eChapters

Tomato (Lycopersicum esculentum Miller, 2n = 2x = 24, also known as Solanum lycopersicum, Family Solanaceae) has been the leading vegetable crop globally. Tomato genome is composed of approximately 950 Mb of DNA, more than 75% of which is heterochromatin and largely devoid of genes. The global production of tomato in 2017 has been 182 million tons from 5 million ha area giving a productivity of 36.4 tons/ha. Top 10 countries in tomato production in descending order are China, India, Turkey, USA, Egypt, Iran, Italy, Spain, Mexico and Brazil. Tomato is planted almost throughout the year in different parts of India in an area of 8 lakh ha (0. 8 million ha) with production of 20.8 million tons giving a productivity of 26 ton/ha. Tomato area in India is almost 10% of total vegetable area. The states accounting for major tomato production in India are Andhra Pradesh, Orissa, Telangana, Madhya Pradesh, Karnataka, Maharashtra, West Bengal, Chhattisgarh, Bihar, Gujarat, and Himachal Pradesh.

Out of total area, about 78% is planted with F₁ hybrid seed while remaining 22% of the area still goes to open-pollinated varieties. The average productivity of tomato close to 26 tons/ha is still very low compared with the global productivity of 36.4 tons/ha. However, with the introduction of high performing and disease resistant hybrids, the productivity and production are continuously improving. Most of hybrid tomato seed (95 tons) is sold by the private seed companies. There are more than 375 tomato hybrids in the commercial chain in India produced and marketed by different companies. About 50 hybrids out of these 375 hybrids are being grown on more than 80% of the area under tomato in India. Leading companies in tomato hybrid seed segment are Seminis (Bayer), Syngenta, Rasi HyVeg, and Namdhari (NHB, 2015; Kapur, 2016).

Chilli (Capsicum annuum, 2n = 2x = 24, family Solanaceae) also known as hot-pepper, classified as often-cross-pollinated crop is consumed both as fresh green and dry spice type. It is a rich source of vitamin C and pungency to the consumers and world food industries. The global area and production statistics often run into different figures due to inclusion of some times only fresh green chilies, sometimes red-dry chillies and sometimes inclusion of sweet peppers also in this broad category. The global production of fresh and dry chillies in 2014 has been reported to be 32.32 million tons where China alone accounted for 16.12 million tons followed by India with over 5 million tons of production. Other major countries growing chilli are Mexico, Indonesia, Spain, Turkey, USA, Korea, Bangladesh, Pakistan, Nigeria, Thailand and Ethiopia. More than 65% of global green and dry chillies production is in Asia, while Europe contributes 12% and Africa around 10%. China is the leading producer of green and dry chillies, Area under chillies in China is less than that in India, but productivity is almost double than that in India.

Solanum melongena L. (2n = 2x = 24, family Solanaceae, often cross-pollinated) is known as eggplant in the United States and aubergine in France and England. It is one of the few cultivated solanaceous species originating from the Old World. It is known as brinjal in its home country, India, where it was domesticated long ago and where the greatest diversity exists. Widely grown in temperate and tropical Asian countries, eggplant has been also a common crop in the Middle East and around the Mediterranean basin and is now cultivated worldwide. Although an Old World taxon, S. melongena unexpectedly shares strong genetic similarities with New World Solanum species, namely, tomato and potato. These syntenic features have been discovered and will undoubtedly assist in an unlocking of the genes controlling eggplant key horticultural traits (Daunay, 2008).

As per FAOSTAT website-2018 quoted by Ministry of Agriculture and Farmers Welfare, Government of India, Horticulture Statistics Division (2018), the world production of eggplant was 51.29 million tons from 1.79 million ha with a productivity of 28.65 tons/ha during 2016. Top ten countries in eggplant production during this period were China, India, Egypt, Turkey, Spain, Iran, Indonesia, Italy, Japan, and Philippines. The bulk of eggplant production came from top ranking China (0.78 million ha area, 32.03 million tons production and 41.06 tons/ha productivity) followed by India (0.66 million ha area, 12.60 million tons production and 19.09 tons/ha productivity) occupying the second rank. Productivity-wise, Spain is top rank holder with productivity close to 65 tons. Leading brinjal producing states in India are West Bengal, Odisha, Gujarat, Bihar, Andhra Pradesh, Madhya Pradesh, Maharashtra, Chhattisgarh, Karnataka, Haryana, Jharkhand and Assam.

Okra or lady’s finger (Abelmoschus esculentus L. Moench, 2n = 2x = 130, family, Malvaceae) is classified as fruit vegetable like tomato, and eggplant and is grown in the tropical and sub-tropical regions of world. Okra growing major countries are India (occupying the first rank), Turkey, Iran, Iraq, Egypt, Saudi Arabia, Cameroon, Mexico, Lebanon, Israel, Jordan, Greece, Yugoslavia, Bangladesh, Afghanistan, Pakistan, Myanmar, Japan, Malaysia, Brazil, Nigeria, Ethiopia, Sudan, Ghana, Benin, Cyprus, and southern USA. Though, virtually it is not grown in Europe and north America, yet lot of people in these countries have started liking this common vegetable because of good amount of vitamin A and folic acid, besides, carbohydrates, phosphorous, magnesium, and potassium. In India, okra is extensively grown throughout the country but the states with substantial acreage under okra are Gujarat, Maharashtra, Andhra Pradesh, Telangana, Uttar Pradesh, Madhya Pradesh, West Bengal, Assam, Rajasthan, Tamil Nadu, Karnataka, Haryana and Punjab, both in rainy and spring-summer season. The global total area and production under okra is reported to be close to 1.15 million ha and 7.9 million tons giving a productivity of 6.8 tons/ha. India with approximately 0.5 million ha (5 lakh ha) area and production and productivity of an average of 6 million tons and 12 tons/ha, respectively accounts for close to 75% of share of world production of okra and hence has been accorded a prominent place in the list of crops under R&D by the private seed companies in India. In India, okra has huge export potential as fresh vegetable to the neighbouring countries in the Middle East, like, Bahrain, Qatar, Kuwait, Saudi Arabia, Muscat, Tehran, and Abu Dhabi and SouthEast Asia, particularly Singapore, Mauritius, Malaysia, Sri Lanka and Bangladesh. Therefore, any company with its own R&D in India treats okra a worthwhile crop to keep it under its portfolio and naturally okra becomes an important crop for commercial breeding. Unless a crop makes business sense on account of substantial acreage, production and seed sale volume, there will be no point in launching a full-fledged commercial breeding programme on that particular crop. Thus, okra qualifies a good candidate for commercial breeding in India.

Cabbage (Brassica oleracea, ssp. capitata, 2n = 2x = 18, family Brassicaceae = Cruciferae, cross-pollinated due to sporophytic incompatibility) comes under generic name cole crops. It is a rich source of calcium, and vitamins A and C. It is generally consumed as cooked vegetable, boiled or stewed, raw salad, soup and sauerkraut which is cabbage cut into fine slices that undergo lactic acid fermentation in a brine made of its own juice with salt. Sauerkraut was traditionally made at home in Germany and other European countries, but nowadays it is mainly an industrial product.

