eChapters

Tillage is the physical manipulation of the soil with tools and implements which, results in good tilth for better germination and subsequent growth of crops.

Tilth is the physical condition of the soil resulting from tillage. Soil is said to be in good tilth when it is mellow, friable and adequately aerated. Tilth is dynamic. Mechanical forces may change the roughness of the soil surface, the total porosity and bulk density of the tilled layer and the aggregate or clod size. Heavy rainfall and high velocity wind or water destroys the tilth. The action of wetting and drying, freezing and thawing regenerates desirable tilth. The roughness of the soil surface is an index of the amount of water that can be stored in soil depressions and may also be related to the resistance of the soil surface to sealing. Roughness may be related to rate of evaporation, transfer of heat and air between the soil and atmosphere.

A seed consists of a plant embryo, stored food material surrounded by a seed coat. Seeds of cereals and grasses consist of embryo or germ, endosperm and the pericarp.

Seeds of legumes contain no endosperm, the bulk of the seed being made up of the two cotyledons. The cotyledons constitute the food storage portion.

The embryo of the grass seed is made of epicotyl, hypocotyl and scutellum- the single cotyledon of monocots, the epicotyl gives rise to the shoot and the hypocotyl produces the roots.

Criterion for essentiality of plant nutrients

Arnon’s (1954) criteria for essentiality of elements for plant growth:

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.

Manures are the plant and animal wastes that are used as source of plant nutrients. They release nutrients upon their decomposition.

Bulky organic manures contain small percentage of nutrients and they are applied in large quantities. e.g,. farmyard manure, compost, green manures.

Knowledge of fertilizer dose, selection of fertilizer sources, time and method of application is essential for achieving efficient use of fertilizers and profitable yield.

A. Fertilizer Dose

Fertilizer dose for crops is determined based on the field experimentation. It varies with the crops and varieties, initial fertility of the soil, soil properties, cropping system, climate, season, rainfed or irrigated crop, expected yield etc. Fertilizer dose for rainfedcrops (Kg/ha)

Plant growth is defined as the progressive development which is irreversible. It is expressed in terms of dry weight plants, height of plants, girth or diameter of the stem or tree trunks, spread of the tree canopy, number of branches or tillers. Plant growth is a function or various factors which may be expressed as G = f (x, x₂, x₃ x_n ).Some factors may be controlled while some cannot be controlled. The following are the factors which influence the plant growth.

An ideotype is a crop plant having desirable morphological and physiological characteristics or both for cultivation in a specific agroclimate situation. An ideotype is constructed by the breeder on the basis of indepth study of morphological and physiological characters including their interrelationships, and intuition of the breeder based on his experience.

Adaptation is any feature of an organism which has survival value under the existing condition of its habitat. The basic of successful crop production is the selection of an adapted plant species and varieties. Plants may have morphological adaptation or physiological adaptation or both for the existing environment.

Adaptation to soil moisture

Hydrophytes: More number of stomata on the upper surface of the leaf, aerenchyma tissue in the roots of rice plants, stem is hollow/straw, internodes are longer in floating and submerged rice,

Mesophytes: Stomata are normal. Present both on upper and lower leaf surface, medium root growth.

Cropping system is the cropping patterns used on a farm and their interaction with farm resources, other farm enterprises, available technology and environment (Physical, biological and socioeconomic) which determine their makeup (Krantz et al., 1975). Cropping system is subsystem of the farming system.

The cropping system aims at increasing the benefits derived by crop production from available physical resources (land, climate, water resources etc.) that are not readily changed through optimization of input levels for a given crop or cropping pattern. The objective of any cropping system is to increase the efficiency of utilization of resources. The efficiency in measured by the quantity of product obtained per unit resource in a unit time in cropping system.

The problematic areas for crop production may be soils affected with acidity, high concentration of salts, water logged soils or soils in steep sloppy areas. These soils have limitations or ill effects for crop growth and productivity.

Removal of entire plants or the economic parts after maturity from the field is called harvesting. Portion that is left behind on the field is known as stubble. The economic product may be grain, seed, leaf, root or entire plant.

