This document provides information about a guest lecture on sustainable agro-ecosystems with integrated land management. The lecture will cover topics such as integrated land management, land degradation in Sri Lanka, ecosystem principles, ecosystems in Sri Lanka, the concept of agro-ecosystems, ecosystem functions and services, managing agro-ecosystem biodiversity, and food-forest gardens. The lecture will take place on February 1st, 2023 from 10:30am to 12:30pm.

1. Traditional Technology in Sri Lankan Agriculture
Course code: AS 3210
Faculty of Agriculture, Rajarata University of Sri Lanka,
Puliyankulama, Sri Lanka
• P.B. Dharmasena, 0777 - 613234, 0717 – 613234
• dharmasenapb@ymail.com , dharmasenapb@gmail.com
• Links to My Documents:
https://independent.academia.edu/PunchiBandageDharmasena
https://www.researchgate.net/profile/Punchi_Bandage_Dharmasena/contributions
http://www.slideshare.net/DharmasenaPb
https://scholar.google.com/citations?user=pjuU1GkAAAAJ&hl=en
https://www.youtube.com/channel/UC_PFqwl0OqsrxH1wTm_jZeg
Guest Lecture Three – 2 hrs
Sustainable Agro-Ecosystem with Integrated Land Management
At 10.30 am – 12.30 pm, 01.02.2023

2. CONTENT
• Integrated Land Management
• Land Degradation in Sri Lanka
• Ecosystem Principles
• Ecosystems in Sri Lanka
• Concept of Agro-ecosystem
• Ecosystem Functions and Services
• Agro-ecosystem and biodiversity
• Food-forest gardens

3. What is Integrated Land Management?
• Integrated Land Management (ILM) is a strategic, planned
approach to the way we use land and natural resources.
• This approach aims to balance values, benefits, risks and trade-
offs when planning and managing resource extraction, land use
activities, and environmental conservation and management.
Housing & settlements
Livestock
Forestry
Wildlife
Agriculture
Water & fisheries
Human
populations

4. Integrated Land Management Approaches
• The most vulnerable areas in any ecosystem are the ones
at its periphery. Most of the land erosion, degradation of
soil quality, loss of biodiversity, and eventual loss of
productivity occurs in these marginal - but high-priority -
lands.
• Sustainable management strategies in these dry areas are
needed for protection, preservation and reclamation or
rehabilitation in these fragile systems and natural
resources contained therein.
• Development of integrated approaches is critical to
minimizing land degradation and the related societal and
economic impacts. There is a need to promote actions for
building and strengthening existing institutional
capacities for regional, national and basin-level agencies
to effectively address and integrate cross-sectoral aspects.

5. Integrated Land
Management
Approach

6. Technical Dimensions of ILM approach
• All renewable natural resources (water, soil,
vegetation, etc.) should be taken into account
when developing ILM programs.
• Innovative solutions have to be identified for
managing land degradation.
• Potential conflicts and synergies between
highlands and lowlands should be given due
consideration.
• Due consideration be given to trans-ecozone
characteristics of resources - especially water.

7. Human Dimensions of ILM approach
• Localized approaches for land ownership and land
tenure are often critical in conservation of resources;
• Impacts on livelihood of local people need to be
accounted for when designing and discussing resource
management approaches.
• Effects of indigenous practices on natural resources,
both positive and negative, should be accounted for.
• Whenever applicable, indirect social benefits of
integrated management should be explicitly considered.
• Mechanisms for conflict resolution during the
implementation of management approaches should be
built into the programmes.

8. Economic Dimensions of ILM approach
• Evaluation of social, environmental and
economic costs and benefits has to be
undertaken to ensure long-term sustainability
or viability of integrated approaches;
• Capital investment into developing new
infrastructure as well as maintaining existing
and traditional practices should be made; and
• Linkages to national economic development
should be elaborated.

9. Natural Resource Dimensions of ILM approach
• Rehabilitation of ecosystems in marginal lands
should have the highest priority in ILM
programmes.
• Whenever applicable, in-situ conservation of
biodiversity within ecosystems should be
considered.
These dimensions are closely interlinked with each
other and need to be considered explicitly to
develop fully integrated approaches.

