eChapters

For electromagnetic radiation, there are four “laws” that describe the type and amount of energy being emitted by an object. In the following sections, these four laws of radiation e.g. Planck’s law, Wien’s displacement law, Steffan-Boltzman law and Kirchhoff’s law are described briefly.

Planck’s Law

Planck’s law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The spectral radiance of a body, B_í, describes the amount of energy it gives off as radiation of different frequencies. It is measured in terms of the power emitted per unit area of the body, per unit solid angle that the radiation is measured over, per unit frequency. Planck showed that the spectral radiance of a body at absolute temperature T is given by

Introduction

The age-old necessities of life are food, clothing and shelter. The 20^th century had dramatized a fourth-energy. Energy starvation of the technological complex that maintains modern society may soon be as crucial a problem as feeding the hungry. Indeed, energy starvation could well precipitate more wide spread food starvation. Solutions for the energy crisis are strongly dependent on the technology of how energy is produced and used. To make a physical change in the world it is necessary to use four resources: energy, matter, space and time. How well a task has been performed can be measured in terms of amount of fuel consumed, the mass of material used, the space occupied, the hours of labour to accomplish it, and the ingenuity with which these resources are utilized. Squandering of irreplaceable energy resources, waste of materials, or large expenditure of space and time cannot be tolerated if the necessities of life are to be provided for all. Energy is intricately linked to development of a country. Growing demand on account of industrialization, urbanization, transportation and also increase consumption in rural areas is putting added pressure on energy supply network. Electricity generation has been increased from 1,400 MW in the year 1947 to 303,118 MW up to August 31, 2016 in India but still there is 10-15% shortage of power in peak hours and all villages are not electrified. Even many electrified villages receive 6 to 8 hours of electricity per day in India. To overcome this shortage there is a need to utilise new and renewable sources of energy. Fortunately, India is blessed with abundant solar energy. The arid parts of India receives much more radiation as compared to the rest of country i.e. maximum solar radiation i.e. 7600-8000 MJm^-2 (2111-2222 kWhm^-2) per annum, followed by semi-arid parts, 7200-7600 MJm^-2 (2000-2111 kWhm^-2), per annum and least on hilly areas where solar radiation is still appreciable i.e. 6000 MJm^-2 (1667 kWhm^-2) per annum (IMD 1985). In this chapter review of different solar thermal technologies in Indian perspective has been carried out.

Introduction

In Indian Thar desert regions, excessive heat is the major problem that causes human and animal thermal discomfort. Space cooling is, therefore, the most desirable factor for the inhabitants. Various examples of dwellings responsive to climatic constraints are found in vernacular architecture throughout the world. Compact cellular layout with minimum external surface exposure to the sun, whitewashed surfaces to reduce absorptivity, blind external facades, courtyards, vegetation to provide humidity and shade, and heavy buildings constructed from high thermal capacity materials are common passive features in most of the arid regions. Wind towers for cooling ventilation are well known in Iranian and Middle East architecture, which along with cooling of the air by earth and water evaporation keep the building comfortable in hot periods. Building underground to take advantage of the large thermal storage capacity of the earth is also used in Tunisia and central Turkey.

Introduction

The development of any region is reflected in its quantum of energy consumption. With a view to keeping the pace we have to grow our energy resources at a rate that commensurate to sustainable development. There is already shortage of electricity, reflected in power cuts notwithstanding enhancement of electricity production of several folds in the country. The problem is more severe in context with rural areas in India where some 70% of population live and have agriculture as the main occupation. Although statistically few thousand villages are yet to be electrified, the availability of regular supply in far off places has been a problem and the farmers are unable to derive benefits of electricity. The fast depleting kerosene is used for lighting and diesel oil for running agricultural machinery including pumps. In addition people burn firewood, agricultural waste and cow dung cake for cooking food causing irreparable damage to the ecosystem. According to Lester Brown there will be plenty of food to eat but no fuel to cook. The burning of cow dung deprives farmers the use of potential source of organic manure. Further, due to shortage of energy resources, farmers are unable to process the agricultural products to enable them to accrue more benefits. The situation is still worse in arid region where bio mass is scarce and there is no hydro electricity. In addition, farmers are unable to generate additional income due to lack of energy resources to run appropriate device in cottage industries. In this context, solar energy utilization has a tremendous potential for providing needful energy to the farmers for domestic, agricultural and allied applications leading to a sustainable development.

Introduction

In order to keep pace with the development there is rise in energy use but it has adverse effects on climate due to greenhouse gas emissions from burning of fast depleting fossil fuels. In this context, we need to harness and use more and more renewable forms of energy, especially solar energy that is plentiful on most part of India. Also, at several locations harnessing wind power and utilizing biomass could be effective alternatives. Solar based devices may also work in an integrated manner with small wind turbines as hybrid devices. At present, about 20% of the country’s installed electricity generation capacity is contributed by renewable sources e.g. wind, solar, bioenergy, hydro etc., which is about 71.325 Giga Watt (GW) as on 30^th June, 2018. In agricultural sector, energy is directly used for pumping irrigation water, operating different mechanized farm implements/tools and processing of foods. Share of agricultural sector in total energy consumption is about 7-8% and further increase in energy use from its present value of 1.6 kW ha^-1 to 2.5 kW ha^-1 is expected to meet the production target of next 20 years.

