eChapters

Drone

Drones are one of the most innovative new technologies to emerge from the fourth Industrial Revolution. Indian farms may be significantly impacted by drone use in pesticide spraying, hence government cooperation is required for allowing supporting legislative environment.

Advantages

The following are the key advantages of using drones for pesticide spraying:

• Improved agrochemical application efficiency and accuracy. Crop protection products (CPP) are not wasted as a result, which improves pest management and crop output.

• Considerable decrease in operator exposure risk during spray operations.

• Drone-assisted spraying has a field capacity that is nearly 20 times greater in comparison to manual spraying.

• Lower water consumption.

Agricultural drones have emerged as important tools for precision farming, crop surveillance, and field-level data acquisition. This chapter introduces drones as aerial intelligence platforms capable of collecting high-resolution spatial and spectral information about crops, soil, and environmental conditions. It discusses drone architecture, sensing technologies, remote sensing, crop monitoring workflows, and crop health assessment. Artificial intelligence and machine learning enable efficient analysis of aerial imagery for disease detection, irrigation management, precision spraying, crop stress assessment, and yield prediction. The chapter also examines autonomous drones, drone swarms, IoT integration, edge computing, and digital twins. Operational limitations, regulatory considerations, data management, and sustainability implications are also addressed.

EAAMs (Electric Agricultural Aerial Machines) have emerged from drones used for both aerial filming, as toys and even as racing units. A Price water house Coopers’ study revealed that the global market for drone-powered business solutions was valued at $127.3 billion in 2016. For agriculture, prospective drone applications in global projects were valued at $32.4 billion. Stelios Kotakis and colleagues at market research firm IHS Markit projected that there would be around 400,000 shipments of drones to firms in the agriculture and forestry sectors in 2017. The Food and Agriculture Organization (FAO) of the United Nations projects that by 2050 humanity’s ranks will likely have grown to nearly 10 billion people. Farmers will need to produce more with less, while preserving our environment for future generations. And society has a duty to help them achieve this. Although agriculture is perceived as a traditional economic sector, precision agriculture technologies have already boosted crop yields significantly in the last decades. The same study forecast that agricultural consumption would increase by 69% from 2010 to 2050.

Drought

There is no universally accepted definition of drought. Early workers defined drought as prolonged period without rainfall. Drought is a situation when the actual seasonal rainfall is deficient by more than twice the mean deviation. American Meteorological Society defined drought as a period of abnormally dry weather, sufficiently prolonged for lack of water to cause a severe hydrological imbalance in the area affected.

Prolonged deficiency of soil moisture adversely affected crop growth indicating incidence of agriculture drought. It is the result of imbalance between soil moisture and evapotranspiration needs of an area over a fairly long period as to cause damage to standing crops and to reduce the yields.

Importance

Drought is a climatic anomaly characterized by deficient supply of moisture, which may result from sub-normal, untimely and unevenly distributed rainfall. Among the various hazards of nature, drought is one of the major disasters because it brings innumerable miseries to the mankind. Almost every year some part or the other of the country suffers from such calamities. Drought is a recurring phenomena and its occurrence cannot be avoided. However, its impact can be minimized through application of science and technology by developing drought management plans.

The world’s drylands include hyper-arid, arid, semi-arid and dry sub-humid areas where rainfall is highly scanty and variable. Droughts are common in areas / zones where water is the principal limiting factor for agriculture (https:// www.fao.org/3/t0122e/t0122e03.htm) . Dryland soils are characterized by low levels of moisture, organic matter, and biological activity, consequently such soils are very poor in fertility devoid of plant nutrients. When, these soils suffer further degradation in fertility, resulting in erosion, desertification, and salinization when crops are grown on such soils inappropriately without any scientific basis. However, the major factor limiting agricultural production on drylands is the lack of adequate moisture for crop growth or drought.

Low rainfall or failure of monsoon rains is a recurring feature in India. This has been responsible for drought and famines. The word drought, generally, denotes scarcity of water in a region. Though, aridity and drought are due to insufficient water, aridity is a permanent climatic feature and is the culmination of a number of long term process. However, drought is a temporary condition that occurs for a short period due to deficient precipitation for vegetation, river flow, water supply and human consumption. Drought is due to anomaly in atmospheric circulation.