10. Land Resource
• The total land area of Sri Lanka
besides the area occupied by inland
waters is only 6.44 million ha.
• The land–man ratio is low, which is
only 0.37 ha/person,
• Only about 2.5 million ha (nearly 39
%) is available for further
settlements and agricultural
production.
• Thus, the per capita extent of
croplands is as small as 0.14 ha.
• The major land use sectors in the
country are agriculture (paddy, tea,
rubber, coconut and other
perennials, non-perennial crops),
close canopy and sparse forests,
home gardens and others

11. Tea 3.4% Rubber 1.8% Coconut 6.0 %
Other perennials 11.0%
Paddy 8.8 %
Other non-
perennials 1.5 %
Closed canopy natural
forests 22.4 %
Sparse forests
7.2 %
Forest plantations
1.4 %
Other land
uses 21.5%
Home gardens
14.8 %
Use of Land
Resource

12. Manifestations of Land Degradation in Sri Lanka
• Heavy soil losses;
• High sediment
yields;
• Soil fertility decline
and reduction in crop
yields;
• Marginalization of
agricultural land;
• Salinization;
• Land slides and
• Deforestation and
forest degradation.

13. Land degradation & Sustainable Land Management
• Land degradation is the depletion of its physical, chemical
and biological productivity
• To maintain the long-term productivity of land sustainable
land management is required
• Sustainable land management means ‘use of the land to
meet human needs, while ensuring long-term production
potential and maintaining ecological functions’
• Here the land includes soil, water, flora and fauna
• Therefore, the land means the whole ecosystem in more
practical way
• That means ‘land degradation is long-term depletion of the
production potential and function of the ecosystem’
• So, sustainable land management is maintenance of
production potential and functions of the ecosystem

14. Organization of life
Organisms
Populations
Communities
Ecosystems
Biosphere
Biosphere
Ecosystems
Communities
Populations
Organism
s
Ecosystem Principles

15. Scales of Ecological organization

16. Individual, population, community and
ecosystem
A
B
C
D

18. connectivity, interaction and complexity of ecosystem
Ecosystem Principles

19. What you can learn from this picture?
1. Population
2. Genetic
diversity
3. Interaction

20. How do we take care of ecosystems?
1. Knowledge on
ecosystems
• Investigation
• Awareness
• Training

21. How do we take care of ecosystems?
1. Knowledge on
ecosystems
2. Participation in
ecosystem
activities
• Collective
efforts
• Individual
behaviour
• Participatory
ecosystem
management
programmes

22. How do we take care of ecosystems?
1. Knowledge on
ecosystems
2. Participation in
ecosystem activities
3. Management of
ecosystems
• Planning
• Implementation
• Maintenance

23. Ecosystems in Sri
Lanka

24. Ecosystems in Sri Lanka
• Forest and related ecosystems -
tropical forest types, riverine dry
forest, grasslands etc.
• Inland wetland ecosystems - flood
plains, swamps, reservoirs, wet
villus
• Coastal and marine ecosystems -
mangroves, salt marshes, sand
dunes and beaches, lagoons and
estuaries, coral reefs
• Agricultural ecosystems - paddy
land, fruit cultivations, small crop
holdings or other field crops,
vegetables, export crop
plantations, home gardens, chena
lands

25. Agro-ecosystems

26. Property Agro-
ecosystem
Natural ecosystem
Productivity High Low
Species diversity Low High
Genetic diversity within species Low High
Plant life cycles present Few Whole, more
perennial
Competition Negative Tolerable
Flowering, plant maturing synchronized seasonal
Nutrient cycles open closed
Permanence Short Long
Human control High Low
Ecological maturity Early,
immature
Mature (climax)
Comparison of natural and agro-ecosystems

27. NUTRIENT CYCLING
 Inputs:
Plant residue
Animal wastes
Animal residue
Atmosphere
Nitrogen fixation
 Outputs:
Plants animals
grazing on plants
Denitrification
Run-off
leaching
NATURAL ECOSYSTEM
AGROECOSYSTEM
 Using the soil as a
pool of nutrients:
 Inputs:
Fertilizers
Crop residues
Atmosphere
Nitrogen fixation
 Outputs:
Crops  then
removal from
area
Erosion
Leaching
 Run-off
Nutrients cycling

28. Special Features of Agro-ecosystem
• Productivity - the quantity of food, fuel or fiber that
an agro-ecosystem produces for human use.
• Stability - consistency of production.
• Sustainability - maintaining a specified level of
production over the long term.
• Equity - sharing agricultural production fairly.
• Independence – agro-ecosystem self-sufficiency.