Time of Harvesting

If the crop is harvested early, the produce contains high moisture and more immature grains. The yields will be low due to unfilled grains. It is very difficult to store the produce as shriveled grains with high moisture are highly prone to infestation by pest. The quality of the grain as well as germination percentage is also reduced. Late harvest results in shattering of grains, germination even before harvesting in rainy season and breakage during processing. Hence harvesting during correct time is very important.

Plants may be harvested at physiological maturity or harvest maturity. Plants are said to be in physiological maturity when the translocation of the photosynthates ceases to the economic part.

Weeds are the plants growing where and when they are not desired. They compete with crops for soil moisture, nutrients, solar radiation and space, and thus reduce crop yields. Weeds also act as alternate hosts that harbour insect pests and diseases and other microorganisms. Some weeds release poisonous substances into the soil which may be harmful to crop plants, human and livestock. Weeds reduce the quality of marketable produce and render harvesting difficult, leading to increased expenditure on labours, equipment and chemicals for their removal.

Classification of weeds

A. Based on life cycle

Annuals-Complete their life cycle in a year or in a single growing season. Based on the season they may be summer annuals and winter annuals.
Summer annual e.g, Echinochloa crusgalli

India, one of the largest food producer countries (I in milk production, II in fruit and vegetable production and III in food grain production at world level), possesses the potential of being the biggest with the food and agricultural sector contributing around 26 percent of the Gross Domestic Product (GDP). It is a paradox that people of the country producing such huge quantities of food including fruits, vegetables, milk, cereals grains etc. are still suffering from many nutritional deficiencies in their diet, and even in some places, the stomachs of people remain unfilled for the want of food. The credit of this would predominantly go to the poor postharvest infrastructure as well as knowhow and accessibility to the facilities. All this makes us one among those countries having largest postharvest losses. The reduction of losses occuring during food handling, processing, storage, distribution and use would be an indirect way of increasing the food production and making the country self-sufficient in nutritional requirements.

Physiological Development

Fruits and vegetables can be divided into 3 stages based n their physiological development i.e. growth, maturation and senescence.

Growth: This generally refers to cell division, enlargement and differentiation ultimately giving a particular size, weight and volume to the commodity.

Maturation: It is initiated before the ceasation of growth and lasts till the onset of senescence.

Senescence: The stage when anabolic (synthetic) processes almost terminate and catabolic (degradative) processes are initiated and speeded up causing ageing and finally death of tissues.

Ripening: Stage that begins with the last stages of maturation and lasts till the beginning (first stage) of senescence. Ripening is a very important event in the life of a plant as it transforms a physiologically mature but inedible (or not preferred to be eaten) plant part into an edible, visually and olfactorily attractive and tasty commodity. Ripening marks the completion of developmental phase and is an irrevessible event.

Maturity Standards and Harvesting Indices

Harvesting : Harvesting is detaching a commodity from the point of its origin. This point of origin may be an above ground plant part i.e. shoot eg. apple, tomato etc. or an underground plant part eg potato, carrot, etc. or in water i.e. harvesting of fish from a pond (not to be covered in this book).

Storage : It can be defined as keeping the commodity fresh or processed in safe condition with minimum of deteriorative changes for later use.

Reasons of Deterioration During Storage

Packaging : Packaging of fruits, vegetables, flowers or any other commodity is chiefly done to assemble the produce in convenient units of different sizes, shapes & types for storage, transportation, marketing and distribution. The size of units may vary depending on the requirement e.g for retail marketing smaller units are preferred and for bulk transportation and storage, large units would be more convenient.

Why do we Require Packaging?

Imagine there is no packaging material and technology available. How we are going to transport apple, mango etc. to distant markets? Definitely as loose. Then how can we weigh or count the fruits being transported or marketed? This would be very difficult. Had there been no packaging the commodity would have suffered great physical, chemical and microbiological losses. It would have been very difficult to handle, manage, transport and market the produce as loose and unpacked. Therefore, the packaging of fresh as well as processed commodities was needed to contain, unitize and protect the produce.