According to Indian Horticulture Database-2014 (NHB, 2015), global production of cabbage spread over more than 125 countries has been 70.64 million tons from 2.42 million ha area with a productivity of 29.2 tons/ha. Of this total global cabbage production, top ranking China (32.80 million tons from 0.98 million ha) and second ranking India (9.04 million tons from 0.40 million ha) jointly contributed about 59% of the production. Other countries in the descending order of the production were Russian Federation, Japan, South Korea, Ukraine, Indonesia, Poland, Romania and USA. In terms of productivity (tons/ha), South Korea (71.2 t/ha) and Japan (67.6 t/ha) were far ahead than the rest of the countries which were in the range of 20.1 to 42.9 tons/ha.

During 2017-18, also Indian cabbage production was 9.04 million tons from 0.40 million ha (4 lakh ha) area giving a productivity of 22.6 t/ha. Thus in India, cabbage area seems to be stabilized at 4 lakh ha. The top ten cabbage producing states in India are West Bengal, Bihar, Odisha, Assam, MP, Gujarat, Chhattisgarh, Jharkhand, Karnataka and UP (Horticulture Statistics at a Glance-2018, MAFW, 2018).

Cauliflower (Brassica oleracea var. botrytis, 2n = 2x = 18, Family Brassicaceae, cross-pollinated, sporophytic self-incompatibility) is traditional European crop that has become widespread in Asia. As per Horticulture Statistics at a Glance-2018, published by Ministry of Agriculture and Farmers Welfare, Government of India (MAFW, 2018), during 2016, global production of cauliflower and broccoli was 25.23 million tons from 1.34 million ha with a productivity of 18.82 tons/ha. Bulk of area and production (>70%) was accounted for by China, I rank (0.52 million ha area, 10.26 million tons production, 19.73 tons/ha productivity) and India, II rank (0.43 million ha area, 8.20 million tons production, 19.0 tons/ha productivity). Other countries in the descending order were USA, Spain, Mexico, Italy, France, Poland, Pakistan and Egypt.

Within India, as per 2017-18 figures, top 10 cauliflower growing states are West Bengal (74, 000 ha), Bihar (62, 000 ha), MP (46, 000 ha), Orissa (41, 000 ha), Haryana (40, 000 ha), Gujarat (25, 000 ha), Chhattisgarh (24, 000 ha), Jharkhand (22, 000 ha), UP (18, 000 ha) and Punjab (18, 000).

Bottle gourd (Lagenaria siceraria, 2n = 2x = 22, family Cucurbitaceae, monoecious, cross-pollinated but genetically behaving like self-pollinated crop), is grown primarily in India on large scale for consumption as cooked vegetables. Bottle gourd is considered to be one of the earliest species of plants to be domesticated by humans. Bottle gourds are regularly grown and consumed in various parts of the world, particularly Asia. Fruits of bottle gourds are harvested young and used as a vegetable. The mature, dried fruits have been used throughout the world for making storage jars and utensils and hence the name bottle gourd. Shoots and leaves are also cooked and eaten. Lately, bottle gourd juice is also becoming popular in India as a health drink. Other countries growing bottle gourd on limited scale are Sri Lanka, Indonesia, Malaysia, Thailand, Philippines, China, Hong Kong, Tropical Africa, Colombia and Brazil. After seed scooping, the hard rind is used as containers also. Seeds are used for oil extraction and oil is used as cooking oil.

During 2017-18, India produced 27 lakh tons (2.7 million tons) of bottle ground from 1.60 lakh ha (0.16 million ha) and this translated into a productivity of 17 tons/ ha (Horticulture Statistics at a Glance-2018, MAFW, 2018). Top six states producing bottle gourd on significant scale are Bihar, UP, Haryana, MP, Odisha, and Pujab, production being in the range of 135,000 to 650,000 tons.

Bitter gourd (Momordica charantia L., 2n = 2x = 22, family Cucurbitaceae, monoecious, cross-pollinated but genetically behaving like self-pollinated crop), also known as balsam pear, bitter melon, bitter cucumber, and African cucumber is rich source of vitamin C and iron and credited with medicinal use in management of diabetes. Fruits are cooked with other vegetables, stuffed, stir-fried, or added in small quantities to beans and soups to provide a slightly bitter flavor. The bitterness of most cucurbits is mainly due to cucurbitacins. The bitterness of bitter gourd is due to the cucurbitacin-like alkaloid momordicine and triterpene glycosides (momordicoside K and L) as reviewed by Behera et al. (2010). Bitter gourd is grown on approximately 340,000 hectares across Asia, with India and China accounting for more than half the production. Estimated area of bitter gourd in India is about 80,000 ha with production reaching to 10,00,000 resulting into a productivity of 12 tons/ha. States accounting for major area of bitter gourd are Chhattisgarh, Telangana, Andhra Pradesh, Orissa, Madhya Pradesh, Uttar Pradesh, Bihar, Tamil Nadu, Haryana and Assam.

Smooth gourd or sponge gourd (2n =2x = 26, Luffa cylindrica Roem syn. aegyptiaca, family Cucurbitaceae, monoecious, cross-pollinated but genetically behaving like self-pollinated crop) is not a global crop and is a vegetable crop very much indigenous to India and the adjoining countries. As per estimates, the acreage of this crop in India is about 50,000 ha spread over almost all the states but on a limited scale. However, UP, Bihar and West Bengal are the main states growing sponge gourd.

Origin and Domestication

It is agreed that sponge gourd may have originated from Asian sub-tropical areas, particularly India and India itself should be the centre of domestication as well because global presence of this crop is negligible (Kalloo, 1993). NBPGR, New Delhi publications unanimously mention Indo-Chinese and Hindustani gene centres as primary centres/domestication/secondary centres for Luffa species and in their publications, Luffa aegyptiaca is more commonly used than Luffa cylindrica for sponge gourd (Pandey et al., 2019).

Ridge gourd also known as ribbed gourd or angled gourd or silky gourd or angled loofah or vegetable gourd (Luffa acutangula (Roxb. L., 2n = 2x, family Cucurbitaceae, mostly monoecious and cross-pollinated but behaving like self-pollinated crop in term of no inbreeding depression) is not a crop of global importance; rather it is grown and consumed primarily in India and the adjoining countries which used to be part of greater India. In India, estimated area is 50,000 ha spread over almost entire country but the leading states are UP, Bihar, West Bengal, MP, Chhattisgarh, and Maharashtra, Karnataka, Tamil Nadu and north east hill region.

Origin and Domestication

Ridge gourd has similar origin as that of sponge gourd (refer to page 428).

Cucumber (Cucumis sativus var. sativus L., 2x = 2n = 14, normally monoecious, cross-pollinated) is a member of the economically important family Cucurbitaceae which includes squash/pumpkin (Cucurbita ssp.), watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai], melon (Cucumis melo L.) and gourds. After tomato (Solanum lycopersicum L.) and watermelon, cucumber and melon are cultivated more widely than any other vegetable species globally accounting for about 2.5 million ha and producing 43 million tons giving a productivity of over 17 tons/ha under field and greenhouse culture. Production of cucumber is the second largest of all cucurbits, where China, Iran, Russia, Turkey and the United States represent about 75% of the world production.