Exercise No. 1. Rainfall analysis and interpretation

Procedure: Collect the rainfall data from the Department of Agrometeorology and interprete it zonewise and district wise for various districts of Haryana. Correlate it with last year’s rainfall.

For the preparation of this book, the authors have drawn heavily from the following sources.

Aamodt,O.S and Johnston W.A. 1936. Can.J.Res.14: 122-152.

Adams, J. E. 1962. Agron. J. 54: 257-261.

Barrs, H.D. and Weatherley, P.E. 1962. Australian Journal of Biological Sciences, 15:413-428.

Blackman, V.H. 1919. Annals of Botany, 33:353-360.

Chen, D; Sarid, A. and Katchalski, E.1968.Proc. Nat.Acad.Sci;US. 61: 1378-83.

De, G.C. 1989. Fundamentals of Agronomy. Oxford and 1 BH pulishing Co. Pvt. Ltd. New Delhi.

El Sharkawy, M. Loomsi, R.S. and Williams, W.A. 1968. J. Applied Ecol.5:241-51.

Understanding the principles involved in plant growth and development is prime important for managing agronomic practices for higher productivity of dryland crops sustainably. Systematic study of plant growth based on the variability and interpreting plant development based on biometric methods is called as growth analysis. Plant data in turn biometric data is collected from the field and analysed over the period to know the growth condition of the plants. Based on biometric data, agronomic practices like application of fertilizers, irrigation and weed management practices were employed. Several growth indices are devised for identifying environmental or genetic factors as sources of variation in plants. Both whole plant and their component organs (leaf) are basis for calculating growth indices.

The most common parameters used in growth analysis are leaf area index, crop growth rate, relative growth rate, net assimilation rate and leaf area duration.

In dryland areas, moisture conservation accounts prime most important concept for maximizing productivity of dryland crops. Varied topographic and agro- climatic conditions ranging from arid to semi-arid climates with high evaporation because of varied temperature regimes permit the cultivation of drought resistance crops. Reducing the cost of cultivation without compromising the socio-economic status of farmers is prime importance. Conservation of moisture by reducing the weed menace is great task performed by the dryland farmers. Under such situations, effective utilization of dryland tools and implements used are of a primitive nature throughout the dryland farmers for higher factor productivity. Traditional farm tools and implements for self-sustenance have been adapted through experience over generations to meet emerging socio- economic and farming challenges.

Relatively small yields consequently larger areas must be farmed for a given return and the successful exploration of dryfarming requires the adoption of methods. The methods which enable farmers to do the maximum effective work with the smallest expenditure of energy. The type of soils and topographic conditions largely influence the type, size and shape of particular tillage tools/ implements among the dryland farmers. The following is a list of local tools/ implements found in the various dryland regions.

Both dryland crops and irrigated crops experience an assortment of ecological or environmental stresses which include abiotic viz., drought, water logging, salinity, extremes of temperature, changes in atmospheric gases and biotic viz., insects, birds, other pests, weeds, pathogens. Dryland crops are more vulnerable to stress in the present context of changing climatic scenarios. The ability to tolerate or adapt effectively by challenging these stresses is a very complicated phenomenon would be due to various plant interactions occurred in the specific environment. Both biotic and abiotic stresses occur at various stages of plant growth and development and frequently more than one stress concomitantly affects the crop. It is difficult to distinguish effects of these stress factors on the performance of crop plants with respect to yield and quality of harvested products. This is of special significance of maximizing productivity of dryland crops in changing climate scenarios, with complex consequences for ecologically and environmentally sound Indian agriculture. In order to successfully meet this challenge, one should understand the various aspects of stresses in view of the current development and to promote a competitive dryland production system.

Drainage - definition

Agricultural drainage is the artificial removal and safe disposal of excess water either from the land surface or soil profile, more specifically, the removal and safe disposal of excess gravitational water from the crop root zone to create favourable conditions for crop growth to enhance agricultural production.

Benefits of drainage

a)It provides better soil environment for plant growth by creating favourable soil aeration conditions.

b)It improves the soil structure and in turn increases the soil infiltration.

c)High infiltration capacity reduces soil erosion.

d)It hastens the warming of the soils and maintains desirable soil temperature, which accelerates plant growth and bacterial activity.

e)It promotes increased leaching of salts and prevents accumulation of salts in the crop root zone.

f)In well drained soils, less time and less labour are required for tillage operations.

Definition

Soil erosion is the process of detachment of soil particles from the top soil and transportation of the detached soil particles by wind and / or water. The agents causing erosion are wind and water. The detaching agents are falling raindrop, channel flow and wind. The transporting agents are flowing water, rain splash and wind.

Erosion is the process by which soil and rock are removed from the Earth’s surface by exogenic processes such as wind or water flow, and then transported and deposited in other locations.

