eChapters

Introduction

Despite environmental, bio-physical, and resource constraints in most parts of Rajasthan, even though the state’s geography can be classified into three distinct climatic zones: hot arid, semi-arid, and sub-humid, from a horticultural perspective. These diverse zones have excellent vegetable production potential, a wide range of crop plants, and varied opportunities for resource utilization. However, extremes of high (March–October) and low (December–January) temperature situations associated with abiotic stresses in arid regions restrict the choice of crops and their genotypes, quality of product, and productivity levels. Thus, vegetable exploitation with adaptive and native crop plants is generally found to be most productive and stable under the dry-land climate of the state that receives 150–650 mm of rain and has problems from abiotic factors owing to climatic variability, extremes in temperatures, drought, frost, hot and cold winds, and soil and water quality.

Vegetable production in the country is largely uneven and concentrated, mainly in the limited states and areas where the climate is much more favorable and mild for their production. In addition, emphasis is given only to the few numbers of vegetables that are grown with high inputs and irrigations. To meet the increasing vegetable demand and utilization of indigenous resources, there is the utmost need for massive and integrated efforts with unconventional, under-scored, and perennial vegetable production. The increase in vegetable production can be achieved first by developing high-yielding crop genotypes suited to the prevailing conditions of the targeted zones and resource-based technologies under climatic variability. The second approach is to exploit native resources, i.e., varied and untapped land-areas and under-scored horticultural species with vegetable potentialities.

The hot arid regions of India are spread over an area of about 31.7 million ha, mainly in the states of Rajasthan, Gujarat, Andhra Pradesh, Punjab, and Haryana, which inhabit an average of 61 people per square km, making up a population of nearly 20 million people. The Indian arid zone is characterized by high temperature and low and variable precipitation, which limit the scope for high horticultural productivity. However, these conditions greatly favor the development of high-quality production in a number of fruits, such as date palm, ber, pomegranate, citrus, aonla, bael, grapes, and guava. The optimized technologies and inputs could increase the existing low productivity. It is now realized that there is a limited scope for a quantum jump in fruit and vegetable production in the traditional production areas. The amelioration of the extreme conditions is also considered vital for the life support of the inhabitants of this area. The recent awareness regarding the potential of these ecologically fragile lands for the production of quality horticultural produce has not only opened up the scope for providing economic sustenance for the people of this region but also for bringing new areas to increase production through horticulture. The scope of expanding water supplies through the development of water resources is very limited since suitable dam sites are fewer, development costs are prohibited, and environmental concerns are too strong. This has led to the realization that saving on the use of water is an option for expanding the water supply.

Introduction

Stress is any unfavorable condition for a plant’s normal growth and development. In the case of crop plants, such adverse conditions are caused by biological (biotic) and non-biological (abiotic) environmental factors. Abiotic stress is the negative impact of non-living factors on living plants in a specific environment. Usually, abiotic stress is unavoidable, and we can only go for its management.

The most basic stresses include:

• Extreme (high/low) temperatures

• Soil-chemical properties

• Water deficiency

• Excessive moisture

• Element toxicity or deficiency

Salt-affected soils (SASs) are an important ecological entity in world agriculture. It varies with time and space depending on soil, rainfall, irrigation, microtopography, groundwater quality, and depth. Weathering of rocks and minerals, higher rates of evapotranspiration, deposition of wind-blown salt sediments, and seawater ingress are the significant factors contributing to the formation of SASs. Large acreage in canal-irrigated tracts of arid and semi arid areas, which suffers from water logging, is also responsible for secondary salinization. According to an estimate, about 33% of irrigated lands worldwide are affected by varying salinity and sodicity. Other reasons other than improper irrigation that cause soil salinization include deforestation, which results in salt resettling at upper and lower levels, chemical contamination, and air-borne and water-borne salts from industrial outpouring. In addition to soil salinity, the problem of poor-quality water would also significantly increase in the foreseeable future due to planned expansion in irrigated areas and intensive use of natural resources to fulfill the increasing population’s food and other livelihood requirements. Groundwater salinity under irrigated agricultural lands may or may not increase over time. The groundwater salinity will remain the same if the natural river water is used for irrigation. However, if the irrigation water is polluted and contains salts, the salinity of groundwater may show an increasing trend. The rate at which groundwater salinity may increase would depend upon the quality and quantity of recharge water, the depth of the hardpan/barrier layer under the groundwater table, and the substrate’s porosity.

