BAHAN KAJIAN
PRINSIP-PRINSIP
AGROEKOSISTEM
Diabstraksikan oleh:
SOEMARNO
Malang , 2012
AGROEKOSISTEM
An agroecosystem is the basic unit of
study for an agroecologist, and is
somewhat arbitrarily defined as a spatially
and functionally coherent unit of
agricultural activity, and includes the
living and nonliving components involved
in that unit as well as their interactions.
(Agro-ecosystem Health Project. 1996. Agroecosystem
health. University of Guelph, Guelph, Canada.)
http://en.wikipedia.org/wiki/Agroecosystem ….. Diunduh 22/2/2012
An agroecosystem can be viewed as a subset of a
conventional ecosystem. As the name implies, at the core
of an agroecosystem lies the human activity of
agriculture. However, an agroecosystem is not restricted
to the immediate site of agricultural activity (e.g. the
farm), but rather includes the region that is impacted by
this activity, usually by changes to the complexity of
species assemblages and energy flows, as well as to the
net nutrient balance.
Traditionally an agroecosystem, particularly one
managed intensively, is characterized as having a simpler
species composition and simpler energy and nutrient
flows than "natural" ecosystem.
Elske van de Fliert and Ann R. Braun. 1999. Farmer Field School
for Integrated Crop Management of Sweetpotato. Field guides and
Technical Manual. Bogor, Indonesia: International Potato Center.
ISBN 92-9060-216-3.
http://www.eseap.cipotato.org/MF-ESEAP/Abstract/FFS-ICM-SPInd.htm
http://en.wikipedia.org/wiki/Agroecosystem ….. Diunduh 22/2/2012
Agroecosystem analysis is a thorough analysis of an
agricultural environment which considers aspects from
ecology, sociology, economics, and politics with equal weight.
There are many aspects to consider; however, it is literally impossible
to account for all of them. This is one of the issues when trying to
conduct an analysis of an agricultural environment.
In the past, an agroecosystem analysis approach might be used to
determine the sustainability of an agricultural system.
It has become apparent, however, that the "sustainability" of the
system depends heavily on the definition of sustainability chosen by the
observer.
Agroecosystem analysis is used to
bring the richness of the true
complexity of agricultural systems to
an analysis to identify
reconfigurations of the system (or
holon) that will best suit individual
situations.
Diunduh dari: http://en.wikipedia.org/wiki/Agroecosystem_analysis
Agroecosystem analysis is a tool of the multidisciplinary
subject known as Agroecology
Agroecology and agroecosystem analysis are not the same as
sustainable agriculture, though the use of agroecosystem
analysis may help a farming system ensure its viability.
Agroecosystem analysis is not a new practice,
agriculturalists and farmers have been doing it since
societies switched from hunting and gathering (huntergatherer) for food to settling in one area.
Every time a person involved in
agriculture evaluates their situation to
identify methods to make the system
function in a way that better suits their
interests, they are performing an
agroecosystem analysis.
Diunduh dari: http://en.wikipedia.org/wiki/Agroecosystem_analysis
Agro-ecosystems, natural resources management and human health related
research in East Africa: Case studies
Agro-ecosystem health: Principles and methods used in high-potential
tropical agro-ecosystem
2,3
T.Gitau,J.J.McDermott ,D. Waltner-Toews3,J.M. Gathuma1, E.K.Kang1,
V.W.Kimani4, J.K.Kilungo5, R.K. Muni6, J.M. Mwangi1 and G.O. Otieno7
A simplified conceptual model of the agro-ecosystem.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Agro.htm
Productivity, Stability, Sustainability, Equitability and Autonomy as
Properties for Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Some basic definitions for agroecosystem assessment.
Agroecosystems and agricultural technology systems
It is necessary to start with some definitions, including the
distinction between agroecosystems and agricultural technology
systems. An agroecosystem is a complex of air, water, soil, plants,
animals, micro-organisms, and everything else in a bounded area
that people have modified for the purposes of agricultural
production. An agroecosystem can be of any specified size. It can be
a single field, it can be a household farm, or it can be the
agricultural landscape of a village, region, or nation.
Sumber: http://www.gerrymarten.com/publicatons/agroecosystem-
AGROECOSYSTEM PROPERTIES
Productivity - the quantity of food, fuel or fiber that an
agroecosystem produces for human use.