29. Tank-based agro-ecosystems
Components

30. Ecosystem Functions/Services
• Ecosystem Functions/Services are
the conditions and processes
through which natural ecosystems
and the species that make them up,
sustain and fulfill human life.
• Biophysical necessities for human
life provided by natural ecosystems
• Functions provide goods and
services
• Currently threatened by most
human activities
• Important (but new) conservation
tool

31. • Cover a wide range of
processes and scales
– Global scale
• Carbon sequestration
• Global warming
– Landscape scale
• Water purification
• Erosion prevention
– Community scale
• Crop pollination
• Pest control
– Field, plot or individual
person scale
• Local nutrient levels
• Disease and pest prevention

32. • The combined activity of soil
organisms results in ecosystem
functions that sustain life on the
planet. Ecosystem functions
that generate benefits to society
have been defined as ecosystem
services. The centrality of
belowground biodiversity to
global sustainability is because
soil organisms of different
types, shapes and colours are
responsible for different
ecological functions…
• Complex
• Dynamic
• Interact
• Multiple within an ecosystem

33. 1. Supporting
• Habitat
• Biodiversity
• Photosynthesis
• Soil formation
2. Provisioning
• Food
• Clean water
• Fish
• Wood
• Pollination
• Cool temperature
3. Regulating
• Control flooding
• Purify water
• Store carbon
• Clean air
4. Cultural
• Education
• Recreation
• Aesthetic
• Stewardship

35. Distinguish: ecosystem services and
functions
• The terms ‘functions’ and
‘services’ can be confusing.
• Usually, functions are
considered as the biological
processes underpinning and
maintaining the ecosystem,
while ecosystem services
are defined as the direct and
indirect contributions of an
ecosystem to human well-
being

36. Why we need to protect our ecosystems?
1. Supporting services
(that help maintain the
conditions for life on
earth):
– Soil formation and
retention;
– Nutrient cycling;
– Primary production;
pollination;
– Seed dispersal;
– Production of O2;
– Provision of
habitats.

37. Why we need to protect our ecosystems?
2. Regulatory services (i.e. benefits
from regulation of ecosystem
processes):
– Air quality maintenance;
– Climate and water regulation;
– Flood and erosion control;
– Water purification;
– Waste treatment;
– Detoxification;
– Human disease control;
– Biological control of
agricultural and livestock pests
and disease;
– Storm protection.

38. Why we need to protect our ecosystems?
3. Provisioning processes
(i.e. products obtained from
ecosystems):
– Food, fruit, vegetables;
– Wood fuel;
– Fibre;
– Bio-chemicals;
– Natural medicines;
– Genetic resources;
– Ornamental resources;
– Freshwater;
– Minerals,
– Sand and other non-
living resources.

39. Why we need to protect our ecosystems?
4. Cultural services (i.e. non-
material benefits obtained from
ecosystems):
– Cultural diversity and
identify;
– Spiritual and religious
values;
– Knowledge systems;
– Educational and aesthetic
values;
– Social relations;
– Sense of place;
– Cultural heritage;
– Recreation and ecotourism;
– Communal;
– Symbolic.

40. Genetic Resources
• Genetic material of living organisms of potential use
• Animals, plants, micro-organisms and invertebrates (අපෘෂ්ඨවංශීන් ) used as
food, in agriculture and in forestry
• Important for sustainable food security, to resolve the problem of narrow
genetic base and is a value of local land races in plant breeding
– Land race is a domesticated locally adapted traditional variety, which
has adaptation to its natural and cultural environment of agriculture
– Cultivar is shorter form of cultivated variety. It is selectively bred to
conform to a particular standard of characteristics.
– Plant germplasm is the genetic source materials used by plant breeders
to develop new cultivars
• Sources of plant germplasm
– Wild relatives
– Land races and primitive cultivars
– Obsolete (defunct) cultivars
– Advanced breeding lines and other products of plant breeding
programme
– Current cultivars

41. CROP
Land races
Genetic
stocks
Farmers
varieties
Parental lines of
hybrids
Released
varieties
Wild and weedy
relatives
Primitive
cultivars
Plant Genetic
Resources

