al. 2009). In the context of climate change mitigation, now a days adoption of climate smart agriculture work as an effective practice.

Introduction

Globally, now scholars accepted that the climate is changing and it has implications on human culture, social systems, economic stress and ecological problems (Ford et al. 2010). The IPCC advocates to search and develop local solutions for climate change adaptations (IPCC 1996; IPCC, 2001), however, it does not recognize the breadth and strength of centuries-tested community knowledge/traditional knowledge systems (Salick et al. 2009) which are available with the people of developing world, and has been for adaptation practices and strategies to extreme weather and climate change (Turner and Clifton 2009; Salick and Ross 2009). It is well recognized that with fragile ecosystems, poor economic status and with less robust technologies required to adapt climate change, marginal and poor people of developing countries are likely to be more vulnerable with the changing climate than the industrialized countries (Tompkin and Adger 2004; Agrawal, 2008).

Introduction

Agroforestry is the intentional combination of agriculture and forestry technologies to create integrated, diverse, productive, profitable, and sustainable land-use systems (Rietveld 1995). It creates complex systems with impacts ranging from the site or practice level up to the landscape and beyond (Ellis, 2004). It is one of the most conspicuous land use systems that consists of annual and perennial plants, which are often integrated with livestock. It provides ecosystem services and reduces anthropological impacts on natural forests, arrests soil degradation, enhance soil fertility in many situations and improve farm resilience (Thangataa and Hildebrand 2012; Tewari et al. 2013). Agroforestry is a land management and farming system that are not only capable of fulfilling household needs but also maintaining and improving environmental quality. Itplays a vital role in achieving integrated rural and urban development. The changing climate has potential impacts on ecosystem goods and services by means of increased variability with greater risk of extreme weather events, such as prolonged drought, storms and floods (Lindner et al. 2010). Agroecosystem and forests are the ecosystems which are the most adversely affected by climate change by means of prevalence of pests, diseases, invasive species, species endangerment and high levels of food insecurity.

Introduction

It is well known that, over 50% of requirement of food for the entire humanity is obtained from just three crops- rice, maize and wheat though 150 crops are commercialized globally. Ethnobotanically, over 7000 plants species are cultivated or harvested from the wild which represent immense agro-biodiversity. Most of these species are under exploited but have the potential for contributing to food security, health (nutritional/medicinal), income generation and environmental services. Examples include little millets which provide calcium and iron and vitamins like niacin and sulphur containing amino acids, having more fiber than rice and wheat. Some other species which have in the recent past contributed to income generation in Indian arid zone include ber, anola, karonda and gonda. Likewise the perennial grasses in this area are not only source of nutritious fodder but also the grains e.g. gramana (Panicum antidotale) are consumed during famine. They have acquired importance being alternative sources of income as also alternate life support system during crisis. They often have neutraceutical, medicinal uses or often multiple uses. Demand for traditional food in large multi-ethnic cities and metros have brought these species into sharp focus, Hence, these are being viewed now as potential candidate for diversification in the cropping system, conservation of bio-diversity, enhancing the limits of green revolution even during climate change and finally as provider of molecules for curing various ailments of men and animals.

Introduction

Low and erratic rainfall, extreme temperatures, long sunshine duration, high wind velocity, high evapotranspiration, low fertility of soil and paucity of water resources characterize hot arid region of India. Despite these hostile conditions, the region supports a large number of human and livestock population. However, the ever increasing human and livestock population and developmental activities exerts enormous pressure on natural resources and posing serious threat to sustainability of the region. In these hostile environmental conditions, several indigenous agroforestry systems are being practiced by farmers of this region (Shankarnarayanan et al. 1987). The agroforestry, which is a dynamic, ecologically based natural resource management practices that, through the integration of trees and other tall woody plants on farms and in the agricultural landscape, diversify production for increased social, economic and environmental benefits (ICRAF 2000). A number of studies have recognized the multiple benefits of agroforestry that include carbon sequestration, reducing forest degradation, biomass production, food security, income diversification, improvement and maintenance of soil biodiversity, provision of wildlife corridors, and a host of other ecological services and social benefits. In the last three decades, agroforestry has been widely promoted in the tropics as a natural resource management strategy that attempts to balance the goals of agricultural development with the conservation of soils, water, local and regional climate