During 2017-18, India produced 1.25 million tons of cucumber from 0.08 million ha (80, 000) area resulting into a productivity of close to 16 tons/ha (MAFW, 2018). Top ten cucumber producing states in India in the same period are Haryana (17000 ha), MP (9500 ha), Karnataka (8300 ha), Assam (6900 ha), Maharashtra (4500 ha), Andhra Pradesh (4400 ha), Bihar (3900 ha), Punjab (3600 ha), Kerala (3400 ha) and UP (3300 ha).

Pumpkin (Cucurbita moschata, 2n = 2x = 40, family Cucurbitaceae, monoecious, cross-pollinated, behaving like self-pollinated crop genetically) is grown globally throughout in the tropical, sub-tropical and temperate regions of both the New and Old World. The term pumpkin is normally applied to the edible fruit of any species of Cucurbita when ripe as a table vegetable or in pie (Whitaker and Robinson, 1986). Squash and pumpkin are the words quite often used interchangeably. However, the term squash or summer squash is commonly used for Cucurbita pepo which is eaten as immature fruit also. The term pumpkin is used generally for all kinds of five cultivated species under the genus Cucurbita but is quite commonly used for C. moschata. Besides C. pepo (summer squash) and C. moschata (winter or baking squash), the other three species under the genus Cucurbita are C. mixta (squash), C. maxima (winter or baking squash), and C. ficifolia (squash, fig-leaf gourd, Malabar gourd).

While compiling statistics FAO clubs squash and gourd together with pumpkin. In 2017, world production of pumpkins (including squash and gourds) was 27 million tons, with China (7.8 million tons from 0.4 million ha) and India (5.0 million tons from 0.5 million ha) accounting for 47% of the total production. Russia, Ukraine, and the United States each produced about one million ton. As per APEDA (The Agricultural and Processed Food Products Export Development Authority), India produced 1.44 million tons of pumpkin which translates into 72000 ha area assuming a productivity of 20 tons/ha during 2015-16. The major states growing pumpkin in India are Orissa, UP, MP and Chhattisgarh. It is clarified that in context of India, pumpkin means C. moschata only although IIHR released a variety of C. maxima under the name Arka Suryamukhi in 1987 (Ram, 2012). However, now it is nowhere to be seen. Fruits of C. pepo (summer squash or zucchini) now can be seen in limited scale in superstores and limited scale cultivation is certainly happening under protected cultivation of this crop in India. Under this chapter, only C. moschata is being dealt with under the term pumpkin. Pumpkin is now becoming popular in India due to its high productivity, nutritive value, good storability, long period of availability and better transportability. It is rich in vitamins particularly precursor of vitamin A and minerals.

Watermelon (Citrullus lanatus (Thunb.) Matsam. & Nakai, 2n = 2x = 22, family Cucurbitaceae, cross-pollinated crop) is grown commercially in areas with long frost-free warm periods. Three-fourths of the world production is grown in Asia, with China the leading country in production. Watermelon is a nutrient-rich food full of vitamins, minerals and antioxidants. It also contains niacin, thiamin, vitamin B-6, zinc, magnesium and many more nutrients. There are many health benefits to watermelon as it is low in calories so it promotes phyto-nutrients and anti-oxidants essential for the optimization of health.

At global level, China tops in watermelon production (79 million tons) with other countries falling far behind, namely, Turkey (3.9 million tons), Iran (3.8 million tons), and India (2.5 million tons). During 2017-18, India produced 2.5 million tons of watermelon from 0.1 million ha (1 lakh ha) acreage and thus Indian watermelon productivity is 25 tons/ha. Top five states having area more than 10,000 ha in India are West Bengal (17,000 ha), UP (14,000 ha), Odisha (12,000 ha), AP (11,000 ha) and Karnataka (10,000 ha).

Melon or muskmelon (Cucumis melo L., 2n = 2x = 24, family Cucurbitaceae, mostly andromonoecious, cross-pollinated as well as self-pollinated) has latest global production close to 30 million tons where top ten producing countries are China (16.0 million tons), Turkey (1.8 million tons), Iran (1.6 million tons), Egypt (1.1 million tons), India (1.0 million tons), Kazakhstan (0.9 million tons), USA (0.8 million tons), Spain (0.7 million tons), Italy (0.6 million tons), Guatemala (0.6 million tons). India produced 1.2 million tons melons from 54000 ha acreage during 2017-18 giving a productivity of 22 tons/ha (MAFW, 2018).

US melons encompass the netted, salmon-flesh cantaloupe; the smooth-skinned green fleshed ‘Honey Dew’, the wrinkled-skinned, white-fleshed ‘Golden Beauty’ and several other dessert melons. Other forms with different fruit characters (white-fleshed, green-fleshed, having striped thin skin and juicy) are commonly found in India and in Orient as indigenous land-race cultivars. These are getting displaced by the cultivar types as cantaloupe, Madhuras and Galia due to their long shelf life.

Melon is mainly cultivated for the consumption of the fruits which can be harvested immature; in this case, the fruit is not sweet and can be eaten raw, cooked or pickled. In most cases, the fruit is harvested at maturity with high sugar content (mainly sucrose). Fruit is mainly eaten raw; marginal uses are cubes canned in syrup, in “fruits confits”, candies, ice-creams, biscuits and also in cosmetics. Locally, seeds can also be consumed (Pitrat, 2008).

Onion (Onion cepa, 2n = 2x 16, highly cross-pollinated, family Amaryllidaceae), is a valuable vegetable crop for the people all over the world. Tomato, onion and potato put together have been given a nick name as TOP seeing their combined importance globally. As per Ministry of Agriculture and Farmers Welfare-Horticulture Statistics Division, Government of India (MAFW, 2018), the global acreage, production and productivity of onion during 2016 were 4.96 million ha, 93.17 million tons and 18.80 tons/ha. Top 10 onion producing countries in the world are China, India, Egypt, USA, Iran, Turkey, Russian Federation, Pakistan, Brazil and Argentina. During 2016, China occupied I rank with area, production and productivity figures of 1.09 million ha, 23.91 million tons and 22.00 tons/ha. India was closely at II rank with corresponding figures of 1.20 million ha, 19.20 million tons and 16.18 tons/ha. Productivity-wise, USA is at the top rank (56.40 tons/ha), followed by Iran (37.95 tons/ha) and Egypt (36.71 tons/ha). The Netherlands is the world’s largest onion exporter with a total of around 800,000 tons, which is ca. 80% of its total annual production (Shigyo and Kik, 2008).

Within India, which produced 19.20 million tons of onion from 1.20 million ha (12 lakh ha), the major onion producing states during 2017-18 have been as given

Radish (Raphanus sativus, 2n = 2x = 18, family Brassicaceae or Cruciferae, cross-pollinated crop) is grown over 7 million ha where China, Japan, India, South Korea, and Europe are the main producers. As per Horticulture Statistics at a Glance-2018 (MAFW, 2018), India produced 30 lakh tons of radish from 2 lakh ha acreage with a productivity of 15 tons/ha during 2017-18. Ten top ranking states in India with acreage within the range of 6000 to 33000 ha are West Bengal, Haryana, Bihar, Assam, Punjab, Chhattisgarh, Orissa, Madhya Pradesh, Uttar Pradesh and Karnataka.

Today, radishes are grown throughout the world. Different local people prefer to use various parts of the radish plants including roots, leaves, sprouts, seed pods and oil from seeds as their food according to their own custom. Radishes are low in calories and high in vitamin C, folate, and potassium. Radishes contain sulfurous compounds, such as sulforaphane, which have anti-cancer properties, and are expectorant.

