eChapters

Matrix is a rectangular array of numbers arranged in rows and columns. The order of a matrix is written as r x c, where r is the no. of rows and c is the no. of columns. The numbers included in a matrix are called elements of the matrix. The name of the matrix is denoted by an uppercase English alphabet.

Frequency Distribution is the arrangement of various values of a variable in order of magnitude either individually or in groups alongwith their corresponding frequencies or class frequencies. Frequency distribution is necessary for data condensation and revealing pattern within the data. Frequency distribution can be (i) Ungrouped Frequency Distribution (ii) Grouped frequency distribution.

In case ofungrouped frequency distribution, the individual values ofthe variable are arranged in ascending order alongwith their frequencies. Frequency is the number of times a particular observation is repeated.

In case of grouped frequency distribution, the values of variable are grouped into classes alongwith their corresponding class frequencies. Class frequency of a class is the number of observations lying within the upper class limit (maximum value) and lower class limit (minimum value) of the class.

Let us first illustrate the preparation of ungrouped frequency distribution. Consider 50 petridishes each containing 6 no.s of seeds for germination. Let the variable x_i denote the no. of seeds germinated in a petridish.

Diagrams and graphs are the effective and attractive ways of presenting data. Widely used diagrams for data presentation are pi chart and bar diagrams. Bar diagrams are also of various types; (i) Simple bar diagram (ii) Component or sub-divided bar diagram (iii) Multiple bar diagram (iv) Percentage bar diagram. The widely used graphical presentation are histograms, frequency polygon and frequency curve.

There are numerous libraries to create charts and graphs in R programming language.

Pie-chart- A pie-chart is a representation of values of variable as sectors of a circle with different colours/shadings. The colours/shadings used for different sectors are indexed at the side of the graph. pie() function is used to create pie chrt in R.

Let us create an exel file names as ‘exp_sports’ which contains the expenditure made (in Rs.) under various sports in a sports club. The name of the sports are cricket, hockey, tennis and football. The names of sports are placed under the column head ‘sports’. The corresponding expenditure (in Rs.) are 7200, 3600, 1800, 1800 and they are placed under the column head ‘expenditure’.

The basic syntax for creating a pie-chart using the R is.

The branch of statistics which describes the data is called descriptive statistics. After collection, the data are presented in form of tables, diagrams or graphs. This facilitates the further analysis of data. The most basic form of data analysis is descriptive analysis of data collected and presented for the study. The descriptive statistics summarises the data and helps to find the representative value of the entire data set and the variation of the other values in the data set around the representative value. The descriptive statistics includes the measures of central tendency or averages, measures of dispersion or scatteredness, measures of skewness and the measures of kurtosis. Before going to discuss the R codes for various measures of descriptive analysis, we would first discuss in brief about these measure. This will help in better understanding of the R codes.

Measures of central tendency or averages: They are the representative values of the data series. They give an idea about the concentration of the values in the central part of the distribution of the data. There are five types of averages. They are 1. Arithmetic Mean (A.M.) 2. Geometric mean (G.M.) 3. Harmonic Mean (H.M.) 4. Median 5. Mode.

The human body consists of trillions of cells and to be healthy it needs variety of foods and nutrients. The food around the globe includes a variety of spices which have many health benefits. It has been found that spices and vegetables in the diet are very important for living healthy. The traditional foods, nuts, seeds, wild fruits and vegetables which are used in the diet are grown in specific areas. Traditional food system plays a significant role towards maintaining the well-being and the health of people in any specific region.

According to Indian Philosophy (Bhat, 2012) the physical body is called Annamaya Kosha.A body, when well nourished grows well by absorbing the energies from the food consumed. Fasting is another aspect of traditional food system. It is meant to purify the mind and the body.

We all eat food because it provides the nutrients that are needed for the various functions of the body. Energy is required for growth and repair of tissues, to maintain body temperature and for physical activity. Energy comes from foods which are rich in carbohydrates, proteins and fat. This provides energy to the body from other nutrients and helps to keep the skin and nervous system healthy. They help towards the various biological activity in the human body. These nutrients are grouped into carbohydrates, proteins, lipids (fat), water, vitamins and minerals. These are used for growth, maintenance, repair and other needs of the body. Protective foods are which contain adequate amounts of vitamins, minerals and high-quality proteins which protect against the development of a deficiency disease. There are various chemical reactions taking place within each cell of a living organism. These provide energy for vital processes and for synthesizing new organic materials. This process is known as Metabolism. Living organisms get energy from the environment and use it for movement, growth, development and reproduction.

We get energy from food. We need energy for all the activities which we get by eating. The body structures as muscles, organs and bones are composed of the nutrients contained in food which are absorbed by the body.

Nutritional requirement of the major nutrients

Nutrients are the substances which are found in food and drive biological activity. They are essential for the human body. These are categorized into proteins, fats, carbohydrates (sugars, dietary fiber), vitamins and minerals (Sugishima, 2019). They perform the vital functions like building all parts of the body as muscle, bone, teeth and blood. Out of the 20 different kinds of amino acids that make up proteins nine are not synthesized in the body and are therefore called essential amino acids. These essential amino acids have to be supplemented through food. High-protein, low-carbohydrate diets have been found to be effective.Protein is an important component of every cell in the body. Large part of hair and nails are made up of proteins. The human body uses protein to build and repair the tissues, helps in making enzymes hormones and other body chemicals. Protein is an important building block of bones, muscles, cartilage, skin and blood.

To look into the nutritional security around the globe, FAO and WHO, have undertaken the analysis of policies. They have covered many issues which include; World Summit on Food Security, pillars of food security and availability, access, utilization, stability, effects of food insecurity, stunting and chronic nutritional deficiencies, depression, anxiety and sleep disorders. There are many challenges to achieve food security. These include global water crisis, land degradation, climate change, agricultural diseases, food versus fuel, politics, food sovereignty, food wastes, risks to food security, population growth, fossil fuel dependence, homogeneity in the global food supply, price setting, land use change, global catastrophic risks, agricultural subsidies and role towards children.