While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. Excessive erosion causes problems such as desertification, decreases in agricultural productivity due to land degradation, sedimentation of waterways, and ecological collapse due to loss of the nutrient rich upper soil layers. Water and wind erosion are now the two primary causes of land degradation; combined, they are responsible for 84% of degraded acreage, making excessive erosion one of the most significant global environmental problems.

Industrial agriculture, deforestation, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of denuded soils.

Tillage

The mechanical manipulation of soil with tools and implements for obtaining conditions ideal for seed germination, seedling establishment and growth of crops is known as tillage. Tillage may be described as the practice of modifying the state of the soil in order to provide conditions favourable to crop growth.

Land capability classification

Introduction: The United States Department of Agriculture (USDA) land classification system is interpretative, using the USDA soil survey map as a basis and classifying the individual soil map units in groups that have similar management requirements. At the highest of categorization, eight soil classes are distinguished, namely, arable lands (I to IV) and non arable lands (V to VIII).

Origin of land capability classification (1933) : The Georgia Piedmont Land Capability Classification (LCC): First U.S. effort to systematically determine the best use of lands by classifying and mapping erosion rates and potential in relation to both physical characteristics and agricultural capacity.

Definition: Land capability classification is a system of grouping soils primarily on the basis of their capability to produce common cultivated crops and pasture plants without deteriorating environment over a long period of time.

Classes: Land capability classification is subdivided into capability class and capability subclass nationally. Some states also use a capability unit.

The capability classification provides three major categories of soil groupings: (1) Capability unit, (2) capability subclass, and (3) capability class.

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

Watershed management

Watershed is defined as a geohydrological unit draining to a common point by a system of drains. All lands on earth are part of one watershed or other. Watershed is thus the land and water area, which contributes runoff to a common point.

A watershed is an area of land and water bounded by a drainage divide within which the surface runoff collects and flows out of the watershed through a single outlet into a lager river or lake.

Intercropping is growing two or more crops simultaneously on the same piece of land with a definite row pattern. The crops may or may not be sown or harvested at one time.

Advantages of intercropping

Intercropping provides yield advantages as compared to sole cropping. These are not by means of costly input but by the simple expedient of growing crops together.

1.It provides greater surety and stability of higher yield over different seasons.

2.It economizes the space and time of cultivating two or more component crops of comparable agronomic practices grown separately.

3.It helps to restore soil fertility when legumes are included as component crop.

4.It utilizes a greater total volume of both below and above ground environment.

5.It helps to avoid intra-crop competition and thus a higher number of crop plants can be grown per unit area.

6.It helps in better use of growth resources.

7.It also helps in better control of weeds pests and diseases.

8.It also controls erosion through providing continuous leaf cover over the ground surface.

9.It is the small farmers of limited means who is most likely to benefit.

Natural resources conservation and their management hold key to sustainable agriculture and livestock production. It is all the more crucial for countries with predominant agrarian economies where development of sustainable agriculture is essential for overall growth, redressal of poverty and security. Conservation of both soil and rain water as very crucial and basic resources have been practiced since ancient times in India. However, there has been renewed emphasis on conservation and efficient utilization of these resources in the recent past. The fact that 70% of the arable area of India is rainfed with precarious supply of water and that rainfed agriculture supports 44% of India’s human population and contributes 90 per cent of coarse cereals and pulses, 80 per cent of oilseeds and 65 per cent of cotton and growing realization that further gains in productivity of crops and livestock will emanate from rainfed regions, leave no room for complacency in this regard.

Year after year, the fate of a vast majority of Indian farmers hangs in balance, as success with rainfed agriculture continues to be a gamble. It is evident that crop yields in semi-arid areas depended more on rainfall distribution than on total rainfall and lack of serious efforts to create the water supply for crops through scientific management of rainwater is a factor favoring this avoidable uncertainty. In rainfed agriculture no other input can perhaps enhance the yield without effectively tackling of the rainfall aberration related sub-optimal moisture availability. Therefore a prerequisite for substantial improvement in the agriculture production in the semi-arid region is to manage runoff water and to use it either at the time of moisture stress even during the monsoon or in next season. It has been reported that only one supplementary irrigation at proper stage can double of rabi crops. But supplemental water is a developed resource and is more expensive than the natural resources. Hence, it is all the more necessary to use this water judiciously and efficiently. Standardization of techniques by which as much of precipitation as possible can be conserved for crop use, either directly in the soil profile through infiltration or through runoff collection and recycling is an area of priority in research.

Soil and moisture conservation measures are a prerequisite for ensuring a good crop stand, growth and development of crop, and higher crop yields. These measures depend mainly on the land (topography and slope), soil type, rainfall pattern, and nature of the crop. The various management practices are:

Tillage

Off-season tillage is necessary to get a weed free seedbed having good tilth and better moisture conservation. Pre-monsoon showers should be utilized for deep ploughing (where necessary) and blade harrowing. This will enable sowing of large areas in limited time- a necessary in dryland areas. Higher yield advantage with deep ploughing (22 cm) has been obtained in case of sorghum, pearl millet, maize, and rice. In case of rice, use of mould board plough to a depth of 30 cm every year increased the rice yield at Ranchi. For small seed crops like finger millet, soil compaction below the seeding zone is absolutely necessary for getting good crop stand establishment and higher yields. Tillage requirement for pulse crops (cowpea, mungbean, black gram) varies with the type of soil on which they are grown. For loamy sand or sandy loam soils, one or two cross cultivation using a sweep harrow, will be enough to provide a good tilth.