Introduction

The Indian arid zone, which occupies 38.7 million hectares in the states of Rajasthan, Gujarat, Punjab, Karnataka, and Andhra Pradesh, is characterized by low and erratic rainfall with a coefficient of variation fluctuating from 40 to 70% and extremes of temperature (1–48º C), poor-quality underground water, high wind velocity, and sandy soils. These vast land resources are blessed with rich agro-biodiversity despite all these aberrations that support the high human and livestock populations and have beneficial climatic conditions for producing quality fruits and vegetables. Recently, the immense potential of arid horticulture has been realized, and the area under cultivation of arid crops is increasing enormously. The production also increases with the increased cultivated area, which opens up the probability of establishing a market glut with underutilized foods.

Arid Fruits and Vegetables

Arid and semi-arid regions of the country are blessed with a variety of horticultural crops such as date palm, bael, aonla, pomegranate, fig, mulberry, Jamun, ker, karonda, lasora, wood apple, ber, bordi, khejri, kachri, snap melon, drumstick, cluster bean, and methi. Most of these crops are highly perishable and cannot be stored for extended periods due to uncongenial atmospheric conditions such as high temperatures and low relative humidity.

Seed is the basis of agriculture. It is the cheapest and most critical input for sustainable crop production. The response of all other inputs depends upon the quality of the seed to a large extent. The direct contribution of quality seed alone to crop production is about 15 to 20%, and it can be further raised to 45% with improved crop management practices. Quality seed ensures good germination and vigorous growth, resulting in a good crop stand. The Green Revolution witnessed in the country during the mid-sixties resulted from the seed revolution in wheat and rice. After that, there was a consistent increase and record production in food grains, oilseeds, pulses, and all other crops, including fruits and vegetables, due to the development of high-yielding varieties.

The seed itself is a technology that is inherited in a capsulated form. Therefore, the seed sector plays an essential role in disseminating the most recent technology to farmers through the quality seed of high-yielding varieties. The success of any developmental program in agriculture, like NFSM, RKVY, oilseed mission, horticulture mission, etc., depends upon the availability of good quality seed and planting material. Seed security is a prerequisite for food and nutritional security. Therefore, recognizing the facts, many emphases are being given to seed replacement and varietal replacement rates. The growth of the Indian seed industry is faster than the global rate.

Introduction

Ber belongs to the family Rhamnaceae, which consists of about 45 genera and 950 species. Out of 950, the genus Ziziphus consists of about 80 species of evergreen and deciduous climbers, shrubs, and trees found in the old world tropics, subtropics, and warmer temperate regions. The fruits of almost all species are edible, and jujube (Z. jujuba Mill.) and ber (Z. mauritiana Lamk.) are cultivated commercially. Liu and Cheng (1995) believed that the Indo Malaysia region (South and South East Asia) is the center of both the evolution and distribution of the genus Ziziphus.

Ber is the most common fruit of arid and semi-arid parts of the world due to its hardy nature and wild adaptability to soil and climatic conditions. It survives and produces economically viable yield in the hyper-arid zone where most of the trees fail to grow due to lack of moisture, extreme temperature, and poor soil conditions. It performs well under saline and alkaline soil conditions. It can produce economically viable yield with moderately saline irrigation water. Ber can withstand extreme heat but is susceptible to frost. Furthermore, due to its deep root system and other xerophytic characteristics, it is extremely drought tolerant but requires adequate soil moisture during fruit development. While high atmospheric humidity is unsuitable for ber cultivation, low humidity during fruit development improves fruit quality.

Introduction

Pomegranate (Punica granatum L.) is an important fruit crop in arid and semi arid regions. In India, it is grown commercially in Maharashtra, Gujarat, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu, Madhya Pradesh, and Rajasthan. India is one of the largest producers of pomegranate in the world. During 2020–2021, pomegranate was cultivated over 2.71 lakh ha with an annual production of 30.88 lakh tonnes and a productivity of 11.39 tonnes/ ha in India. Maharashtra is the leading state, with 63% of the area and 62% of total production. In India, pomegranate is available throughout the year (January–December). India has the largest area of pomegranate cultivation globally.

