organic agriculture

Lecture –1

HISTORY AND GENESIS OF ORGANIC

FARMING IN INDIA AND WORLD- PROSPECTS AND CONSTRAINS


Why Organic Farming ?
•What is available is not safe for consumption.
•By 2020 underground water will be full of fluorides
•Pollutants in the food chain -- due to toxins in agrochemicals
•1 molecule of chlorine affects 100,000 molecules of ozone (Shivashankar, 2001)
In tropics OC of 2.5-3.0 % or SOM of 5-6 % would possibly lead to sustainable
crop production (Hunsigi, 1997)
•Possible to increase crop yield by 12 % for every 1 % organic matter


What is Organic Farming?


Not just raising crops without using fertilizers and pesticides.

An ongoing dynamic process.

Aims at harmony with nature and production without destruction of the environment.



Characteristics of Organic Farming

Maximal but sustainable use of local resources.

Minimal use of purchased inputs, only as complementary to local resources.

Ensuring the basic biological functions of soil- water- nutrient-humus continuum.

Maintaining a diversity of plant and animal species (bio-diversity) as a basis for ecological balance and economic stability.



Genesis
•Consumer concern : Food quality – protection of environment
•Business strategy – E.U, USA – Major companies, processing, handling packing and
promotion of organic food
•1967 – Organic agriculture community – U.K – National Legislation system
•1974 – USA – States of Oregon,California organic adopted organic legislation
•1980 – IFOAM


1985-1991 – France adopted E.U – Regulation providing financial compensation for loss during period

1995-2000 – Organic land area trippled – in Europe and USA

280 % Increase in area – Argentina

Cuba – adopted organic agriculture as official agricultural policy with high financial investment in research and




India

•Nutrient use efficiency – low
•Soil health hazard
•Residue in food chain
•Health hazard
•Ground water pollution
•Environmental pollution




q Government organisations Private institutions, NGOs – Created awareness on organic farming
q Bombay Burma trading corporation (BBTC) – market organic tea – internationally
q Ecological development society – Pondicherry
q Institute for Integrated rural development (Aurangabad)


v Society for equitable voluntary actions ( SEVA) – West Bengal
v Indian agency for organic agriculture – (IAOA) – ( Cochin)
v Peekay tree crops development foundation –( PTC DF) – Cochin
v All India federation of organic farming ( AIFOF)
v Government of India constituted a team on alternate technology of low cost – eco-friendly -1992. Suggested organic farming


• 2000- National programme for organic production ( NPOP)
• APEDA
• 2001 – GOI formed working group – suggested organic farming and bio dynamic farming technology
• India – Export – Organic – tea, coffee, spices, fruits, vegetables, cereals, cotton, rice and nuts.



Major soft agricultural activities in India
A.P : Bharatiya Kisan Sangh,Hyderabad - Cowdung,residues of pulses,traditional
varieties.

Bihar : Use of neem leaf powder or its ash against biotic losses.

Delhi : Navdanya - Fore front organisation for organic movt.- Promotes biodiversity maintenance.

Goa : Peaceful Society,Ponda-Conducts periodical workshops to promote O.F.

Gujarat: Sajiv Kheti Farm,Vinoba Ashram,Kalpavriksha Farm-Mixed community of
dense vegetation- Weeds original Children of soil-mulching,trench for
trees,composting,GM,earth worms,organic fencing.

J&K: Ladakh Ecological Devt. Group(LEDeG)-Right livelihood Award. Intensively
practices O.F.

Karnataka:Janapada Seva Trust,Melkote-Promotes O.F.

Kerala: KOFA,Alappuzha-Natural ecosystem surrounded by cultivation with open space, Sprinkling fish-wash over vegetable crops to control pests.


M.P: Friends Rural Centre,Hoshangabad -No chemical fertilisers,no pesticides and don’t disturb the soil.

Maharastra:Redstone Farm,Panchagani-Composting,mulching,neemcake application,donkey dung,leaf mold,ash+compost.
Rishi Kheti Prakalpa Jagar Society promotes O.F.

Orissa:SAMBHAV Farm,Nayagarh-Ecofarm.

Rajasthan :Rajasthan Kissan Sangathan,Jaipur-Traditional farm practices.

Major soft agricultural activities in India (Cd.,)
U.P: Purakkheti - agri with pro-life, pro-envt. & pro-nature.
Shoor Vir Singh Farm - Investigating the possibilities of Masanobu Fakuoka under Indian conditions.
TERMICOMPOST, Filling cow dung in horn and put in wet piece of land for 6 months, 25 gm in water/acre.

W.B: SEVA(Society for Equitable Voluntary Actions)-Conduct experiments on NF,OF,LEISA,HEIA.Birds chirping indicates safety.


Major NGO networks in India and TN
•ARISE, Auroville (Pondicherry)
•SOA, Rasulpura (Secundarabad, AP)
•APIGR, Ahemadabad (Gujarat)
•AIFOF, Thane west (Maharashtra)
•KOFA, Alapuzha (Kerala)
•OFK, Bangalore (Karnataka)
•Manviya Tech. Forum, Vadodara (Gujarat)
•KUDAMBAM - LEISA net work, Pudukottai (TN)
•SEVA – Virattipathu, Madurai – in collaboration with SRISTI, CIKS and WWF – India – carried out experiments to evaluate the efficacy of botanicals for paddy and documented 250 traditional agricultural technologies – Nam vazhi velanmai through Honeybee network of IIM, Ahmendabad.

Agencies involved in Organic Farming in India
All India Federation of Organic Farmers (AIFOF),
Bombay (On the pattern of the International
Federation of Organic Agriculture Movement (IFOAM), Germany)

© Society for Organic Agriculture (SOA),Hyderabad

© SEWAK, Nainital

© M.S. Swaminathan Foundation, Chennai

© SRISTO Innovations, Ahmedabad

© I I R D, Aurangabad



• Organic farming – Definition


• FAO : Organic agriculture is a unique production and management system which promotes and enhances agro ecosystem health, including bio diversity, biological cycle and soil biological activity and this is accomplished by using on – farm agronomic, biological and mechanicals methods in exclusion of all synthetic off – farm inputs


USDA – Organic farming system which avoids or largely excludes the use of synthetic inputs ( such as fertilizer, pesticides, hormones and feed additives etc., ) used to the maximum extent feasible rely upon crop rotation, crop residues, animal manures, off-farm organic wastes, mineral grade rock additives and biological system of nutrient mobilization and plant protection



• Codex committee – on Food labeling –

• Organic agriculture as a holistic production management system, which promotes and enhances agro-ecosystem health, including biodiversity, biological cycles and soil biological activity. Non use of synthetic materials

Prospects of organic farming
v Sustainability of soil health – adds organic matter, OC, physical, chemical properties
v Soil moisture conservation
v Quality and shelf life of produce
v Effective land utilization – intercropping, cover cropping green manure crops
v Reduced environmental hazards
v Improved health of humanbeings and animals
v Increased employment opportunities
v Increased farm income

Constraints of organic farming
ØOrganic farming technology – location specific
ØOrganic manures bulky in nature – high transport application cost
ØSmall farm holdings less scope for in-situ organic manure production
ØLack of awareness in scientific compost making
ØLack of scientific data on organic farming
ØLimited domestic market
ØPossible yield reduction







Lecture No.2

STATUS OF ORGANIC FARMING IN INDIA WITH SPECIAL REFERENCE TO TAMIL NADU

•What is available is not safe for consumption.
•By 2020 underground water will be full of fluorides
•Pollutants in the food chain -- due to toxins in agrochemicals
•1 molecule of chlorine affects 100,000 molecules of ozone (Shivashankar, 2001)
In tropics OC of 2.5-3.0 % or SOM of 5-6 % would possibly lead to sustainable crop production (Hunsigi, 1997)
•Possible to increase crop yield by 12 % for every 1 % organic matter
Export: Certified Organic Products and Volume- India
Year
Population (m)
Requirement ( m.t)
Projected potential of nutrients from organics (m.t.)