42. Plant genetic resource of Sri Lanka
• About 7 500 plant species constitute the flora of Sri
Lanka.
• Flowering plants constituted about 3 360 species,
belonged to 1 350 genera and 200 families.
• The flora contains by about 830 endemic species.
• The low-country wet zone and mountainous areas in
Southwest harbour 90 percent of endemic species.
• Over 600 species have been used as medicinal plants.
• A number of cultivated food plants have their wild
relatives:
– Artocarpus heterophyllus (Jackfruit),
– A. Incisus (Breadfruit),
– Citrus,
– Mangifera zeylanica (etamba), and Yams.
– Black pepper, cardamom, cinnamon have their wild
relatives in the wet zone forests.
– Wild species of rice (Oryza
rufipogon), Rhynchosia, Dunbaria, Viscosa
– Wild relatives of Cajanus Cajan) – pegionpea

43. Managing Agro-ecosystem Biodiversity

44. Biodiversity
• Wide range of terrestrial and freshwater ecosystems
which carry a high biodiversity.
• One of the global biodiversity hotspots in the Asia–
Pacific region
• The ecosystem diversity extends from forest ecosystems
to coastal and marine ecosystems.
• Terrestrial ecosystems include tropical lowland rain
forests, where 90 % of the endemic woody plants and
75 % of the endemic animals are found

45. Biodiversity
• In terrestrial and freshwater ecosystems: fresh water crabs (98
%), amphibians (85 %) and land snails (83 %) show the highest
endemism.
• The conserved biodiversity would provide a wide range of
ecosystem services :
– proving fresh water, improving the climate, reducing soil
erosion, regulating surface runoff and providing bio-resources

46. Agro-biodiversity
• Agro-biodiversity = Agriculture + Biodiversity
• It includes all components of biological diversity relevant to
food and agriculture:
the variety and variability of
plants, animals and micro-organisms at genetic,
species and ecosystem level,
which are necessary to sustain key functions in the
agro-ecosystem, its structures and processes

47. Importance of Biodiversity in Agriculture Ecosystems
In agriculture ecosystems biodiversity is important:
1. for the production of food, fibre, fuel, fodder
………(goods);
2. to conserve the ecological foundations to sustain life for
future;
3. to allow adaptation to changing situations like climate
change, natural disasters etc.

48. Components of Agro-biodiversity
• Habitat diversity (Land use varies with soil and
terrain)
• Inter-species diversity ( different species of
plant, animal and microbial)
• Intra-species diversity (Very important for agro-
biodiversity) Genetic resources, unique traits –
resistance to drought, cold, disease etc. ,
rooting, aspect, taste, storage etc.
• Harvested species (Species used for food like
wheat, rice, maize etc.)

49. Benefits of Agro-biodiversity
• Environmental benefits
– Improves air, water and
soil quality
– Improves wildlife habitats
• Economic benefits
– Energy conservation
through crop mixing,
which is the basic idea of
agro-biodiversity
• Social benefits
– Improves quality of life in
a fresh environment

50. In Sustainable Development Goals
1. No poverty
2. Zero hunger
3. Good health and Wellbeing
4. Quality education
5. Gender equality
6. Clean water and Sanitation
7. Affordable and clean energy
8. Decent work and economic
growth
9. Industry, innovation and
infrastructure
10.Reduced inequalities
11.Sustainable cities and
communities
12.Responsible consumption
and production
13.Climate action
14.Life below water
15.Life on land
16.Peace, justice and strong
institutions
17.Partnerships for the
goals

51. Need of Sustainability
• Biodiversity loss in
agricultural
landscapes affects not
just the production of
food, fuel and fiber,
but also a range of
ecological services
supporting clean
water supplies,
habitats for wild
species, and human
health.

52. Sustainability of Agro-ecosystems
Problems:
• Biodiversity loss from farms - reduces agro-ecosystem
productivity and stability
• Land degradation, mono-cropping, weedicides
• Damaging chemicals - manufactured N and other fertilizers
have doubled the amount of N circulating in the planet’s
land and water systems.
• N loss, GHG emission, loss of micro-bial population
• Restoring food nutrient density to improve our health
• soil erosion, soil chemical degradation, ecosystem deterioration
• Regenerative agriculture for a resilient, sustainable future
• depletion of soil organic C level, poor micro-bial communities and
functions, accelerated soil erosion