Stability - consistency of production.
Sustainability - maintaining a specified level of production over
the long term.
Equitability - sharing agricultural production fairly.
Autonomy - agroecosystem self-sufficiency.
Plant Nutrient Balances in the Asian and Pacific Region - the Consequences
for Agricultural Production
Ernst W. Mutert
East & Southeast Asia Program, Potash & Phosphate Institute,
126 Watten Estate Road, Singapore 287599, 1995-11-01
Asia and the Pacific will have to feed an additional 1.8 billion people over
the next 30 years. It is vital for the region's future to meet the rising food
demand from a limited production area by intensification. The recent
stagnation of rice yields observed in the lowlands of the region has become
a major agronomic concern.
The main reasons are a decrease in nutrient productivity and an increasing
imbalance in the nutrient supply. Nutrient input/output balances for main
crops and for rice in ten selected Asian countries are presented. Negative
balances for N, P, K, Mg, Ca, to a total of 7 million mt, were observed in
lower income economies with large and growing populations (e.g.
Bangladesh, Indonesia, Myanmar, Philippines, Thailand, Vietnam). An
oversupply of nutrients (a total of 1.1 million tons) was found in higher
income economies with stable populations (Japan, Korea, Malaysia).
The principle of balanced fertilization requires that this damaging
trend be halted through judicious use of fertilizers, in order to sustain
an economically viable and environmentally friendly agriculture
which meets the requirements of the future.
Plant Nutrient Balances in the Asian and Pacific Region - the Consequences
for Agricultural Production
Ernst W. Mutert
East & Southeast Asia Program, Potash & Phosphate Institute,
126 Watten Estate Road, Singapore 287599, 1995-11-01
NERACA HARA DALAM SUATU AGROEKOSISTEM
Plant Nutrient Balances in the Asian and Pacific Region - the Consequences
for Agricultural Production
Ernst W. Mutert
East & Southeast Asia Program, Potash & Phosphate Institute,
126 Watten Estate Road, Singapore 287599, 1995-11-01
Plant Nutrient Balances in the Asian and Pacific Region - the Consequences
for Agricultural Production
Ernst W. Mutert
East & Southeast Asia Program, Potash & Phosphate Institute,
126 Watten Estate Road, Singapore 287599, 1995-11-01
Figure 1 Rothamsted 1852-1967: Comparison of Wheat Yields
Plant Nutrient Balances in the Asian and Pacific Region - the Consequences
for Agricultural Production
Ernst W. Mutert
East & Southeast Asia Program, Potash & Phosphate Institute,
126 Watten Estate Road, Singapore 287599, 1995-11-01
Figure 2 Trends in the Use of N Versus P and K in Europe and North
America, Relative to Asia
Source: vonUexlullandMutert1993
Agro-ecosystems, natural resources management and human health related
research in East Africa: Case studies
Agro-ecosystem health: Principles and methods used in high-potential
tropical agro-ecosystem
2,3
T.Gitau,J.J.McDermott ,D. Waltner-Toews3,J.M. Gathuma1, E.K.Kang1,
V.W.Kimani4, J.K.Kilungo5, R.K. Muni6, J.M. Mwangi1 and G.O. Otieno7
Hierarchy in agro-ecosystems: The central highlands of Kenya.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Agro.htm
Agro-ecosystems, natural resources management and human health related
research in East Africa: Case studies
Agro-ecosystem health: Principles and methods used in high-potential
tropical agro-ecosystem
2,3
T.Gitau,J.J.McDermott ,D. Waltner-Toews3,J.M. Gathuma1, E.K.Kang1,
V.W.Kimani4, J.K.Kilungo5, R.K. Muni6, J.M. Mwangi1 and G.O. Otieno7
PAR (participatory action research) tools used in the study and the
expected outputs.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Objectives
Introduction
Tools
Expected output
Self introduction,
Acceptance/permission to carry out exercise
pairing, speeches, icebreakers
Planning for
Time schedules,
Workshop logistics, trend-setting for community
the workshop assigning roles and
participation
responsibilities
Village
Social map
Location of farms and households, names and
boundaries
sex of HH heads, boundaries
and
inventory of
resources
Resource map
Inventory of resources, infrastructure, state of
resources, identify problems
Historical
Historical profile
Community identity and history, past events and
background
their impacts, coping strategies
Trend-lines
Trend charts
Lists changes, direction of change, triangulation
and time-lines
of (4) above
Seasonal
Seasonal calendars Seasonal trends in climate, economic and social
trends
activities
Transect
Route mapping
Identification of issues and problems
walks
Walk