Food
Plant nutrients
2001
2006
2011
2016
2021
1006
1086
1164
1244
1324
230
248
266
284
302
32
37
40
43
46
28
30
32
34
36















CURRENT STATUS IN INDIA
v Area under certified cultivation : 25 lakh ha
v Number of projects : 218
v Number of farmers involved : approx
11000
v Products exported : 18 items
v Total exports (2002-03) : 63452 m t
v Approximate value : Rs. 89.42 cr
v Total agriculture exports : Rs.27720cr
v Organic exports : 0.32 %

MARKET
v Current market : 23-25 B us$
v Annual growth : 15 - 20%
v U.s. A : 11-13 b us$
v Japan : 350-450 m us$
v Europe : 10 -11 B US$
POTENTIAL PRODUCTS
q Rice
q Cereal products
q Pulses
q Honey
q Canesugar
q Jaggery
q Fruits ( Juices,Concentrates & Nectars )
q Herbs and spices
q Peanuts
ADVANTAGE INDIA
v Conducive agro climatic conditions.
v Prevailing traditional farming.
v Many areas in the state are not yet exposed to chemicals .
v Progressive farmers .
v Availability of manpower. Govt. Initiatives.
In Tamil Nadu –
80 NGOs
10 Districts – LEISA
3000 Farmers – following organic farming


Lecture –3

IMPACTS OF GREEN REVALUATION ON ECOSYSTEM QUALITY


INDIAN AGRICULTURAL BEFORE GREEN REVOLUTION
♣ Small – marginal farmers producing food and because animal products for families
and village communities
♣ Crops d/o on soil – climate
♣ Soil health – pest control – shifting cultivation, conversation, FYM, legume crop
rotation
♣ 1892 -10 million people died in famine and frequent famine before 1947 – National
and International cooperation - managed




Green revolution – 1965 -66
•Hybrids and HYV
•More irrigation
•Fertilizer use
•Pesticides
•Herbicides

Higher yields




Impacts of Green Revolution on Ecosystem Quality
The ills of green revolution are stated to be :

vReduction in natural fertility of the soil
vDestruction of soil structure, aeration and water holding capacity
vSusceptibility to soil erosion by water and wind
vDiminishing returns on inputs ( the ratio of energy input to output halves every 10 years ).

Indiscriminate killing of useful insects, microorganisms and predators that naturally
check excess crop damage by insect pests


Breeding more virulent and resistant species of insects
Reducing genetic diversity of plant species
Pollution with toxic chemicals from the agrochemicals and their production units


üEndangering the health of the farmers using chemicals and the workers who
produce them
üPoisoning the food with highly toxic pesticide residues
üCash crops displacing nutritious food crops
üChemicals changing the natural taste of food
üHigh inputs increasing the agricultural expenses
üIncreasing the farmer’s work burden and tension


qDepleting the fossil fuel resources
qIncreasing the irrigation needs of the land
qBig Irrigation projects often resulting in soil salinity and poor drainage
qDepleting the ground water reserves
qLowering the drought tolerance of crops
qAppearance of ‘difficult’ weeds
qHeightening the socio-economic disparities and land holding concentration
qHigh input subsidies leading to inflationary spirals


¤Increasing the political and bureasucratic corruption
¤Destroying the local culture (commercialization and consumerization displacing self-
reliance )
¤Throwing financial institutions into disarray ( as impoverished farmers demand write –
off of loans)
¤Agricultural and economic problems sparking off social and political turmoil resulting
in violence


Fertilizer – 1950-0.6 kg ha-1
1987-50 kg ha-1
2000-145 kg ha-1
•No humus
•Deficiency of Zn, Fe, Mn, Cu, Mg, Mo & Bo
•Affects soil physicals, chemical and biological properties
•Release of N2o to atm.- depeletes O3 – Green house effect – Global warming
•Kills soil living organism



Pesticides

Ø Newer pest buildup
Ø Loss of natural enemies
Ø Only portions of pesticides - kill pests – major portion reaches air, soil and water- effect living organisms – environment
Ø Pesticides donot break down easily – absorbed in food chain


Herbicides
*Residual effect in soil, affect crops in rotation
*Kill soil living organisms
*Residue in grain and straw
*Affects human and animal health
*Pollution soil and water


Irrigation
Ø Over exploitation of ground water
Ø High cropping intensity
Ø More pest and disease
Ø Stalinization
Ø Monocropping of paddy – impervious layer of soil – prevents nutrients from deeper layer


Ø Todays ecology is more important than tomorrows economy
Ø Because no economy without ecology



Lecture- 4

INTRODUCTION TO BIO-DIVERSITY ITS IMPORTANCE AND PRESENT SCENARIO


Introduction to bio-diversity, its importance and present scenario

Popular interest protecting the world’s plant and animal species has intensified during last 20 years. Around the globe, biological communities that took millions of years to develop are devastated by human activities. Viz., habitat destruction such as clear cutting of forests, over-grazing grass lands, draining wetlands and polluting the ecosystem.
Bio-diversity:
The variety and variability among living organisms and the ecological complexes in which they occur (U.S. office of Technology, 1987) this concept subdivided into three levels.
1. Genetic diversity:
At finer levels of organization, biodiversity includes the genetic variation within species, both among geographically separated population and among individuals within single population .
2. Species diversity.
Biodiversity at its most basic level includes the full range of species on earth, from micro organisms such as viruses, bacteria and protists through the multi-cellular kingdoms of plants, animals and fungi.
3. Community / Eco system diversity
On a wider scale, biodiversity includes variations in the biological communities in which species live, the ecosystem in which communities exist and the interactions among these levels.
v Western Ghats and Eastern and N.E Himalayas – high floristic diversity- “hotspot” region.
v 45,000 plant species
v 81,000 animal species – representing 7% of world flora
6.5% world fauna of 33% flora and 62% fauna are endemic.
Bio-diversity is the result of two opposite actions
Ø The processes that produce new genotypes new varieties and new species
Ø The processes that eliminate mutations, variants and species from the system.
Estimated rates of extinction
Estimate
% of global loss per decade
Ø One million species – 1975 -2000
Ø 15 -20% of species 1980 -2000
Ø 50% of species by 2000 and
100% by 2010 -2025
4
8 -11
20 -30
(Mawdsleys stork 1995)

Plant and animal species extinct since 1600
Animals
Plants
Molluscees - 202
Ferns 16
Crustacean - 4
Gymnosperm 12
Insects - 61

Fishes - 33
Angiosperm
Amphibians - 2
Dicot 458
Reptiles - 23
Monocot 120
Birds - 117

Mammals - 62

Total 504
Total 596


Keystone Species
With in biological communities some species may be important in determining the ability of large number of other species to persist in community. These crucial species have been termed keystone species. To protect keystone species is a priority for conservation efforts; because if a keystone species is lost from a conservation area, numerous other species might be lost as well. For example, the severe decline and extinction of many species of pteropid bats bats, or flying foxes, in the Old World tropics has a dramatic effect many important plant species in the islands. Flying foxes are widespread throughout the Old World tropics. About 50 species of the genus pteropus are concentrated in the islands of the South Pacific where they are the most important, and often the only, pollinators and seed dispersers for literally hundreds of species of tropical plants. Important timber species like (Diospyros melanaxylon) and (Calophyllum inophyllum) medicinal plants, and plants yielding fibers, dyes and other products, wild bananas are also bat pollinated.
Many tropical insect species appear to be highly specialized in their feeding behaviour, subsisting on just one or a few related plant species. Extinction of each tropical plan species potentially results in an extinction cascade.
In many localities where have been hunted to extinction by man, deer populations have exploded. Fig flowers are pollinated by small wasps developing fig fruit - birds and other fruit-eating vertebrates, even during dry seasons - elimination of a keystone species.

Measuring Biodiversity
[I] Alpha diversity
This refers to number of species in a single community. This diversity comes closest to the popular concept of species richness and can be used to compare the number of species in different ecosystem types.
[II] Beta diversity
This refers to the degree to which species composition changes along an environmental gradient. Beta diversity is high for example, if the species composition of moss communities changes at successively higher elevations on a mountain slope, but is low if the same species occupy the whole mountain side.
[III] Gamma diversity
This applies to larger geographical scales and defined as ‘ the rate at which additional species are encountered as geographical replacements within a habitat type in different localities. Thus gamma diversity is a species turnover rate with distance between sites of sililar habitat or with expanding geographic areas”.
No.of species worldwide
1,413,000 identified species. A large number unidentified. If it is done number could be 5 million or more
Insects
-
751,000
Plants
-
248,000
Other animals
-
281,000
Fungs
-
69,000
Protests
-
30,000
Algae
-
26,000
Bacteria
and similar forms
-
4,800
Viruses
-
1,000

Why biodiversity is rich in the tropics ?
(1) Over geological times the tropics have had a more stable climate that the temperate zones.
(2) Tropical communities are older than temperate ones and, therefore, there has been more time for them to evolve. This could have allowed them greater degree of specialization and local adaptation to occur.
(3) Warm temperatures and high himidity in most tropical areas provide favourable conditions for many species.
(4) In tropics, there may be greater pressure from pests, parasites and diseases. This does not allow any single species to dominate and thus there is opportunity for many species to co-exist. On the contrary in temperate zones there is reduced pest pressure due to cold.
(5) Higher rates of out crossing may lead to higher levels of genetic variability.
(6) Tropical areas receive more solar energy over the year more productive or greater resource base that can support a wider range of species.