Introduction

Agroforestry, the word coined in the early seventies, has made its place in all the developed and the developing countries of the world and is now recognized as an important approach to ensuring food security and rebuilding resilient rural environments (Luedeling et al. 2014).  Agroforestry applies to private agricultural and forest lands and communities that also include highly erodible, flood-prone, economically marginal and environmentally sensitive lands (Continents 1986). The typical situation is agricultural, where trees are added to create desired benefits. Agroforestry allows for the diversification of farm activities and makes better use of environmental resources (Taylor et al. 2007). Agroforestry is defined as a land use system which integrates trees and shrubs on farmlands and rural landscapes to enhance productivity, profitability, diversity and ecosystem sustainability. It is a dynamic, ecologically based, natural resource management system that, through the integration of woody perennials on farms and in the agricultural landscape, diversifies and sustains production and builds social institutions. India has been an all-time leader in agroforestry (Chavan et al. 2015).

Introduction

Agroforestry is the science of designing and developing integrated self-sustainable land management system, which involves introduction or retention of woody components such as trees, shrubs along with agricultural crops including pasture/animals simultaneously or sequentially, on the same unit of land and at the same time, to meet the ecological as well as socio-economic needs of local people. A typical agroforestry system will allow economic and ecological interactions between woody and non-woody components and also increase, sustain and diversify the total land output. Agroforestry systems are very important for the area currently under agriculture, the number of people who depend on land for their livelihoods, and the need for integrating food production with environmental services (Garrity, 2004; Makundi and Sathaye 2004). Agroforestry provides a unique opportunity to combine the twin objectives of climate change adaptation and mitigation. Although agroforestry systems are not primarily designed for carbon sequestration, there are many recent studies that substantiate the evidence that agroforestry systems can play a majorrole in storing carbon in above ground biomass (Sathaye et al. 2001;

Introduction

India is the seventh-largest country in the world, with a total area of 3,287,263 square kilometres, roughly 2.5 percent of global landmass but is home to 17.9 percent of global human population and 1/5 of the livestock. Most of this increase in human population has occurred in second half of 20th century. Similarly, India has the highest number of cattle (210.2 m), buffaloes (111.3 m) and goats (150.4 m) in the world. It ranks second in sheep (74 m), fifth in chickens (866 m) and sixth in ducks (26 m). The increased population and associated increased demand of resources has led to significant impact on land use-land cover and has consequence in negatively impacting various ecosystem services i.e., hydrology, soil conservation, wildlife support, biodiversity and environmental protection, these agroforestry systems used to provide. Agroforestry has traditionally been a way of life and livelihood in India for centuries. Now it is a modern science inviting deliberate management of trees on farms and surrounding landscape (Bargali et al. 2009; 

Introduction

The green revolution in mid-sixties stirred by research based new technological developments involving new materials, models and ways of organizing farm inputs (water, fertilizer, chemical etc) and government’s policies transformed the agriculture dramatically. The outcome chewed a many fold increase in production and productivity viz. food grain production of 211 million tonnes (which was only 74.23 million tonnes in 1966-67) and food grain productivity of 1697 kg ha-1 (which was only 644 kg ha-1 in 1966-67). The country thus became self-sufficient in food production despite tremendous pressure to sustain 16% of world human population and 10% of cattle population with just 2.4% of total land.

Introduction

Tree growing in hot arid region is basically concerned with the management of trees for conservation and for limited production objectives like wood for fuel, poles and fencing material; leaves for livestock fodder; and pod/seeds for many types use in human diet. The role of trees to conserve the fragile ecosystems of hot arid regions has been well recognized (Mann and Muthana 1984). The trees also provided so many services to mankind, which make them an intricate part of man-livestock-agriculture continuum, the lifeline of hot arid regions (Saxena 1997). 

Introduction

The rate of increase in anthropogenic CO₂ concentration of the atmosphere is increasing at an alarming rate from 1.7 µmol mol-1 yr-1 in 2009 (Tans 2009) to 2.2 µmol mol-1 yr-1 in 2013 (WMO 2013). At this rate, its level in the atmosphere will reach around 450 µmol mol-1 by the turn of century from its current concentration of 400 µmol mol-1, leading to increased global warming and concomitant climate change. There is, thus, a very strong scientific interest in finding ways to slow or reverse this trend. Mitigation strategy of diverting CO₂ from atmosphere to soil by adopting appropriate agricultural practices such as conservation agriculture (CA) is a recognized such method (Lal 2008 a, b). Broadly, CA has three major components- reduced tillage, crop residue management, and intensive cropping. Conservation tillage practices which include reduced tillage (RT) and no-tillage (NT) have been amply demonstrated as the agricultural practices that are very helpful in this direction (West and Post 2002; Franzluebbers 2010).