Indian Spices: These are dried, fragrant, aromatic or pungent vegetables or plant substances. They can be whole, broken or in ground forms. Primary function in food is seasoning rather than nutrition and which contributes to the flavour and piquancy in foods and beverages. These have been used as food additives widely since ancient times [http://www.imedpub.com/articles/herbal-medicines-possible-risks-andbenefits.pdf,https://www.ncbinlm.nih.gov/pmc/articles/PMC3170500/pdf/nihms307509.pdf). They also exert digestive stimulant action of food enhancing the taste. A few medicinal properties of spices are as being a tonic, carminative, stomachic, diuretic and antispasmodic (Aboaba et al., 2011; Achi, 2006 and Adefegha et al., 2012). This has led for pharmacological applications in the indigenous systems of medicine as digestive stimulants and to relieve digestive disorders and makes the food more palatable. In many countries around the world these are grown and reared for the purpose of trade and distribution. In the ancient times the spice merchants have been the most popular traders. India is well known for spices with a wide variety of recipes that are laced with them.

With increasing food production, availability and accessibility the global agro-industrial food system has improved.However, malnutrition, biodiversity loss and climate change are newer challenges. The best solution to this is the utilization of indigenous and traditional crops which will bring a transformative change in the food system. There is a need to look into the development of smallholder producers. The agro-industrial food system has improved the food supply and has made way for significant trade-offs with agro-biodiversity, dietary diversity, environmental sustainability and socio-economic stability mainly amongst the rural poor. Now is the time to mainstream the underutilized indigenous and traditional crops into the food system. This will provide opportunities to develop a sustainable and healthy food system.It will also help towards the societal goals which include employment creation, wellbeing and environmental sustainability.

Food fortification is the procedure in which micronutrients (essential trace elements and vitamins) are added to the food. As a public health policy fortification can be carried out by the food manufacturers or by the governments to help people in combatting dietary deficiencies within a population. Fortification can be done in food even if these nutrients are originally present or not. However, it improves the nutritional status of a population by overcoming the deficiencies of micronutrients. Deficiency of micronutrients is known as hidden hunger which is a serious health risk. Access to safe and nutritious food is a must.Due to the lack of consumption of a balanced diet, adequate micronutrients are not supplied to the body. Therefore, there is a considerable loss of nutrients during the processing of food. One of the strategies to address this problem is fortification of food.

For Indian foods

Food processing industries are the fastest growing in India. India is the largest producer of milk, bananas, mangoes, guavas, papaya, ginger and okra. It is the second largest producer of wheat, rice, fruits, vegetables, tea, sugarcane and cashew nut. It is the third largest producer of cereals, coconut, lettuce, chicory, nutmeg, mace, cardamom and pepper at the global level (Highlights of Agriculture Census, 2010-11, http://pib.nic.in/newsite/PrintRelease.aspx?relid=132799). Most part of the income is spent on foods. It is important to establish and nurture mutually beneficial relationships with global food processing, food retail and related supply chain organizations. This will in turn help in the realization of significant business growth opportunities in India, through newer technologies, innovations and ways of value additions. The geographical location of India helps in the export of items to other countries. It is connected to Europe, Middle East and Africa from the western coast and to Japan, Singapore, Thailand, Malaysia, Korea, Australia and New Zealand from the eastern coast. Food processing is a priority sector for the Indian Government, especially in recent times with “Make in India” initiative.The country is considered as one of the most favourable markets because of the easy and affordable credit and other fiscal incentives. The total consumption of food and beverages in India is US$ 369 billion which is expected to increase to US$1.142 trillion and the output in the food processing sector might increase to US$ 958 billion by 2025. This offers a vast market opportunity by the Indian food processing, food retail, transport, logistics and related infrastructure sectors to players in the food processing value chain. The market for plant and machinery in the food processing sector is estimated in the year 2024-25 to be USD 51.41 billion as compared to the current value of USD 17.3 billion (2016-17).

It has been found that at the household level the health of female members in any family suffers to a large extent. It could be encountered to low health care, poor housing or/and environmental conditions. Due to malnutrition it affects the health to such an extent that it gives rise to many diseases. For a sustainable nutritional status food and various aspects of health needs attention. Looking into that, nutrition is directly related to the health status. For food and nutrition security it is vital to see the availability, accessibility and utilization of food. The World Food Programme (WFP) developed the Vulnerability Analysis and Mapping (VAM) project to analyse the vulnerability to food insecurity of target populations. A prominent part of VAM is related to food access. The demographic and Health Survey (DHS), funded by USAID, provides health data for many countries to help them design their national policy. FAO has developed the Global Information Early Warning System (GIEWS), which collects data related to temporary food insecurity. Under the leadership of WHO, several health surveillance systems have been developed and implemented to monitor the epidemiology of various forms of malnutrition and of selected diseases. At the meso or sub-national level, food market surveys provide data on the availability of food. Agricultural production surveys, intra-household food frequency interviews, immunization surveys and anthropometric surveys of children under five can be used to assess the availability, accessibility and utilization of food and its stability at micro level. Most common Food and Nutrition Security (FNS) indicators at different social and administrative levels depends on the supply and demand. To determine the national situation of food availability data on the production of different food commodities, fertility rate and the trends in internal population needs to be seen. Food prices and per capita food consumption are indicators for national food accessibility. The rates of stunting, wasting and underweight in children, low Body Mass Index (BMI) in adults and low birth weight are FNS impact indicators that designate the extent to which food is adequately being used, utilized and converted into a satisfactory national nutrition situation. Fluctuations and shortages of food availability or accessibility in food prices make the national FNS unstable. Sensitive indicators for accessibility of food are the prices in the market. The sewage disposal and diarrheal diseases (DD) rates affect food utilization.A temporal food and nutrition insecurity arises due to pre and post harvest food availability and accessibility along with low BMI.If the food is in shortage leading to the consumption of more wild foods indicates reduced food availability at household level. Also if the number of meals per day goes down and unemployment increases it indicates low food accessibility.Malnutrition indicators like wasting, goitre or anaemia among the household members show reduced food utilization at micro level. Finally, changes in pre-harvest food consumption practices are good indicators for temporal food insecurity.

A number of innovations have taken place towards ready to eat instant food mixes of traditional origin. These have helped people to eat traditional food in which ever part of the world they go.