Human activity is the major threat to biodiversity and following are the chief causes of extinction of species caused by man to fulfill its needs.
[I] Habitat destruction
Expansion of human populations and human activities. Human population went from 1 billion in 1850, to 2 billion in1930, to 5.3 billion in 1990, 6.5 billion by the year 2000. More than 50% of the wildlife habitat has been destroyed in 49 out of 61 Old World tropical countries.
Bangladesh (94%), Hong Kong (95%), Sri Langa (80%),and India (80%). Mining, cattle ranching, commercial fishing, forestry, population, agriculture, manufacturing, and dam construction, initiated with the goal of making a profit. Huge amounts of habitat are lost each year as the world’s forests are cut down. Rain forests tropical dry forests, wetlands, mangroves and grasslands are threatened habitats and leading to desertification.
[II] Habitat fragmentation
Habitat that formerly occupied wide areas are now often divided up into pieces by roads, fields, towns, canals powerlines etc. Habitat fragmentation is the process where a large, continuous area of habitat is both, reduced in area and divided into two or more fragments.
[III] Habitat dégradation and pollution
some activities may not affect the dominant species in the community but other species are greatly affected by such habitat degradation. For example, physical degradation of forest habitat by uncontrolled ground fires, might not kill the trees, but the rich perennial wild plant community and insect fauna on the forest floor would be greatly affected.
[IV] Introduction of exotic species
Introduction of exotic species increased levels of diseases, and excessive exploitation of particular species by people.
[V] Disease
Animals held in captivity are also more prone to higher level of disease.
[VI] Overexploitation
Increased use of natural resources.
[VII] Shifting or Jhum cultivation
Rural people destroy biological communities and hunt endangered species because they are poor and have no land of their own.

Biodiversity problem in agriculture :
Convergence on specialized varieties of species
Only 35-45 species were domesticated and cultivated for human consumption directly. Such domesticated species were cultivated through modem agriculture for higher yield over the years. Due to monoculture of several species, biodiversities of both plants & animals gradually shrinking with times.

Examples of genetic uniformity in selected crops
Crop
Country
Number of varieties
Rice
Sri Lanka
From 2000 varieties in 1959 to 5 major varieties today 75% of varieties descended.
Rice
India
From 30,000 varieties to 75% of production from less than 10 varieties.
Rice
Bangladesh
62% of varieties descended from one maternal parent.
Rice
Indonesia
74% of varieties descended from one maternal parent
Wheat
USA
50% of crop in 9 varieties
Potato
USA
75% of crop in 4 varieties
Cotton
USA
50% of crop in3 varieties
Soybean
USA
50% of crop in 6 varieties

Biodiversity and food security
Preserving these germ pool is an integral part of food security. It is evident that preservation of wide range of germ pool is an integral part of breeding programme. If we unable to combat the problems of genetic erosion, it may lead to losing sources of resistance to pests, diseases and climatic stress and finally leading to crop failure in future. World having over 3,500 species of mammals, 9.000 species of birds and considerable numbers of insects & other animals. But almost all meat, milk, eggs and other animal product today come from just five categories of animals viz., cattles, pigs, goats, sheep and poultry birds.

Some of the major crop failures viz., wheat failure in Eastern India, in 1943 cassava mealy bug attack in Zaire in 1973; black sigotaka attack on banana plantation of Fiji in 1920; leaf blight fungus attack on rubber plantation of South America in 1950s, have experienced as long ranging consequences. Thus agricultural scientists and professional forests require a special attention on this subject for appropriate mitigatory plan formulation. Many wild relatives of present day cultivated crops have unique gene pool that could be used for saving the crop failures from insect pest attack or even from natural calamities like drought and flood hazard.
Ireland’s potato blights resistance source was found in a wild potato growing in Mexico. Wild rice varieties of Silent Valley (Kerala) is shown to carry disease resistance genes. Central American’s banana industry was saved from devastating Panama disease from a banana plant collected in a botanic garden in blight and with genes saving the US spinach crop.
Considering their importance in 1983. Food and Agricultural Organisation (FAO) made a convention on International undertaking on plant genetic resources which stressed that genetic resources were a common heritage.

Importance of Biodiversity
(i) Human Food Supply: Human food of everyday use comes from other organisms. So many wild plant species therefore make important contributions to human food supplies. Some four thousand native plant species for food and medicine are used by villagers in Indonesia. Indonesia has 250 edible fruits and only forty-three of which are cultivated widely (Source: 1975 study by the National Academy of Science (US)).
(ii) Drugs and Medicines: Living organisms (plants and flowers) provide useful drugs and medicines. More than half of all prescriptions contain some natural products. The value of pharmaceutical products worth $ 30 billion. Realise the success story of vinblastine and vincristine. They are anticancer alkaloids. They are derived from the rosy periwinkle (name of plant 0 from Madagascar. The total value of periwinkle crop is estimated to be $ 1.5 million per year.


Natural Medicinal Products and their use

Product
Source
Use
Penicillin
Fungus
Antibiotic
Bacitracin
Bacterium
Antibiotic
Tetracycline
Bacterium
Antibiotic
Erythromycin
Bacterium
Antibiotic
Digitalis
Foxglove
Heart stimulant
Quinte
Chincona bark
Malaria treatment
Diosgenin
Mexican yarm
Birth control drug
Cortisone
Mexican yarm
Anti-inflammation treatment
Cytarabine
Sponge
Leukemia cure
Vinblastine, Vincristine
Periwinkle plant
Anticancer drugs
Reserpine
Rauwolfia
Hypertension drug
Bee venom
Bee
Arthritis relief
Allantion
Blowfly larva
Wound healer
Morphine
Poppy
analgesic

(iii) Ecological Benefits: Biodiversity provide ecosystem stability. Soil formation, air and water purification, nutrient cycling, solar energy absorption and management of hydrological cycles all depend on the biodiversity of life. Wild species provide significant services in suppressing pests and disease carrying organisms. It is estimated that 95% of potential pests and disease-carrying organism in the world are controlled by species.

The PRAYING MANTIS (insect like a grasshopper) is an effective predator against garden pestsand is harmless to humans. Ladybird beetles (ladybugs) prey on a variety of pests both as larvae and adults. For a few dollars you can buy several thousand of these hardy and colourful little garden protectors from gardening supply stores.

iv) Aesthetic and Cultural Benefits : The diversity of life on this planet open many doors of aesthetic and cultural benefits to man in an innumerable manner. Millions of people enjoy hunting, fishing, hiking, wildlife watching and other outdoor activities based on nature.
a) Americans spend $ 18 billion every year watching wildlife.
b) 8 million bird watches in USA spend $ 5.2 billion per year.
c) To enjoy nature and experience other cultures inexpensive inter continental air-flights are arranged to visit remote and exotic places in USA.

Biodiversity conservation strategies : Global scenario
Considering the immense value of biodiversity and subsequent rapid loss of the same, during past couple of decades, enormous conservation efforts were made for restoring the biodiversity of various habitats.
Protecting biological diversity
On-site protection
Off-site protection
Ecosystem maintenance
Species management
Living collections
Germplasm storage

Management systems

National parks
Agroecosystems
Zoological parks
Seed and pollen banks
Natural research areas
Wildlife refuges
Botanic gardens
Semen, ova, and embryo banks
Marine sanctuaries
In-situ gene banks
Field collections
Microbial culture collections
Resource development
Games parks and reserves
Captive breeding programs
Tissue-culture collections

Conservation objectives

To establish a reservoir of genetic resources
To promote genetic interaction between semi-domesticated species
To maintain breeding stock
To provide a convenient germplasm source for breeding programs
To preserve evolutionary potential
To maintain viable wild population for sustainable exploitation
To facilitate field research and the development of new varieties and breeds
To preserve germplasm of uncertain or threatened species
To preserve various ecological processes
To safeguard viable populations of threatened species
To facilitate off –side cultivation and propagation
To maintain reference type collections as standard for research and patenting
To preserve species
To preserve species that provide important indirect benefits (as for pollination or pest control)
To maintain captive breeding stock of populations threatened in the wild
To provide access to germplasm from wide geographic areas
To preserve representative ecosystems
To provide “keystone” species with ecosystem support
To make wild species readily available for research, education, and display
To preserve genetic materials from endangered species.






Lecture No. –5

AGRICULTURAL ECOLOGY AND ENVIRONMENT – BASIC PRINCIPLES

ECOSYSTEM AND HOW THEY WORK

Ø Ecology was created by Ellen swallow, 100 years ago.
Ø Ecology , from the Greek Oikos (house or place to live) and logos (study of ) , is the study of how organisms interact with one another and with their physical and chemical environment.
Ø Ecology involves examining various ecosystems. Communities of species interacting with one another and with their non living environment of matter and energy.

Key concepts and definitions

‘Spheres’ of the environment the hydrosphere (water), the atmosphere (air), the geosphere (earth), the biosphere (life) + anthrosphere (dealing with human activities and technology).

Ecology
v Ecology is the science that deals with the relationships between living organisms with their physical environment and with each other.
v Ecosystem consists of an assemblage of mutually interacting organism and their environment, in which materials are interchanged in a largely cyclical manner. Ecosystem has physical, chemical and biological components along with energy sources and pathways of energy and materials interchange.