Effect on SOC and N losses through runoff and soil erosion

With increase in population, agriculture is being extended to even marginal soils which were hitherto uncultivated. Such soils are more seriously prone to erosion losses (FAO 2008), mostly because of their topographical position. Overall, soil organic matter and nutrient rich surface soil erosion could become more serious threat in the wake of changing climate in future; therefore, it is necessary to find suitable remedy measures to sustainable food production while protecting the soil from erosion.

Introduction

Arid environs are delineated by extreme and harsh weather conditions due to excessive heat and inadequate, variable precipitation; however, contrasts in climate occur. These climatic disparities are the result of temperature variation, distribution and season of rainfall and the degree of aridity. Moreover, high evapo-transpiration, periodic droughts, low organic matter levels, different associations of vegetative cover and soil enhances the problems of these regions. In general, hot arid climates have excessive heat and strong prevailing winds, unhampered by obstacles on the ground and as result aeolian erosion is common with frequent seasonal drought occurrence (Sharma and Tewari 2005). These climatic limitations make very difficult place for the inhabitants to attain their livelihood. People of these areas have spent their life within these constraints for centuries. They have faced serious challenges due to lack of sufficient resources and very low productivity which has added to the vulnerability of the region. 

Introduction

Agroforestry system (AFS) is a form of sustainable land use that combines trees, shrubs, crops and livestock so as to increase and diversify farm and forest production along with conserving natural resources. Microorganisms play a crucial role in improving nutrient availability to plants, thereby decreasing the dependence on chemical fertilizers and achieve sustainable agriculture through agroforestry (Araujo et al. 2012). Arbuscular mycorrhizal (AM) fungi, plant growth-promoting rhizobacteria (PGPR), and the association of rhizobia with leguminous plants are symbiotic associations of high economic importance for increasing agricultural production. Yadav et al. (2010) studied soil biological properties under different tree based traditional agroforestry systems in a semi-arid region of Rajasthan, India and concluded that biological properties can be optimized in the soil under AFS. Many authors have reported that soil microbial biomass and microbial diversity are greater in the AFS due to the ameliorative effects of trees and organic matter inputs and the differences in litter quality and quantity and root exudates (Mungai et al. 2005; Sørensen and Sessitsch, 2007). Also, the presence of a large and diverse soil microbial community is crucial to the productivity of any agroecosystem. Moreover, more than one plant species in AFS have been reported to have shown a larger diversity and/or abundance of mycorrhizal fungi than monocultures (Cardoso and Kuyper 2006) and more efficiency in biological fixation of the nitrogen, especially in tropical soils (Freitas et al. 2010). Also, soil microbial biomass has other important functions in the soil such as nutrient cycling and the degradation of pollutants (Watanabe and Hamamura 2003; Araújo and Monteiro 2006).

Introduction

Rainfall is the principal source of water in arid areas, which augments soil moisture, groundwater and surface flows. Agriculture and several of the other economic activities in arid areas depend on rain. This region is devoid of any well defined perennial river system. Under such circumstances every drop of water becomes very precious. Of the total water use about 85% of water is used for irrigation and remaining 15% is used for drinking, industrial and other purposes. About 65% of irrigation water and 30-40% of drinking water is subjected to serious losses. Hence, increasing water use efficiency coupled with increasing availability of water through rainwater harvesting and management is of prime importance for sustainable development of arid areas. Rainwater harvesting, its conservation and efficient utilization can solve problem of water scarcity to the greater extend. Rainwater harvesting in small ponds (nadis), underground tanks (tankas), Khadins (Low lying areas) etc. is an age-old tradition in arid zone of Rajasthan. These traditional rainwater harvesting structures vary in design, shape and size. These traditional methods have undergone several changes for being more economical and efficient. Central Arid Zone Research Institute (CAZRI), Jodhpur since its inception in year 1959 is continuously working for development and refinement of water efficient techniques for crop production, individuals and for the communities for development in hot arid zone of India.

