eChapters

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).

The Fourth Assessment Report of the United Nations Intergovernmental Panel on Climate Change (IPCC), after analysis of more than 6000 peer reviewed publications has assessed potential effects of changing climate on various spheres of life (Solomon et al., 2007). Under different scenarios, the estimated temperature rise of 1.1 to 6.4 °C in the global surface temperature is predicted at the end of 21st century (period 2090-2099 relative to 1980-1999). Global average sea level in the last interglacial period (about 125,000 years ago) was likely 4 to 6 m higher than during the 20th century, mainly due to the melting of ice in the polar regions. It has been detected in changes of surface and atmospheric temperatures in the upper several hundred metres of the ocean, and in contributions to sea level rise (Solomon et al., 2007). The change in climate is concurrent with the changes in global levels of carbondioxide, methane, oxides of nitrogen etc, loss of biodiversity, natural habitat and other natural resources. The IPCC report also estimates a confidence level of 90% that there will be more frequent warm spells, heat waves and heavy rainfall and a confidence level of 66% that there will be an increase in drought, tropical cyclones and extreme high tides. The magnitude of the events will vary depending on the geographic zones of the World (Solomon et al., 2007).

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

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

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

Global food production, already under the credit crunch, must double by 2050 to level off hunger. According to the UN World Food Programme (WFP), this will be possible only if food security is given top priority. The food security has become a complex issue influenced by climate and non-climate induced stressors which operate independently or in combinations are tackled appropriately. This climate induced stress is further augmented by climate change which affects agriculture and food production in complex ways. It affects food production directly through changes in agro-ecological conditions and indirectly by affecting growth and distribution of incomes, and thus demand for agricultural produce. Climate change has emerged as a major challenge in achieving goals of sustainable agriculture. Climate change refers to any change in climate over time, whether due to natural variability or/and as a result of human activity (IPCC, 2007). Agriculture impacts climate change with greenhouse gas emissions, and is at the same time impacted by effects of climate change as well. Amongst elements of climate change, the most important relate to increasing uncertainty in availability of water due to increasing frequency of drought and/or excess water events resulting in uneven water availability over time and space. Drought is a normal, recurring feature of the climate in most parts of the world. Drought is defined as the absence of rainfall or supplemental irrigation for a period of time sufficient to deplete soil moisture and injure plants. According to USDA drought occurs when annual precipitation is 75 percent of normal, or monthly precipitation is 60 per cent of normal. Drought stress results when water loss from the plant exceeds the ability of roots to absorb water and when the plant’s water content is reduced enough to interfere with normal plant processes.

Tamil Nadu has unique physiography with western and eastern Ghats on the west and northwest, Bay of Bengal in the east and Indian Ocean to the south. Tamil Nadu has high dependence on natural resources and hence faces the threat of climate change and its impacts. Available evidence shows that there is high probability of increase in the frequency and intensity of climate related natural hazards (Stephen, 2012). Out of 13 million hectares of geographical area, about 7 million hectares of land is under cultivation. Of this 55 per cent is irrigated and rest is under rain fed / dry lands. In Tamil Nadu, ground water has been harnessed fully and dry land productivity is found oscillating with ruling variability in seasonal monsoon rain and hence agricultural productivity is always under stake.

Conservation Agriculture (CA) is an agro-ecological approach for sustainable crop production and intensification. CA comprises the resource conserving agricultural production practices that aim to achieve more produce at less cost while enhancing the quality of the natural resource base. CA is all about providing multiple options for farmers, endowed differentially. The basic components of CA include drastic reduction in tillage, adequate retention of crop residues on the soil surface, use of economically feasible diversified crop rotations, avoidance of freewheeling and practice of controlled traffic, if possible. These elements of CA are not site-specific but represent unvarying objectives that are practised to extend CA technologies efficiently across all production conditions. No-till agriculture is considered as a revolutionary step in the direction of preventing land degradation and rehabilitation of the resilient but fragile lands. No-till agriculture together with other associated management practices such as direct seeding into loose crop residues to provide soil cover and to conserve soil moisture, judicious choice of crop rotations and agro-forestry tree species constitutes CA. CA is thus being widely accepted as an important component of the overall strategy for enhancing productivity, improving environmental quality and preserving natural resources for food security and poverty alleviation in such areas.  Recent CA trials conducted in Karnataka, Andhra Pradesh and Tamil Nadu seem to bring out that the rainfed tropical India stands to benefit more from CA than the irrigated areas.