Nature has made such a beautiful system that a fruit does not spoil unless its outer covering is removed and till it is there on the plant. For example banana will not spoil for long time if we do not remove its peel. Similar is the case with apple, guava, mango and many other fruits and vegetables. But as soon as the outer covering is removed the damage begins and the commodity is spoilt very soon.

Preservation is extending shelf life of fresh or processed food by using various methods and prevention or reduction of spoilage. Better the preservation, lesser the spoilage, more the spoilage poorer and inefficient is the preservation.

Therefore, in order to prevent or reduce the spoilage, we have to first identify and understand the causes of spoilage. There are chiefly 3 agencies that cause spoilage in fruits and vegetables i.e. (i) microorganisms, (ii) enzymes & chemical changes and (iii) man, animals, rodents, insects, etc. For effective preservation we have to check the growth and activity of these spoilage causing agencies. So, in order to prevent spoilage and preserve a perishable commodity for long time the following principles and methods are to be followed.

Essentials for Quality Product Preparation

Plant ripened red tomatoes should be selected. Yellow and green fruits on processing yield dull colour and turn brown due to oxidation.

Never use iron equipment for processing. Lycopene oxidizes and turns brown when comes in contact with iron. It also forms black compounds with the tannins present in tomatoes or the spices which are used for product preparation.

Avoid prolonged heating and cool immediately to avoid over-cooking.

Pickles known to be good appetizers, aid digestion and pallate are edible products preserved and flavoured in a solution of common salt and vinegar. Spices and oil may also be added. There are a number of pickles very popular in India i.e. mango pickle, cauliflower pickle, lime and lemon pickles, ginger chilli pickle etc. But, some pickles like Sauerkraut are not very common in India but are very popular in European countries.

Jam : It is a product prepared by boiling to a suitable consistency, fruit pulp with sufficient quantity of sugar, acid and pectin so as to set and become firm enough to hold the tissues in position. About 45 parts of pulp are used with every 55 parts of sugar. The finished product should not contain less than 68 per cent total soluble solids.

Jelly : Jelly is prepared by boiling the fruit pectin extract with sugar in the presence of appropriate amounts of acid so as to set into a clear gel. A perfect jelly is transparent, devoid of haziness or any suspended material well set, but not too stiff and should have original flavour of the fruit. When cut it should retain its shape and show a smooth cut surface.

Marmalade : It is a fruit jelly like product in which slices of fruit or peel are suspended in the set gel. Mostly they are prepared from citrus fruits like oranges, lemons etc.

Canning : Process of preservation of various food stuffs including fruits and vegetables whole or in pieces, in sugar syrup or brine by heat processing them in hermetically sealed containers.

Drying/ Dehydration means the process of removal of water.

Drying : Removal of water (moisture) by using non conventional energy sources like Sun or wind.

Dehydration : Process of removal of moisture by the application of artificial heat under controlled conditions of temperature and / or humidity and air flow.

Freezing : Freezing is a process where temperature of food (fruits, vegetable etc.) is lowered down considerably below freezing point so that the water present inside the food undergoes change in state from liquid to solid (ice) and gets frozen immediately eg Frozen Pea. Water is immobilized and solutes are concentrated to reduce the water activity.

Principles of preservation : Combination of low temperature, low water activity, and pre-treatments like blanching, dipping in sugar syrup etc. stop (reduce) the growth and activity of microorganisms.

Theory of freezing : Freezing takes place in two main steps

Beverage: It includes all drinks whether they are fermented or unfermented, prepared from fruits or non-fruit, sweetened or unsweetened eg. tea, coffee, coca cola, cider, maaza are all beverages.

Fruit Beverages : Beverage which is prepared partly or fully from fruit juice or pulps with or without additives eg. pure fruit juice, squash, cordial, RTS beverage etc.

Non-fruit Beverage : Beverage which does not contain any fruit part eg. Coca cola, pepsi, sherbet etc.