Introduction

Arid regions of the world are diverse in terms of climate, soils, vegetation, animals and life style and activities of people. The binding feature of all arid regions in the world is aridity. Of the total area of arid zones of the world, Africa, accounts for 46.1 % followed by Asia (35.5 %). Majority of rest 19.4 % of arid zones are spread over in Australia, North America (Mexico and Southern part of USA), and South America. The Indian arid zone covers around 12 % of country’s geographical area occupying 31.8 million ha of land of which major part is in northwestern India (28.57 Mha) and some in southern India (3.13 Mha). It covers parts of Andhra Pradesh, Gujarat, Haryana, Karnataka, Maharashtra, Punjab and Rajasthan states of India (Table 1 and Fig. 1). The arid regions of Rajasthan, Gujarat, Punjab, and Haryana together constitute Great Indian Desert, better known as Thar. As arid western Rajasthan accounts for 61% of hot arid region of country, therefore it is considered principle hot arid region. Major part of it occurs between Aravalli ranges on the east and southeast and Thal desert of Pakistan (Thal desert is simply the western extension of Thar, only name has been changed) which is spread up to Suleman Kithara ranges in extreme west.

Introduction

Livestock sector plays an important role in the rural economy at national level and this sector is emerging as a driving force in agriculture by contributing towards the income and employment of rural households. Livestock contributed 16% to the income of small farm households that indicates importance of livestock sector as a whole. In 2010-11, livestock generated outputs worth Rs 2075 billion (at 2004-05 prices). Agriculture sector grew at low rate of 4.7% during 2013-14 and contributed 13.9% to National GDP (Economic Survey 2013-14). The livestock sector contributed over 4.1 per cent of the total GDP in 2012-13, that nearly accounts for 29.5% of the agricultural GDP (Economic Survey 2013-14) indicating a significant contribution of the livestock. Sheep and goats are an important livestock species for a large number of rural poor, especially socially backward, marginal and landless labourers in India. Sheep are mostly reared for wool and meat purpose. India ranks third in sheep population and account for nearly 6% of world sheep population, currently India has 65.06 million sheep as per Livestock census 2012.

Introduction

Agriculture has always been vulnerable to fragile environmental conditions of dry areas, where droughts of varying amplitude and frequency influenced by insufficient and uncertain rainfall are common features. Recent anthropogenic activities have accelerated the rate of green house gas (GHGs) accumulation in atmosphere influencing atmospheric temperature and local patterns of temperature and precipitation, which ultimately affect agricultural production and food securities. About 35.5 percent of the total world’s population resides in dry areas, which is facing the problems of land degradation and food securities.

Introduction

Arid lands are among the world’s most fragile ecosystems, made more so by periodic droughts and increasing over exploitation of meagre resources. Arid and semi-arid lands cover around one-third of the world’s land area and are inhabited by about one billion people, a large proportion of whom are among the poorest in the world (Malagnoux et al. 2007). Arid environments are extremely diverse in terms of their land forms, soils, fauna, flora, water, and human activities. Aridity is usually expressed as ratio of mean annual precipitation (P) to the mean annual potential evapotranspiration (EPT) where potential evapotranspiration is calculated by method of Penman, taking into account atmospheric humidity, solar radiation, and wind speed. UNEP (1997) has recognized four main classes of aridity: hyper-arid (P/EPT < 0.03), arid (0.03 < P/EPT < 0.20), semi-arid (0.20 < P/EPT < 0.50), and dry sub-humid (0.50 < P/EPT < 0.65). Of the total land area of the world, the hyper-arid zone covers 4.2 %, the arid zone 14.6 %, and the semi-arid zone 12.2 % (FAO 1989). Therefore, almost one-third of the total area of the world is “arid land”. 

Introduction

India has a long tradition of agroforestry which is widely practiced in all ecological and geographical regions of the country. Traditional agroforestry systems are broadly based on indigenous knowledge and the species are selected as a part of the cultural patterns of the community. The farmers and land owners in different parts of the country integrate a variety of woody perennials in the crop and livestock production systems depending upon the agro-climatic conditions and local requirements.