Introduction

The study of abiotic stresses in plants has advanced significantly in recent years. However, the majority of experiments testing the response of plants to changes in environmental conditions have focused on a single stress treatment applied to plants under controlled conditions. In contrast, in the field, a number of different stresses can occur simultaneously. These may include conditions such as high irradiance, low water availability, extreme temperature, or high salinity and may alter plant metabolism in a novel manner that may be different from that caused by each of the different stresses applied individually. The response of plants to abiotic stresses in the field may therefore be very different from that tested in the laboratory (Cushman and Bohnert, 2000).

Drought is a situation when the demand for water is much greater than the availability of water. Drought is a creeping phenomenon and it is experienced only after it has set in. The scarcity of water compared to demand will have greater impact on every activity of human life including failure of crops, food shortages, decline in ground water table, drying tanks, lakes or reservoirs, acute shortage of drinking water for humans and livestock shortage for cattle etc.

Drought will have very serious impact on economy of households as well as that of nation. There are five different types of droughts depending upon the nature of shortage of water

10.1 Meteorological Drought

Meteorological drought occurs when the water received through rainfall during a given period is much less than long period average rainfall of the area. The meteorological drought is associated with either failure of rain or due to long gap between the successive rainfall events. In India, meteorological drought occurs due to failure of south west monsoon or long breaks in south west monsoon rainfall. In Tamil Nadu the drought occurs due to failure of north east monsoon rainfall during months of October to December.

Introduction

Drought is defined as “when a region receives below average precipitation,  resulting in prolonged shortages in its water supply, whether surface  or ground water or atmospheric. It can have a substantial impact on the  ecosystem and agriculture of the affected region.” When drought arises in  a particular area, obviously it affects the crop and livestock production. In  order to reduce the effect of drought on farm productivity and to stabilize farm  income, farmers have to take some systematic measures, and such measures  are referred to as drought coping mechanisms. The objective of the study was  to identify the determinants of the adoption of drought-coping mechanisms to  balance and stabilize the farm income of the stakeholders. The study also helps  to know how to mitigate the effect of drought on farmer’s livelihoods.

The existing literature on the adoption of drought coping mechanisms is  quite meager. Akwango et al., (2016), Chandan Kumar Jha et al., (2017),  Emmanuella Ellis (2017), Ronald Twongyirwe et al., (2019) assessed the adoption strategies by considering multinomial logistic regression and the  results state that the use of different tree planting, crop varieties, soil and water  conservation, early and late planting, and furrow irrigation. The data related to  the adoption of any agriculture technology have qualitative response variables  with two or more categories. Most of the studies used qualitative response  models such as the logit model, probit model, and multivariate techniques like  discriminant analysis to measure the farmer’s perception toward the adoption  of any agriculture technology. In this study, we chose machine learning models  such as Decision tree, to assess the classification ability and to determine the  factors influencing adoption.

5.1 Introduction

Out of the many climatic events that influence the earth’s environmental fabric, drought is perhaps the one that is most linked with desertification. Drought is a natural hazard originating from a deficiency of precipitation that results in a water shortage for some activities or some groups and is often associated with other climatic factors (such as high temperatures, high winds and low relative humidity) that can aggravate the severity of the event. Drought differs from aridity in that the latter is restricted to low rainfall regions and is a permanent feature of the climate. Drought occurrences are common in virtually all climatic regimes.

Widespread and severe drought conditions in Asia, Latin America and the Caribbean in 2000 have raised serious concerns about the continuing vulnerability of the world community to extended periods of droughts and water shortages. In 2000, major droughts affected much of south-eastern Europe, the Middle East, and the area through central Asia to northern China. Especially hard hit was Afghanistan, Bulgaria, Iraq and the Islamic Republic of Iran and parts of China. In North America, months of above-average temperature coincided with below-normal precipitation through northern Mexico and much of the southern and western regions of the USA, leading to one of the worst wildfires in the past 50 years.