Unfermented Juice or Pure Fruit Juice: This is the natural juice pressed out of the fruit and practically its composition remains unaltered during preparation and preservation. No additives like sugar, acid, water etc. are added. eg apple juice, orange juice.

Fruit Juice Beverage: This is the fruit juice that has been considerably altered in composition by adding water, sugar, acid, flavour, colours, preservatives etc. before consumption. It may or may not be diluted before it is served as a drink eg. squashes, nectars, appetizers etc.

Alcoholic Beverages

These are the beverages which are prepared after alcoholic fermentation of sugars by yeast, contain varying amounts of ethyl alcohol (5-42%), and are consumed directly or after dilution in water.

Wine : Product made by alcoholic fermentation of grapes or grape juice unless otherwise specified, by yeast (Saccharomyces cerevisiae and a subsequent ageing process. Alcohol content is 11-14 %, but may be as low as 7%.

Enzymes are biocatalysts that change the rate of reaction without being changed themselves. All (Most) enzymes are proteins but all proteins are not enzymes. Ribonuclease is the enzyme which is non- protein in nature.

Properties of Enzymes

Spoilage may be defined as the deteriorative process which renders the food inedible or results into reduction of quality.

Spoilage is Mainly of Two Types

Abiotic Spoilage: Less potential for causing health hazards to consumers. Occurs due to

In a commercial horticultural enterprise, if the product is not marketed properly, safely and beneficially, all the investment, inputs, hard work goes in vain. Basically every commodity that is produced should reach the consumer and marketing is all about how the commodity reaches the consumer. There is no fun of producing any commodity if it does not reach the consumer.

The word market has been derived form Latin word “marcatus” meaning merchandise, where people conduct business. Market therefore refers to place where goods/ commodity and services are bought and sold.

Marketing is a sum total of business activities through which the goods and services are either bought or sold. Cundiff and Still defined marketing as “the business process by which products are matched with markets and through which transfer of ownership are affected.

Why Marketing of Fruits and Vegetables is Complex and Risky as Compared to Other Goods

Before beginning the actual work on the establishment of a Fruit and Vegetable Processing Industry the following points should be considered:

Availability and possibilities of obtaining Funds: Investment of own money or obtaining loans from banks etc.

The scale of industry (Large, Small, Cottage or Home): Has to be decided based on availability of raw material, funds availability, land, labour and other resources.

The location: The processing unit should be located near to the actual production site of raw material so that the transportation costs of high bulk raw materials is reduced. There is no fun or justification of establishing apple processing industry in Lucknow or Bangalore and mango processing industry in Shimla as the related raw materials would have to be transported through long distances.

Site: Site selected in the location should be sunny area free from dampness and sufficient space for waste disposal should be ensured.

With the increasing health consciousness of consumers, there has been an increasing concern over the use of thermal processing methods like blanching, pasteurization, sterilization etc. for enhancing the shelf life of foods as these methods fail to preserve the fresh like nutritional, therapeutical and sensory qualities of the food. With the increased consumer demand for fresh and fresh-like foods, interest in minimal processing of foods is increasing. The trend is also shifting from the traditional heat processing to those technologies that employ no or minimum heat application, thereby retaining the quality to a maximum level. One of the ways to accomplish this is via use of non-thermal processes. Over the past few years a number of non-thermal processes or cold preservation methods have been invented and developed. These methods are being evaluated in pasteurization and sterilization of various foods or in the extension of shelf life of various packaged foods. Some of such novel technologies and the products prepared, have been discussed here under.

1. Extrusion

Extrusion is a size enlargement process wherein small granular food or powdered particles are re-formed into larger pieces with different shapes, textures, colours and flavours from the basic ingredients. In extrusion food is compressed and forced to pass through a fine opening (die). As soon as it comes out of the opening, the outside pressure is very less as compared to the pressure inside the screw of extruder and the food expands instantaneously. If the food is heated the process is called as extrusion cooking. It is a process which combines several unit operations including cooking, mixing, kneading, shearing, compressing, shaping and forming. Extrusion adds a variety to the products by changing shape, size, texture and even some of the minor ingredients of the food and at a reduced cost than most of the other processing methods. Extrusion cooking (not extrusion) is a high temperature short time (HTST) process that reduces microbial contamination and inactivates enzymes.