Introduction

Two types of interactions, i.e. competitive and complementary, are found in ecosystems and agroecosystems (Callaway 1998), which shape community structure, plant diversity and system’s functions (Callaway 1995; Pugnaire et al. 1996; Bruno et al. 2003). Competitive interaction in ecosystems (Wedin and Tilman 1993) and agro-ecosystems (Pandey et al. 1999) is well documented. Mechanism of complementary interaction, however, is not much understood so far. Some studies (Bertness and Callaway 1994; Callaway 1998) argue that complementary interaction is facilitative, either facultative or obligatory, and occur generally in harsh physical environments. This suggests that habitat amelioration by neighbours is a common denominator of positive interactions (Bertness and Callaway 1994; Callaway and Walker 1997). Other studies report that complementary interaction is mutualistic (Boucher et al. 1982). Irrespective of whether facultative or mutualistic, it is now well established that complementary interaction is evolutionary (Bertness and Callaway 1994). But, it is still inconclusive how two species exist together in ecosystems and agroecosystems (Bertness and Callaway 1994).

Introduction

Human civilization used to undergo several form of disasters throughout its life history. Most of such events are unpredictable, sudden and short in duration, and such events can easily classifiable as either natural (e.g. cyclones, earth quake, natural forest fires and tsunami) or manmade such as spread of toxic chemicals (e.g. Bhopal disaster 1984), nuclear explosions, civil war, diseases (Minamata, itaiitai, etc.). However, climate change is a real time prolonged disaster which is caused by both natural (caused by variation in solar irradiance, variations in orbital parameters of earth, volcanic activities, natural forest fire, methane release from thawing of permafrost from ocean floor, natural wetlands and cattle) and anthropogenic means (by greenhouse gases resulted from human activities-all kinds of combustion, industrial production of greenhouse gases and agricultural water lodging activities such as paddy cultivation and artificial wet lands, and deforestation).

Introduction

Throughout the arid zones, there is no dearth of problems, but rapidly increasing desertification (some call it land degradation) is a problem of worldwide dimension. Water is a scare commodity in arid zones. Much of rainfall is lost by evapo-transpiration and as a result, ground water recharged only by seepage through soil profile. However, it is a common phenomenon in arid zones of the world that ground water is frequently used at the rate that exceeds recharge. The situation in arid tropics of India, which is spread over an area of 31.7 million ha, is no more different. Considering the role of agriculture in the social and economic progress of developing countries, the vulnerability of agricultural systems to the impacts of climate change has received considerable attention from the scientific community (Fischer et al. 2002; IISD 2003; Kurukulasuriya and Rosenthal 2003). Much of the available literature suggests that the overall impacts of climate change on agriculture especially in the tropics will be highly negative, although in a few areas there may be minor increases in crop yields in the short term (Maddison et al. 2007). Research on agroforestry as an adaptation to climate change and as a buffer against climate variability is in the process of evolving.

Introduction

Rain fed agroecosystem occupies 68% of India’s cultivated area and supports 40% of the human beings and 65% of the livestock population. It produces 44% of food requirements, thus has and will continue to play a critical role in India’s agriculture (Singh et al. 2004). Besides their well established role in agriculture, livestock have crucial role in food security and as risk aversion mechanism for sustaining family, whenever there is crop failure. Indian hot arid zone which is about 12% of total geographical area of the landmass of 0.32 million km2 has maximum covering in western Rajasthan i.e. 61% of the total area whereas the other areas in arid region are available in the states of Gujarat, Punjab, Haryana, Andhra Pradesh and Karnataka accounting for 20, 5, 4, 7 and 3% of hot arid area whereas the cold arid area of 8.4 million ha lies in the state of Jammu & Kashmir covering the Leh and Ladakh region.

Introduction

A number of researchers have used morphological descriptors such as growth habit, leaf, shoot, flower, fruit morphology to classify and discriminate different varieties/cultivars and or detect inter and intra-specific variations in different tree species of economic importance (Saran et al. 2006; Holland et al. 2009). Such morphological descriptors are quite homogenous and often found insufficient to distinguish varieties within morphological groups. The choice of suitable cultivars is of paramount importance for its success. The lack of breakthrough has been due to under utilization of genetic variability for superior quality and high yield potential. Most of the fruit tree species demonstrates a rich genetic diversity mainly through natural cross pollination due to self incompatibility (Godara 1980). The elite plant types with desirable traits have been released as varieties, mass multiplied and propagated through standard vegetative multiplication. However, the authenticity of cultivar identification remains unclear (Devanshi et al. 2007).