Carrot (Daucus carota, 2n = 2x = 18, family Apiaceae or Umbelliferae, cross-pollinated) is among the top ten most economically important vegetable crops globally in terms of area, production and market value (Simon et al, 2008). Almost half of the more than 42 million tons of the global production -by far- is harvested in China, followed by Uzbekistan, Russia and the United States of America. Ukraine, Poland, United Kingdom, Germany, France and Japan complete the top 10.This production comes from approximately an area of 1.5 million ha giving a productivity of 28 tons/ha. India produced 1.6 million tons of carrot during 2017-18 from 96000 ha area resulting into a productivity of 16.66 tons/ha. In India, top 7 states in carrot production are Haryana, Bihar, Punjab, MP, UP, Karnataka and Assam. Because of breeding of cultivars adapted to both summer and winter seasons, carrot is available round the year.

The conventional orange colour varieties of Europe are rich in beta carotene, a precursor of vitamin A and contain appreciable quantity of thiamine and riboflavin. The red carrots are rich in lycopene, an important pigment for healthy eyes and general body growth, besides having anti-cancerous properties. Black carrots are rich in anthocyanins. Further, carrots have medicinal properties.

Carrot has two distinct groups with regard to flowering and seed production. These are tropical and temperate types. Tropical or oriental cultivars are annual and adapted to high temperature conditions and these do not require low temperature exposure for flowering. They flower and set seeds freely in Indian plains after winter months with the advent of long day conditions in spring. The temperate/European types behave like biennial crops and require 6-8 weeks of vernalization at mean temperature of 4.8 to 10° C after they have passed the full root development phase for production of seed stalks (Sureja and Kalia, 2012).

Vegetable pea also known as garden pea (Pisum sativum, 2n = 2x = 14, family Fabaceae, formley Leguminosae, sub-family Papilionaceae), is rich in vitamins and sugars. Its green immature grains are consumed as fresh vegetables. Picked peas, are canned, frozen and dehydrated or freeze dried for super stores markets. Those associated with the immature pod are the snow, sugar or sugar snap types where pods are consumed. The total pea production world-wise has steadily increased owing to increasing green pea volume and top five countries are China (1.4 million ha), India (0.50 million ha), United States (0.08 million ha), United Kingdom (0.04 million ha) and Algeria (0.04 million ha). For field pea, the major producing countries are Russia, China, Canada, Europe, Australia and United States.

India produced 5.42 million tons of garden pea from 0.54 million ha area during 2017-18 giving a productivity of 10 tons/ha. The major garden pea producing states in India in descending order are UP, MP, Punjab, Himachal Pradesh, West Bengal and Assam. UP alone accounts for 40% of the total garden pea area. Within UP, major districts contributing to the vegetable pea are Jalaun, Lalitput, Jhansi, Mahoba, Kasganj, Etah, Sultanpur, Azamgarh, Hamirpur, and Amethi (MAFW, 2018).

ABSTRACT

The global market for baked products has reached up to $495 billion in the year 2019. It is estimated that its value will reach up to $580 billion by the end of 2025 with a growth rate of 2.7 % between 2020 to 2025. Ovens are operated with the help of LPG/diesel/electricity. The hybrid ovens can give higher energy efficiency along with targeted quality parameters. The previous data such as oven temperature, heat supplied per unit time, the moisture content and variety of the raw material used can be provided to a specific computer programme. The heat recovering unit is a unit which captures the escaping hot air and the same may be reused by pumping the hot air to the front of the oven to preheat the incoming cold air. The biogas can be generated from the bakery waste. There will be 45 % or more methane production from bread and biscuit waste in the retention time of about 12 to 55 days in a biogas plant. To make the bakery fully operated on green technology, solar renewable energy can also be utilized.

ABSTRACT

The food industry has many the environmental challenges in terms of emerging microbial strains, bacteria, viruses and accumulation of toxic chemicals. Ozone (O₃), environmental bluish gas is an extremely potent oxidant, which is effective solution for disinfection, sanitization for various kinds of products. The application of ozone treatment in agro processing has become green technology with increasing acceptance. It can apply in liquid form, gaseous form to sanitize food, food packaging materials, process water and to disinfect equipments. Ozone can be generated by different methods such as ultraviolet radiation method, corona discharge method etc. In this chapter, ozone properties, its generation, antimicrobial power and advantages with application of ozone has covered. Fruits and vegetables treatment with ozone have shown increased shelf-life and many hazardless advantages of the products. Some products preserved with ozone. Anti microbial activity, no residues in foods, assurance about preservation of sensory, nutritional and physicochemical properties of food have made ozone application as a promising technology for all kinds of food products

ABSTRACT

Packaging plays an important role in food industry. The huge waste of packaging generated every year poses a great threat to the environment. The recycling and reuse of the food packaging is limited. Plastic packaging in particular are the serious concern with respect to their disposal. This is the high time when eco-friendly green technologies for the food packaging should be explored. This chapter discusses various possibilities to use the green and eco-friendly approaches for food packaging.

Keywords: Green packaging, bio-degradable, recycle, reuse, edible packaging.

ABSTRACT

The ancient fruit “Jackfruit” is one of the most remunerative and important underutilized native fruits of India. It is extremely versatile sweet tasting fruit and vegetable rich in nutritional value. Modern technologies are evolved for the development of value-added products from jackfruit is studied in the present study. To prevent from post-harvest losses the wine production from jackfruit juice which is a very good substrate for fermentationcan be done at larger scale. Popularity of jackfruit from the limited regions can be explored over the country. There is a good scope and possibility of marketing the value added products in the country. Value addition is carried out by minimal processing by changing its form to a valuable product having more shelf life. The developed products enhance good income opportunities for farmers and also entrepreneurship opportunities for small and medium enterprises for the popularization of jackfruit to a wider region.

Keyword: Jack Fruit, Value Addition, entrepreneurial opportunities.

ABSTRACT

Fruits and vegetables are rich source of bioactive compounds such as polyphenols, antioxidants and flavonoids. Drying is one of the common methods for preservation of food and agricultural commodities. However, drying may negatively affect the product quality attributes. This article is a capsule overview of current state of art ultrasound (US) assisted drying on technical aspects and bioactivity of fruits and vegetables. US assisted drying is an economical and sustainable technique compared to other existing conventional techniques used for food processing and preservation. US as a pretreatment before drying of agricultural-products enhances drying efficiency, inactivate enzymes and improve overall quality of dried products. Current developments and available solutions in drying have shown that US assisted drying may be used to restrict the loss of crucial bioactive components occurring naturally in fruits and vegetables. US when combined with hot air drying helps in achieving adequate drying rate at lower temperatures and improves overall dehydration process. This technique has found no practical application commercially due to various difficulties in achieving high-intensity US in air. One practical benefit of using US assisted drying is the minimization of the drying time along with reduction in total energy consumption.