1. Multiple Choice Questions

The term Rainfed agriculture is used to describe farming practices that rely on rainfall for water. It provides much of the food consumed by poor communities in developing countries. In India, about 52% of total net sown area comes under rainfed lands. Rainfed crops account for 48 per cent area under food crops and 68 per cent under non-food crops. India ranks first among the rainfed agricultural countries of the world in terms of both extent and value of produce. Due to population pressure on agricultural lands, the poverty is concentrated in rainfed regions. The climate in India’s rainfed regions is characterized by complex climatic deficiencies, manifested as water scarcity for rainfed crop production. The climate is largely semi-arid and dry sub-humid with a short (occasionally intense) wet season followed by long dry season. Rainfall is highly unreliable, both in time and space, with strong risks of dry spells at critical growth stages even during good rainfall years. The fluctuations are due to numerous factors affecting the monsoonal climate including the atmospheric circulation and strong links to El-Nino Southern Oscillation (ENSO) phenomenon in the Pacific Ocean.

Rainfed areas in India are highly diverse, ranging from resource rich areas to resource-constrained areas. Some of the resource rich areas are highly productive and have experienced widespread adoption of technology. However, most of the areas are resource constrained and dry areas. In the resource constrained and dry areas, the farming is a survival mechanism rather than a growth oriented activity. Rainfed agriculture is practiced under a wide variety of soil type, agro-climatic and rainfall conditions ranging from 400 mm to 1600 mm per annum. Rainfed Crops are prone to breaks in the monsoon during the crop growth due to water stress. This water stress may be due to variability of rainfall, delay in sowing, diversity in crop management practice and variability of the soil type. The prolonged breaks can result in partial or complete failure of the crops.

With renewed interest in rainfed agriculture during 1970s, both the national (AICRPDA and CRIDA) and international institutions (ICRISAT) have studied several aspects of rainwater management. Recommendations have been made after their through testing both at the research Stations and on farmer’s fields. Initially these technologies were accepted by the farmers because of the pursuation by the Scientists and the incentives, but many of them are forgotten once the support is withdrawn. It is now time for us to examine whether the technologies themselves were weak or certain components were missing malfunctioning of the software may be due to a bug right from the beginning or it entered into the system at a later stage. It is also possible that we neglected certain critical inputs which became major constraints making the system defunct. Whatever the reason it should be identified and set right if the technology has to continue as tool for tackling the challenges of rainfed agriculture.

Main constraints of dry land agriculture to enhance the productivity are classified as follows:

Soil is the top layer of the earth surface in which plants can grow, consisting of rock and mineral particles mixed with decayed organic matter and having the capability of retaining water. Soil is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Earth’s body of soil, called the pedosphere, has four important functions

Meteorology is defined as the branch of science concerned with the processes and phenomena of the atmosphere. It is also defined as the climate and weather of a region. The word meteorology is derived from two Greek words: Meteor and logus. Meteor means event occurring above the earth surface and logus means to study. Meteorology is science deals with the physics, chemistry and dynamics of atmosphere and also their direct and indirect effects upon the earth surface, oceans and thereby life in general.

Climatology: Climatology is scientifically defined as weather conditions averaged over a period of time. Different regions of the world have different characteristic climates which determine the crops of any region. Climatology is derived from Greek word ‘klima’ – place/zone or slope of the earth and logs is study. It discovers, describes and interprets the climate on the basis of causes and long term effects on variation in regional and global climate. Climatology is the science which studies average condition of weather or the state behavior of the atmosphere over a place or region for a long period of time.

Agrometeorology: Agrometeorology is the study of weather and use of weather and climate information to enhance crop production. Agrometeorology is defined as the branch of meteorology that deals with relationship between weather and climate on crop, livestock production and soil management.