MTR Company

In India the best example is of MTR company which manufactures a range of packaged foods which includes breakfast mixes, ready to eat meals, masalas and spices, snacks and beverages. Snacks, such as kodubale, khara boondi and masala groundnut are very popular as they are ready to eat packets and contain healthy food with less oil. The different spices used for mixes are procured from famous countries which give the perfect taste and avoid rancidity.As a summer launch, milkshake with canned chikoo, banana and cold filter coffee are available. MTR Foods Pvt. Ltd. is a subsidiary of Norwegian conglomerate Orkla and is an acronym of Mavalli Tiffin Rooms. According to the company, India is on the verge of explosive growth in packaged instant foods. MTR has an aim to target a market of Rs 30, 000 crore with their products of traditional meals, breakfast, snacks and desserts. The Nielsen India study has shown that in 2020, the number of consumers in this category will be 2.7 times than the current base.

Mother’s Recipe is a brand which make traditional pickles in bottles with a distribution network to 20 states in India and exporting the products globally. The manufacturing is done in-house and the raw materials are procured seasonally in large quantities. After cleaning they are cut according to the recipe. Each variety of mango pickle has its own cutting process. Some are automatically cut, while others need manual work. The use of right oils, spices roasted inhouse, and marination of the pickles according to the practices of the particular region allow many consumers to relish them. Bottling and packaging are done only when the orders come.

Benjamin et al., (2016) have focused on the small-scale food processing enterprises (SSFPEs) as one of the important measures for national development and addressing food security challenges, particularly in Nigeria. The authors have explained the need for food processing as there has been tremendous food losses and wastages in the country. Enhancing the food processing and productivity for mechanization of food processing unit operations, development of new and existing technologies, design and development of machinery, systems for processing and preservation of different agricultural produce of high target have been undertaken. SSFPEs have played an important role in the economy of a developing country, particularly in terms of employment creation, income generation, post-harvest losses reduction, food preservation, value addition, improvement of food safety, nutritional quality, increase in shelf-life of a product and to act as training grounds for entrepreneurs before they invest in large scale enterprises. SSFPE’s around the world and especially in Nigeria are faced with significant challenges that compromise their ability to function and contribute optimally to the economy. Financial constraints and lack of management skills are the major constraints. It is important that governments and non-governmental organizations must encourage and facilitate the development of SSFPE’s. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO or GAIN in preference to others of a similar nature that are not mentioned. FAO’s Nutrition and Food Systems Division (ESN), in collaboration with the Global Alliance for Improved Nutrition (GAIN) 2018,

A sustainable and healthy food system is one which can provide food and nutrition security for all, in an economical way which is socially and environmentally sound for future generations. Underutilized indigenous and traditional crops can support and strengthen the existing food system, as they are in particular economical and friendly with the environment. Several underutilized indigenous and traditional crops are nutrient dense and adapted to marginal conditions, suggesting that they could be used to champion sustainable and resilient agriculture and food systems for smallholder farmers residing in these environments. The mainstreaming of underutilized indigenous and traditional crops and foods should be recognized for their attributes to make them desirable and to conserve them. In this regard, the fact that value chains for underutilized indigenous and traditional crops are poorly developed at present has created many opportunities to diversify the current food systems. This will create a new employment, market and distribution opportunities.It will also help to combat poverty. It will be if the smallholder farmers and women in rural areas are given the opportunity to utilize underutilized indigenous and traditional crops and re-enter the manistream system. A significant role which is played by the women for the production and conservation of underutilized indigenous and traditional crops offers opportunities for women empowerment through their inclusion in the food system. Promotion of gender equality and empowerment of women is directly linked for strengthening the sustainable food systems that can fight hunger and malnutrition and improve the lives and livelihoods of rural populations. The mainstreaming of underutilized indigenous and traditional crops into the food system would support women to diversify in a sustainable way, feed their own households and to provide nutritious food into the local markets. This will also help in addressing, the Sustainable

Sustainable agriculture’s benefit to farm and community economies is grounded in four well-established economic development principles and a fifth, concern for the community:

Lower input farming system (LIFS)

Lower input farming system means reduced production levels with larger area of land used in order to maintain the same revenue; or reduced dependency on external inputs with similar production structure but improved valorization of the product through transformation and or direct marketing, cutting the length of the production chain is a sustainability concept (produce and consume locally). LIFS are seeking optimization of on-farm resources, minimization of off-farm resources use. It also leads to mixed farming system, characterized by animal valorization of vegetal production on farm and organic manure restitution to farm soil from farm husbandry. Mixed character of farming system optimally combines annual and perennial crops and animal production on the same farm. Lower input farming also maintains ecological infrastructures (at least 5% in integrated farming)-which prove to be very beneficial for biodiversity – can provide shelter for organisms providing biological control and also be a source of raw material (wood) for producing on-farm energy.

Introduction

Nature is dynamic; it causes inheritable changes in all living organisms. For thousands of years, farmer around the world have been selecting and conserving varieties of different crop plants that they cultivated. This process has generated a rich wealth of varieties in each crop plant, seen to be most abundant in countries near the equator and India is no exception. In the world there are Mega centers of biodiversity of which aware present in India, this is because in India, the different soils and agro-climatic situations are present, so Indian farmers grow a large number of crops. Generation of Indian farmers, with their continued selection and conservation, has created a rich wealth of varieties in many crops. Therefore India is the original home of many crops such as rice, little and kodo millets, red gram, moth bean, jute, pepper, cardamom, many vegetables and fruit species. These plants were identified from the wild, selected and cultivated by Indian farmers over hundreds of years. The present wealth of varieties in India includes both crops that originated in the country and those that were introduced from the other countries during the distant and recent paste are soybean, sunflower, oil palm and kiwi fruit.

The Indian economy is predominantly rural and agriculture oriented. In agriculture, 85% of the holdings are less than two hectares and the declining trend in the average size of the farmer holdings, poses a serious problem. Majority of them are dry lands, which depend on erratic monsoon rains. The rest of the area is cultivated with supplemental irrigation. The farmers concentrate mainly on crop production, which is invariably subjected to a high degree of uncertainly income and employment.

In India the cultivable land is 143.8 million hectares and there is very little possibility of extending it further. Therefore, to meet the requirement of food grains for increasing population, the only option open is through time and effective space utilization in agriculture. The time concept relates to increasing the intensity of cropping under assured irrigated conditions, whereas space utilization pertains to building up of vertical dimension through multi-tier cropping and farming system approach. Thus by making use of these time and space concept either in irrigated or in rained areas, the productivity per unit area per unit time can be substantially enhanced. Therefore the only way to increase an agricultural production in the small/marginal units of farming is to increase the productivity per unit time and area. This may be achieved of quicker maturing varieties with equal yields or by improving techniques of culture, fertilizer use, weed and pest control.