ABSTRACT

Green technologies are required in the field of food processing and production in order to achieve food security and to reduce adverse environmental impact. Application of nano technology in food processing and production can advance the food safety and quality, increase the bioavailability of nutrients and thereby improving human health. Nanotechnology can be applied to achieve green perspective like development of biodegradable packaging materials thereby reducing adverse environmental effect. Use of naturally occurring nanoparticles as additives can reduce the use of chemicals in food products. This chapter deals with the potential of nanotechnology to achieve green aspects in food processing and production.Main focusses are on achieving food security and environmental sustainability. Chapter also describes about the principles of nanotechnology and methods to achieve green aspectin food sector with the application of nanotechnology. Application of nanotechnology in food processing and production along with safety, regulations and accompanying laws are discussed in this chapter.

ABSTRACT

Approximately 30 % of fruits and vegetables are getting wasted each year in country like India. Not only that, there is a huge loss of agro based commodity during industrial processing and will be considered as industry generated waste. Utilization of such unexplored nutrients from agro processing sectors for making a sustainable food system will be a healthy approach to bring food security and nutrition to all of us. With this aim the present work addresses the utilization of jackfruit seeds, an agro-waste, to value added products. Jackfruit seed flour has a great potential in new food formulation along with wheat flour. The 15% (w/w) blending of jackfruit seed flour with wheat flour could be used in bread and the substituted bread is protein and fibre enriched. This attempt in developing such bakery items with blended flours could address the scarcity problem of non-wheat producing countries. Present study also looks into the alternate source of starch from spice processing industries. The nutrient starch could be explored for isolation from a nonconventional source from turmeric processing sector. The isolated starch could also be modified to enhance some of its functional properties and may be utilized in preparing value added product with a better acceptability and nutrition.Thus, the isolation of nutrients and value-added products out of fruits and vegetables and spice-processing waste would be a stepping stone to an initiative to zero hunger.

ABSTRACT

Microencapsulation is one of the latest technologies used in the food, pharmaceutical, nutraceutical and cosmetic industry where it is used for maintaining the stability of the food ingredients and slow release of the active food ingredients. For many decades the encapsulation technique was used in the pharmaceutical industries, but from last three decades it has been effectively used in the food industries showing enhanced results in flavour masking and retention of bio- active components present in the food. The production of the microcapsules can be achieved by the various process technologies. The process technologies have been reviewed in this paper such as spray drying, extrusion, spray chilling, emulsions, fluidized bed coating, freeze drying, molecular inclusion, crystallization, co-acervation etc. the encapsulation of food materials has shown a promising result in the newly growing food processing industries. Some of the recent developments in the microencapsulation viz. sweetener immobilization, controlled release and the carrier materials are also being presented in the reviewed paper.

ABSTRACT

Malting is the process accompanied by restricted sprouting of cereals in humid atmosphere along with controlled set of conditions. It is a process of soaking, germination and drying that causes changes to the microstructure of grains. Malting causes changes in functional and nutritive value of grains. Malting results in increase in protein content, mineral availability, in vitro protein digestibility, oil absorption capacity, water absorption capacity, water solubility index and fall in level of antinutritional factors, viscosity and bulk density. The malting conditions are significantly affected by varietal difference, maturity of grains and structural composition. Therefore, optimum malting conditions should be determined for grains in order to avail the health and nutrition benefits.

ABSTRACT

The commencement of the 21^st century has endorsed an extended requirement for safe and wholesome food. The fact is that consumer preferences, awareness and their concern towards food safety have been tremendously increased. Therefore, inactivation of pathogenic microorganisms through any treatment becomes essential for food processors to ensure that food is free from disease causing microorganisms and parallelly unaltered with respect to its organoleptic, functional and nourishing characteristic. Food industries predominantly adopt thermal inputs for the preservation of food. Thermal methods, however, lead to unfavourable changes in organoleptic and nutritional attributes, more particularly proteins and vitamins. Hence, there has been continuous development and advances in finding alternatives to conventional processing. Cold plasma technology is one such technique. Plasma can be defined as a quasi-neutral ionised gas and is more commonly termed as 4^th state of matter. Advances in plasma engineering have made it possible to generate plasma at atmospheric pressure which ultimately resulted in broadening the spectra of research on cold plasma at various interfaces of biological sciences. This chapter summarises the overview of cold plasma technology processing, numerous findings related to its application in the area of food decontamination, food fortification, seed germination, milk and milk products and modification of starches.

Keywords: cold plasma, non-thermal, plasma chemistry, fortification, modification, germination, plasma generation, novel

ABSTRACT

The improper disposal of food waste poses an environmental threat. The management of food waste in a sustainable way is always a challenge. Food waste is generated at various stages starting from food production till consumption. The cooked food waste generated due to various reasons leads not only to a loss of the food produced but also the water and energy used to cook it. This cooked food leftover can be served to the needy people or if not possible, can be processed further. This chapter focuses on various technological options for the management of cooked food waste in a sustainable way.

Keywords: Cooked food waste, Compost, Bokashi, Bio-surfactants, Environment

ABSTRACT

Green packaging is a technique used to develop sustainable and eco-friendly packaging materials. In this review paper we have examined the data currently available on the use of plant by-products and plant extract in the development of green packaging. The use of plant fibres is especially beneficial because they often contain a high concentration of bioactive compounds. These compounds lend a preservative effect to the packaging material. Further we have also discussed the degradability of such packaging and the additives which need to be added in order to enhance their utility. Lastly, we have examined the possible applications of green packaging in the food industry.

Keywords:GreenPackaging,Plantby-products,Fruitfibres,Biodegradability, Bioactive compounds, Nanocomposites, Renewable resources, Biopolymers

ABSTRACT

Banana plants areextensively known for their fruits butby-products (pseudostem, root, leave, male banana flower, and banana peel) from banana farms also have potential applicability because recycleprocess of these wastes can convert waste of banana farms into an outstandingresource of valuable raw materials for other industries. This practice avoids huge losses of unused biomass and environmental hazards. Banana flowers are discarded in banana farms during the harvesting of banana fruit bunches and produce a great amount of agricultural waste. Consumption of banana flower as a vegetable is trendy in some parts of Asian countries but the cleaning process of banana flower is an unwieldy practice because of the time and the laborengaged in separating the calyx and the pistil portion of these flowersbefore processing. Itis an abundant source of well-balanced essential amino acids, unsaturated fatty acids, dietaryfiber, vitamins, minerals,and flavonoids. This flower also having tremendous medicinal properties as they possess several secondary metabolites. Thepresent review discusses the transformation of this agricultural waste into a different value-added product. The transformation of banana flowers into highly commercial outputs can be beneficial forsupplementary income to small scale farming industries.

Keywords: Banana, Banana flower, By-product, Value-added product, Antioxidant, Pre-treatments, Processing.

ABSTRACT

The rapid growth in population has created the need of industrialization and as a result there has been a significant increase in milk production and processing. Milk is a commodity which is consumed by persons of all age groups due to its nutritive value and health promoting attributes. However, the rapid growth in dairy sector has adversely affected the environment by emitting various greenhouse gases and thereby, resulting in global warming. Apart from it, there has been an increased usage of non- renewable resources like natural gas and coal in dairy sector. As a result, a viable balance has to be maintained between milk production and processing, environmental health and the rapidly growing population. This can only be achieved with the application of green or environment friendly technologies in all the stages of milk production and processing. This chapter will mainly deal with the various sources of greenhouse gases from dairy sector and on application of life cycle assessment and carbon foot printing for computing the impact of greenhouse gases on the environment. Also, this chapter will enclose various green technologies which can be applied in dairy sector to curb the greenhouse gas emissions.