Observation of type and status of resources,
problem identification, triangulation
Transect profile
Resource inventory
Semi-structured
Observation of type and status of resources,
interviews
problem identification, triangulation
Resource
Mobility charts
Flow of goods, services and resources to and
mobility
from village
Identification
Venn (chapati)
Types, numbers and importance of institutions,
and analysis
diagrams
problem identification
ofDiunduh
institutions
dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Agro.htm
Agro-ecosystems, natural resources management and human health related
research in East Africa: Case studies
Agro-ecosystem health: Principles and methods used in high-potential
tropical agro-ecosystem
2,3
T.Gitau,J.J.McDermott ,D. Waltner-Toews3,J.M. Gathuma1, E.K.Kang1,
V.W.Kimani4, J.K.Kilungo5, R.K. Muni6, J.M. Mwangi1 and G.O. Otieno7
A simplified conceptual model of the agro-ecosystem.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Agro.htm
Concepts of sustainability, agro-ecosystem health and applications to
agricultural production1
B. Smit
University of Guelph, Guelph, Ontario, Canada
Production, resources management and human health in East African
highlands: A summary of the issues as outlined in ILRI (1998).
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Concepts.htm
Concepts of sustainability, agro-ecosystem health and applications to
agricultural production1
B. Smit
University of Guelph, Guelph, Ontario, Canada
Agricultural sustainability and agro-ecosystem health
Once the term 'agro' is appended to 'ecosystem' we have explicitly included
human components, such that 'agro-ecosystem' is fundamentally equivalent to
a broad definition of 'agriculture', which includes ecological and human
components. Sustainable agriculture has been defined in many ways (Smit
and Brklacich 1989; Cai and Smit 1994; Smit and Smithers 1994b), but most
cover the same essential features. Consider two representative definitions:
1. agri-food systems that are economically viable, meet society's need for
safe and nutritious foods, while conserving natural resources and the
quality of the environment for future generations (SCC 1992), and
2. agricultural system that can indefinitely meet demands for food and fibre
at socially acceptable economic and environmental costs (Crosson 1992).
In both of these, agricultural sustainability is defined with respect to societal
needs or demands for food, including nutrition, and hence implying human
health economic viability, referring to the maintenance of production systems,
and environmental quality, addressing the condition of biophysical resources.
Definitions of sustainability also note the maintenance of these features over
time ('future generations' or 'indefinitely'). Definitions of agro-ecosystem
health cover essentially the same features. Waltner-Toews (1994) and Smit
and Smithers (1994b) describe agro-ecosystem health as incorporating
human well-being
economic performance, and
ecological condition.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Concepts.htm
Concepts of sustainability, agro-ecosystem health and applications to
agricultural production1
B. Smit
University of Guelph, Guelph, Ontario, Canada
the essence of the agro-ecosystem health (AESH) perspective is that it
recognises the existence of, and interrelationships among, these several
domains of agricultural systems (economic, human and ecological), and
that the overall 'health' of the system is a function of the condition, of and
interdependencies among, these components.
A simple conceptualisation of agro-ecosystem health is given in Figure
(from Smit and Smithers 1994b).
Agro-ecosystem health: A sample diagramatic representation.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Concepts.htm
Concepts of sustainability, agro-ecosystem health and applications to
agricultural production1
B. Smit
University of Guelph, Guelph, Ontario, Canada
The conceptual foundations of these two paradigms, AESH and agricultural
sustainability (AS), are fundamentally synonymous. Both are explicitly
evaluative of the overall conditions of rural environments, economies, and
peoples. It is noteworthy that the goals of CGIAR also mirror these
components
increase food security
alleviate poverty, and
protect environmental quality.
In other respects as well, AESH and AS are very similar. Both are
applicable at different spatial and temporal scales (Smit and Smithers
1994a).
For both, considerable effort has been expended in developing indicators,
and similar kinds of indicators (often very long lists) have been proposed.