Introduction

Solid waste management is a worldwide problem and it is becoming more and more complicated day by day due to rise in population, industrialization and changes in our life style. Large quantities of organic wastes are produced from agricultural production and farming systems which include animal manures, sewage biosolids, food wastes, and industrial organic wastes. Globally, these wastes have the potential of increasing soil and water pollution as because they are currently disposed of by land-spreading, incineration, or into landfills. As much as 50%-60% of the total wastes that are disposed into landfills are organic wastes. If these were turned into materials useful in farming system, there would be great savings in primary plant nutrients and metabolic energy.

Vermicomposting has been arising as an innovative eco-technology for the method by which compost or mixed manure of organic origin or conversion of various types of waste is prepared by the use of earthworms. It is a controlled degradation (non-thermophilic, boioxidative process) of the organic wastes for the consumption of earthworms, helps in the recycling of food wastes, reduces the waste bulk density and the final product may contain hormone-like substance which accelerates the plant growth. Vermicompost is humus like, finely granulated and stabilized material which can be used as a soil conditioner to reintegrate the organic matter to the agricultural soils. Industrial wastes remain largely unutilized and often cause environmental problems like ground and surface water pollution, foul odours, occupying vast land areas etc. Non-toxic and organic industrial wastes could be potential raw material for vermitechnology. In the last two decades, vermin-technology has been applied for the management of industrial wastes and sludges and to convert them into vermicompost for land restoration practices. The success of the process depends upon several process parameters like quality of raw material, pH, temperature, moisture, aeration etc., type of vermicomposting system and earthworm species used. Vermicomposting and vermiculture are two interlinked and interdependent processes where vermiculture can be done in the presence of decomposable waste organic matter

Introduction

Cyanobacteria are often called “blue-green algae”, this name is convenient for talking about organisms in water that make their own food, but does not ref lect any relationship between the cyanobacteria and other organisms called algae. Cyanobacteria are relatives to bacteria, not eukaryotes, and it is only the chloroplast in eukaryotic algae to which cyanobacteria are related. Some cyanobacteria are aquatic and photosynthetic, that is, they live in water, and can manufacture their own food. They are quite small and usually unicellular, though they often grow in colonies large enough to see. In fact, it may surprise you then to know that the cyanobacteria are still around; they are one of the largest and most important groups of bacteria on earth (Berry et al., 2008). The great contribution of cyanobacteria is the origin of plants chloroplast with which plants make food for themselves is actually a cyanobacterium living within the plant’s cells. Sometime in the late Proterozoic or in the early Cambrian, cyanobacteria began to take up residence within certain eukaryote cells, making food for the eukaryote host in return for a home. This event is known as endosymbiosis, and is also the origin of eukaryotic mitochondrion (Issa et al., 2002).

Introduction

Plant growth in agricultural soils is inf luenced by a myriad of abiotic and biotic factors. As a routine practice growers normally use physical and chemical approaches to manage the soil environment to improve crop yields while the application of microbial products for this purpose is less common. An exception to this is the use of rhizobial inoculants for legumes to ensure efficient nitrogen fixation; a practice that has been occurring in North America for over 100 years (Smith, 1997). The region around the root, the rhizosphere, is relatively rich in nutrients, in expense of as much as 40% of plant photosynthates from the roots (Lynch and Whipps, 1991). Consequently, the rhizosphere supports large and active microbial populations capable of exerting beneficial, neutral, or detrimental effects on plant growth. The importance of rhizosphere microbial populations for maintenance of root health, nutrient uptake, and tolerance of environmental stress is now recognized (Bowen and Rovira, 1999; Cook, 2002). These beneficial microorganisms can be a significant component of management practices to achieve the attainable yield for in other words a crop yield limited only by the natural physical environment of the crop and its innate genetic potential (Cook, 2002).

The prospect of manipulating crop rhizosphere microbial populations by inoculation of beneficial bacteria to increase plant growth has shown considerable promise in laboratory and greenhouse studies however, responses have been variable in the field (Bowen and Rovira, 1999). The potential environmental benefits of this approach, leading to a reduction in the use of agricultural chemicals are fitting the sustainable management practices. Realizing the biological interactions occurring in the rhizosphere, recent progress are in need to fulfill the practical requirements of inoculant formulation and timely delivery which would increase the technology’s reliability in the field and facilitate its commercial development.

Introduction

Water is a vital component of agricultural production. It is essential to maximise both yield and quality. Water has to be applied in the right amounts at the right time in order to achieve the right crop result. At the same time, the application of water should avoid waste of a valuable resource and be in sympathy with the environment as a whole. Understanding, measuring and assessing how water f lows around the farm, and recognising how farming practices affect f lows, will help farmers to manage water efficiently and reduce pollution risks. Land management and advanced technologies can help maximise the “crop per drop” that farmers produce worldwide. Water used in irrigation accounts for 90% of agricultural water demand. Improving irrigation systems is therefore crucial to making contributions to water savings in agriculture. In any agricultural production system the promotion of good agricultural practices and product stewardship is fundamental for sustainable agriculture. Industry is part of various multi stakeholder partnership initiatives that support efforts to protect water quality. These include reducing soil erosion, avoiding pesticide run-off and maintaining wildlife habitats as part of a holistic farm or land management approach.

Is it possible to feed a world population projected to reach 8.5 billion by 2030, 9.7 billion by 2050 and exceed 11 billion in 2100? India expected to surpass China as the most populous country in the world within seven years (UN report July 2015). Besides that there is an immense decline in yield and quality over the past three decades may be at the point of diminishing returns (Bouis 1993; Cassman et al. 1995; Flinn and De Datta 1984). Furthermore, the soil is partially under tremendous pressure to sustain yield and production. The excessive and exhaustive agriculture practices have not only declined the soil quality but it’s also reported for different human and animal health issues. Thus, keeping pace with population growth and health safety appropriate soil management practices must be addressed. Now burgeoning population load, declining yield, soil health diminution, and effect on human and animal health arises the opportunity for sustainable soil management to cater the problem at the right time. Figure 1 clearly indicates the tremendous load on soil and subsequent results. Burgeoning increase in population and a load of food production intensification, sustainable soil management will become increasingly important in future. Soil being the powerhouse of the mineral nutrients also retains most living organisms within it. The appropriate soil management practices ensure the critical level of mineral elements which finally come into the human body.