The conservation of soil and water is very essential for sustainable production, environment preservation and balanced ecosystem. Fifty percent of total geographical area (329 m ha) of our country needs soil and water conservation measures. About 5334 million tonnes of soil is lost annually along with 10 million tonnes of fertilizer and other essential nutrients and organic carbon. Loss of nutrients is almost equal to their total production in India. In India about 70% of the cultivated area falls under the category of dryland conservation measures for soil and water and efficient utilization of these resources is needed in these areas. The fact that rainfed agriculture supports 44% of India’s human population and contributes 90 percent of coarse cereals and pulses, 80 percent of oil seeds and 65 percent of cotton and growing realization that further gains in productivity of crops and live stock will emanate from rainfed regions, leave no room for complacency in this regard.

In these areas, rainfall frequently occurs with high intensity that produces higher runoff due to non adoption of soil and water conservation (SWC) measures and poor permeability of the soil. As a result crop grown during rainy season often suffer from moisture stress due to inadequate moisture storage in the soil profile. Secondly soil erosion problems such as sheet, rill and even gully erosion are common in the region.

It has been reported that the black soils of peninsular region of India, under cultivated fallow gives runoff of about 23.4 percent of rainfall and results in a soil loss of 8.94 t ha^-1 at 1.0 percent slope (Verma et al., 1990). They further reported that the rate of siltation reduced by 83 percent within a span of five years due to adoption of agronomic measure of SWC. These studies clearly showed that soil erosion and runoff are the major factors causing land degradation in the region that needs appropriate SWC measures so that crop productivity could be maintained.

Importance of Rainfed Farming

In India, rain dependent areas are vast and they have a great contribution to make in agricultural production, with just 1/40^th of the world land. India supports over half of its buffaloes and over one seventh of its cattle and goats that also share land utilization with humans and add to the national wealth. The second largest number (after Africa) of drought victims of the world live in India, out of 143 m ha cultivated land about 43 m ha are under irrigation and the rest of the area (about 70%) is rainfed but all is not too dry. About 90% of it located in the north-west part, out of which 60% is located in Rajasthan and sustains a human population of 20 million and a total livestock population of 23 million. The dry land areas contribute about 42% of food grains, almost all the coarse grains and about 75% of pulses and oil seeds of the total production of the country. About 2/3 of rice and rapeseed mustard and 1/3 of wheat are grown in rainfed areas. A large portion of industrially important crops such as cotton, groundnut and castor are cultivated under dry land conditions and has a great contribution to make to the production of food, fibre, fuel and furniture timber etc. Dry land agriculture may be classified into three groups on the basis of annual rainfall.

a) Dry farming : Cultivation of crops in areas where annual rainfall is less then 750 mm and crop failures due to prolonged dry spells during crop period are most common. Dry farming is practiced in arid regions with the help of moisture conservation practices. Alternate land use system is suggested in this region.

b) Dryland farming: Cultivation of crops in areas where annual rainfall is more than 750 mm but less than 1150 mm is called dryland farming. Dry spells may occur, but crop failures are less frequent. Higher evapotranspiration (ET) than the total precipitation is the main reason for moisture deficit in these areas. The soil and moisture conservation measures are the key for dryland farming practice in semi-arid regions. Drainage facility may be required especially in black soils.

Exercise 1: Studies on climate classification

The Köppen climate classification is one of the most widely used climate classification systems. It was first published by the Russian climatologist Wladimir Köppen (1846-1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936.Later, the climatologist Rudolf Geiger introduced some changes to the classification system, which is thus sometimes called the Köppen–Geiger climate classification system.

Integrated watershed management programme (IWMP)

The main objectives of the IWMP are to restore the ecological balance by harnessing, conserving and developing degraded natural resources such as soil, vegetative cover and water. The outcomes are prevention of soil run-off, regeneration of natural vegetation, rain water harvesting and recharging of the ground water table. This enables multi-cropping and the introduction of diverse agro-based activities, which help to provide sustainable livelihoods to the people residing in the watershed area. In addition, there is a Scheme of Technology Development, Extension and Training (TDET) is also being implemented to promote development of cost effective and proven technologies to support watershed management.

Till 1.4.2008, Department implemented 3 watershed programmes viz. Integrated Wastelands Development Programme, Drought Prone Areas Programme, Desert Development Programme. Since then, they have been brought under a comprehensive programme named Integrated Watershed Management Programme (IWMP) to be implemented under Common Guidelines on Watershed Development, 2008.