Ecosystem and Energy flow in Ecosystem

Ecosystem ‘Eco’ means the environment and ‘system’ means a set of inter-acting and inter-dependent living and non – living components.
Eco-system is a complex, in which living organisms and environment form an interacting unit, out of others.
Eg. pond, desert, ocean, biosphere………

Kinds of ecosystems
Terrestrial / Aquatic
(Grassland, forest)
Running water
Fresh water
Aquatic ecosystem Standing water
Sea
Marine
Ocean
· Natural / Artificial


· An eco-system has both structure and function.
· The structure of an eco-system describes the composition of biological community and physical features of environment (nutrients, climate).
· From structural view- point, each eco-system has 2 components :
1. Biotic components
2. Abiotic component.
From functional point of view, each eco-system has two basic components ;
Autotrophic component
Heterotrophic components
The function of an eco-system is related to the flow of energy and cycling of materials through the structural components.

BIOTIC COMPONENTS OF AN ECO-SYSTEM
§ Biotic components include all the living organisms present in the environment system.
A. Autotropic components (Auto- self; troph-nourishing)
§ Autotrophs are known as producers Eg. Green plants, photo-synthetic bacteria etc.
§ Producers absorb solar energy and prepare complex organic compounds with the help of inorganic substances like Co2 and water from environment. This process is photo-synthesis, carbon assimilation or primary biological productivity.
6 Co2 + 6 H2o chlorophyll C6H12O6 + 6 O2
Thus solar energy is converted into chemical energy.
§ Based on size of producers, there are two types:
a) Micro – producers : Phytoplanktons, algae etc
b) Macro-producers : Green plants.


HETEROTROPHIC COMPONENTS
(Hetero – different : troph – nourishing).
§ These are living organisms which are unable to prepare their own food but these consume, rearrange and decompose the complex food material prepared by the producers.
§ Heterotrophs are of 2 types :
a) Consumers
b) Decomposers and transformers.
Consumers – Based on dependency, classified into:
i) Primary consumers, ii) Secondary c , iii) Tertiary c, iv) Parasites, Scavengers and Saprobes.
Primary consumers purely herbivorous animals
Eg. Cow, rabbit, insects etc.


Secondary consumers may be carnivorous and omnivorous.
Eg. fox, snakes, dogs, etc.
Tertiary consumers Top carnivores.
Eg. Lions, hawks, vultures etc.
Parasites, scavengers and saprobes
Parasitic plants and animals feed on living tissues of different plants and animals.
Scavengers and saprobes consume dead animals and plants as their food.


DECOMPOSERS AND TRANSFORMERS
These are living organisms which constantly decompose organic substances in dead organism and derive food and energy from them.
Dead plants and animals decomposers simpler organic
Compounds transformers inorganic forms.

ABIOTIC COMPONENTS
v This components includes non-living part of the eco-system.
v The non-living substances enter the body of living organisms, participate in different physiological activities and finally return to the environment.
v Abiotic components can be divided into :
A) Inorganic components O2, CO2, Water, Phosphate etc.
b) Organic components proteins, carbohydrates, lipids etc.
c) Physical components light, temperature, humidity etc.
v there is a direct link between biotic and abiotic components (thro’ metabolic bio-geo-chemical cycle and energy flow
v Pont as an eco-system
v Grassland as an eco-system.

FOOD CHAIN
v A food chain may be defined as the transfer of energy and nutrients from the source in plants, through a series of organism with repeated processes of eating and being eaten.
v Food chain of different eco-system:
Grassland Eco-system
Green Grasshopper Toad Snake
Grass Rat Snake Hawk
Grass Goat Man Tiger

Pond Eco-system
Phytoplankton zooplankton small fish big fish.
v The shorten the food chain, the more is the amount of energy available to the last trophic levels.

FUNDAMENTALS OF ENVIRONMENT

ü Environment is defined as a holistic view of the world as it functions at any point of time, with a multitude of spatial, elemental and socio-economic systems, distinguished by quality and attributes of space and mode of behaviour of abiotic and biotic forms.
Types and components of environment
· Environment may be divided into two basic types- physical or abiotic environment and biological or biotic environment
· The physical environment is subdivided into : i) lithosphere (solid earth). ii) Hydrosphere (water component) and iii) atmosphere (gas).
· The biological environment is subdivided into : floral environment, faunal environment and microbial environment.


Need for Environment studies
There is urgent need to protect the environment awareness (environmental education)
It helps in the maintenance of life and health and in the preservation of the human, plant and animal race.
It helps to understand different food chains and ecological balance in nature.
It helps in appreciating and enjoying nature and society.
It generates concern for the changing environment for the welfare of mankind.
It directs attention towards the problems of population explosion, exhaustion of natural resources and pollution of the environment and throws light on the methods of solution.

Environmental problems of India
About 50 percent of the land is degraded and the situation continues to worsen.
There is need for more food production.
Each year 6 billion tons of rich top soil is being lost.
In many areas, subterranean water levels have declined almost five to ten times below the surface, during the lat 50 years.
At least 35% of the people get their cooking fuel from the firewood they collect by cutting down forest trees.
Each year, the country is loosing nearly 1.7 million hectares of life-sustaining forests, in spite of many afforestation programmes.
The country has been adding annually 20 million people.



v Environment means conditions of life. All flora (plants) and fauna (animals) needs suitable condition for survival. The environment of earth is combination of two things,
1. Physical environment – non –living elements viz., land, water and air.
2. Biological environment – (living elements viz., plants, animals and micro organisms.

v The ever changing surroundings or conditions under which a person or things exists and develop referred as “ Dynamic Environment”
v Environmental planning means optimum utilization of earth’s resources for sustainable growth.
v Environmental management means rational adjustment of and with nature called eco-friend ship by way of explanting and utilizing natural resources without distributing ecological equilibrium


Lecture No. 6

NATURAL RESOURCES POTENTIAL AND UTILIZATION
FOR THE LAST HUNDRED YEARS AND ITS IMPACT


Resource can be defined as anything that is necessary or useful for human needs in the form of matter and energy, tending to improve people’s life. Natural resources, which furnish materials, constitute the base of our material wealth. Natural resources can be broadly classified into biological and nonbiological. Resources may be renewable or nonrenewable


The renewable resources include plants and animals and these are often referred to as the bioresources or living resources; for example , plant resources, wildlife resources, fishery resources , agricultural and forestry resources, medicinal plants etc. Renewable resources are crucial to an ending human civilisation

The non renewable resources of the earth’s crust include elements like copper, aluminium, iron and deposits of nonmetallic minerals out of phosphate rock from which fertilizers are extracted. The nonrenewable resources also include the fossil fuels like coal, oil and natural gas. Nonrenewable resources consist of geochemical concentrations of naturally occurring elements and compounds that may be exploited profitably.



MINERAL RESOURCES

• The world’s present per capita mining indicates that five minerals are mined to the maximum extent-coal, petroleum, iron ore, aluminium and phosphate rock.

• The major non-metal resources include asbestos, carbonates, C12, granite, O2, phosphate, potash, sand and gravel, Na compounds and H2O



Forests
Forests play a very significant role in the Socio-economic development by improving the quality of life by supplying pole, wood, fuel, fodder, medicine, timber, pulped papers, plywood, oil, resin, rubber etc. clearance for timber and overgrazing now pose serious threats to some seasonal forest areas such as those in Nothern India


Deforestation
Half of all plant and animal species in the world live in the rain forests. If deforestation continues unabated, the ecological riches of these unique ecosystem will soon be lost forever.

Land
Land is the surface area of the earth excluding open water bodies. The plants and animals, the soils, and the life-supporting nutrients provided by land make up a single interdependent unit – an ecosystem.

Soil
The living community of the soil comprising millions of tiny organisms, involved in the modification of the soil environment or the soil building process, are all valuable resources.





Soil Faunal Resources
The organic matter occurring abundantly in the superficial layers of the soil is the abode of an extremely rich and diverse insect faunal resources.

Arthropods like insects, millipedes, centipedes, spiders, larvae of flies, ants and termites help in soil aeration through burrowing, feed on decaying vegetation and in some cases play a useful role as predators in soil food chain.

Biotic Resources of the Soil A health soil is vibrantly active or “alive” teeming with bacteria, fungi, moulds, yeasts, algae, protozoa, worms and insects living in the top cores. Abundance of soil organism.



Land Forms and types
Land forms have a direct bearing on the general appearance of ecosystems and also influence the microhabitat and microclimates. Land forms are of different types such as flat or slope.

When land is damaged by industrial or other developmental activities, it goes out of beneficial use. Such land is called derelict land. Derelict land can be treated and redeemed by restoration, reclamation and rehabilitation.