Biodiversity is a magnificent contribution of nature on our planet. The great variety of life forms on earth has catered for man’s needs over thousands of years. This diversity of living creatures which forms a support system has been used by each civilization for its growth and development. Those that used this “bounty of nature” carefully and sustainably survived. Those that overused or misused it disintegrated. The attempt to classify and categorize the variability existing in nature for over a century has led to an understanding of its organization into communities of plants and animals. This information has helped in utilizing the earth’s biological wealth for the benefit of humanity and has been integral to the process of development. This includes better health care, better crops and the use of these life forms a raw material for industrial growth which has led to a higher standard of living for the developed world. However, this has also produced the modern consumerist society, which has had a negative effect on the diversity of biological resources upon which it is based. The diversity of life on earth is so great that if we use it sustainably we can go on developing new products from biodiversity for many generations. This can only happen if we manage biodiversity as a precious resource and prevent the extinction of species.

The sustainable management of biodiversity is one of the most important challenges facing humanity. Biological diversity, abbreviated to biodiversity, refers to the variety of life forms at all levels of organization, from the molecular to the landscape level. These are the legacy of billions of years of evolution, shaped by natural processes and increasingly, by the activities of humans. Losing biodiversity has eroded the basis for social and ecological resilience, which has resulted in reducing the capacity for adaptive responses in a rapidly changing world. However, human activities still continue to have a large impact on the environment and on biodiversity. Agricultural, urban and infrastructural developments and climate change has exacerbated biodiversity loss. As a result, ecosystem functions and services are affected with serious consequences. The Sustainable Development Goal should be devoted to “protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss”. It is high time to realize the linkages between the severity of global biodiversity loss and degradation of ecosystems and the negative impact that this situation have resulted on food security, nutrition, access to water, health of the rural poor and people worldwide.

Agroforestry: At a Glance

Agroforestry as a landuse system is gaining wide importance and acceptance in the current global scenario to mitigate global climatic conditions. It is a highly efficient system of sustenance for the rural population with ample livelihood opportunities. The benefits from agroforestry is immense for socio-economic as well as in ecological perspective. From the vivid ecosystem services like climate regulation, carbon sequestration, soil productivity and biodiversity conservation to food security and sustainable livelihood enhancement, agroforestry envisages immense services. The implication of the agroforestry system and practice varies from area to area. Traditional agroforestry can be modified by implementing different species combinations suitable for vivid regions thus enhancing the long term productivity. An important specification of agroforestry is with a minimal labour input maximum production and utilization of resource could be attained. National Agroforestry policy, implemented is a big step forward for new agroforestry initiatives in the country. Conduction of region specific agroforestry studies and policy implementations with involvement of rural populations will be an effective breakthrough approach for a sustainable future.

Introduction

During the past 60 years, conventional agriculture has become increasingly dependent upon petroleum-based. Chcmically-synthesized fertilizers and pesticides for crop protection and to supply plant nutrients. Certainly, these energy intensive technologies have contributed greatly to this Nation’s agricultural productivity. However, sharply escalating production costs associated with the increasing cost and uncertain availability of energy i.e., fuel and fertilizers, have generated considerable interest in less expensive and more environmentally compatible production alternatives such as organic farming (USDA, 1980). The apparent decline in soil productivity throughout the world from excessive soil erosion, nutrient runoff and loss of soil organic matter; the impairment of environmental quality from sedimentation and pollution of natural waters by agricultural chemicals and the potential hazards to human and animal health and food safety from heavy use of pesticides, have also stimulated interest in organic farming systems of food production.

Use of organic wastes and residues in agriculture

Most countries have traditionally utilized various kinds of organic materials to maintain or improve the fertility, and productivity of their agricultural soils. However, several decades ago organic recycling practices were largely replaced with chemical fertilizers which were applied to high yielding cereal grains that responded best to a high level of fertility and adequate moisture, including irrigation. Soil cultivation was also intensified to improve weed control and seedbed conditions. Consequently, the importance of organic matter to crop production received less emphasis, and its proper use in soil management was neglected, or even forgotten. As a result of this and failure to implement effective soil conservation practices, the agricultural soils in a number of developed and developing countries have undergone serious degradation and decline in productivity.

Introduction

Chemical pesticides play an important role in plant protection in India and most of the developing countries of the world. These synthetic organic insecticides provide spectacular control of insects. Chemical control is one of the effective and quicker methods in reducing pest population. However, over reliance and injudicious use of pesticides resulted in a series of problems in the agricultural ecosystem mainly, the development of resistance in insects to insecticides, pest resurgence, outbreak of secondary pests into primary nature, environmental contamination and residue hazards, destruction of natural enemies of insect pests etc. All these problems aggravate the pest problem in agricultural crops. Thus, the importance of eco-friendly pest management techniques is being realized more and more in the recent past. The modern concept of pest management is based on ecological principles and involves the integration of different control tactics into a pest management system. This is not altogether a new concept. It was practiced before the advent of modern chemicals. Integrated Pest Management is an ecological approach in which utilization of all available techniques of pest control to reduce and maintain the pest population at levels below economic injury level. The UN’s Food and Agriculture Organisation defines IPM as the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimize risks to human health and the environment. IPM emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms. A well-defined Integrated Pest Management (IPM) is a program that should be based on prevention, monitoring, and control which offers the opportunity to eliminate or drastically reduce the use of pesticides, and to minimize the toxicity of and exposure to any products which are used. So, IPM is an eco-friendly approach which encompasses cultural, mechanical, biological and need based chemical control measures.