By August 2001, much of Western Asia, Central Asia, and the Middle East was suffering the third year of a continuing drought that severely reduced many countries’ crop yields. The countries most affected were Afghanistan, India, Islamic Republic of Iran, Pakistan, and Tajikistan.

1. Introduction
Drought’ which apparently means lack of water, is one of most vulnerable natural hazards. It alone causes a huge crop loss annually. But history says it not only affects crop but destroys human lives.in the year 1972 almost 600000 people died due to starvation caused by huge drought in Northern India. In simple language drought means shortage of water mainly caused by abnormal climatic condition and damaging to the environment. Ideally there is no such proper definition of drought because it should be region specific and circumstances specific. A per McMahon and Diaz Arenas (1982) define drought as “a period of abnormally dry weather sufficiently prolonged for the lack of precipitation to cause a serious hydrological imbalance, carrying connotations of a moisture deficiency with respect to man’s usage of water”. Apart from these several general definitions have been provided by many authors. Beran and Rodier (1985) gave a definition based on hydrological aspect of drought that, ‘The chief characteristic of a drought is a decrease of water availability in a particular period and over a particular area’. India meteorological department (IMD) has defined drought as a situation in a subdivision in a year when the actual rainfall is less than 75% of the normal annual rainfall. Basically, to define drought the impact on environment and society and their complex interaction must be considered. Drought is defined as a state of total water capacity being within the range of 12-20% for a period of 16 days and can be distinguished from water deficit, which is the state of water capacity falling below 30%. Drought affects crop development, production, productivity and quality and on other hand soil physical, chemical and biological properties.
2. Classification of Drought
As per the hydrological point of view drought can be classified into different Categories: i) On the basis of source from which water is available: -a. Meteorological Drought b. Hydrological drought c. Agricultural Drought. ii) On the basis of time of occurrence: - a. permanent drought area b. Seasonal Drought Area contingent drought. iii) On the basis of medium: - a. soil drought atmospheric drought.

There are reports in financial newspapers that the ongoing (2010) drought affecting nearly 200 districts in the country may not have much effect on GDP, since the farmers in the drought-affected areas contribute hardly 3 per cent to GDP.  It is sad that such a measure of the impact of drought on the lives and livelihoods of millions of rural families is even considered. It is this mindset, typical of the growing insensitivity to human suffering in our country, that is responsible for India being the home for the largest number of undernourished and malnourished children, women and men in the world.  No wonder we are finding it difficult to achieve the first among the UN Millennium Development Goals, namely, reducing hunger and poverty by half by 2015.  Unless we realise that agriculture in India is not just a food- producing machine, but is the backbone of the livelihood of over 60 per cent of our population, rural deprivation and suffering will not only continue to persist, but will get worse, leading to severe social unrest.

Improving water use efficiency or enhancing agricultural water productivity is a critical response to growing water scarcity, including the need to leave enough water in rivers and lakes to sustain ecosystems and to meet the growing demands of cities and industries. Rainfall is the main source of water for the existence of life on the earth. Timely onset of rainfall and its distribution during the crop growing season determine the success of agriculture and food production. Unfortunately, the human life has hardly any control over nature and prevailance of delayed onset of monsoon and dryspells during different stages of crop growth are commonly observed in the dryland agriculture. Drought is a weather-related natural disaster which makes greater impact on food production and it reduces life expectancy and the economic performance of large regions or entire countries. Drought is a recurrent feature of the climate. It occurs in virtually all climatic zones, and its characteristics vary significantly among regions. Drought differs from aridity in that drought is temporary; aridity is permanent characteristic of regions with low rainfall. Drought is related to a deficiency of precipitation over an extended period of time, usually for a season or more. This deficiency results in a water shortage for some activity, group or environmental sector. Drought is also related to the timing of precipitation. Other climatic factors such as high temperature, high wind and low relative humidity are often associated with drought.