Water
Great civilizations have flourished by the riverside, such as the Mesopotamian, Egyptian, Chinese and Aryan, on account of ample fresh water availability


Lecture No.7

CONSERVATION OF PLANT TO DIVERSITY INCLUDING WEED FLORA AND SOIL FOUNA

Biodiversity Conservation
• Biodiversity is the basis of survival of many life forms. Now we are in strong conclusion that it must be protected at any cost.
• This thought is simple. But..

• How to protect?

• What to protect?
is complicated



• Every human civilization on earth has been rooted in the biodiversity of nature.

• The domestication of wild crops made the first farming possible.

• Genetic resources taken from the wild, still sustain modern societies, providing food, fodder, medicines and industrial raw materials.

• Future of the our agriculture depends upon the gene pool of the wild relatives of modern crop plants which are found in the tropical forests.

• Only 8 crops supplying 85% of the world food, new types of crops could be essential for human survival on earth.


• Fungus penicillium - penicillin

• Chinchona tree - quinine

• Both these drugs saved millions of lives during world war II and after.


I. Genes from wild species incorporation for high yield and diseases resistance:

• Asia - 1979 incorporating dwarf genes into both crops from their wild relatives. Increased wheat production by $2 billion and rice production by $ 1.5 billion.

• Genes from a wild wheat in Turkey saved epidemic of the wheat diseases in USA in the 1960’s. Provided resistance to this and 50 other diseases and is saving worth $ 50 million annually to the US alone.

• One genes from a single Ethiopian barely plant now protects California's $ 160 million annual barley crop from yellow dwarf virus.

II. Wild species in crop improvement:
• In sugarcane Saccharam spontaneum was introduced in S. officinarum against the red rot diseases and other environmental conditions.

• Using 13 rice varieties from 6 countries including the dwarf genes from Taiwan and several land races from India and the wild O. nivara from Central India, plant breeders at IRRI, Manila, Philippines developed the most widely cultivated rice variety Ir 36.

• Wheat : dwarf gene namely Norin – 10 from Japan and dwarf genes Sonora – 64 and Lerma roja 64 from mexico resulted high yielding wheat variety- green revolution in the 1970’s.

• The potato crop Solanum tuberosum has been greatly benefited from its wild relatives.
• S.acaule has conferred resistance to potato virus –X and potato leaf roll virus.

• S.soloniferum .. To potato virus Y.

• S. demissum.. To Phytopthora infestans, the fungus that wiped out the potato cop and caused the great potato femine of Ireland in 1845.

• High sugar containing wild tomato species namely Lycopersicon chmielewskii to produce larger redder, 2.5% sweeter .





• Worldwide medicines from wild products are worth some $ 40 billion a year

• New food from the wild species.
• Three crops namely wheat, rice and maize for our food requirement. Disease can wipe out these handful of crops as it happened in the case of Irish potato famine in the 1845’s causing one fifth of the country’s people to die.

• Some 5000 plant species have been used as food by the civilization across the world and another 75.000 are expected to be edible which is not known. They need to be domesticated.

Alternative foods from Biodiversity:
• In future civilization has to depend upon alternative foods grown an a medium other than the soil with a short harvest cycle. This would be necessary because land is a finite resource on earth and population continues to rise.
• The blue green algae have higher food value than the conventional crop plants. Ex. Spirulina, anabaena, Spirulina has 60% protein value which is highest among any known food plants and the cheapest source of protein on earth. One g of spirulina is equal to 1 kg of assorted food.
• The global production of spirulina { example for single cell protein (SCP} is about 15000 t/year.




V. Industrial raw materials from biodiversity

• The aquatic weed water hyacinth (Eichhornia crassipes) can be moulded into useful and commercially viable cement boards and work as the sybstitute for asbestos which is a serious human health hazard.

VI.Bio-diversity: the key to sustainable Agriculture:

• Traditional farmers grow a variety of crop plants to gain maximum yield and diversified products. This also minimize the risk of crop losses due to pest attack.

• Many of the traditional varieties of crop plants grown by the farmers are disease and pest resistant – used for breeding programmes
• Bio-diversity controls agricultural pests without the use of pesticides.

• The intercropping of diverse plant species in a polyculture farming systems helps provide habitats for the natural enemies.

• In a biologically diverse agroecosystems several species like algae, azolla, insects, fish, frogs, lizards, snakes, birds, bats, weeds and trees, all live together in an interdependence of food web and such agricultural systems are highly stable and sustainable.

• The frogs, reptiles and birds eats the pests and also fertilize the soil by their droppings.




VI. Significance of species in the maintenance of ecosystem integrity

Ø In the year 1970 in Malaysia, the yield of durian fruit declined threatening $ 100 million fruit industry per year. This was happened due to decline in population of a specific species of bats which pollinates the fruit tree.



IUCN Red Data Books

• International Union for conservation of Nature and Natural Resources (IUCN) has established the five main conservation categories. These are extinct, endangered, vulnerable, rare and insufficiently known species. IUCN, also known as the World Conservation Union with Headquarters at Gland, Switzerland.

• World Conservation Monitoring Centre (WCMC) has evaluated and described threats to about 60,000 plant and 2000 animal species in its series of Red Data Books.

• IUCN have estimated that about 10% of the world’s vascular plant species totaling to about 20,000 – 25,000 species are under varying degrees of threat.






ü In India, the problem on threatened plants was first discussed in the 11th Technical Meeting of the IUCN in 1969. in 1980, the Botanical Survey of India published a small booklet entitled Threatened Plants of India – A State-of-the Art Report.

ü Botanical Survey of India as Project on Study, Survey and conservation of Endangered Species of Flora (POSSCEF) under a PL-480 scheme, supported by the U.S.

Germplasm Banks

Ø IBPGR (International Board for Plant Genetic Resources). IBPGR could establish ex situ conservation facility in about 100 countries. Later IBPGP expanded to IPGRI (International Plant genetic Resources Institute) with it Head quarters at Rome. A number of germplasm banks have also been established in Europe and North America. A network of gene banks to conserve a variety of medicinal and aromatic plants has also been established by the G-15 countries (Argentina, Algeria, Brazil, Egypt, India, Jamaica, Malaysia, Mexico, Nigeria, Peru, Senegal, Venezuela, Ex-Yugoslavia and Zimbabwe). This network would ensure conservation of seeds, embryos, pollen, and cultured tissues of important plant species.


v Indo-Us project on Plant Genetic Resources was taken up in 1988 to establish a National Gene Bank. The National Facility for Plant Tissue Culture Repository was established at NBPGR (National Bureau of Plant Genetic Resources) in 1986 at New Delhi with the financial support from DBT (Dept. of Biotechnology), Govt. of India.

v Seeds of most plant species are stored in cold, dry conditions in seed banks for long periods and than later germinated to form new plant. Seed banks have been established for wild species, agricultural crop plants as well as woody plants. Centre for International Forestry Research (CIFOR) looks for long-term ex situ conservation of the gene pool of woody plants. An International Centre for Research on Agroforestry (ICRAF) is exploring the possibility of growing trees in areas where they normally do not grow.

Protected Areas

The ICUN (1985) has developed the following system of classification for
protected areas that rage from minimal to intensive allowed use of the habitat
by man:

• Scientific reserves and Strict nature reserves. They are strictly protected areas maintained for scientific study, education and environmental monitoring. As far as possible populations and the ecosystem processes are allowed to remain undisturbed.

• National parks. They are large areas of scenic and national beauty maintained for scientific, educational and recreational use. They are not usually used for commercial extraction of resources.

• National monuments and Landmarks . They are often smaller areas designed to preserve unique areas of special national interest.

• Managed wildlife sanctuaries and Nature reserves. They are similar to strict nature reserves but some human manupulation may be necessary to maintain the characteristics of the community and some controlled harvesting may be allowed.




• Protected landscapes. They allow nondestructive uses of the environment by resident people and provide opportunities for tourism and recreation.

• Resource reserves. These are areas in which resource use is controlled in ways compatible with national policies.

• National biotic areas and anthropological reserves. They allow traditional societies to continue to maintain their way of life without outside interference. These people often hunt and extract resources for their own use.



• Multiple-use management areas. They allow for the sustained production of natural resources like water, wildlife, grazing for livestock, timber, tourism, fishing etc. Only 2% of the earth’s surface is in the strictly protected categories of scientific reserves and national parks. The world’s largest parks is in Greenland, covering 700,000 km2. Excluding this, only 1.6% of the earth’s surface is strictly protected.


International approaches
• 12 mega diversity countries that together contain 60 -70% of the world’s biodiversity : Mexico, Columbia, Brazil, Peru, Ecuador, Zaire, Madagascar, Indonesia, Malaysia, India, china, and Australia. These countries are on the priorities for funding and conservation attention.