Indicators can take a wide variety of forms, including state and functional
indicators, diagnostic and early warning indicators (Smit et al 1998).
There are also many examples of particular empirical studies employing
indicators, especially of sustainable agriculture (Smit and Smithers 1994a),
but also for agro-ecosystem health (Smit et al 1998).
Smit B. and Smithers J. 1994a. Sustainable agriculture: Interpretations, analyses and prospects.
Canadian journal of regional science 16(3):499–524.
Smit B., Waltner-Toews D., Rapport D., Wall E., Wichert G., Gwyn E. and Wandel J. 1998. Agroecosystem health: Analysis and assessment. University of Guelph, Guelph, Canada.
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Concepts.htm
Concepts of sustainability, agro-ecosystem health and applications to
agricultural production1
B. Smit
University of Guelph, Guelph, Ontario, Canada
Approaches to agro-ecosystem health indicators
Holistic
This approach, of which several versions have been proposed, aims to
define a set of very generic 'criteria', essentially from first principles, which
will be applicable to all dimensions. Thus, we get such 'holistic indicators'
as integrity, efficiency, resilience, effectiveness, response capability,
balance, richness, transformation ability, self-regulatory capacity,
flexibility, stability, and so on (Figure : A conceptual framework for agroecosystem health).
Diunduh dari: http://www.ilri.org/InfoServ/Webpub/fulldocs/Aesh/Concepts.htm
Dennis S. Ojima and William J. Parton
Integrated Approach to Land Use Analyses
a hierarchical or spatially nested analytical framework is needed in order to
understand how driving forces of land use and climate changes transform
land covers at local to regional scales .
Analytical structure for assessment of land and climate change effects on
agroecosystems of the US Great Plains.
Diundu dari: http://www.ncgia.ucsb.edu/conf/SANTA_FE_CD-
Dennis S. Ojima and William J. Parton
Integrated Approach to Land Use Analyses
Our ability to predict ecosystem dynamics relative to climate or land use changes is
dependent on the development of analytical tools to integrate our current
understanding of how these ecosystems behave relative to human and environmental
factors. The analysis of this information will need to incorporate the critical factors of
the physical environment, including climate and soil factors, but also include the
human factors related to land use practices (Figure ).
The dynamics of the agroecosystem will depend on the joint influence of the physical
environment and the specific mix of land use practices implemented with a location.
The land use decisions are controlled by a number of factors economics, policy,
technological advancements, and socio- cultural factors.
Simplified structure of the CENTURY agroecosystem model (Parton et al 1987, 1995) indicating the
physical environmental controls and the set of land use management options implemented.
Parton, W.J., Schimel, D.S., Cole, C.V., and Ojima, D.S. (1987) Analysis of factors controlling soil organic
matter levels in Great Plains grasslands. Soil Science Society of America Journal 5:1137-1179. 465
Dennis S. Ojima and William J. Parton
Integrated Approach to Land Use Analyses
A framework to simplify the complex interactions within and between
various subsystems is provided using a modeling approach that includes all
the major components and links them together in a spatially integrated
fashion (Figure: Linkage of social-cultural-economic factors influencing the
land use decisions which modify agroecosystem processes).
Dennis S. Ojima and William J. Parton
Integrated Approach to Land Use Analyses
In recent analysis of assessing changes in land use management in the corn
belt region of the United States, CENTURY simulations of improved land
use practices resulted in a recovery of 47 to 79% of the initial soil C lost
after approximately 50y of cropping (Figure 4, modified from Parton et al.,
1995, Donigian et al. 1995). These analyses indicate that changes in land
management practices can affect C storage in the soil without greatly
affecting yield of corn in this region. The factors influencing crop rotation
and crop selection also affected the level of C stored in this mesic region of
the US (Donigian et al. 1995).
Figure: The effect of changing land management in the cornbelt of the
United States on soil carbon levels in the surface 20 cm of soil.
Donigian, A.S., Jr, PatwardhamA.S., Jackson, R.B. IV, Barnwell, Jr., T.O., Weinrich, K.B. and Rowell, A.L.
1995. Modeling the impacts of agricultural management practices on soil C in the Central US. P.121- 145. In
R. Lal, J. Kimble, E. Levine, and B.A. Stewart (eds.), Soil Management and Greenhouse Effect. Advances in
Soil Science. CRC Press. Boca Raton, FL.