Keywords: Carbon footprint, LCA, Greenhouse gases, Green Technology, Milk production, Milk Processing

The species is commonly found in tanks, ponds, lakes, reservoirs, canals, swamps, etc in freshwater plains. It is air-breathing in nature and survives easily low oxygen stress. During drying-up of water bodies in summers, it has been reported to penetrate deep under moist-earth and come out live on arrival of rains. The name 'murrel' encompasses its resemblance to reptile (snake) due to presence of body scales all over its body including head region. Fully-grown adults are dark greenish brown with faint black and white vertical bands visible across its entire abdominal length below the lateral line and a black ocellus at posterior end of dorsal fin.

Striped murrel is one of the important food fish of high commercial value due to preference for its meat quality, therapeutic and antinociceptive properties and hence consumed by many to induce healing and pain control after clinical operations. It contains high arachidonic acid (AA), which is a precursor of prostaglandin that may initiate blood clotting and enhance tissue growth. Geographically, the species is distributed in Western to Southeast Asia including Bangladesh, Cambodia, China, India, Indonesia, Lao People’s Democratic Republic, Malaysia, Myanmar, Nepal, Pakistan, SriLanka, Thailand and Vietnam (Chaudhary, 2019). It is supposed to be introduced in countries like Fiji, New Caledonia (Welcomme, 1988), Madagascar (Stiassny and Raminosoa, 1994) and Hawaii (Courtenay et al., 2004). The species has been reported to grow to a length of 100 cm (Rahman, 1989) and categorized„ Least Concern under the IUCN Red List (IUCN, 2020).

Globally, 92523 ton of striped murrel is produced (FAO, 2016), of which the major share of 70802 ton is contributed from capture fisheries and 21721 ton from aquaculture (Figure 1). Though capture fisheries of striped murrel is quite stable in terms of global production, the aquaculture has shown a steady rise in last two decades. In India, though no production data is available, the production of this species is mainly contributed from the capture fisheries with meager contribution from aquaculture. This has caused serious stress in past few years on its resources, more particularly due to habitat degradation and man-made hazards in aquatic ecosystem.

Knowledge on fish reproductive biology is extremely important to understand various issues relating to reproduction and fishery management. Reproductive success in aquaculture systems depends to a greater extent on our knowledge about sexual differentiation, gonad structure, gametogenesis, spawning, larval metamorphosis, etc for successful captive breeding of a fish species. This chapter therefore, contains information on secondary sexual characters, sex-ratio, gonad structure, gonadal maturity, fecundity and embryonic development of striped murrel.

2.1 Secondary Sexual Characters

The sexes are separate in striped murrel however differentiation of sex is not easy when fish is immature. The differentiations in sexes become distinct with advancement of maturity during spawning season. On attaining full maturity, a good fecund mature female could be easily distinguished with having bulged belly originating nearing the site of pectoral fins and extends near to the vent.

3.1 Spawning Season

Striped murrel breeds in stagnant waters and commence breeding in ditches, ponds, tanks, flooded paddy fields, wetlands and dead end of rivers; a little prior to or with the onset of monsoons (Bhattacharya 1946; Chacko 1947). Striped murrel is a batch spawner species and hence breeds several times in a year. According to Courtenay et al. (2004), spawning occurs in this species all through the year. In northern states of India, the breeding season of this species coincides with south-west monsoon and extends from June to September with peak in mid of June to mid of August (Qasim and Qayyum, 1961). However, the species has been reported to breed during November to January in southern India (Alikunhi, 1953).

In order to get assured supply of quality seed weaned on formulated diet, the captive spawning is the right choice for successful farming of striped murrel. Captive spawning involves several activities such as broodstock development, induced breeding, hatching of eggs, larval rearing, etc. These activities are given in detail in the following sections.

4.1 Broodstock Development

Brood stock development is an integral part of captive breeding programme in fish and the success of breeding largely depend on it. It involves rearing of healthy brooders of both sexes in captive conditions to meet the targeted production of seed. In striped murrel, maturation of gonad begins in the first year of their life. However, brooders of 2⁺ year age or above are better and recommended for captive breeding (Pati et al., 2004). A size of 400g to 1500g is considered ideal (Fig. 10). Brooders may be procured from wild sources or reared on-farm from farm-raised fingerling. Brooders from wild stocks are to be procured at least 2-3 months prior to spawning season so that they acclimatize to the farm conditions. It is recommended to give them a bath of 50 ppm formalin for about 8 hours under vigorous aeration before stocking in the tank/pond. Formalin treatment removes external pathogens from the fish body. Brooders raised at the same farm do not require formalin treatment, if they are free from any wound.

Predation and cannibalism are entirely two different processes. In predation, the animal used to consume other species then their own, whereas cannibalism is a practice of eating one’s own kind. Cannibalism is a common behavior in animal kingdom and has been recorded in more than 1500 species. It is reported in an increasing number of fish species belonging to group/ families such as air-breathing catfishes (Clariidae), pikes (Esocidae), percids (Percidae), characids (Characidae), latids (Latidae), gadids (Gadidae) and in over 30 other families, including cyprinids (Cyprinidae) and salmonids (Salmonidae) (Smith & Reay, 1991; Hecht & Peinaar, 1993; Folkvord, 1991; Baras, 1998; Qin et al., 2004). Cannibalism is a common ecological interaction and depends on genetics and fish behavior; mediated by appetite and metabolism and is promoted by size differences, and is more intense among fast growing larvae and young juveniles than among older fish (Hecht and Pienaar, 1993; Baras, 1998).

Cannibalism is a serious problem in the farming of striped murrel that starts from the early larval stage (Ng and Lim, 1990) and continues at all sizes including during parenting also. Murrels have large mouth gape; sharp jaw teeth for catching & grasping prey and can consume prey fish more than half to two-third of its length (Wee, 1981; Diana et al., 1985; Ng and Lim, 1990 and Qin and Fast, 1996). Its aerodynamic body shape allows fast movement in water and catching the prey with ease. Striped murrel observes two types of cannibalism, Filial and Intracohort, which is discussed in detail in the subsequent sections.

The objective of larval rearing is to mass-produce high-quality and healthy juvenile fish. In larval rearing, the management of both rearing environment and feeding regime are the most important aspects. Improving larval rearing technique requires understanding of larval morphology & behaviour and requirements of live food, artificial diet and environmental conditions at different ages of larvae (Liao et al., 2001). Striped murrel is predatory as well cannibalistic species in nature. Therefore understanding about its behavior with respect to feeds and feeding, stocking density with growing age is utmost important. It is a general thinking that fish hatchlings do not require exogenous food until yolk-sac attached to their body is exhausted. But this is untrue with many carnivorous fish species, particularly those observe cannibalism. Larvae of such fish species start feeding much before the yolk-sac absorption; rather delay in getting feed make them weak or force them to feed on the conspecifics. Therefore in order to understand larval behavior of this species in respect of feeds and feeding, knowledge on its ontogenic development is crucial particularly in respect of age at which mouth opens; mouth gape size, food choice, size of food particle at different age-groups and finally the age when gut digestion starts.