Roll of species and creatures in the natural ecosystem

• Pollinators such as bees –food crops reproduce.
• Bats ,lady bugs and dragon flies control pests.
• Earthworms and termites help in aerating soils-destroyed by pesticides
• Many Predators are facing extinction. Otherwise Rodents destroy crops.
• Mangroves prevent erosion near the coastline. Destroyed for firewood.
• Oysters (Chespeak bay (USA)) could filter water in a few days. But declined by 99% , leaving the bay water muddy and oxygen deficient.
• Frogs survive on larvae and insect. An adult frog consumes it own weight of insect per day. But decline in frog population has resulted in increased pest damage and recurrence of Malaria.
• In tropical rainforest, the thick and diverse vegetation prevents rapid flow of water, binds the soil particles together and prevents soil erosion. But loss of diversity resulting in rapid loss of nutrients from the soil.

Economic values

• Our homes, livestock, fruits, vegetables grains, grams are all derived from the diverse and healthy ecosystems.
• Food supply from 30 crops supplies 90% calories to human being. The total number of plant species on earth is 8-80 million, only 1.4 million species are known and only 2500 are exploited.
• Just 14 animal species make up 90% of the livestock.
• The biological wealth represents a vast source for mankind. The basis of life support will be lost if this species are not exploited.
• The tropical rain forest nurture 50% of world’s flora(plants) and fauna. Eg. A plant in west Africa - katemfe produces proteins that are 1600 times sweeter than sucrose.
• Recreation brings money Eg. Parks, gardens , natural animal forests, mountains, seashores etc.

Ecologists and Economists estimated the monetary value of nature’s service to society to be atleast $33 trillion each year = 2*GNP (Gross national product)


Examples of genetic modifications.
• The saccharum Spontaneum from Indonesia has provided genes for resistance to red rot disease of sugarcane.
• A wild variety of rice grown in UP saved millions of hectares of paddy crop from grossy stunt virus.
• The genes from a wild melon grown in UP helped in imparting resistance to powdery mildew in musk melon grown in California.
• About 20 cultivars of rice grown in rice growing countries of the world were benefited by the genes from a wild variety identified in kerala.
• Mexican corn varieties provided genes for blight resistance to the U.S. varieties which were attacked by fungus, causing about 50% damage in some regions.
• Two species of wild tomatoes discovered in Peru supplied the genes for better pigmentation and higher pulp in tomatoes.
The Genetic diversity has enormous value in the field of agriculture , research industry and medicine. So we could have a collection of useful traits or a large gene pool for future use.

Natural Calamites
• Floods, Drought, forest fires , earth quakes, volcanic eruptions, epidemics etc .
• The tropics are more prone to damage by floods.
• Drought –result drying of ground vegetation.
• Forest fires –during hot seasons.
• Volcanic eruption destroy plants and animals and throw thick ash and sulphur containing compounds .
• At times virulent strains appear cause diseases which cause Epidemics.

Conserving biodiversity in protected habitats
Two basic approaches:

i. Ex-Situs Conservation: maintenace and breeding of endangered species both plants and animals , under partially or wholly conditions in zoos, gardens nurseries and laboratories.

ii. In situ Conservation: conservation of species in its natural habitat in places where the species naturally occurs.

Ex-Situs Conservation
Steps:
• Establishing minimum target population target goals .
• Distributing founders through captive breeding programs
• Combining animal husbandry programmes.
• Implement GASP (Global Animal Survival Plan.)


Advantages of Ex-situs conservation
• In captive breeding animals are assured food, water, shelter and also security and hence longer life span.
• More number of offspring.
• Survival of endangered species increase due to special care and attention.
• Improve species using genetic Techniques.

Disadvantages
• Expensive :Maintenance and breeding under captivity is very expensive.

• The freedom of natural wilderness is lost.

• The gene pool remains stagnant.

• Animals cannot survive in natural environment.


Captive Breeding and species reintroduction
• It aims at maintaining viable and healthy genetic captive stocks with conservation facilities.
• Possible reintroduction into the wild at a later stage.
• The species recommended are those which have suffered from human pressures at species level and not at habitat level.
• So Zoos in India may need to restrict their efforts to few species such as Chiroptera, Rodentia, and Insectivora.


In-situ Conservation
Steps:

• Natural ecosystems or surroundings are maintained.

• All the constituents in that area whether known or unknown are preserved.


Advantages

• Very cheap and convenient

• In natural system species are not only survive and multiply also evolve as well.

• The species gets adjusted to natural disasters like forest fires, drought, floods, snow, fluctuations in temperature, pathogens.


Disadvantages

• A large area of the earth’s surface is required to preserve the full complement of biodiversity.

• Maintenance of the habitats are not proper, for shortage of staffs and pollution.

Conserving bio diversity in Gene pools and seed Banks
• The seeds of various plants are collected and stored in gene banks, seed banks or germ plasm banks.
• Germplasm- is new plant is generated from any part of plant.
• Tissue culture and cryo-preservation techniques can be applied.
• Tissue culture- A region of a plant tissue consisting of actively dividing cells are kept in synthetic asceptic medium and allow to multiply into clumps called callus. These callus can be preserved in liquid nitrogen and can be multiplied as and when required.

Advanced Reproductive Technology
• The technology applied to preserve germplasm and maintenance of genetic diversity is advanced reproductive technology.

• It involves:
1. Artificial insemination
2. Embryo transfer technology
3. cryo-preservation of gametes and embryos


Restoration of biodiversity
• Restoration of ecosystems and biological community is an important method of reducing Biodiversity loss.

• Species can be saved.

• Restoration Techniques based on type of ecosystem.


Restoration Techniques
• Vegetation plantation – to control erosion.
• Fertilization of existing vegetation - ensure growth.
• Removal of contaminated soil.
• Fencing to prevent cattle grazing.
• Reintroduction of species that are completely destroyed.
• Restoration of hydrological connections to wetlands.
• Forestation can be carried out on barren land, road sides, hill slopes with the plants that are native to that area and useful to the people.


Other biodiversity conservation techniques
• Imparting Environmental Education
• Environmental Legislations
• Population control
• Reviewing the Agricultural Practices -Sustainable use
• Controlling Urbanization
• By adopting the above measures we can stop doing harm to the biodiversity and conserve it.


Biodiversity conservation strategies : Global scenario
Considering the immense value of biodiversity and subsequent rapid loss of the same, during past couple of decades, enormous conservation efforts were made for restoring the biodiversity of various habitats.


Lecture No- 8

CLIMATIC CHANGE ON CHEMICAL AND ORGANIC AGRICULTURE IN THE WORLD AND INDIA


1. Introduction
Agriculture is situated at the interface between eco-systems and society. As such agriculture is affected by the changes in the global environmental conditions, but agriculture also contributes to about 20% of the emissions of greenhouse gases, notably methane and nitrous oxide (Rosenzweig and Hillel, 2000). There is a growing concern about the potential effects of climate change on agriculture production in different regions of the world including India.
Climate change is expected to affect agriculture very differently in different parts of the world. The resulting effects depend on current climatic and soil conditions, the direction of change and the available resources and infrastructure to cope with change.
In the decades to come, India's agricultural sector is expected to be significantly impacted by the concurrent processes of climate change and globalization. Climate change could lead to sea level rise, increased weather variability, more drought and the spread of infectious diseases. At the same time, market changes brought about by globalization may affect the price farmers receive for their products. Already, market restrictions such as tariffs and price controls are being reduced under World Trade Organization agreements and policies related to fertilizer subsidies and energy are changing.

2. Climate change and its impact
Climate change is likely to have a significant impact on the global environment. In general, the faster the climate changes, the greater will be the risk of damage. Mean sea level is expected to rise 15-95 cm by the year 2100, causing flooding of low-lying areas and other damage. Climatic zones could shift towards the poles by 150-550 km in the mid-latitude regions. Forests, deserts, rangelands and other unmanaged ecosystems would face new climatic stresses. As a result, many will decline or fragment and individual species will become extinct.
Human society will face new risk and pressures. Food security is unlikely to be threatened at the global level, but some regions are likely to experience food shortages and hunger. Water resources will be affected as precipitation and evaporation patterns change around the world. Physical infrastructure will be damaged, particularly by sea-level rise and by extreme weather events. Economic activities, human settlements and human health will experience many direct and indirect effects. The poor and disadvantaged are the most vulnerable to the negative consequences of climate change.