Pomegranate can tolerate heat, drought, and moisture deficit. The area under pomegranate cultivation in India is increasing daily due to its high demand, hardy nature, low cost of cultivation, high yields, better storage quality, and therapeutic values. It has enormous medicinal and nutritional value and is one of the richest sources of antioxidants. Several processed products such as juices, squash, jelly, anardana, and mouth fresheners are prepared by fruit processing. The fruit is mainly used as an ingredient in cooling and refrigerant mixtures and in the preparation of juice, concentrates, condiments, and pastes. The juice is highly nutritious and is recommended for patients suffering from gastric troubles. It contains 16.5% TSS and 0.33% acidity; total sugars, 13.93; reducing sugars, 13.60 and non-reducing sugars, 0.33%; and 9.27 mg/100 g ascorbic acid.

India is the second-largest producer of fruits in the world after China. As per the National Horticulture Database (3rd Advance Estimate), the area under cultivation of fruits is 6.914 million hectares with a production of 103.027 million tonnes. Mango (34.71%) ranks 1st in the area, followed by citrus (15.42%), banana, and grapes (2.14%), standing in the 9th position. Likewise, Mango (22.4%) occupies the 2nd position in production, followed by Citrus (12.89%) and Grapes, sharing around 3%. Underutilized fruit crops, such as aonal, bael, ber, Jamun, and tamarind, and minor fruit crops like phalsa, karonda ker, salvadora, etc., are grown in drier tracts of the country, including the arid region. Some of the crops introduced as non-traditional crops have revolutionized the fruit industry in India. Although the total acreage of cultivation and production of fruit crops has accelerated annually, the productivity of fruit crops has been on a declining trend due to several factors impacted by abiotic stresses. Since plants’ first line of defense lies in the roots, the success or failure of orcharding enterprises depends upon rootstocks.

Introduction

Date palm (Phoenix dactylifera L.) is a monocotyledonous and dieocious species belonging to the family Palmae. The Latin name of the date palm, Phoenix dactylifera, is derived from the Phoenician name “Phoenix,” which means date palm, and dactylifera is derived from the Greek word “daktulos,” which means a finger. In India, generally, two species of Phoenix are found, of which, Phoenix sylvestris Roxb. called “desi khajoor,” is found throughout the country but t produces inferior quality fruits. The fruit contains large stones with less pulp content.

Date palm is considered one of the world’s oldest cultivated fruit trees. Archeological evidence suggests that the date palm was domesticated some 6000 years ago in the Mesopotamian region. It is widely cultivated in arid regions of the Middle East and North Africa. It is also one of the most appropriate fruit trees, and it can be easily grown under saline soil and water conditions. It grows well in poor, arid soils due to its hardy plant characteristics and deep root system. Date palm is believed to be indigenous to countries around the Persian Gulf. In the Indus Valley, date palm is believed to have been introduced by the soldiers of Alexander the Great in the fourth century B.C. and during the Muslim invasions at the beginning of the eight century AD. Date palm was commercially cultivated in Iraq, Saudi Arabia, Algeria, Iran, Egypt, Morocco, Tunisia, Pakistan, and Sudan, among many other Near East and North African countries. In India, dates are grown in the states of Gujarat, Rajasthan, Punjab, Haryana, and Tamil Nadu (Table 1).