Introduction to sustainable disease management

Plants and pathogens are involved in ongoing interactions over millennia that have been modified by coevolutionary processes to limit the spatial extent and temporal duration of disease epidemics (Zhan et al. 2015). These interactions are disrupted by modern agricultural practices, such as intensified monoculture using high yielding varieties. Agricultural intensification and monoculture coupled with globalization disrupt the coevolutionary dynamics of plant-pathogen interactions which escalating the evolutionary rate of pathogens and increasing the risk of plant disease epidemics. These activities, when supplemented with high resource inputs, create unique conditions which is conducive to widespread plant disease epidemics and rapid evolution of pathogen. Disease management requires a significant shift to include ecoevolutionary principles in the design of adaptive disease management strategy for minimizing the evolutionary potential of plant pathogens by reducing their genetic variation, stabilizing their evolutionary dynamics, and preventing dissemination of pathogen variants carrying new infectivity or resistance to pesticides (Zhan et al. 2014). As environmental and ecological issues continue to impact on agriculture, all the crop-specific and regional-specific, Good Agricultural Practices (GAP) to be developed for crop production, must be economically feasible, ecologically sound, environmentally safe and socially acceptable. Numerous non-chemical methods for management of crop diseases such as pathogen-free seeds, disease resistance, crop rotation, plant extracts, organic amendments and biological control agents are considered less harmful than chemical pesticides and therefore, offer great potential for application in modern agriculture (Marshal et al. 2008). No single method can provide satisfactory management of crop diseases. Integration of all the effective and eco-friendly measures in accordance with the dynamics of the agro-ecosystem management would be the best strategy for efficient plant disease management.

Introduction

Weeds are the most costly category of agricultural pests, causing more yield losses and added labor costs than either insect pests or crop disease. Weeds are a constant fact of life in annual row crops, vegetables, and other horticultural crops. In India, the manual method of weed control is quite popular and effective. The usage of herbicides in India and elsewhere in the world is increasing due to possible benefits to farmers. At the same time, the continuous use of herbicides of the same weed shift, herbicide resistance in weeds and environmental pollutions. Application of herbicides also kills species of bacteria, fungi and protozoa thereby upsetting the balance of pathogens and beneficial micro organisms. The complexity of these situations has resulted in a need to develop a holistic sustainable eco-friendly weed management programme throughout the farming period (Gnanavel and Natarajan, 2014). Sustainable development of agriculture is concerned about the conservation of land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable. Sustainable weed management is the use of weed control methods that are socially acceptable, environmentally benign and cost-effective.

Introduction to sustainable livestock

Sustainable development has been defined by FAO as “the management and conservation of the natural resource base, and the orientation of technological and institutional change in such a manner as to ensure the attainment and continued satisfaction of human needs for present and future generations. In other words, the development that meets up the needs of the present without compromising the ability of future generations to meet their own needs. Such sustainable development (in the agriculture, forestry and fisheries sectors) conserves land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable”. (FAO Council, 1989). Hence, sustainable livestock farming is “the efficient production of safe, high quality products, in a way that protects and improves the natural environment, the social and economic conditions of farmers, their employees and local communities, and safeguards the health and welfare of all farmed species”.

Introduction

With India’s population to catapult to a gigantic figure of 1.63 billion by 2050, it rests upon the shoulders of the country’s dwindling land resources to cater to the food demand to the surging human race with an eco-friendly manner. This requires a mammoth effort from the food producing machinery of the country-an effort which has to be inclusive of the technological innovation and extension in this field and to the fullest possible extent. Coping with the short-run challenges to food security posed by food price volatility is indeed a daunting task. But the serious concern is the long-term challenges of avoiding a perpetual food crisis under conditions of global warming. The decline of contributions of Indian Agriculture to the National GDP and an apparent stagnation of the growth rate in agriculture, non remunerative agricultural system, ever increasing population pressure, shrinking land resources, global warming and climate change, indiscriminate use of agricultural inputs, over exploitation of natural resource base and environmental quality have made the situation more vulnerable towards food security. In this backdrop, agricultural knowledge and technology accumulation, transfer, application, and diffusion are key to sustainable development and food security in an eco-friendly manner. The knowledge and technology revolution is critically different from the past industrial revolution in that it is based upon a shift of wealth creating assets from physical things to intangible resources based on knowledge and technologies. Thus, effective management and transfer of knowledge and technologies are believed to be the most critical capability of individuals, organizations, and nations in the globalized 21st knowledge society. Extension could play a pivotal role in fostering sustainability through its educational programs but there has been a growing realization that traditional extension models have not been sufficiently effective in promoting socialization of sustainable agricultural practices. Since sustainable agriculture is a knowledge-intensive system, it requires a new kind of knowledge, which differs from other forms on the basis of conventional agricultural practices. In fact, conventional extension system cannot accomplish sustainability in agriculture; because today’s agricultural extension must consider environmental implications, social issues, and overall economic growth within the agriculture sector. In such a situation, the present conceptual discussion shall be envisaging the dictum and destiny of evolving extension approaches by cherishing a clear focus on extension management perspectives towards sustainable development and environment protection and management so as to the well established extension approaches can be restructured and applied in the niche of extension management towards sustainability.

Our production systems are at a pivotal stage in terms of meeting consumer demand for affordable food while improving sustainability. Current intensive crop production practices designed to maximize yield have created an unstable, fragile, and non-sustainable production system. Such systems are prone to reduced soil quality, frequent insect and disease resurgence, emergence of resistant weed species, reduced food quality, and detrimental effects on the health and well-being of our communities. With increasing awareness among consumers of produce quality, nutritional value, methods of crop production and effects of production techniques on the environment, there has been a strong move to improve the quality of our production systems. Grower response to this change has been supportive. Growers have shown interest in developing resilient and stable production systems through the adoption of production practices that enhance soil health, crop productivity, and improve long-term farm sustainability and profitability. Such practices emphasize the use of natural processes within farming systems, often called ‘ecologically sound’ practices which build resilience through synergies and complementarities within the field, the farm, and across our landscape and communities.

Sustainable horticulture is nothing but a contemporary approach to horticulture that emphasizes organic/natural approaches and allows an integrated meshing of ideas with synthesized chemicals used sparingly or relegated to the “last resort.” High Tech & Low Tech are encouraged to create a long-term viable result. Short-Term techniques that impact the environment negatively and thwart the biodynamic continuum are rejected.

ESSENTIAL ELEMENTS FOR PLANT GROWTH

Arnon (1954) set three criteria to state an element is essential to plants. They are:

1. The plant must be unable to grow normally or complete its life cycle in the absence of the element,
2. The element is specific and cannot be replaced by another and,
3. The element plays a direct role in metabolism.

Accordingly there are 16 elements essential for plant growth. They are carbon, hydrogen and oxygen called primary nutrients, calcium, magnesium and sulphur called secondary nutrients; iron, zinc, manganese, copper, boron, chlorine and molybdenum are known as micronutrients.