Introduction

The area under salt-affected soils in India is estimated to be 6.73 Mha spread over a number of states across the country. This 6.73 million ha are lying barren or produce very uneconomical yields of crops due to excessive accumulation of salts. These soils are agriculturally unproductive because of the high content of soluble salts which had harmful effects on plant growth due to moisture stress and toxicity/deficiency of some of the ions and the exchangeable sodium ions in clay complex lead to the unfavorable physical conditions of for the plant growth and water movement (Bhumla 1977). Saline and sodic soils have excess concentration of either soluble or exchangeable sodium, calcium and magnesium primarily in the form of chlorides and sulphates. Salt affected areas an expected to increase with spread of waterlogging and salinity due to increase in canal irrigation, and intensive exploitation of poor quality ground waters for agriculture in non canal commands. Certain states like Rajasthan and Haryana located in the western part of the country are endowed with 84 and 62% of poor quality ground waters, respectively. Continuous use of such waters for irrigation to agricultural crops is bound to increase the problem of salinity and sodicity in India (Yadav 1989; Minhas and Bajwa 2001). Introduction of irrigation without making proper provision for drainage is the major cause for the development of salinity in canal commands.It is severe on irrigated lands of the dry zone. It reduces crop yield and in severe cases causes complete abandonment of agriculture (Joshi and Dhir 1989; Joshi et al. 2000; Mahesh Kumar et al. 2016). The present paper deals with extent, causes, characteristics and management options of these soils for sustainability of agriculture in the area.

Introduction

Desertification is affecting the livelihoods of millions of people, mainly poor in the dry lands, which occupy nearly 41% of the Earth’s land area and are the residence of more than 2 billion people of the world. In India, the western part of Rajasthan is mostly affected by desertification process dominated by wind erosion. Kar et al. (2009) reported that 15.2 mha land in western Rajasthan is affected by wind erosion out of total 22.96 mha area under desertification. A brief account on issues and priorities related to wind erosion processes in Thar desert was reported in Santra et al. (2006). Plenty of incident solar energy in the region makes the desert surface very hot especially during summer months. Wind speed also remains very high in the region for most of the time in a year. Therefore, the loss of top fertile soils through wind erosion process is very active in the region. Eroded dust particles during severe wind erosion events commonly known as dust storms not only create the soils poor but also pose several environmental threats through generating aerosols in atmosphere. 

Introduction

The world demand for wood is continuously increasing due to increase in population. The ever increasing population has led to depletion of existing timber reserves and the forestland base has been reduced by increased allocation of forest areas to urban, agricultural, recreational and other uses. The growing awareness towards development of plantations has generated a voluminous increase in the demand for quality planting material. Conventionally, propagation is achieved through sexual (seeds) or vegetative methods (rooting of cutting, grafting, layering, etc). Propagation through seeds is routinely used for production of planting material but it generates immense genetic variability which is not desirable while propagating perennial tree species. In order to propagate selected trees with desirable features vegetative propagation methods like rooting of cuttings, grafting, layering etc have been developed. These methods can produce genetically identical off springs thereby preserving the advantageous traits;

Introduction

Trees play an important role in ecosystem in all terrestrials and provide a range of products and services to rural and urban people (Gogoi 2015). As natural vegetation is cut for agriculture and other types of development, the benefits that trees provide are best sustained by integrating trees into agricultural system - a practice known as agroforestry. Agroforestry focuses on the wide range of trees grown on farms and other rural areas. Among these are fertilizer trees for land regeneration, soil health and food security; fruit trees for nutrition; fodder trees for livestock; timber and energy trees for shelter and fuel wood; medicinal trees to cure diseases and trees for minor products viz. gums, resins or latex products. Many of these trees are multipurpose, providing a range of benefits. Although effective and valuable tools have been introduced to evaluate the risk to construction in areas prone to geo-hydrological hazards, fewer steps have been made in the field of ordinary land use planning at different scales. 

Introduction

There is a growing interest in the role of different types of land use systems in stabilizing the atmospheric CO₂ concentration and reducing the CO₂ emissions or on increasing the carbon sink of forestry and agroforestry systems. Forestry has been recognized as a means to reduce CO₂ emissions as well as enhancing carbon sinks. There is considerable interest to increase the carbon storage capacity of terrestrial vegetation through land-use practices such as afforestation, reforestation, and natural regeneration of forests, silvicultural systems and agroforestry (Brown 1996; Canadell and Raupach 2008). Agroforestry systems are very important given the area currently under agriculture, the number of people who depend on land for their livelihoods, and the need for integrating food production with environmental services (Garrity 2004; Makundi and Sathaye 2004).