Background

Water is the most precious input for dryland horticulture, and therefore, its use should be planned judiciously. Rainwater harvesting and its management play a significant role in horticultural production. The rainwater can be diverted either directly to tree basins in situ or in suitable structures ex situ, which can later be utilized as lifesaving irrigation. In sandy soils, in situ conservation should be popularized, while in heavier soils, ex-situ conservation should be popularized. The water thus collected remains stored deep into the soil profile, escapes from evaporative losses, and is available during critical periods of demand. Perennial fruit trees, once established, get the advantage of any time it rains during the year, unlike annual crops. Water harvesting in khadins in parts of the Jaisalmer district of Rajasthan and its use in raising crops and trees is the age-old practice of in situ water harvesting. The hilly, rocky, and sloppy lands generate runoff, which can be collected in ponds or tanks and recycled for the establishment of fruit plantations and lifesaving irrigation at critical stages. In the same stance, nutrient management also plays an important role in the successful cultivation of horticultural crops under dryland. The arid zone soils are very poor in the majority of nutrients except potash. Enrichment of soil with organic and inorganic sources is essential for optimum production of fruits and vegetables. The application of chemical fertilizers has made miracles initially in agriculture and horticulture. However, increasing awareness of environmental degradation due to various anthropogenic activities has been expressed worldwide about the over-reliance on mineral fertilizers, which causes environmental penalties. It has also led to a deficiency of several micronutrients. Therefore, the option left is whether to revert back to traditional farming using organic input or to follow some middle path by integrating both organic and inorganic. So far as present knowledge is concerned, organic manuring alone cannot maintain the required productivity and demand for food.

The Indian arid zone is one of the largest subtropical deserts in the world, of which 20% is arid and the rest is semi-arid. A hot arid zone is spread over 31.7 million ha and confined to Rajasthan, Gujarat, Andhra Pradesh, Punjab, and Haryana. The major part of the hot arid region of the country lies in western Rajasthan (19.62 million ha), followed by north-western Gujarat (2.16 million ha). It is characterized by a high aridity index, extremes of temperature, low and variable precipitation, very high wind velocity and dust storms, high soil pH, a high infiltration rate, and minimal availability of groundwater and saline ground irrigation water. Under such harsh climatic conditions, cultivating vegetable crops in open conditions results in meager and poor-quality yield, which fetches less return per unit area. By creating a suitable microclimate for plant growth throughout the year, vegetables can be cultivated under adverse climatic conditions. It is possible through protected cultivation, which has tremendous scope in peri-urban areas of the country. It is the best way to increase the productivity and quality of vegetables, especially cucurbits. India is the world’s second-largest producer of vegetables, next only to China.

Introduction

The ill effects of chemicals used in agriculture have changed the mindset of consumers in different countries, who are now buying organic products with a high premium for health. Policymakers are also promoting organic agriculture for the restoration of soil health and the generation of the rural economy, apart from making efforts to create a better environment. The world principles of organic farming have emerged in the form of biological farming, ecological farming, permaculture, biodynamic agriculture, green farming, bio-intensive farming, zero-input agriculture, etc..

Organic agriculture is one of the broad spectrums of production methods that are supportive of the environment. Organic production systems are based on specific standards precisely formulated for food production and aim at achieving agroecosystems that are socially and ecologically sustainable. Organic farming practices help in increasing carbon sequestration, soil and water conservation, and minimizing risk in agriculture. The important aspects of organic farming with respect to water conservation are mentioned in this chapter.

Nutraceuticals have received considerable attention for their expected safety and potential nutritive and therapeutic effects. These were used as alternatives to modern medicines that promote quality of health, increase the nutritional value of the diet, and prolong life expectancy. Major constituents of nutraceuticals are herbals; various nutrients and dietary supplements are involved in preventing different diseases and minimizing the pathophysiology of the disease too. It also acts as an immune boosting, natural antioxidant, anticancer, anti-inflammatory, anti-diabetic, cardioprotective, and organ protective agent, in addition to different health-promoting effects. Ultimately, they ensure a better quality of life.

The scope of the nutraceutical field is plenty both in terms of type and the varieties. The nutraceuticals industry in India is one of the rapidly growing markets. Higher- and upper-middle-class consumers are perceiving nutra ceuticals as alternatives to prescribed drugs and exclusively for their beneficial properties without any side effects. Consumers are showing sharp interest in nutraceuticals for boosting energy and improving their physical endurance and mental alertness. Nutraceutical industries are focusing on developing new products with innovative formulations and using proper advertisements to choose the right products. Nutraceuticals have significant promise in the promotion of human health and the prevention of disease. They are widely accepted by all age groups due to their safety, higher quality, purity, efficacy, health-promoting, and disease-curing activities. The newest trend is moving toward nutraceuticals, leading to a new era of medicine and health. It is still in its infancy in India. But in this hype era, we must say, “let food be your medicine” and “proper nutraceuticals daily can keep the medicine away.”