Concept of nutrient availability: The ions in the soil solution are available to plant provided they can reach an active root or it can reach them. The concentration of ions in the soil solution at any given moment is however; usually low, except immediately after the application of water soluble fertilizers.

Most of the nutrients are taken up by the plant in the form of cations which are positively charged. Available cations either in the soil solution or held against leaching by negatively charged clay or humus particles are easily taken up by the plants. Other plant nutrients notably phosphorus, boron and molybdenum are taken up by the plant as anions which are negatively charged. The concentration of anions in the soil solution is usually low because they become converted to new less soluble forms e.g., soluble phosphate ions forms less soluble iron or aluminium phosphates. Minerals upon weathering and organic matter upon mineralization release nutrient ions.

Physical factors

However, much readily available nutrients a soil may contain various physical features of the soil make it impossible for the plant roots to absorb it. It then becomes positionally unavailable. These features include hard pans, undesirable soil structures, presence of hard clods, dry soil horizons and water logged situation.

Low soil cation exchange capacity leads to less retention of calcium, magnesium, potassium, copper and zinc.

Plants are the generators or the primary source of organic matter while animals are the transformers- secondary source of organic matter. In agriculture, plants add 10–30 percent of organic matter through their roots stubbles and leaf fall and exudations. The excreta of livestock, the organic wastes of urban and rural residential areas include the garbage and sewage and sludge. The by products of agro based industries viz. bagasse, vinasse, pressmud from sugar industries, the coir dust from the coir industries, dust of cotton from ginning industries, the fruit and food processing industries wastes.

Greek scientist Theophrastus (300 BC) advocated legume rotation. As early as 1750 AD it was known that plants require Nitre. Louis Pasteure in 1860 AD stated the possibility of atmospheric nitrogen fixation by microorganisms. Hellriegel and Willfarth (1886) strengthened the views of Louis Pasteure by his observations on the irratic behaviour of legumes to nitrate nutrition. Beizerink (1890) isolated the organism involved in nitrogen fixation. The systematic field experiments conducted at Rothemstead experimental station showed that the plants respond to inorganic nitrogen.

ROLES OF NITROGEN IN CROPS

Plants contain 1-5 per cent nitrogen by weight. It is a structural component of chlorophyll, aminoacids and proteins. Plant proteins contain 16 per cent nitrogen (6.25 × %N = protein). Plants are dependent on protein for their propagation. Cereals possess a threshold protein level below which grain will not form.

Liebig (1840) on the basis of soil and plant analysis deduced the phosphorus requirement of plants. J.B. Lawes conducted series of field experiments to improve the fertilizer value of common sources of phosphorus such as bone meal, apatite, rock phosphate. Lawes (1843) produced super phosphate by treating apatite mineral containing phosphorus with sulphuric acid. He also stated that the phosphorus present in bones of higher animals can be made available by treating with sulphuric acid.

Phosphorus is the second most deficient nutrient in the world. Annual application of phosphorus fertilizers to crops is 36 million tons of which

1.32 m tones are consumed in India. Most of the arable soils in tropical and subtropical regions are deficient in phoshphorus, but the response of crops to phosphorus is uncertain. Phosphorus concentration in plants ranges from 0.1 to 0.4 per cent.

Glauber J. R. (1604–1670) in Netherlands first proposed that the salt peter (KNO₃) was the principle of vegetation. He obtained large increases in crop yield by addition of salt peter.

Mineral soils contain 0.04–3.0% K. Total potassium content of soils range from 3000 to 100000 kg per ha in the upper 0.2 m of soil profile. Of this total potassium approximately 98 percent is bound in mineral form whereas 2% in soil solution and exchangeable phases.

ROLE OF POTASSIUM

It is Involved in activating the enzymes (as many as 80) responsible for carbon dioxide reduction and required for synthesis of adenosine triphosphate. Hence deficiency of potassium reduces crop growth and yields.

CALCIUM

Calcium is important in imparting structure and permeability to cell membrane. Deficiency produces general breakdown of membrane structure. Calcium enhances the uptake of NO₃ ^– N and interrelated with NO₃ ^– metabolism. It regulates cation uptake, required for cell elongation and cell division. Deficiency causes failure of terminal buds and apical tips of roots to develop. Blossom end rot of tomato, bitter pit of apples are due to calcium deficiency. Calcium is beneficial in imparting good soil structure.

It is immobile in plant. Very little translocation of calcium in the phloem is observed. Hence there is poor supply of calcium to fruits and storage organs. Downward translocation of calcium is also limited. Hence roots fail to enter the low calcium soils.

ZINC (Zn)

Chandler et al., (1932) deduced the requirement of zinc by plants while working solution for little leaf or “rosette” on peach. Zinc plays significant role in assimilation of NO₃ and for synthesis of tryptophan. Involved in biosynthesis of indole acetic acid which is responsible for f lowering and fruiting, it is an activator of several enzymes (triphosphate dehydrogenase and tryptophan synthetase), involved in photosynthesis and nitrogen metabolism.

Deficiency results in poor growth of the terminal bud. Decrease in stem length resulting in resetting and whorling of leaves. Zinc deficiency disorder in rice is called khaira. Common when zinc availability is < 0.7 ppm. White bud in maize and malformation of fruits, reduction in water uptake. Interveinal chlorosis often with necrosis and pigmentation and reduced leaf size in broad leaved crops known as little leaf and malformation of leaves.

The crops which are known to respond for zinc application are maize, rice, soyabean, castor, onion, barley, wheat, potato, sorghum and cotton

Farmyard Manure is the manure prepared by using the mixture of dung and urine soaked litter by microorganisms.

Good farmyard manure is one

Green manure is defined as fresh organic matter/undecomposed plant material/ real organic matter, natural plant food added to the soil for the purpose of supplying plant nutrients.

CLASSIFICATION OF GREEN MANURES

Nonlegumes: Rape seed, buck wheat, niger, rye, oats and maize

Legumes:

Grain legumes: cowpea, mungbean, pigeon pea, soybean, khesari (Lathyrus sativus)

Dual purpose legumes: cluster bean (Cyamopsis tetragonoloba). pillipesara, Sesbania speciosa.

Non grain legumes: sunnhemp, dhaincha, pillipesera (Phaseolus trilobus), stylosanthes and desmodium.