Green house gases
Global Warming Potential (GWP) is an index defined as the cumulative radioactive forcing between the present and some chosen time horizon caused by a unit mass of gas emitted now, expressed relative to a reference gas such as CO2, as is used here. GWP is an attempt to provide a simple measure of the relative radioactive effects of different greenhouse gases. The future global warming commitment of a greenhouse gas can be calculated over a chosen time horizon (such as 100 years) by multiplying the appropriate GWP by the amount of gas emitted. The choice of time horizon will depend on policy considerations.

i) Canbon di-oxide
The primary source of carbon dioxide build up is combustion of fossil fuel; gasoline, natural gas, coal, peat firewood and indiscriminate clearing the forests and extensive cultivation of land in crop production which result in irreversible oxidation of soil organic matter. The level of CO2 in the earth’s atmosphere has been recorded daily for several years at the Mauna Loa observatory at Hawaii, and by scientists from National Oceanic and Atmospheric Administration, USA. The level has risen from 315 ppm in 1959 to more than 342 ppm in mid-1980. For India (1988-98), contributions from coal, petroleum natural gas and transportation emissions are around 85, 35, 5 and 15 million tonnes of carbon respectively giving a total of about 1.4 x 1014 g as against a global total of 5 x 105 g carbon / year. Thus, Indian contribution is 2.8 per cent of global CO2 warming (Mitra, 1991).



ii) Chloroflorocarbons
The concentrations of chlorofluorocarbons (CPCs) virtually negligible 50 years ago, as now posing a grave concern. CPCs are responsible for destruction of the ozone layer, a protective shield that surrounds the earth at an altitude of 10-30 km. During the past two decades, ozone layer has been depleted 2 to 3 per cent at the global level.
The production of CFCs in India is around 5000 tonnes per year as against the global production of 7,00,000 tonnes per year, thus India’s contribution is less than one-hundredth of the total world production (Mitra, 1991). The concentration of CFCs in the atmosphere is less than 1 ppm, but each molecule is 16,000 times more effective than carbon dioxide in absorbing heat and survives as long as 400 yeas.

iii) Methane
Methane contributes about 15 to 20 per cent towards green house effect. Most methane is generated by bacteria breaking down organic matter in the absence of oxygen, e.g. the flooded rice fields, guts of cattle, garbage dumps, leakage in the process of mining, transport, and use of coal and natural gas, and burning of biomass. Swamps and rice fields are thought to contribute about 25-30 per cent to the world methane production.
Almost 90 per cent of world’s paddy fields exist in Asia and about 60 per cent of these are found in India and China. India produces 3.9 x 1012 g methane per year as against a global production of 110 x 1012 g methane per year i.e., about 2 per cent of the global paddy emissions. The contribution of Indian cattle is around 7 x 1012 g per year as against the world aver of 80 x 1012 g per year (Mitra, 1991). Although methane lasts only 10 years, molecule for molecule it absorbs 20 to 30 times more heat than carbon dioxide.

iv) Other gases
Nitrous oxide is a green house gas and is also responsible for the destruction of ozone layer. Sources of N2O include burning of forests, grassland and other biomass, natural soil and chemical fertilizers. N2O lasts up to 180 years, is 200 times as heat absorbent as carbon di oxide and constitutes about 5 per cent of man-made emissions. Ozone in the stratosphere acts as a protective layer because it absorbs much of UG radiation from sun. However, in the troposphere its concentration is increasing and it acts as a greenhouse gas. It is responsible for about 10 to 20 per cent of the greenhouse effect.

Changes in global temperature
Using the IS 92 emission scenarios, projected global mean temperature changes relative to 1990 were calculated up to 2100. Climate models calculate that the global mean surface temperature could rise by about 1 to 4.5o C by 2100 (Fig 1).
Average surface temperature
The combined land-surface air and sea surface temperatures (oC) 1861 to 1998, relative to the average temperature between 1961 and 1990.The mean global surface temperature has increased by about 0.3 to 0.6°C since the late 19th century and by about 0.2 to 0.3°C over the last 40 years, which is the period with most reliable data.
Warming is evident in both sea surface and land-based surface air temperatures. Urbanization in general and desertification could have contributed only a small fraction of the overall global warming, although urbanization may have been an important influence in some regions. Indirect indicators such as borehole temperatures and glacier shrinkage provide independent support for the observed warming. It should also be noted that the warming has not been globally uniform.

Changes in sea level
Using the IS 92 emission scenarios, projected global mean sea level increases relative to 1990 were calculated up to 2100. Taking into account the ranges in the estimate of climate sensitivity and ice melt parameters, and the full set of IS 92 emission scenarios, the models project an increase in global mean sea level of between 13 and 94 cm.
CO2 use from land use change
Emissions of carbon dioxide due to changes in land use mainly come from the cutting down of forests and instead using the land for agriculture or built-up areas, urbanisation, roads etc. When large areas of rain forests are cut down, the land often turns into less productive grasslands with considerably less capacity of storing CO2.

CO2 use from industrial processes
This map depicts the unequal distribution of industry in the world. The significant part of carbon dioxide emissions comes from energy production, industrial processes and transport. The industrialised countries consequently must bear the main responsibility of reducing emissions of carbon dioxide.

Precipitation changes
Precipitation has increased over land at high latitudes of the Northern Hemisphere, especially during the cold season. Decrease in precipitation occurred in steps after the 1960s over the subtropics and the tropics from Africa to Indonesia. These changes are consistent with available data analyses of changes in stream flow, lake levels and soil surface. Precipitation averaged over the Earth's land surface increased from the start of the century up to about 1960, but has decreased since about 1980. There is a lack of data on precipitation over the oceans.
Lecture No –9

CLIMATIC VARIABILITY AND ITS IMPACT ON AGRICULTURE – STRATEGIES TO MANAGE ITS IMPACTS

Impact of climate change on agriculture
The comprehensive analysis of the data from WMO (World Weather Watch) and world climate programme by the scientist of UK so that global temperature has increased by 0.5°C over the 100 years with a similar increase in both the hemispheres (Data, 1991).
The effects of climate can be broadly classified as direct and indirect effects on agriculture.

Direct effects
Despite the increasing CO2 concentrations and consequent warming of the planet due to the greenhouse effect, the yield of major food crops in USA, Western Europe, India, China etc., which may be attributed to the advanced agriculture and management technologies. On the other hand, it may be due to fertilizer effect of CO2 enrichment. The increase in CO2 in the atmosphere could enhance plant growth by increasing the rate of photosynthesis is the net accumulation of Carbohydrates formed by the uptake of CO2, so it is increases with increasing CO2.

The response to CO2 varies according to the biochemical path way for photosynthesis. The C3 plants (Wheat, rice, barley, groundnut, cotton, sugarbeet, potatoes, chick pea, coconut, etc.,) respond more favourably to increasing CO2 than C4 plants (Maize, sorghum, millet, sugarcane etc.). Higher CO2 concentrations have comparatively little effect in directly stimulating photosynthetic response and the increase in yield is 0 to 10% (Warrick, 1990). Although C4 crops account for only about 1/5th of the world’s food production, maize alone accounts for 14 per cent of overall production and about three quarter of all traded grains. On the other hand, C3 crops in temperate and subtropical regions could also benefit from reduce weed infestation.
The effects of changed environment on different crops are discussed below.
i) Wheat
Generally, wheat is sown in relatively cool season and matures under warmer and drier climatic conditions. Increase in temperature is capable of changing time sequence and tillering behaviour. It may cause decrease in crop stand. But this will be compensated by high tillers produced subsequently. While both early (Mid-October) and late (December to January) planting will suffer because of warmer temperatures in November and late January coincide with tillering phase and adversely affect tiller number. There exists an inverse relationship between spikelet number and duration of the developmental phase prior to anthesis, therefore and increasing temperature will cause reduction in spikelet number and hence a decrease in potential grain number. Further and increase in temperature above 25° C during grain filling period tends to depress grain weight.

In plains of north India, wheat yield can be reduce with 1-2°C elevated temperature above mean temperature of 17°C during grain filling period due to increased rate of senescence of flag leaf and reduction in grain filling duration. While warming may adversely affect wheat production in rainfed areas of central India, irrigated wheat in Punjab, Haryana and U.P. will have 20-30 per cent increase in productivity over rainfed wheat in hilly regions and irrigated wheat in Punjab, Haryana and U.P.(Singh et al., 1991).

ii) Rice
Rice is cultivated in hot arid and high altitude areas of India. Temperature, rainfall and solar radiation are the important factors that influence rice fields directly by affecting physiological processes involved in grain production and indirectly through their effects on disease and insect pressure. Higher CO2 (900 ppm) for rice, especially 30 days before flowering, increased grain yield by 30 per cent through increase in grain number. The root shoot ratio, water use efficiency and specific leaf weight also increased, enabling better crop photosynthesis, accumulation of soluble sugars and their transport to developing grains (Yoshida, 1981). However, higher CO2 may often induce partial closure of stomata and also induce early leaf senescence in crop plants affecting the ultimate photosynthetic productivity.
Temperature is the dominant factor affecting growth process and yield in rice. The critical low and high temperature, normally below 20°C and above 30°C, vary among growth stages. The optimum temperature for rice decreases as growth advances from vegetative stage. Rice is most sensitive to high temperature at flowering and temperature higher than 35°C at flowering time may increase spikelet sterility (Yoshida, et.al., 1981) and hence reduced yield.

iii) Pulses and oilseeds
In India, more than 12 tonnes of pulses are produced from about 23 million hectares of area. The latitude differences cause significant difference in photoperiod, temperature and precipitation which individually and in combination affect the growth and differentiation. In north India, at the current ambient CO2 concentration the optimum temperature for the maximum rate of photosynthesis lies between 20-26oC for winter season crops. During December till first week of February, low temperature resulted in ineffective flowering in chick pea (Singh et al., 1987) and frost damage in oilseed Brassicas (Dhawan et al., 1983). Therefore, an increase in temperature due to warming is expected to enhance the canopy photosynthesis and growth during cool months in sensitive crops like brassica and chickpea while in February – March, when winter cereals and pulses enter the anthesis and grain filling stages, the elevated temperature resulted in accelerated leaf senescence, decline in canopy photosynthesis and forced maturity (Singh et al., 1987). Chickpea yield vary considerably when grown in contrasting environments. Low temperature leads to longer vegetative phase and hence extended crop duration leading to higher yields.