Natural disasters are of meteorological or hydrometeorological origin. Disasters such as earthquakes and tsunamis are occasional, but rainfall-related hazards, flood or drought, are very frequent and thus call for proper monitoring of large-scale rainfall variation, and better manage- ment and planning to combat the problem(s). Variation in rainfall is very large spatially and temporally compared to any other atmospheric parameter, such as pressure or temperature. The large temporal variability in the Indian rainfall has produced frequent flood/drought and periods of above/below normal rainfall for several centuries past. Areas of high rainfall and runoff are flooded in the summer monsoon season whereas others face water stress and drought conditions. The influence of global warming on rainfall variations over India is reported in numerous observational (Singh et al., 1991, 1992) and modelling studies (Lal, 1994). 

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 

Conservation tillage has been defined based on percent cover of the soil surface with crop residue (CTIC, 2000). Quantifying crop residue cover on the soil surface is important for improving estimates of surface energy balance, net primary productivity, nutrient cycling, and carbon sequestration. Quantifying crop residue cover is also an important factor in controlling soil erosion and evaluating the effectiveness of conservation tillage practices (Barnes et al., 2003). Collecting this information by conventional method of survey and line transact are time-consuming, labor intensive, costly and can involve destructive sampling (Morrison et al., 1993). Moreover, field data are limited because they provide point, rather than area information. Remote sensing technique revealed as promising tool in providing such spatial data over a large area in a time and cost-effective manner.

Introduction

The Indo-Gangetic plain (IGP) is of great importance for the food security of India. It extends over 1,600 km with a width of 320 km, including the arid and semi arid environments in Rajasthan and Punjab and the humid and per humid deltaic plains in west Bengal (Shankaranarayana, 1982). During the green revolution period in the early 1960s, production increased through area expansion and intensification of the rice –wheat system. Driving forces included suitable thermal regimes for rice and wheat cultivation, development of short- duration, nitrogen responsive cultivars, expansion of irrigation and an ever increasing demand for food from the rising population. The rice –wheat system, covering an area of around 10 million hectares (mha), is the major cropping system in the IGP. These two crops together contribute more than 70 % of total cereals production in India from an area of around 25 mha under wheat and about 40 mha under rice. The small states of Punjab and Haryana contribute 20 % of the total national grain production and 50 % and 85 % of the government procurement of rice and wheat, respectively (Singh, 2000).

Conservation agriculture (CA) refers to a set of agricultural practices involving three basic principles of proven scientific soundness. These include continuous minimum mechanical soil disturbance; permanent organic soil cover with crop residues or cover crops; and diversified, efficient, economically viable, appropriate spatial and temporal crop sequences providing opportunities for saving on inputs (labor, fuel, machinery etc.), improving resource use efficiency (water, nutrient, energy etc.) and mitigating GHGs emission with climate change adaptation. Recently research efforts have been made to refine the crop management technologies which are more resource efficient, improve production and income, and reduce GHGs emission compared to the conventional practices. Resource conserving technologies (RCTs) are increasingly being adopted by farmers in the rice-wheat belt of the Indo-Gangetic Plains because of advantages of saving on labor, water, fuel and cost along with timeliness in operations particularly early planting of wheat.

Introduction

The subject of conservation agriculture CA has emerged as a need given the declining productivity of land and increasing costs of input that is putting tremendous pressure on the farming community. Higher yield expectation from land given also brings pressure to the subject of food security. Considering the markets with the globalisation influence is beyond a farmer’s means of influence and price realisation is not a point of control, the situation has deteriorated to their disadvantage. Climate change and soil degradation on the other hand is a reality and agriculture is both a sufferer and contributor, and cannot ignore this reality. Good physical management of soils is one of the key factors to maintain or improve agricultural productivity, in tropical and subtropical regions, and to reduce soil and environmental degradation (Lal, 2000). Tropical soils often have a stable structure and are well aggregated but management practices like intensive ploughing or avoiding the use of cover crops can lead to rapid deterioration (Madari et al., 2005).