Management of watershed in India

It involves management of water, land, energy and greenery, integrating all the relevant scientific approaches appropriate to socio-economic background for a pragmatic development of a watershed. In practice, it means allowing load free rainfall run off from the watershed. Clear outflow imply management of effective soil and water conservation and generating a lush green carpet in whole of the area. In other worlds, it is greening of a watershed through proper management of land, water and energy sources. The comprehensive development of watershed seems to make productive use of all its natural resources and also protect them is termed as watershed management.

The Banave terraces in Indonesia and those in Nepal, Mediterranean are examples of integration of human elements into a system of land management, which is an early achievement in watershed management. Watershed management is not merely anti-erosional and anti-run off approach but also a comprehensive integrated approach of land and water resources management. The approach is preventive, progressive, corrective as well as curative. Here wasted land resources could be fruit fully harvested into a productive face for rural development.

Watershed

A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place. John Wesley Powell, scientist geographer, put it best when he said that a watershed is: “that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community.”

Watershed is defined as a hydro-geological unit of area from which the rainwater drains through a single outlet. Watershed development refers to the conservation, regeneration and judicious use of all the natural resources (like land, water, plants, animals) by human beings. Watershed Management brings about the best possible balance between natural resources on the one side and human beings on the other. Human beings and the ecology are interdependent. The changes in the environment directly affect the lives of the people depending on it. A degraded environment means a degraded quality of life of the people. This degradation can be tackled effectively through the holistic development of the watershed. A watershed provides a natural geo-hydrological unit for planning any developmental initiative. The approach would be treatment from “ridge to valley”.

A watershed, also called a drainage basin or catchment area, is defined as an area in which all water flowing into it goes to a common outlet. People and livestock are the integral part of watershed and their activities affect the productive status of watersheds and vice versa. From the hydrological point of view, the different phases of hydrological cycle in a watershed are dependent on the various natural features and human activities. Watershed is not simply the hydrological unit but also socio-political-ecological entity which plays crucial role in determining food, social, and economical security and provides life support services to rural people.

Crop plan and practices for rainfall scarcity prone areas

The appropriate crop plan and practices, which have so far been generated and recommended for achieving the objective of increased and stable crop production in dry land areas have been summarized in the following points:-

1.Proper and timely tillage

2.Early sowing

3.Choice of suitable crop/good plant material

4.Proper plant population

5.Cropping system

6.Fertilizer use

7.Timely weed control

8.Efficient rain water storage and its use

9.Alternate land use system

10.Planning for aberrant weather hazard

Soil and water conservation measures

Soil conservation is using and managing the land based on the capabilities of the land itself involving application of the best management practices leading to profitable crop production without land degradation.

Water erosion control

Water erosion occurs simultaneously in two steps : detachment of soil particles by falling raindrops and transportation of detached soil particles by flowing water. Therefore, water erosion can be minimized by preventing the detachment of soil particles and their transportation.

Natural resources conservation and their management hold key to sustainable agriculture and livestock production. It is all the more crucial for countries with predominant agrarian economies where development of sustainable agriculture is essential for overall growth, redressal of poverty and security. Conservation of both soil and rain water as very crucial and basic resources have been practiced since ancient times in India. However, there has been renewed emphasis on conservation and efficient utilization of these resources in the recent past. The fact that 70% of the arable area of India is rainfed with precarious supply of water and that rainfed agriculture supports 44% of India’ s human population and contributes 90 per cent of coarse cereals and pulses, 80 per cent of oilseeds and 65 per cent of cotton and growing realization that further gains i n productivity of crops and livestock will emanate from rainfed regions, leave no room for complacency in this regard.

Year after year, the fate of a vast ‘majority of Indian farmers hangs in balance, as success with rainfed agriculture continues to be a gamble. It is evident that crop yields in semi-arid areas depended more on rainfall distribution than on total rainfall and lack of serious efforts to create d water supply for crops through scientific management of rainwater is a factor favouring this avoidable uncertainty. In rainfed agriculture no other input can perhaps enhance the yield without effectively tackling of the rainfall aberration related sub-optimal moisture availability. Therefore a prerequisite for substantial improvement in the agriculture production in the semi-arid region is to manage runoff water and to use it either at the time of moisture stress even during the monsoon or in next season. It has been reported that only one supplementary irrigation at proper stage can double of Rabi crops. But supplemental water is a developed resource and is more expensive than the natural resources. Hence, it is all the more necessary to use this water judiciously and efficiently. Standardization of techniques by which as much of precipitation as possible can be conserved for crop use, either directly in the soil profile through infiltration or through runoff collection and recycling is an area of priority in research.

Drought

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

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

Climatic conditions prevalent in rainfed areas

Weather, which is part of climate, plays an important role in crop planning in dry farming area. Out of the several elements of weather, rainfall has key position in success of dry farming. In dryland areas, South West Monsoon brings the bulk of rainfall. The South West Monsoon is followed by North East Monsoon which supplements to South West Monsoon are the main source of rainfall. There are four types of rainfall characterized by the nature in different parts of India. Generally, the rainfall is scanty, erratic and ill distributed.

1. Rainfall

The monsoon period is not one of continuous rains in any part of the country. Meghalaya that is uncommon in the behavior of monsoon in the country. There are at least four variations in rainfall.