An increase in global temperature may shorten the duration of pulse crops thereby nullifying the beneficial effects of increased CO2 concentration. Seed development at higher temperature will also affect the yields adversely. Change in rainfall pattern with climate change would greatly influence pulse production. Increase in rainfall in North India and in plateau would be beneficial to both pulses and oilseed productivity.

iv) Cotton
Temperature is the major environmental factor that affects the cotton production. Temperature of 35 to 40oC is frequently observed in cotton producing areas. The interception and absorption of photosythetically active radiation also decrease with increase in temperature. Varieties tolerant to high temperature will be more productive in warmer environment (Bharadwaj and Singh, 1991).




Indirect effects
i) Cropping pattern
The combination of effect of climatic change on agricultural crops likely to bring about a spatial shift in crop potential. The areas that are at present judged to be most suited to give a crop or a combination of crops may no longer remain as such after climatic shift. Wheat belts may replace by barley, barley by maize and maize by soybean and so on.
The area under rainfed wheat in central India may require either alternative crops or development of suitable genotypes tolerant to water stress and high temperature. This region however contributes very little to total wheat produced under irrigated conditions in Punjab, Hariyana and U.P. Therefore, the effects of elevated temperature of 1 to 2oC could be absorbed by adjusting seeding time and developing suitable varieties of wheat. Thus the CO2 enrichment has a positive effect on the productivity of rainfed wheat. In hilly regions and irrigated wheats in plains of north India (Singh et al., 1991).
Similarly, under 1°C warming and 100 mm precipitation yields of rice are expected to increase in India if late maturing varieties needing high temperature for cultivation are adopted (Singh et al., 1991). Increase in temperature promotes sterility in rice resulting in reduction in yields but increase in precipitation would lead to increase in area and yield. Since, almost one third of rice in reduction in yields but increase in precipitation would lead to increase in area and yield (Sinha et al., 1989). Since almost one-third of rice is grown in non-irrigated conditions, it may benefit from increased precipitation leading to yield increase in many developing countries. Even shortening of maturity duration of rice with global warming will beneficial to maintain proper soil health Haryana and U. P. (Singh et al., 1991). Cultivation of groundnut and cotton is also likely to be benefited. The reduction in the length of growing season of cotton with rise in temperature will make this crop even more suitable in double cropping systems. Groundnut cultivation may shift from monsoon to spring season and from monsoon maize to winter maize in north India (Singh et al., 1991).
Jhalawar district in Rajasthan is located in a semi-arid area that receives an average of 943 mm of rainfall annually. In addition to high degrees of climate sensitivity, it also ranks among the districts with the lowest adaptive capacity. Over the past 10 years, many farmers in Jhalawar have shifted from traditional crops, such as sorghum and pearl millet, to soybean, which receives higher market prices and yields quick returns owing to a shorter life cycle.
The vulnerability of India’s coastal areas is highlighted in Jagatsingpur, where loss of mangroves due to biotic and abiotic pressures in the past few decades has left the coast exposed to the fury of cyclones and storm surges. The aftermath of the 1993 super cyclone witnessed intensive rehabilitation and reconstruction efforts, not all of which have been correctly targeted and effectively applied.
Anantapur district in Andhra Pradesh is another drought-prone area that can be considered ‘double exposed’ to climate change and globalization. Groundnut is the principal crop grown in Anantapur, but farmers are now facing a crisis due to growing import competition and stagnating market prices, which have coincided with a multi-year drought. Without irrigation, water harvesting systems, or alternatives to groundnuts, dry land farmers in Anantapur are highly vulnerable to both climate change and trade liberalization.

ii) Water requirement
Higher than normal levels of atmospheric carbon di oxide induce greater water use efficiencies (ratio of crop biomass accumulation to the water used in evapotranspiration). On the higher atmospheric CO2, leaf transpiration rate (Allen, 1990) and hence increase the water use efficiency. This protects crops from drought and other water related stresses and also decreases the irrigation requirements of the crops. On the other hand, increased leaf area index with rising CO2 while allows greater interception of solar radiation, but it can also increase canopy evapotranspiration due to presence of more transpiring surface. Water use efficiency with increasing carbon di oxide increased in winter wheat but deceased in soybean (Jones et al., 1985) because in soybean while the rate of photosynthesis remained unchanged in increased canopy, its evapotranspiration was increased.
In Indian sub continent, it is expected that with the doubling of CO2 here will be 1 to 2°C rise in temperature and 5 to 10 per cent increase in precipitation. It is known that higher temperatures accelerate plant development and shorten the growth period. This could lead to drought escape and realization of some yield in water deficit season but could be detrimental to attain higher productivity in good rainfall years from dryland areas in general and irrigated areas in particular (Singh et al., 1991). This has implications for arable dryland in India which constitutes about 68.6 per cent of the 142 million ha. cultivated area and contributes 45 per cent of cereals and 75 per cent oilseeds and grain legumes.

iii) Pest problems
Since insect pests are cold-blooded (poikilothermous) animals, their body temperature varies with the surrounding temperature. Hence, any change in the climate and weather is bound to influence the activity of insect pests. Insects may be directly influenced by temperature, precipitation, humidity, wind speed and other climatic parameters, in terms of their rate of development, reproduction, distribution, migration and adaptation. In addition, they may be indirectly influenced by the effect of climate on the insect host plants, natural enemies and interspecific interactions with other insects. Thus, the potential climatic changes may have a significant bearing on the development, distribution and population density of agricultural insect pests (Parry et al., 1990).
The increase in temperature as a result of future climatic changes may have the following implications for agricultural pests: (i) changes in population growth rates; (ii) increased number of generations, (iii) extension of development season, (iv) extension of geographical range (v) increased over wintering, (vi) changes in crop pest synchrony, (vii) changes in interspecific interactions, (viii) increased risk of invasion by migrant pests, (ix) introduction of alternate hosts, and (x) availability of over wintering hosts (Porter et al., 1991).
The climatic changes may, thus, result in increased problems with agricultural insect pests. However, there is still great uncertainty about some aspects of climatic change which are important for insect pests. These include regional and local variations in climate, changes in annual and seasonal variations in rainfall, changes in wind speed, relative humidity and the rate at which climate is likely to change. Hence, much more work is required to identify the specific effects of weather and climate on important pests and determine the climatic variables to which different species are most sensitive.



iv) Management practices
With a changing climate, agriculture may have to undergo a great change in terms if suitable crop adjustment, developing proper genotypes and adopting proper technology for the changed environmental conditions. There will be substantial increase in the need for irrigation which will probably lead to higher cost of production and possible shift towards less water demanding uses.
Conversely, increase in rainfall particularly in regions characterized by monsoon rainfall will require changes in management practices to prevent soil erosion. Besides, in areas where greater rainfall is likely increased fertilizer use may be required (Parry, 1990).
The different response of C3 and C4 crops may encourage changes in areas sown. For example, sugarbeet, a temperate C3 crop will gain some advantage over sugarcane, a tropical C4 crop. Therefore, the sugar exporting tropical countries will have to find alternatives to cane sugar for export. Likewise, for staple starchy C4 crops like maize and sorghum, gradual partial substitution by CO2 responsive C3 alternatives like sweet potato, cassava, rice or wheat bred for high temperature areas might be possible. In India, recent trend towards wheat, rice, and away from maize and millet has been largely driver by the promise of greater increases in yield.

Future strategies
Agriculture has an ability to adjust to limited climatic change with the use of proper technology and agronomic manipulations. This capability, however, varies greatly between regions. It is important to establish in more details the nature of this adaptability and the critical rates of climatic change that agriculture can adapt to under Indian conditions. In order to improve our understanding of the significance of climatic change and its consequences for agriculture and humankind, considerable research is needed into how agriculture can best adapt to avoid or gain from annual, seasonal and intra-seasonal variability in climate in different agroclimatic regions of the country. Improved knowledge is needed to effects of changes in climate on crop yields and physical processes such as rates of soil erosion, salinization, nutrient depletion, insect pests, diseases and hydrological conditions. Information is also needed on the range of potentially effective agronomic adjustments such as irrigation, crop selection, sowing time fertilization, etc. New research programmes should be aimed at identifying or developing cultivars and management practices appropriate for altered climates.