Introduction

Agroforestry is a land-use management system where trees or shrubs are grown around or among crops or in pasture lands. It combines agricultural and forestry technologies to create more diverse, productive, profitable, healthy, and sustainable land use systems.
India has been at the forefront of agroforestry research ever since organized research in this area started worldwide about 25 years ago. Considering the country’s unique land use, demographic, political and socio-cultural characteristics as well as its strong contributions to agricultural and forestry research, India’s experience in agroforestry research has proved important to agroforestry development especially in developing countries.

Introduction

The literatures and researcher data showed that there is negative impacts of agricultural expansion, landscape modification and deforestation on biodiversity, ecosystem services, alteringthe species composition and their ecological functions (Tscharntke et al. 2005; Priess et al. 2007; Flynn et al. 2009; Senior et al. 2013; Deguines et al. 2014; Kumar 2016) which can lead to considerable changes in critical ecosystem processes. On the other hand, an increasingly industrialized global economy, rapid population growth, land degradation, land use pattern and role of various human activities have led to dramatically increased the pressure on the natural resources such as the available land for sustaining the livelihoods, and with over exploitation and extraction of the natural resources the ecosystems are becoming unsustainable and fragile since last century (Kumar 2017). Standardization of cultural practices is one of the primary objectives to make the system ecologically, sustainable and economically viable (Gill et al.2009).

Introduction

Forest cover of India has been estimated to be 7,01,673 km2 (70.17 million ha) which is 21.34 per cent of the total geographical area of the country. The tree cover of the country is estimated to be 92,572 km2 which is 2.82 per cent of geographical area. The total forest and tree cover is 7,94,245 km2 which is 24.16 per cent of the total geographical area of the country. Out of this, 9.14per cent forest cover is in the form of open forests and another 1.26 per cent is scrub forests (FSI 2015). According to National Forest Policy 1988, one-third (33.33%) of the land area should be under the forest cover for sound ecological balance. It means that we have to bring another 11.66 % area under forest cover and at the same time improve quality of the degraded forests. However the horizontal expansion of land under tree cover is not possible. In order to increase the tree cover and fulfill the requirements of the people and industries,

Introduction

Homegardens are traditional agricultural systems, particularly common in the tropics characterized by a high plant diversity (Kumar and Nair 2004, 2006; Scales and Marsden 2008; Galluzzi et al. 2010), maintain high level of productivity, stability, sustainability and equitability (Soemarwoto and Conway 1992), serve as a refuge for wildlife (Perfecto and Vandermeer 2008), contributing significantly to the household diet by producing a large variety of food commodities (Kumar and Nair 2004; Wiersum 2006; Pulido et al. 2008; Kortright and Wakefield 2011; Kumar 2017; Kumar and Tripathi 2017), nutritional supplies (Mendez et al. 2001; Perrault and Coomes 2008; Vlkova et al. 2010; Balooni et al. 2014), supplementary cash income for owner (Huai et al. 2011; Arifin et al. 2012; Yang et al. 2014) and important spaces for transmission of cultural heritage (Galluzzi et al. 2010). Many native or endangered species can be found in homegardens (Albuquerque et al. 2005; Akinnifesi et al. 2010; Milow et al. 2013), and they are niches for domesticating semi-wild species (Akinnifesi et al. 2010). Plants grown, intentionally or unintentionally, in homegardens are important for household subsistence and economy.

Introduction

Agriculture expanded and forest dwindled. That eventually occurred with the expansion of civilization. Clearing of forests, granted in past, continued in modern times. Cutting of forests reached to such an alarming level that thinking of people turned back to create more forests. Sometimes over extraction of forest resources made forests unstable to yield perpetually according to necessity in future for which forests are turned unsupportive for livelihood and people tried for innovative means to enhance forest productivity in future (Nair 1993). Also with time agriculture faced the similar unfortunate condition towards intensive cultivation. So, peoples’ thinking turned back in agriculture how to make it stable and more supportive for livelihood year after year. Culturally human societies are connected both with agriculture and as well as forests from the time immemorial.