Parton, W.J., Ojima, D.S., and Schimel, D.S. (1995) Models to evaluate soil organic matter storage and
dynamics. In M.R. Carter and B.A. Stewart (eds.) Structure and Organic Matter Storage in Agricultural
Soils. Advances in Soil Science. CRC Press. Boca Raton, FL.
IPM systems modelling
To further illustrate the previous points on the possibilities of systems
modelling in IPM some additional explanation is provided. The research
components of a typical IPM modelling application are found in Figure
(Components of Agroecosystem Analysis). At the ecosystem level, the
integrating technologies are modelling and GIS. Population models must be
built up from the individual physiological and behavioural level and be
driven by soil factors and weather. Policy issues must include social science
components impinging on the agroecosystem structure and function.
Diunduh rari: http://www.fao.org/WAIRDOCS/TAC/Y4847E/y4847e07.htm
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties
for Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
The Southeast Asian Universities Agroecosystem network (SUAN) has used five
system properties to assess agroecosystem performance: productivity, stability,
sustainability, equitability and autonomy. Assessing these properties can be useful for
agricultural research and development, but the assessment is complicated by several
factors. First is the multidimensional character of these properties, due to (a)
independent measures of agricultural production and (b) differences in the same
property at different hierarchical levels of an agroecosystem. Secondly, there are
significant limitations in generalizing agroecosystem assessment from one set of
environmental and social conditions to another. The SUAN network has examined
trade-offs between these properties and implications of the trade-offs for
agroecosystem design. Increases in productivity can be at the expense of other system
properties, or they can be mutually reinforcing, depending on how the agroecosystem
is organized.
System Properties
Agroecosystems are overwhelmingly complex. The numerous ecological
processes that tie people, crops, weeds, animals, micro-organisms, soil, and water
together into a functioning, on-going ecosystem are so intricate that they can
never be fully described, nor can they be fully comprehended. Simplification is a
practical necessity of analysis. Simplification is also essential for effectively
communicating the results of analysis to agricultural practitioners. The dilemma
is how to simplify without losing the essence of key relationships in the
agroecosystem as a whole. One approach to simplification is system properties
(also called agroecosystem properties in this essay), which combine large
numbers of agroecosystem processes into single, highly-aggregated measures of
performance that suggest how well an agroecosystem is meeting human
objectives (Gypmantasiri et al, 1980; Conway, 1985; Rerkasem & Rambo, 1988).
The SUAN network has focused on five system properties:
Productivity - the quantity of food, fuel or fiber that an agroecosystem produces
for human use.
Stability - consistency of production.
Sustainability - maintaining a specified level of production over the long term.
Equitability - sharing agricultural production fairly.
Autonomy - agroecosystem self-sufficiency.
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties for
Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Differences in the Agroecosystem Production Properties of Two
Hypothetical Agricultural Technology Systems
Rainfed
Productivity
Stability
Low
Low
Irrigated
High
High
Sustainability
High
Low
Equitability
High
Low
Autonomy
High
Low
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties for
Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Multidimensional character of stability and sustainability
Stability concerns fluctuations in productivity that result from numerous fluctuations in an
agroecosystem's physical and social environment: variations in rainfall, periodic pest
attacks, price fluctuations, etc. Stability is assessed in terms of the fluctuation of
production about a long-term average (Fig. 2) or the fluctuation of production about a
long-term trend.
The stability concept can be described in abstract terms by considering movements of a
small ball on the landscape, as in Fig. 3. The position of the ball on the landscape
represents all the numerous aspects of agroecosystem organization and function, including
production; point A represents the average condition of the agroecosystem (including its
production). Stability concerns movement of the ball about point A under the impact of
disturbances that are not large enough to knock the ball all the way out of the valley. Less
movement (i.e. less fluctuation in production) represents greater stability.
Because stability derives from productivity, stability is multidimensional in exactly the
same respects. A given agroecosystem can be relatively stable with regard to some
measures of productivity and low with regard to others. Maize production for subsistence
can be considered stable as long as yields (and therefore food production) are consistent,
but the same crop may be considered unstable if grown for a market economy with
fluctuating prices.