Water is a very essential component for human civilization, living organisms, and natural habitats. It ma.kes up a major part of plant biomass (about 90% of plant cytoplasm; Singh, 2014). Irrigation, the largest water user sector, is currently under pressure to produce more with higher quality by using limited water to feed the increasing population of the country. The highest proportion of water is consumed by agricultural crops, which is called the blue water footprint, and it is assumed that the water scarcity will increase in the future in view of the changing climate. India has 18% of the world population; however, the water resources are only 4%. Even with all the planning and development, the country has not even been able to provide sufficient drinking water to all at the end of the 20th century. The water sector is facing a number of challenges regarding the availability, accessibility, use, and sustainability of its fresh water resources. Further, the distribution of water in the country is also uneven over space and time. Unfortunately, Rajasthan is the driest state in the country and has been water scarce (with per capita water availability below 1000 m3/year) since 1991. The efficient use of water in agriculture/ horticulture without affecting crop productivity or quality by adopting water saving irrigation techniques is the foremost need. Fruit crops, which have gained commercial attention in recent years, are an important component of Indian agriculture. Due to low irrigation and water use efficiencies, irrigation managers are looking for the introduction of effective water-saving devices and practices for water management in fruit crops.

In irrigated agriculture, water is the most important and precious input among all the inputs required for the biological activities of the plant. It is also a key input not only for ensuring food security but also for sustainable socio economic development. Water plays a crucial role in enhancing agricultural production and provides food security. On a global scale, 97.5% of water resources are salty ocean water, with only only 2.5% being fresh water. The bulk of the latter occurs in the polar ice and glaciers, as well as deep aquifers, some in water bodies like rivers and lakes, and in soil moisture. On the whole, less than 1% of the world’s fresh water resources are available for human use. The world’s average annual precipitation of about 1100 mm, marked by wide variation in water availability, is creating a great divide in regions, resulting in plenty of regimes and scare/acute shortage regions.

In India, the average annual precipitation, including snowfall, is 4000 billion cubic meter (bcm), of which water availability in the river systems is estimated at 1869 bcm, and out of which only 1122 bcm can be used. About 690 bcm is surface water and 432 bcm is ground water. As compared to the world’s average annual rainfall of 1100 mm, India receives 1170 mm, which is highly erratic and uncertain in both time and space. Thus, in India, very limited fresh water is available for use because of competitive and conflicting demand from the agriculture, industry, power, and domestic sectors, which is expected to increase from 10.7% in 1990 to 22.5% in 2025. While that of agriculture will decrease from 89.3% in 1990 to 77.6% in 2025. The projected requirement of water for use by the different sectors shows an increase in energy and industry as compared to the domestic and irrigation sectors by 2025, indicating a growing scarcity of water availability in the future.

1. Introduction

Human activities significantly lead to deterioration of ecological systems, affect individual organisms, and disrupt natural ecosystems. The rise in foreign compounds, such as heavy metals and pesticides, in aquatic ecosystems due to human activities has spurred extensive global research efforts (Wester et al., 2002). The Union’s Water Framework Directive (WFD) mandates monitoring programs to assess water body health. In environmental studies, understanding the impact of contaminants on aquatic life requires a multifaceted approach (Ullah and Zorriehzahra, 2015). Biomarkers that observe biological responses at various levels offer crucial insights into the presence and bioavailability of toxicants, complementing traditional methods (Yancheva et al., 2016). These indicators, termed early warning signals, are vital for evaluating exposure, effect mechanisms, susceptibility to contaminants, and enhancing predictive models (Yancheva et al., 2016). Integrating biomarkers into ecological studies provides a holistic understanding of environmental stressors and their implications in aquatic organisms.