Yulintine et al. (2017) have given ontogenetic details of striped murrel larvae since hatching. According to him, mouth opens and exogenous feeding begin in this species when hatchling grows to a size 4.63+0.25mm on second say of hatching. On day-3 after hatching, the buccopharynx channeled with the anterior intestine through a short oesophagus and rather narrow lumen, with having prominent liver developed by this time. Two pyloric caeca appeared on day-25 hph, indicating the transition from larval to juvenile stage and acquisition of an adult type of digestion. This chapter provides strategy for larval rearing of striped murrel based on ontogenic studies and work carried out by various workers in this field including that of authors.

Stocking fingerlings in grow-out ponds increases survival rates, cut-down culture duration, better feed management and reduce risk-factors on account of natural as well disease occurrence. In pond culture, good amount of fry-size seed suffer predation from enemies such as snakes, birds and predator fishes, if any and mortalities due to disease occurrence as smaller size fish is more vulnerable. However, fingerling stocking reduces predation loss to a greater extent, increase survivals, allow better feed management and highe production. This is truer with carnivorous fishes and particularly those observe cannibalism. Qin and Fast (1996) stated that the rate of cannibalism is higher in small size (TL) predators than the larger in case of striped murrel, so stocking large size fingerling in culture ponds reduces chances of ICC and hence recommended for grow-out production.

7.1 Traditional Methods of Fingerling Rearing

Wee (1981) has defined traditional system of murrel farming in Thailand in which seed of murrel was procured from wild resources and raised to large fingerling size before stocking. Two type of practices being used to raise fingerlings. In the first one, the pond(s) designated for fingerling production are stocked with brooders of SFs so they could spawn in the stocking pond(s) few days before the stocking of striped murrel fry and could directly feed upon the juvenile SFs. In second system, the fingerlings were reared to accept small-size fish (SF) along with rice bran to cut down cost of feeding on production of fingerling. In recent, more systematic approaches have been made to wean the seed collected from the wild resources on inert diets totally. The protocol adopted for weaning the fingerling on inert diet includes initial feeding with cut pieces of SFs and then gradual supplementation of inert diet till fingerlings start relishing inert diet completely.

The farming of striped murrel is quite old in many south-eastern and south Asian countries including India under traditional farming system. Wee (1981) has given an account of traditional farming of striped murrel in Thailand, where seed of wild stock was stocked in very high density (75-460 numbers/m²) in ponds. Freshwater small fish (FSF) were fed to the seed during pre-monsoon and monsoon seasons and subsequently marine small fish (MSF) mixed with rice bran to satiation level. The fish grew to 700-1000 g in 7-10 months with an FCR of 6.5:1 and production of 9.0-15.6 kg/m². In another culture trial, Diana et al. (1985) have described a poor survival of 9-13%, when they stocked seed @ 40-80 number/m² collected from wild sources and fed them on FSF for 9-11 months. There are records of backyard production of this species also (Wan et al., 1992). The major problems with traditional farming were poor & uncertain survivals, problems of getting SFs and occurrence of diseases due to poor management protocols.

Therefore for a scientific farming of this species, the major bottlenecks are the non- availability of hatchery seed, species & size specific feed, cannibalism at all stages and disease occurrence. These bottlenecks have been addressed to a greater extent by the researchers in recent and protocols for hatchery seed production and cannibalism reduction have been simplified to a greater extent with the availability of commercial pellet diets to boost its farming. Vietnam has been pioneer in the production of farmed striped murrel in recent, following new initiatives and based on its success, neighbouring countries such as Indonesia, Camobodia, Thailand, Myanmar, etc have also taken initiatives to boost production of this high value species in their countries.

1.1. What is Earth?

The Earth is a layered body consisting of three parts: core, mantle, and crust. The radius of the Earth is nearly 6370 km of which crust, mantle and core share a depth of 40, 2850 and 3480 km, respectively (Figure 1.1). Exterior of the Earth contains the outer lithosphere which is surrounded (70% of surface) by water (hydrosphere). Solid and liquid sphere are surrounded by gas (atmosphere). The atmosphere is of 320 km above the lithosphere / hydrosphere. It is believed that there is a progressive increase in temperature with depth, if one goes to the core from the Earth crust. There is a rise of approximately about 1°F for every 64 feet depth on an average. Therefore, one could imagine that the interior of the earth is in molten condition.

2.1. Minerals

Primarily, minerals are usually inorganic substances possessing a definite chemical composition and a definite molecular arrangement which is usually expressed in geometric form. The mineral matter is made up of various elements, combined to form compounds. Usually, minerals consist of more than one constituent elements. Quartz contains two elements, silicon and oxygen. Other minerals may contain many elements, such as amphibole consists of several elements that include sodium, calcium, magnesium, iron, aluminium, silicon, and oxygen. Some elements exist as such without forming compounds. They contain exceptionally one element. Graphite (C), diamond (C), and Sulphur (S). Minerals are naturally occurring crystalline solid where the atoms are arranged in a regular three-dimensional array. A crystal is a solid, formed by a repeating three-dimensional pattern of atoms, ions, or molecules & possessing fixed distances between the different parts. Minerals that do not grow in these regular or crystalline patterns are called amorphous solids. When we talk about ‘naturally occurring’, we exclude the laboratory-synthesized crystalline solids. Glass and amber are also naturally occurring solid, but they are not crystalline and thus, they are not considered as minerals, rather they are referred as amorphous solids.

3.1. What is weathering?

Weathering may be defined as the transformation process of solid rocks, involving the disintegration and decomposition of rocks and minerals, into soil.

There are different types of weathering: physical, chemical and biological.

3.1.1. Physical weathering

In physical weathering the chemical composition of the weathered products remains same as that of the parental rocks. It is involved in fragmentation of rocks into comparatively smaller sizes. It does not transform the parental rock into a newer one that may differ from the parental rock in chemical composition. The process is totally physical in nature. But this is also true that physical weathering encourages chemical weathering, and both may be carried out simultaneously because physical weathering promotes more surface area of parental rocks for more interaction with agents of chemical weathering.

4.1. What is pH?

pH is used to classify substance as acidic, neutral and alkaline, based on the prevalence of free H⁺ ions. Water molecules on autoionization dissociate to produce H⁺ and OH^- in equal number, although degree of dissociation is very small because of its stability (about one molecule in 10 million is ionized at any one time). H⁺ ions later attached to un-ionized water molecule to give rise hydronium ions, (H₃O)⁺

5.1. What is soil organic matter?

Plant and animal residues which are not yet added to the soil are considered as organic materials. However, once they are added to soil, they become soil organic matter. Therefore, organic materials contributing to the soil matrix are referred as Soil Organic Matter (SOM). Sometimes SOM is also used to highlight only the non-living organic materials produced by living organisms. But SOM should be regarded as a broad term that includes biomass, partially decayed residue, and highly decomposed and transformed organic substances, humus. Agricultural soil contains nearly 1-5% of SOM, which is regarded as least amount in soil as compared to other three soil components, minerals (45%), air (25%) and water (25%). However, it contributes enormously to soil productivity. Soil productivity and fertility exhibit direct positive relationship with SOM content in soil. Plants and animals are considered as primary and secondary sources of soil organic matter, respectively. Plant residues and application of organic manures e.g., farmyard manure, compost or green manuring help to build up organic matter in soil and thus, enrich the soil with organic carbon and other plant nutrients. Under natural conditions, roots of grasses in grasslands, the leaves including shoot portion of the large trees in forest lands and after harvesting the crop remnants in agricultural field provide enough incorporation of organic materials in soil. SOM plays a vital role to maintain sustainability in agricultural production through producing healthy soils and thus, healthy crops.