Climatic classification is the method of identifying climatologically homogenous regions. The systematic study of climate and its analysis and processing, which is referred as climatology plays an important role in national weather, planning activities and decision making in human activities. Iso climatic regions are those regions which have same climatic conditions.

Specific objectives of climatic classification

To identify the climates for transfer of production technology developed at particular center.

To provide adequate indices of moisture availability for successful crop production in drylands.

To quantify the risk levels associated with production constrains to agriculture production.

Soil is a living, dynamic ecosystem that nurtures plants. Soil is responsible for Sustaining plant and animal life below and above the surface, Regulation water and fertilizer/pesticide runoff, Storing and cycling nutrients. But, the natural soil balance was disturbed by man due to agricultural activities to get food. The intensification of agriculture leads to soil erosion, which leads to creation of unproductive soils.

In agriculture, soil erosion refers to the wearing away of a field’s topsoil by the natural physical forces of water and wind or through forces associated with farming activities such as tillage. As a result of improper cultivation practices, deforestation and overgrazing aggravates the problem of soil erosion.

Globally soil erosion has reached a level that endangers the sustainable supply of food for the growing global population. It already threatens food production and ecosystem service delivery and therefore, there is a pressing need to address this threat. This is especially true in India where, in a total area of 328 million hectares (m ha), 121 m ha is undergoing soil degradation, 68% of which is attributed to water erosion. Water erosion rates range from 5 t ha^–1 yr^–1 in dense forest regions to rates in excess of 80 t ha^–1 yr^–1 where erosion is most severe, such as in the Shiwalik mountainous region. India’s average soil loss has been estimated to be 15t ha^–1 yr^–1; however, given the limited coverage of measurements, this should be treated with caution. In the light of the serious threat that soil erosion poses in the country, there is a pressing need for a systematic nationwide assessment of land degradation due to erosion using appropriate techniques. The area under ravine soil erosion is highest in UP to a tune of 12.30 lakh hectares and lowest in Maharashtra to a tune of 0.20 lakh hectares

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

Successful crop production both in the rainfed and irrigated ecosystems depends on timely onset of monsoon, its distribution during the crop life cycle and collection of water in various storage structures viz; tanks, reservoirs and ground water table. It is therefore important that adequate supplies of water should be developed to sustain life. Development of water supplies should, however, be undertaken in such a way as to preserve the hydrological balance and the biological function of our ecosystems.

Consequently, the human endeavour in the development of water sources must be within the capacity of nature to replenish and to sustain. If this is not done, costly mistakes can occur with serious consequences. The application of innovative technologies and the improvement of indigenous ones should therefore include management of the water resources to ensure sustainability and to safeguard the source against pollution.

As land pressure rise, cities are growing vertical and in country side more forest area encroached and being used for agriculture. In India small farmers depends on monsoon where rainfall is from June to October and much of the precious water is soon lost as surface runoff. While irrigation may be the most obvious response to drought, it has proved costly and can only benefit a fortunate few. There is now increasing interest in the low cost alternative-generally referred to as “Rain Water Harvesting (RWH)”.

Water harvesting is the activity of direct collection of rainwater, which can be stored for direct use or can be recharged into the ground water. Water harvesting is the collection of runoff for productive purposes.

Rivers, lakes and ground water are secondary source of water. In present times, we depend entirely on such secondary source of water. In the process, it is forgotten that rain is the ultimate source that feeds all these secondary sources and remain ignorant of its value. Water harvesting is to understand the value of rain, and to make optimum use of rainwater at the place where it falls.

The occurrence of periods of water deficit for crop production, referred to as climatic drought, is commonly observed and leads to low water availability for crops. Besides climatic drought, crop water stress may also result from low levels of plant available water in the soil profile due either to the existence of physical barriers to water infiltration (e.g., surface sealing) or to soil chemical or physical limitations to plant root growth and root water uptake. Drought resulting from such factors will be referred to as edaphic drought since it is caused by soil specific conditions rather than by limited rainwater supply, and can occur even under conditions of sufficient and well-distributed rainfall. Finally, even where water is very scarce, particularly in the driest areas, a surprisingly small proportion of the available water is actually transpired by the crop. Non-productive losses include surface runoff, deep drainage, evaporation from the soil surface and deep cracks, and transpiration by weeds. Dry land farming is a system of crop cultivation depending on rainfall as the only source of moisture and the technologies refers to the cropping pattern/ rotation and agronomic practices adjusted and adopted in accordance with the moisture regime. The crops selected should have short duration, deep root system, erect leaves, moderate tillering and photosynthetically efficient.