Biofertilizers act as complementary and supplementary sources of plant nutrients. Biofertilizers help in increasing the biologically fixed atmospheric nitrogen and enhancing phosphorus availability to the crops. Among the biofertilizers for increasing nitrogen supply, nitrogen fixing bacteria (Rhizobium, Azotobacter and Azospirillum), blue green algae (BGA) and Azolla are important. The availability of phosphorus is improved by phosphorus solublizing microorganisms (PSM) and mycorrhizae (VAM).

Rhizobium is of vital importance to various pulses and some of the oilseeds and fodder legumes as 80–90 per cent of their nitrogen requirement is met through biological nitrogen fixation (BNF). Rhizobium fixes atmospheric nitrogen ranging from 50–60 kg per ha in groundnut, 100–300 kg per ha in alfalfa. In pulses it is estimated at 50–110 kg/per ha. Field studies indicated a yield increase of 14–53 per cent due to Rhizobium inoculation. Nitrogen left over the demand of legumes in combination with the nitrogen present in roots of the legumes will enhance the soil fertility. Consequently the nutrient needs of the subsequent crop from applications will be reduced.

Integrated plant nutrition system conceptualized by food and agriculture organization is the maintenance or adjustment of soil fertility and of plant nutrient supply to an optimum level for sustaining the desired productivity through optimization of benefits from all possible sources of plant nutrients viz. organic manures, fertilizers, crop residues, compost or nitrogen fixing crops etc. in an integrated manner.

SOIL MANAGEMENT PRACTICES

Good soil management is the basic for deriving greater benefits from the fertilizers used in crop production. Some of the good soil management practices are

Good tilth is the first feature of good soil management. It means a suitable physical condition of the soil and implies in addition a satisfactory regulation of soil moisture and air.

The maintenance of soil organic matter which encourages granulation is an important consideration of good tilth.

Tillage operations and timings should be adjusted as to cause the minimum destruction of soil aggregates. Good tilth minimizes erosion hazards.

The choice and sequence of adaptable crops or crop rotation are other very important considerations. These are related to climate, particularly rainfall and its pattern of distribution and the characteristics of the soil profile, including drainage and extent and duration of available soil moisture. A proper sequence of crop varieties greatly influences soil conditions. It is more realistic to evolve cropping patterns and land management practices according to land capability. Cropping patterns chosen and management practices adopted should aim at soil and moisture conservation for efficient nutrient and moisture utilization.

Salt affected soils occupy 962.2 m ha globally which accounts for 33% of the arable land. In India 8.373 m ha is affected with salts. Of which 2.359 m ha are alkali soils, 3.829 m ha are saline soils and 2.185 m ha coastal saline soils. Reclamation of these soils provides additional area for food grains production and employment.

Soil represents a medium or substrate in which numerous microorganisms live and bring about a great variety of processes that are responsible for the continuation of the cycle of life in nature. The numerous living forms which spend their life in the soil, ranging from submicroscopic forms to the lower animal forms. With the growing recognition of the numerous processes carried out by the microorganisms in the soil there gradually emerged a branch of microbiology, which came to known as soil microbiology. It is a branch of soil science concerned with soil-inhabiting microorganisms and their functions and activities.

Since soil microbiology concerns soil microorganisms and their processes it is closely associated with soil biochemistry. Medical bacteriologists are interested in the soil as a medium for the growth and survival of disease-producing organisms. Agricultural chemists are also interested in the soil processes that result from the activities of microorganisms. General bacteriologists, zoologists, botanists are interested in a certain special group of organisms found in the soil. Recently, soil microbiology has expanded to include the study of the role of soil microorganisms in genetic engineering, in the biological control of pests and diseases, the degradation of pollutants, production and destruction of radioactive gases and its transfer. Thus microbial participation in several important processes emphasizes that soil microbiology has become a global science.

History of Soil Microbiology

There is enough evidence in the literature to believe that microorganisms were the earliest of the living things that existed on this planet. Man depends on crop plants for his existence and crop plants in turn depend on soil and soil microorganisms for their nutrition. Scientists from the beginning studied the microorganisms from water, air, soil, etc. and recognized the role of microorganisms in natural processes and realized the importance of soil microorganisms in the growth and development of plants.Thus, microorganisms have been playing a significant role long before they were discovered by man. Today, the soil is considered to be the main source of scavenging the organic wastes through microbial action and is also a rich storehouse for industrial microflora of great economic importance.

Unlike soil science whose origin can be traced back to Roman and Aryan times, soil microbiology emerges as a distinct branch of soil science during the first half of the 19^th century. Some of the notable contributions made by several scientists in the field of soil microbiology are highlighted in the following paragraphs.

Anton Von Leeuwenhoek (1673) discovered and described microorganisms through his own made first simple microscope with a magnification of 200 to 300 times. He observed minute, moving objects which he called “animalcules” (small animals) which are now known as protozoa, fungi, and bacteria. He for the first time made the authentic drawings of microorganisms (protozoa, bacteria, fungi).

Soil is a bioorganic - mineral complex of the loose surface layer of the earth’s crust. Soil microbiology is the science that deals with the millions of microscopic forms of life found in the soil. It is stated that one hectare - foot (one hectare to a depth of 30cm) contains 2 to 10 metric tons of living microorganisms. Soil microorganisms are in a constant struggle for existence and are believed to be in a state of dynamic equilibrium. Without microorganisms, the soil would be an inactive geological mass incapable of supporting plant life and without plant life, animal life would not be possible. This soil population consists mainly of bacteria, fungi, actinobacteria, algae, and protozoa. The soil ecosystem includes these microbial groups as well as the inorganic and organic constituents of a given site. The collections of cells represented in the community are considered as distinct populations. All the inhabitants of the particular locality make up the community.

Types of Microorganisms in Soil

Living organisms both plants and animals, constitute an important component of soil. The pioneering investigations of several early microbiologists showed for the first time that the soil was not an inert static material but a medium pulsating with life. The soil is now believed to be a dynamic or rather a living system, containing a dynamic population of organisms/microorganisms. Cultivated soil has relatively more population of microorganisms than the fallow land, and the soils rich in organic matter contain much more population than sandy and eroded soils. Microbes in the soil are important to us in maintaining soil fertility and productivity, cycling of nutrient elements in the biosphere, and sources of industrial products such as enzymes, antibiotics, vitamins, hormones, organic acids, etc. At the same time certain soil microbes are the causal agents of human and plant diseases.