1.The commencement of rains may be quite early or considerable delayed according to the dates of monsoon for central Maharashtra zone is 10th June but is started as early as 28th May 1925 and its onset was delayed upto 26th June 1954 according with the date of onset of monsoon in Rajasthan is between June 21 to 30 but is started as late as up to end of July 1987 to 1992.

2.There may be prolonged breaks in rainfall. These breaks in monsoon rains can be different duration. The breaks of 5-7 days may not be all serious concern but breaks of longer duration of 2-3 weeks created the situation of plant water stress leading to reduction in agricultural production. Another important point is the physiological properties of soil and available water holding capacity in the relation to the breaks and drought, some of the soils e.g. deep black soils have capacity to store more than 300 mm of water per meter depth where as the desert soil can ensure only 100 mm. The impact of drought is felt more quickly in the soil having less water holding capacity but in sols with high storage capacity 15 days dry break may not affect the crop where as the soils of less storage capacity show wilting symptoms in and dry break such breaks cannot be predicted for a given season in advance. The drought caused due to this break is therefore of different magnitude and severity.

Problems Associated with Rainfed Farming Agriculture

It is a dream desire to eliminate drought from this region. There are many problems that are associated with rainfed farming systems. The problems may be grouped into four major factors: climatic, edaphic, technological and socio- economic.

Climatic

1.Scarcity of rain-water which is low and unpredictable with respect to intensity and distribution;

2.High ET (nearly 3650 mm annually compared to total annual precipitation ranging from 350 to 1400 mm);

3.Extreme thermic values (upto 490C with the mean annual temperature exceeding 180C at some places);

4.High solar incidence (450 to 500 Cal cm² day^-1);

5.High wind velocity with desiccating winds causing a high rate of ET and wind erosion;

6.Low relative humidity;

7.Extensive climatic hazards such as weather aberrations, drought, flood, frost, gale, cyclones and burning winds due to dry, deserted and denuded situations.

Rainfed Agriculture - A historic view

Historically, famines and scarcities have been recorded from the earliest times in India. They were mentioned in the epic Mahabharata, and there is Jain legend of a 12-year famine in the fourth century A.D. During the reign of the Moghul Emperor Shah Jehan in 1630-32, The official historian recorded in ‘Badsha Namah’ that soup Kitchens were opened, a lakh and half coins were given in charity and one eleventh of land revenue was remitted in the drought effected area.

In the remote past, these famines were tided over by saving grains and fodder from years of bumper harvest and by migration of people and cattle to greener pastures. With the rise of population pressure on arable land, the effects of scarcity and famine became progressively severe because the traditional methods of tiding over were no longer adequate. The successive famines in the closing decades of the 19th century closing decades of the 19th century led to the setting up of three Famine commissions.

The Commissions made several suggestions which formed the basis of the Famine Code promulgated in 1883 onwards and adopted by the then provincial governments. Apart from the relief works to be taken up during famine, the Commission recommended protective irrigation projects in dry and scarcity area and establishment of department of agriculture at the center and in the province. Later, the Royal commission on Agriculture (1928) reiterated in its report the problem of dryland agriculture and recommended a close attention by departments of agriculture to these problems.

The first systematic approach was made in 1923 by setting up small plots at Manjri, near Poona. This was followed by a more comprehensive research scheme on dry farming sanctioned by the Imperial (then Indian) Council of Agricultural Research during 1933-35. Under the scheme, research was conducted in low rainfall areas at Rohtak, Solapur, Bijapur, Raichur and Agra. Based on the results of this scheme, a series of dry farming practices were evolved which were known as ‘ the Bombay Dry farming ‘, ‘ the Madras Dry farming ‘ and ‘ the Hyderabad Dry farming ‘ practices. These practices emphasized soil and water conservation as basic to dryland production programs. The Scheme was terminated in 1943, since it was felt that the immediate objectives had been achieved.

Importance of Rainfed Farming

In India, rain dependent areas are vast and they have a great contribution to make in agricultural production, with just 1/40th of the world land. Of the 141 M ha of net sown area in the country, 80 M ha is rainfed. Rainfed agriculture contributes 40% of food grain production and supports 2/3rds of the livestock population. Despite considerable progress in irrigation development over the five year plans, 85% of coarse cereals, 83% in pulses, 42% in rice, 70% in oilseeds and 65% in cotton are still cultivated as rainfed. A large portion of industrially important crops such as cotton, groundnut and castor are cultivated under dry land conditions and has a great contribution to make to the production of food, fibre, fuel and furniture timber etc. Though, impressive gains were noted in some of the rainfed crops in recent times, the gap between attainable and farmers’ yields still remain high which is a major cause of concern. Small and marginal farmers who are the backbone of rainfed farming are resource poor and risk averse. Moreover, both public and private investments in technology adoption and infrastructure have been quite low in rainfed agriculture resulting in a vicious circle of low yields-low net returns-low investments in improved technologies.