Green Revolution has increased food grain production by four fold since 1950–51 with the adoption of HYVs, intense input use, extensive tillage, burning of residues and irrigation. The intense cultivation has lead to degradation of natural resource such as soil, water, vegetation etc. In this context, globally conservation agriculture (CA) has opened a new paradigm as it has potential for higher resource use efficiency, water productivity and climate change mitigation through its key principles. Total area and percentage of total area under no tillage practised as part of conservation agriculture in different continents is given in Table 92.

Climate change is looming large on the globe. Food security is one of the key issues that inevitably needs to be resolved under the specters of climate change, particularly in the fragile ecosystems. Never before in the history has Indian agriculture been as vulnerable and uncertainty ridden as it is today. A glimpse of the dynamics of Indian agriculture reveals that it has systematically deviated away from its base environment, the prop that nourishes all biological resources. Today’s agriculture is valued against the prices it fetches from the market, especially the global market. Its contribution to human health and welfare, ecological integrity, resilience of nature etc., are grossly neglected.

Agriculture in developing countries must undergo a significant transformation in order to meet the related challenges of achieving food security and responding to climate change. Projections based on population growth and food consumption patterns indicate that agricultural production will need to increase by at least 70 per cent to meet demands by 2050. Most estimates also indicate that climate change is likely to reduce agricultural productivity, production stability and incomes in some areas that already have high levels of food insecurity. Developing climate–smart agriculture is thus crucial to achieving future food security and climate change goals.

The production, processing and marketing of agricultural goods are central to food security and economic growth. Products derived from plants and animals include foods (such as cereals, vegetables, fruits, fish and meat), fibers (such as cotton, wool, hemp and silk), fuels (such as dung, charcoal and biofuels from crops and residues) and other raw materials (including medicines, building materials, resins, etc.,). Production has been achieved through a number of production systems which range from smallholder mixed cropping and livestock systems to intensive farming practices such as large monocultures and intensive livestock rearing. The sustainable intensification of production, especially in developing countries, can ensure food security and contribute to mitigating climate change by reducing deforestation and the encroachment of agriculture into natural ecosystems

Watershed is defined as a natural hydrological unit that covers a specific land surface area from which runoff passes through a common outlet or area with common drainage or outlet. In simple terms, it implies a catchments or drainage basin from which water drains towards a single channel. It may extend over a few acres only or may cover thousands of acres.

Watershed management is the integration of technology within the natural boundaries of a drainage area for optimum development of land, water and plant resources to meet the basic minimum needs of the people in a sustained manner.

It is also defined as the development and management of watershed resources in such a manner as to achieve optimum production without deterioration of resources base or disturbing the ecological balance. It is also termed as “Resource centered technology” since it helps in assessment, augmentation and optimal utilization of all natural resources viz., land, water and vegetation, it prevents deterioration of resources and at the same time ensures sustained productivity of land to meet basic needs of people.

Strategies To Improve The Productivity Of Drylands

With renewed interest in rainfed agriculture during 1970s, both the national (AICRPDA and CRIDA) and international institutions (ICRISAT) have studied several aspects of rainwater management. Recommendations have been made after their through testing both at the research stations and on farmer’s fields. Initially these technologies were accepted by the farmers because of the pursuasion by the Scientists and the incentives, but many of them are forgotten once the support is withdrawn. It is now time for us to examine whether the technologies themselves were weak or certain components were missing. Malfunctioning of the software may be due to a bug right from the beginning or it entered into the system at a later stage. It is also possible that we neglected certain critical inputs which became major constraints making the system defunct. Whatever the reason it should be identified and set right if the technology has to continue as tool for tackling the challenges of rainfed agriculture.