Drought, a recurring and often devastating feature of climate variability, presents a unique challenge due to its slow onset, complex nature, and farreaching consequences. Unlike hazards with clear event boundaries, drought manifests across diverse spatial and temporal scales and impacts nearly every facet of the environment and human activity. Effectively understanding and managing this phenomenon necessitates an equally comprehensive approach: drought monitoring. This chapter introduces the essential concepts and methodologies underpinning this critical field, highlighting the remarkable breadth required to capture the full picture of drought conditions. • The scope of drought monitoring is inherently vast. Geographically, it spans from tracking localized water stress affecting a single farm or watershed to assessing conditions across entire regions, nations, and continents. Temporally, monitoring efforts must consider short-term deficits unfolding over weeks or months (critical for agriculture) as well as long-term hydrological imbalances developing over seasons, years, or even decades (impacting reservoirs and groundwater). Understanding current conditions crucially relies on comparing them against a deep historical context, requiring decades of baseline data

Drought is a complex and multifaceted issue that affects various aspects of the environment, economy, and society. Its far-reaching consequences underscore the need for a comprehensive and collective approach to mitigate its impacts. 2.1 Drought Prone Area Delineation Drought-prone area delineation involves using scientific criteria like low and erratic rainfall, groundwater potential and agricultural indicators to identify regions susceptible to drought. Modern methods use GIS (Geographic Information Systems) to integrate data from satellite imagery, weather patterns, soil conditions, and vegetation to precisely map drought-vulnerable zones. This spatial analysis allows for targeted interventions such as improved water management techniques and sustainable agricultural practices in the most affected areas. Here are some additional details on the universal nature of drought and the benefits of a global response:

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Introduction

Chickpea, the world’s third most important food legume, is currently grown on about 10 m ha worldwide, with 95% cultivation in the developing countries. India is the largest producer of chickpea in the world. Chickpea is grown under rainfed conditions in winter in India subjecting it to abiotic stresses. Consequently it experiences water deficit stress at one or the other growth stage(s) which affects the crop productivity.  Among the abiotic stresses to which chickpea is subjected to drought stands to be the number one problem in major chickpea growing regions because the crop is grown on residual moisture and the crop is eventually exposed to terminal drought (Johansen et al., 1994). A distinctive variation exists between the plant in sensitivity to water stress. Chickpea is considered relatively more tolerant, possibly because of its deeper root system is and its smaller leaves and canopy. Several adaptive mechanisms are evoked by plants in response to water stress (Chaves et al., 2003). These traits enable chickpea to ensure its survival in different environmental conditions.

4.1. INTRODUCTION

Water stress is the single most severe limitation to the productivity of rice in the rainfed ecosystem (Widawsky and O’Toole, 1990). Drought has been defined as the inadequacy of water availability, including precipitation and soil moisture storage capacity, in quantity and distribution during the life cycle of the crop to restrict expression of its full genetic yield potential. Drought is actually a meteorological event which implies the absence of rainfall for a period of time, long enough to cause moisture-depletion in soil and water deficit with a decrease of water potential in plant tissues. Under drought conditions, water stress develops in the plants as the demand exceeds supply of water; this may occur either/or both due to atmospheric or soil conditions, and is reflected in a gradient of water potentials developed between the soil or soil-root interface and leaf, the transpiring organ. Moisture stress is likely to develop to a different rate in different plant organs along with the gradient. Drought like many other environmental stresses has adverse effects on plant growth and yield.

Drought Early Warning Systems (DEWS) form the essential foundation for effective and proactive drought management strategies. These systems are crucial in facilitating a fundamental shift from reactive approaches, where responses are implemented after the onset of a crisis, to proactive risk reduction measures that aim to anticipate and mitigate the adverse effects of drought before they fully materialize. By providing timely and accurate information about impending drought conditions, DEWS empower governments, communities, and individuals to make informed decisions and take preemptive actions, thereby minimizing the potential economic, social, and ecosystem losses associated with these events (Fig.6.1). Recognizing the risks posed by drought in a timely manner is of paramount importance for ensuring an effective and comprehensive response that can alleviate suffering and reduce overall vulnerability. The implementation of robust drought early warning systems plays a critical role in minimizing the negative consequences of drought and building longterm resilience to this recurring natural hazard.