Introduction

Rice is grown 43.7 m ha land in India. It is cultivated in 39.51 m ha under kharif and 4.26 m ha under rabi season. As a whole, rice production in India was 104.32 m t (2011-12) with an average productivity of around 2.6 t ha-1. Majority of rice grown in India in the eastern part of the country comprises the states of West Bengal, Orissa, Chattisgarh, Assam, Bihar and Jharkhand. Maximum area under rice in eastern India in West Bengal (5.94 m ha) with a production of 15.04 mt. Productivity was maximum in West Bengal followed by Jharkhand, Assam, Bihar, Orissa and Chattisgarh (DOSE, MOA, GOA, 2011). There is a plenty of scope to increase the productivity of these region with proper policies and technological interventions. Rice area in eastern region (23.4 m ha) would be divided in different ecologies, namely, irrigated (23.2%), rainfed upland (17.9%), rainfed lowland (43.1%) and flood prone areas (25.1%).

Climate change is a statistical variation in properties of the climate system that includes changes in global temperature, precipitation, etc due to natural or human drivers over a long period of time. It may affect distribution and quality of natural resources thereby influencing livelihood security of the people (Status of Indian Agriculture, 2013). Recent climate change activities is the increase in earth’s temperature by 0.74^ºC between 1906 to 2005 (IPCC 2007) due to increase in anthropogenic emissions of green house gases such as carbon dioxide (CO₂), methane (CH₄), ozone (O₃), nitrous oxide (N₂O) and chlorofluorocarbon (CFCs). Increase in concentration of green house gases influence future climate as well as agriculture (Mall et al., 2006; IPCC, 2001; Aggarwal, 2003: Bhatia et al., 2004). For Indian region under South Asia, Intergovernmental Panel on Climate Change (IPCC), 2007 projected a rise in temperature from 0.5-1.2^ºC by 2020, 0.88-3.16 oC by 2050, and 1.56 - 5.44^ºC by 2080. This may anticipate greater instability in agricultural production (Aggarwal, 2008). Beside this, climate change also affects the dynamics and frequency of extreme events like tropical cyclones, associated storm surges, and rainfall events. Low lying regions are more vulnerable to climate change as increase in temperature melt down the glaciers causing floods, submergence, and degradation of these regions. Therefore, there is a need for a ‘wake up call’ at this stage to aware farmers about the climate change, extreme weather events like hailstorm, heat and cold waves, drought, flash and river floods and landslides, and its affect on crop and agriculture, and strategies to overcome it.

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.

Introduction

Climate is one of the main determinants of agricultural production. Throughout the world there is significant concern about the effects of climate change and its variability on agricultural production. Researchers and administrators are concerned with the potential damages and benefits that may arise in future from climate change impacts on agriculture, since these will affect domestic and international policies, trading pattern, resource use and food security. The climate change is any change in climate over time that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere in addition to natural climate variability observed over comparable time periods (IPCC, 2007).

Introduction

In order to define climate it is important to distinguish it from weather. The weather that we experience on a day-to-day basis is a momentary atmospheric state characterized by temperature, precipitation, wind, and so on, and seems to vary in an irregular way, not following any particular pattern. Climate is a very general term that has a variety of closely related meanings. Usually, climate refers to the average weather conditions observed over a long period of time for a given area. In contrast to the instantaneous conditions described by weather, the timescale upon which climate statistics are calculated is typically thirty years. There can be variations in climate from year to year, or one decade to another, one century to another, or any longer time scale. The climate of a region depends on many factors including the amount of sunlight it receives, its height above sea level, the shape of the land, distance from the equator and how close it is to oceans. Generally speaking, the climate remains stable over long periods of time if the various elements within the system remain stable. However, if one or more of the components of the system is altered, the stability of the whole system is compromised and can lead to uncharacteristic behaviour and give rise to weather, which is outside the usual range of expectations. This situation can be described as climate change.

Introduction

Natural phenomena such as solar radiation, volcanic activity and ocean circulation influence climate and contribute to its variability. Evidence suggests that climate is now also changing as a result of human activities, such as the emission of greenhouse gases and changing land uses. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC, 2007) concluded that the global average mean temperature and the frequency of hot extremes, heat waves, and heavy precipitation will very likely increase in response to increased concentrations of greenhouse gases in the atmosphere.

Society will have to make decisions in the coming years about how to adapt to a changing climate. Climate variability and climate change create risks to all sectors of the economy. Climate is already a prime factor in 9 out of 10 disasters, many of which cost billions of dollars and thousands of lives. Effective preparation for the possible effects of climate change requires the engagement of resource managers, planners, public works officials, local managers, community development specialists, businesses, residents, and property owners. The challenge is to provide these diverse stakeholders with trusted, useful, science-based information so that they in turn can make informed decisions.