R software is a programming language used for statistical analysis, graphical representation and reporting, and is currently developed by the R Development Core Team. R software is available freely under the GNU General Public License, and the binary versions are provided for the Windows, Linux and Mac operating systems. To develop R, effort from all over the world is made in a collaborative manner.

What is GNU?

GNU stands for GNU’s Not Unix. It is a Unix like computer operating system, but different from Unix. GNU consists of GNU packages which are program specific and released by GNU project. Free software means that the users of the software have freedom to run and use the software and also can copy, change, improve and distribute the software freely.

Development of R

R software was initially written by Robert Gentleman and Ross Ihaka also known as “R & R” of the statistics department of the University of Auckland, New Zealand. R appeared first in 1993. Since then various contribution to R has been made by a large group of talented individuals by sending code and bug reports. A core group, known as the “R Core Team” modify the R source code archive since 1997. Thus R is a collaborative project with many contributors.

This chapter deals with the objects used in R which contains the data in various formats. The data types used in R has also been mentioned in this chapter. The chapter also includes the functions used in R as the codes for accomplishing several jobs related to data analysis.

Unlike C language and Java, the variables in R are not declared as some data type. The variables are assigned with R object and the data type of R object becomes the data type of the variable. The commonly used R objects in R are vectors, lists, matrices, arrays, factors and data frames. The vector object is the simplest one and other R-objects are built upon the vectors. The different data types of these vectors are logical, numeric, integer, complex, character and raw. The objects in R are stored by the name of a variable and the data type of the object is determined by its content. To know the data type of a variable the class() function is used. The various data types are described as below:

R packages include functions, codes and sample data. The functions used in R are contained in packages. A package in R contains several functions which are related to some particular type of job. A package conatins at least one function and there is no maximum limit to the no. of functions in a package. The set of packages in R which are set by default in the software is called base package. It contains a lot of commonly used functions. The packages in R are stored under a directory called “library” in the R environment. The packages get installed by default while installing R in the computer. Also more packages can be added later on after installation, when required for some specific purposes. The base packages are available by default when we start using R. But the other packages which are already installed while installing R have to be loaded while using R. These packages can be viewed in the package window by clicking on package. To install the package we have to click on install menu in the package window and then write the name of the package.

The packages can also be installed by using the function install.packages(“abc”) where abc is the name of the package to be installed.

Once a package is installed, it remains in the hard disk of the PC/laptop. But the package will have to be called for use in the current R session. The package once installed can be loaded for use in the current R session by checking the box near the name of the package displayed after clicking on the install menu in the Files/ Plots/Packages/Help window. The package can also be loaded by using library() function. The command will be library(“abc”) where abc is the name of the package. The loaded package remains in the memory for the current R session. Once we quit the R session, the installed package has to loaded again if needed.

In R there is facility of reshaping the data. Reshaping of data includes joining of two or more vectors to create a data frame. Also two or more data frames can be merged. Appropriate functions are available for these jobs. While merging the data frames, we can join columns or rows.

Illustration of joining two vectors by using cbind() function.

The most important use of R programming lies in importing of data files which serves as input for the analysis work. After the analysis is over by using R codes, operators and functions, the output result must also be exported in form of files. The files are imported in form of csv files (comma separated variable), text files or excel files.

Before going to the actual content of the chapter we have to have an idea about csv files. CSV stands for Comma Separated value. It is used to store tabular data, such as a spreadsheet or database. CSV is delimited text file in which the values are separated by commas. CSV files occupy much less space than excel files and also gets imported in a program at a much faster rate than Excel files. CSV Files also does not manipulate data and stores as it is.

Let us consider that an excel file named as ‘plant’ which stores three variables, named as ph, pd and yield is created inside the folder named as ‘My Data’ which is placed in the desktop. Thus the path of the file is “C:\\Desktop\\My Data\\plant”

To import excel file the package will be readxl and the command will be library(readxl)