2. Why is fish used as a model organism in ecotoxicological studies?

According to the Water Framework Directive (WFD), fish serves as a crucial indicator of river ecological status (Ullah and Zorriehzahra 2015). Their diverse sizes, ages, trophic levels, and sensitivity to various toxicants make them excellent indicators of water contamination (Wester et al., 2002). Fish adapt their metabolic functions in response to environmental changes, which makes them valuable in toxicological research. Monitoring sentinel fish species is a widely accepted method for assessing toxicant accumulation and its impact on human health (Wester et al., 2002). Fish, with their developed osmoregulatory, endocrine, nervous, and immune systems, are preferred to invertebrates in toxicological studies. Fish can absorb toxicants through both waterborne and dietary exposure, allowing the evaluation of contaminant transfer through the food chain. Key tissues for ecological, toxicological, and pathological studies in teleost fish include the gills, liver, and kidney because of their high metabolic activity and tendency to accumulate toxicants (Wester et al., 2002).

1. Introduction

Recirculatory Aquaculture Systems (RAS) have garnered attention as a sustainable solution to address the environmental and economic challenges associated with traditional aquaculture practices. Recent studies, such as those conducted by Martins et al. (2023) and Chen et al. (2024), have underscored the efficiency and resource conservation benefits of RAS. This section introduces the overarching opportunities and challenges in RAS, laying the foundation for a detailed examination of the latest developments in the field, opportunity presented by RAS lie in its capacity for water conservation. Martins et al. (2023) highlight the continuous filtration and recirculation of water within the system, significantly reducing overall water usage. This not only addresses environmental concerns but also aligns with the broader goals of sustainable aquaculture and provides a unique advantage in biosecurity, as emphasized by Li et al. (2022). The ability to meticulously control water quality parameters minimizes the risk of diseases and contributes to a healthier and more resilient aquaculture system. This enhanced biosecurity is pivotal in mitigating the impact of disease outbreaks on aquaculture operations. Precision control over environmental factors within the RAS facilitates optimal growth conditions, resulting in higher production yields. Anderson and Smith (2023) delved into the advantages of this controlled environment, positioning the RAS as a key driver for meeting the growing global demand for sustainable seafood production.

1. Aquaculture and Shrimp farming

Considering the current population explosion and the speed of human-centered land encroachment, scientists have expressed concern about the availability and production of food to meet global demand. The agricultural sector alone would not be able to cope with such a huge global demand of 7.6 billion people, which does not seem to be decreasing in any way. Approximately 20% of the global population consumes fish, which originate in the aquaculture sector. On the other hand, it has grown many fold with advancements in science and technologies in fish production and post-harvest, which has become a prominent commercial sector. The fisheries sector is broadly classified into two types: marine and inland. In marine fisheries, fishermen venture into the sea to fish with their fishing vessels and gear to harvest fish, whereas in inland f isheries, fishermen go fishing in rivers, lakes, and reservoirs. However, with advancements in technology and growing demand for fish as food sources, people have started growing fish in captivity under controlled and semi controlled conditions in ponds. The history of fish culture tracks back to 2000 BC, which originated in China, where they started growing carp in captivity by providing the required conditions for fish growth. Providing suitable conditions in captivity means providing the required physical and chemical environment in the culture system by keeping the physicochemical parameters at the optimum level as required by the species cultured. Physicochemical parameters of soil and water are key to the successful culture of fish, which is why emphasis has been placed on the scientific study of the physical and chemical parameters of soil and water.

1. Introduction

Bisphosphonates are frequently utilized in treating osteoporosis and cancer induced bone metastases, but they carry the risk of inducing a severe complication known as osteonecrosis of the jaw (ONJ). ONJ manifests as exposed bone in the craniofacial area and persists for over eight weeks in patients who are currently or previously treated with bisphosphonates. Many novel antiresorptive tyrosine kinases, mammalian targets of rapamycin, monoclonal antibodies, and immunosuppressant drugs have been discovered since BRONJ was first identified in 2003 and linked to ONJ (Akita et al., 2020). Current ideas include the prevention of angiogenesis and suppression of bone remodeling, gingival inflammation, gingival fibroblast dysfunction, and compromised immunological function. Wound healing mechanisms may play a role in most instances of ONJ, which occur after dental procedures, such as tooth extraction. In addition to surgical treatment for bone lesions, complementary therapies such as laser therapy, ozone therapy, and the administration of platelet concentrates in solid and liquid forms might help prevent ONJ and promote recovery (Gaurav Kumar et al., 2017; Hampton et al., 2015). Formation of new blood vessels is critical for the initiation and maintenance of wound healing.