With several resource management problems emerging in irrigated regions, rainfed agriculture offers scope to contribute to the growing food needs of future particularly of pulses and edible oils. The high yield gaps between attainable yields realized by progressive farmers using improved technologies and those actually realized by the farmers at large in any given region offer scope for enhancing overall productivity of rainfed crops anywhere between 50 to 70% in the near term with the adoption of the available technologies, provided resource and institutional constraints in delivering the technology and inputs are addressed timely and adequately. With the promised break-through in yields through genetic manipulation and large scale adoption of water saving technologies through conservation agriculture, the yield gains can be further enhanced in the medium to long term.

The 80 million hectares of rainfed farming area is not uniform for resource base, opportunities and constraints. There are areas receiving high rainfall and fertile deep soils where crop yields can be enhanced significantly by double cropping combined with supplemental irrigation with water harvesting. For the relatively lower rainfall regions, the overall system productivity needs to be enhanced by integrating crops, trees and livestock. This agro-eco region based differential approach is the key for realizing the full potential of rainfed agriculture besides addressing the dimension of regional equity.

I. General Information

Use of computers into the design process has benefited landscaping industry in several ways. There are several advantages in using computers for design. The most important factor is that the computer can store and handle large amount of engineering data, which can be used in various stages of design, development and manufacturer, like conceptual design, analysis, component design, documentation, process planning and manufacturing. The product development approach using the computer aided design and computer aided manufacturing (CAD/CAM) results in better and consistently good quality products invariably at a lower cost, with the attendant benefits of faster development of different variants of the product or model. The following table highlights the relative advantage of human designers and computers.

I. General information

I. General information

1. Lotus stem is referred as naval cord of Lord Vishnu
2. Lotus flower is described as the throne of Brahma
3. Vishnu, Brahma and Laxshmi are associated with lotus
4. Poet Asvaghosa reported that Lord Buddha saw lotuses and flowering trees in Nandavana
5. Surface flowering plants of water garden are

I. General information

1. Cacti plants suitable for rock garden are Opuntia, Cereus and Mamillaria
2. Succulents suitable for rock garden are Agave, Aloe, Euphorbia splendens, Sedum, Sempervivum, Stapelia, Yucca, Furcraea
3. Ferns suitable for rock garden are Drynaria, Nephrodium, Nephrolepis, Polypodium
4. Famous rock garden of India is located at Chandigarh
5. The founder of Rock garden in Chandigarh is Nek Chand
6. Annuals suitable for rock garden are

1. Ornamental ferns

Adiantum capillus – Maiden hair fern

Asplenium nidus – Bird’s nest fern

Cheilanthes argentea – Silver fern

Davallia bullata – Squirrels foot fern

Nephrolepsis aureum - Boston fern

Polypodium aureum – Hare’s foot fern

Pteris cretica – Brake/ Ribbon fern

Drynaria quercifolia -Oak-leaf fern / basket fern

I. General information

1. Cool season turf grasses are Perennial rye grass, Creeping bent grass, Colonial bent grass, Kentucky blue grass, Canada blue grass, Poa spp, Festuca spp, Agrostis spp, Lolium spp
2. Warm season turf grasses (25-35^oC) are Cynodon sp, Zoysia sp, Stenotaphrum secundatum, Paspalum notatum, Eremochloa ophiuroides, Axonopus sp, Pennisetum clandestinum, Buchloe dactyloides
3. Broad leafed turf grasses are Arachis pintoi, Dichondra repens
4. Based on mowing height, turf grasses are classified into tall, medium & dwarf
5. Turf grasses which needs high mowing height of>3.5 cm are Tall fescue, sheep fescue, Canada blue grass, fine fescue, wheat grass, orchard grass
6. Turf grasses which requires medium mowing height of d” 3.5 to 1.0 cm are perennial rye grass, Kentucky blue grass, Buffalo grass, etc.,
7. Turf grasses which requires low mowing height of d” 1.0 cm are colonial bent grass, creeping bent grass, Annual blue grass
8. Turf grasses are classified based on their recuperative capacity into fast, medium & slow

I. General information

1. Bonsai is defined as Japanese art of growing trees & shrubs by extreme dwarfing in a shallow container
2. Bonsai, the name is derived from two words, Bon & Sai
3. The meaning for the word ‘Bon’ is tray or shallow container
4. The meaning for the ‘Sai’ is to grow
5. Origin of Bonsai is china
6. In Mamie bonsai, plant height is 2-6 inches
7. In small bonsai, plant height is 6-12 inches
8. In medium bonsai, plant height is 12-24 inches

I. General information

1. Japanese flower arrangement is called as Ikebana
2. Meaning for Ikebana is flowers kept alive
3. Western style of flower arrangement involves symmetrical arrangement of flowering plants in a vase
4. Ikebana style possess asymmetric flower arrangement
5. Tatebana is a type of flower arrangement in which flowers are placed in standing arrangement and are of tall nature
6. Basic lines of Japanese flower arrangement are heaven, man and earth
7. ‘Shin’ in Japanese flower arrangement represents Heaven
8. ‘Soe’ in Japanese flower arrangement represents Man