53. New Concept Emerged!
Evergreen Agro-ecosystem
• Vision: Agro-ecosystem is to sustain a green cover
on the land throughout the year, increasing food and
fodder production sustainably.
• Integration: It integrates trees into crop and
livestock production systems at the farm level and
landscape scales.
• Approach:It is an ecologically sound, knowledge
intensive approach to agricultural production that helps
people to address some of the most challenging food
production issues that we currently face.
• Benefits: Implementing it on a broad scale will be a
major benefit to us both now and in the future

54. Benefits of Evergreen Agro-ecosystem
• Year round soil cover protection and increased soil
organic matter
• Improved plant nutrition via nitrogen fixation nutrient
cycling
• Ecologically sound control of insect pests and weeds
• Enhanced soil structure and soil water recharge
• Increased food production
• Increased production of non-food products such as oil,
fodder, fuel and medicines
• Increased landscape carbon sequestration
• Conservation and enhancement of biodiversity

55. Main features of Evergreen Agro-ecosystems
• Cultivation of crops with different duration to keep green cover even
during the harvesting stage of one crop;
• Cultivation of crops leaving zero fallow period of the land;
• Farming models, which combine seasonal, semi-perennial and perennial
crops ensuring the green cover around the year;
• Green manure plants such as gliricidia, adathoda, erithrina, thespesia etc.
are grown as hedges with strict frequency of pruning;
• Shade management is adopted to minimize light competition and to
maintain the crop land with evergreen situation;
• Live fence is maintained with plants to create a stratification enabling to
act as wind barrier as well as favourable micro-climate in the crop field;
and
• The farmer should have a field management / self-evaluation schedule
for his convenience to ensure the sustainability of the agro-ecosystem

56. Recommended trees and creepers for live fence:
Trees: Gliricidia (Gliricedia sepium), Kathuru murunga (Sesbania
grandiflora), Drumstick (Moringa oleifera), Woodapple (Limonia acidissima),
Pawatta (Adhatoda vasica), Gansooriya (Thespesia populnea), Erabadu
(Erythrina variegate), Teak (Tectona grandis), Beli (Aegle marmelos), Neem
(Azadirachta indica)
Creepers: Aguna (Dregea volubilis), Winged bean (Psophocarpus
tetragonolobus), Halmessan dambala (Lablab purpureus), Passion fruit
(Passiflora edulis), Sponge guord or Niyan wetakolu (Luffa cylindrical)

57. Recommended Creepers for the live fence:

58. Importance of live fencing:
• It makes protection from cattle, wild animals and thieves
• Legume trees planted along the fence provide large amount of green
manure
• The tree belt of the fence acts as a wind barrier
• Fence trees such as drumstick (murunga), Kathurumurunga
(Sesbania grandiflora) etc. provide nutritional vegetables
• Some fence trees can provide fuel wood, timber and fencing poles
• Fence trees such as Neem, Adathoda vasica etc. provide medicine
• Fence environment is favourable for some predators
• Many vegetable plants such as winged bean, bean, bitter gourd,
ribbed gourd, snake gourd, yard long bean etc. can be supported
without any trellis
• The live fence increases the bio-diversity
• Contributes to C sequestration

59. Grow pest repellant plants within the farm
Sera Citronella Turmeric
(Cymbopogon citratus) (Cymbopogon nardus) (Curcuma longa)
Ginger Araththa
(Zingiber officinale) (Alpina calcarata)

60. Food – Forest Garden
• The purpose of a food forest is to foster a sustainable
environment in which humans can live in harmony with
nature, with sufficient food, shelter, and other resources
necessary to thrive. It aims to create a diverse ecosystem that
acts as a favorable habitat for native plants and animal species.

61. Food – Forest Garden
• Characteristics
– Diversity of crops
– Forest effect
– Multi layer architecture
– Shade management
– Nutrient recycling
– Moisture sharing
– Micro-climate
– Habitats
– Pest control
– Livestock integration
– Aesthetic beauty

62. Large
canopy
Medium
canopy
Low
canopy
Ground layer
Creepers
Ground cover
Roots and
tubers
Layers of Food – Forest Garden

63. Large
canopy
Medium
canopy
Low
canopy
Ground layer
Creepers
Ground cover
Roots and
tubers
Layers of Food – Forest Garden
Beli, Wood apple, Neem,
Mango, Coconut
Papaya, Drumstick, Kathuru,
Guava, Pomegranate, Katu
anoda
Anguna, Wingedbean, Passion fruits,
Ginger, turmeric,
vegetables
Gotukola, Mukunuwenna,
Potato, Sweet potato, carrot