6.1. What is colloid and colloidal system?

A colloidal particle may be defined as a substance which is microscopically dispersed evenly throughout another phase and is possessing a size of 10^-7 to 10^-3 mm and representing a larger surface area per unit mass. Thus, a colloidal system refers to a two-phase system in which small particles of one phase which might be of solid, liquid or gas is suspended evenly in the second phase of solid, liquid or gaseous material. These colloidal systems may be of solid in liquid or solid in gas or liquid in liquid or liquid in gas. Unique examples of liquid in liquid colloidal system includes the fat droplets dispersed in water of milk. When you put floor disinfectant liquid in water, it forms a white emulsion. Thus, emulsion becomes a colloidal system of liquid in liquid. Likewise, in fog, water droplets are suspended in gaseous air. So, fog is an example of a colloidal system, constituting of liquid dispersed in gas. When we refer smoke, it contains carbon particles (solid) suspended in air (colloidal system of solid and gas). However, smog is composed of smoke and fog. In case of soil colloidal system, soil colloids, which are of tiny particles (<0.001 mm size) and may be of organic and inorganic nature, are suspended in soil solution (water) and referred to as sol. Colloidal chemistry, which involves in the surface reactivity and charge characteristics of colloids, plays a pivotal role in total soil chemistry.

7.1. Introduction

Like all other living organisms such as humans, animals, and microorganisms, plants also need elemental nutrients for their growth and development. They assemble the nutrients from soil, water and air. However, to obtain economical crop yield, nutrients are also supplied to the crops from external sources such as chemical fertilizers and manures and using biofertilizers. It is the present-day need to handle the soil fertility status in a more realistic and careful way to obtain maximum crop harvest. Under poor management practices, soil may become infertile and loose its importance in agricultural use. In modern days, huge food demand for the burgeoning human population does not permit to show luxury to use only fertile soil. Moderately fertile soil or even degraded soil should also be managed properly so that they may be used to grow crops. For this, plant nutrients status of the soil plays a significant role along with other soil properties. For sustainable soil fertility management, parameters such as crop to be raised, its nutrient demand at various growth stages, current nutrient status of the soil, amount of nutrient application based on the soil testing results etc are important to be considered. Balanced nutrition to the plants is the prerequisite to obtain maximum benefit. If nutrients supplied to the plants are low in quantity than their requirement, crop production is lowered down. Similarly, if the nutrients are provided in more amount in the soil or unbalanced way through fertilizer or manure applications, total crop yield is suffered. It is a very common example that excess of phosphorus leads to zinc deficiency in most crop plants and it has been observed that excess N is responsible for potassium starvation in potato. Again, excess of iron, manganese, zinc, copper shows plant toxicity. Addition of nutrients to soils in excess also causes environmental pollution when the excess nutrients are lost from soil by leaching, surface run-off and volatilization. Unscientific way of soil fertilization leads to increasing cost of cultivation and imparts adverse effect to the environment instead of doing any good. Therefore, one should have a clear knowledge on soil fertility to obtain a sustainable productivity.

8.1. What is an ion exchange reaction and its application in soil system

Ion exchange is a reversible chemical reaction between two substances, either between two electrolytes or between an electrolyte solution and a solid complex as well as between two solid phases (if in close contact with each other), where ions of equal charge may be interchanged in equivalent proportion.

Organic colloids and inorganic micelles (clays) are sites of ion exchange. Soil contains silicate clay minerals which exhibit charges due to isomorphous substitution as well as due to the pH dependant charges for ionisation of hydrogen and hydroxide functional groups. Organic matter present in soil also contributes to the pH dependent charges due to the presence of various active functional groups. Thus, the organic and inorganic colloids present in soil bear positive or negative charges. Electric charge on soil particles is neutralized by equivalent amount of oppositely charged exchangeable counter ions, held by coulomb forces and van der Waals forces. Ca⁺², Mg⁺², H⁺, K⁺, Na⁺, NH₄ ⁺, Al⁺³, Fe⁺³, Fe⁺², Mn⁺², etc. are the common cations present in soil where Ca⁺² serves as the dominant ion. However, Na⁺ and Al(OH)₂ ⁺ are the dominant cations found in the exchangeable phase in strong alkali and strong acid soils, respectively. SO₄ ^- 2, Cl^-, HCO₃ ^-1, NO₃ ^- etc. are the most common anions found in soil to neutralize positively charged soil colloids.

9.1. Introduction

Soil biology is a branch of science that studies the soil inhabiting organisms in relation to their ecology, functions, behaviour and impact on various soil processes and plant growth. Soil fertility is directly dependant on humus content as well as the presence of microorganisms in soil, although surface soil does not contain more than 0.5% by weight of living organisms. However, such a small portion of soil constituent as compared to other organic and inorganic constituents plays a significant and major role in transformation of plant nutrients from their unavailable to available form from organic wastes, soils and fertilizers. They have a direct role in improving soil tilth, providing an appropriate environment for root growth, decomposing organic residues to form humus and in turn releasing nutrients for plants use, releasing many plant growth promoters, fixing inert atmospheric nitrogen in plant usable forms and they promote many other important processes without which plants cannot survive. Absence of living organisms in soil leads to its infertility. An understanding of microbial processes in soil environment, keeping in view of soil nutrient status, carbon sequestration, soil health and quality, overall sustainability in agriculture and also global warming in respect of greenhouse gas emissions (nitrous oxide and methane) through agricultural practices, is very important in regulating nutrient release at different plant growth stages. If we are in a state to understand how various biological processes influence various changes in soil environment or in the opposite way that how different soil conditions alter the soil biota in number as well as in their functions and diversity, it is easier to implement soil management practices that promote to gain more benefits.

Microorganisms are ubiquitous in nature. Possessing a diverse habitat, they are found everywhere in soil, air and water at a varied temperature and pH. One may find the highest genetic diversity of life within the domain of microorganisms. But unfortunately very few are known to us, so far only 1% of the microbial species on the earth are culturable. However, it is believed that soil of one gram may contain hundreds of millions to billions of microbes which may represent several thousand microbial species. In respect of the population, bacteria top the list followed by actinomycetes, fungi, algae and protozoa in accordance with a decreasing numerical order. Out of three important soil fertility components viz. physical, chemical and biological; the biological component is least understood due to its wide complexity.

10.1. Introduction

The soils possessing characteristics that are not suitable and economical for crop growth are termed as Problem soils. These characteristics may be of physical, chemical and biological. For cultivation of crops in these soils, it is necessary to follow specific management interventions and proper reclamation measures. Frequently we come across another term, ’degraded soil’. Degraded soil is also a problem soil. However, there exists a hair-line difference between problem and degraded soil. Problem soils refer to the soils in which the inherent soil characteristics, obtained from its genesis, pose problems for their optimal use, while degraded soils are developed due to anthropogenic activities by unwise management interventions.

10.2. Types of problem

Mainly there are four types of problem that may exist in soils: physical problems, chemical problems, biological problems and nutritional problems as a result of physical, chemical and biological constraints in soils.