I. General information

1. All cacti are succulents
2. All succulents are not cacti
3. All the genus belonging to the family Cactaceae are native of America
4. A genus in Cactaceae family which is not native of America is Rhipsalis
5. Sedum and Sempervivum are native to temperate Europe
6. Aporocactus, Rhipsalis and Schlumbergera are native of Mexico
7. Dischidia and Hoya are native of South-East Asia

I. General information

1. Plants propagated through modified underground stems are grouped into tubers, bulbs, rhizomes
2. An example of a bulbous plant propagated through tuber is dahlia
3. Bulbous plants which are propagated through corms are Gladiolus, Freesia, Tetonia and Tigrida
4. Bulbous plants propagated through bulbs are Amaryllis, Tuberose, Zephyranthes and Crinum
5. Bulbous plants propagated through rhizome are Alstroemeria, Bamboo, Canna, Convallaris, Hydechium, Iris and Zantedeschia
6. Bulbous plant propagated through tubercle is Bowiea volubilis
7. Bulbous plants propagated through tuberous roots are Dahlia, Eranthis, Ipomoea, Mirabilis, Ranunculus and Tapioca
8. Bulbous plants propagated through tuberous stem are Begonia and Cyclamen
9. Bulbous plant propagated through offsets are daffodil, tulip and iris

I. General information

The nature of roots

The roots of palms are usually tough and thick, although slender and wiry types are existing. Some roots creep over the soil’s surface, while a few palms even develop aerial roots that may eventually make them appear to be growing on stilts.

A few palms develop aerial roots at or near the base of the trunk or stems. These include Crysophila warscewiczii (Rootspine palm) and Clinostigma exorrhizum. Other palms with aerial roots include Pinanga aristata, Verschaffeltia splendida (Seychelles stilt palm) and Socratea exorrhiza. Some of these develop into stilt or prop roots, which often form a cone and give the palm extra support, they usually occurs on plams native to wet soils and humid conditions, whereas the base of the palms is at risk from decay. Indeed, in a few instances, the lower part of the trunk withers and the palm is entirely supported by these roots.

I. General information

1. A group of ornamental plants which complete their life cycle in one season or in a year is called annuals
2. Time of sowing of summer annual seeds is February- March
3. Time of sowing of rainy season annual seeds is June- July
4. Time of sowing of winter annual seeds is September- October
5. Based on growing season, annuals are classified into summer, rainy & winter
6. Based on hardiness, annuals are classified into hardy, half hardy & tender
7. Based on photoperiodic requirement annuals are classified into short day, long day, day neutral, long short day, short long day & intermediate

I. General information

1. Climbers which climbs up with the help of tendrils are Antigonon leptopus, Bignonia gracilis, Pyrostegia venusta, Clematis paniculata
2. Climbers which climbs up with the help of thorns or prickles are Bougainvillea spp., climbing rose
3. Climbers which climbs up with the help of root and rootlets are Campsis grandiflora, Ficus repens
4. A climber which climbs up with the help of sticky substances from growing points is Ficus repens
5. A Climber which climbs up with the help of hookers is Combretum comosum
6. Climbers which climbs up with the help of clingers are Passiflora caerulea, Passiflora quadrangularis and Hydrangea petiolaris
7. Climbers which grow well under sunny situation are Pyrostegia venusta, Quisqualis indica, Antigonon leptopus, Adenocalymma alliaceum, Bougainvillea spp., Campsis grandiflora and Wisteria sinensis

I. General information

1. Shrub is a woody or semi-woody perennial plant with little or no trunk and grows up to a height from 50 cm to less than four meters.
2. Shrubbery border is an area of the garden devoted exclusively for growing shrubs planted in a row of rectangular fashion.
3. Plants suitable for shrubbery border.

I. General information

1. Common names of trees

• Acacia nilotica – Black babool, Indian gum-Arabic tree
• Acacia auriculiformis – Golden shower
• Adansonia digitata – Baobab, Monkey bread
• Adenanthera pavonina – Red sandal wood, bead tree, red wood
• Ailanthus excelsa – tree of heaven, paradise tree
• Albizia julibrissin – Pink siris, silk tree

I. General information

1. Formal type of garden is laid out in a symmetrical or a geometrical pattern
2. Features of a formal garden are trimmed formal hedges, cypress, ashoka trees
3. Informal type of garden in which all plants and features are arranged in a natural way
4. Wild garden was laid out by William Robinson
5. Examples for formal type of gardens are Mughal, Persian, Indian and French style
6. Examples for informal type of gardens are English and Japanese garden
7. Main features of English garden are lawn, herbaceous border and rockery
8. Main features of Italian garden are massive flight of marble stairs, decorative urns, fountains
9. Mughal type of garden is a replica of ancient Persian garden

I. General information

1. Lalbagh garden is located at Bangalore
2. Founder of Lalbagh garden is Hyder Ali and his son Tipu Sultan
3. Total area of Lalbagh garden is 50 hectares and developed during 1760
4. Brindavan garden is located at Mysore
5. Government botanic garden, Ooty was established during 1848
6. Total area of Ooty botanic garden is 20 hectares