The meaning of stability and sustainability in terms of the time course of production.
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties for
Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
In the abstract view of Fig. 3, sustainability involves the ability of farm management to
maintain agroecosystem function (including production) at point A, despite natural
ecological processes that tend to change the agroecosystem toward point B. As with
stability, sustainability has a variety of measures associated with various measures of
productivity. Some measures of sustainability can be high while others are low for the
same agroecosystem.
The multidimensionality of sustainability derives in large part from the fact that it may
be necessary to increase certain inputs with successive crops to maintain yields at the
same level. For example, if increasing fertilizer inputs are required to sustain
production per hectare at a given level, the production per hectare may be sustainable
even though production per unit cost is not. If weed problems require increasing labor
inputs, production per hectare may be sustained while production per unit of labor is
not.
A ball and landscape model for visualizing stability and sustainability concepts. The horizontal axis of the
diagram represents different states of ecosystem structure and function.
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties for
Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Resilience is intermediate between stability and internal sustainability. Like stability,
resilience concerns the response of production to external disturbance; like
sustainability, resilience concerns the maintenance of production. Stability concerns
routine fluctuations in response to frequent and generally tolerable disturbances, while
resilience deals with whether the agroecosystem can persist in the face of disturbances
that are occasional but traumatic. The same agroecosystem can be quite strong with
regard to internal sustainability but low in resilience, or visa versa, because these two
kinds of sustainability involve different processes.
Relationships of stability, resilience and sustainability.
Diunduh dari: http://www.gerrymarten.com/publicatons/agroecosystem-
Productivity, Stability, Sustainability, Equitability and Autonomy as
Properties for Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Agroecosystem Strucutal Properties
Agroecosystem structure is a consequence of the particular crops and other
components (weeds, animal pests, soil animals, micro-organisms, etc.) in an
agroecosystem, the way those components are structured by farm management
practices, and the way those components are related functionally to one another.
SUAN research has dealt with numerous aspects of ecosystem structure and their
relationships to agroecosystem function (Table ). However, the SUAN network has not
dealt much with agroecosystem structure at the same organizational level as system
properties for agroecosystem production. It could be useful for agro-ecosystem
research to identify those structural system properties (at the agroecosystem level of
organization) that in fact have strong relationships with the production properties. Such
structural properties could prove useful as guidelines for agroecosystem design.
Table: Examples of Relationships Between Agroecosystem Structure and
Agroecosystem Function that have been Studied in the SUAN Network
Agroecosystem structure
Agroecosystem function
Intercropping
Human nutrition
Intercropping
Pest damage
Annual/perennial crop rotation
Mineral nutrient cycling
Perennial/annual strip cropping on slopes
Erosion, annual/perennial competition
Institutions in irrigation societies
Irrigation water supply
Double and triple cropping
Minor nutrient depletion of soil
Integration of crops and livestock
Soil fertility maintenance
Communications between innovative farmers
and others
Diffusion of new agricultural technology
Diunduh dari: http://www.gerrymarten.com/publicatons/agroecosystem-
An example of the causal connections between system properties of
agroecosystem structure and system properties of agroecosystem
production.
Agroecosystem structure and adaptability
One approach to delineating functional connections between system properties of
agroecosystem structure and production is to address select properties of
agroecosystem function (in addition to those concerning production). Adaptability
(Holling, 1978) is an example of a functional property that can help to bridge the gap
between structure and production.
Holling, C. S. (1978). Adaptive environmental assessment and management, Wiley,
New York.
Diunduh dari: http://www.gerrymarten.com/publicatons/agroecosystem-Assessment.html
Productivity, Stability, Sustainability, Equitability and Autonomy as Properties for
Agroecosystem Assessment
Gerald G. Marten
Agricultural Systems 26 (1988) 291-316
Basic elements in a corrective feedback loop for adaptive agroecosystem
design.
Crop diversity can improve nutritional productivity only if there is a proper mix of
crops (Abdoellah & Marten, 1986): some that have high yields to produce large
amounts of certain nutrients (e.g. calories and protein) that are needed in large
quantities; and other crops that provide smaller quantities of a variety of nutrients for
nutritional balance (e.g. vitamin A, vitamin C, riboflavin, calcium, and iron when
rice is the staple food).
Abdoellah, O. S. & Marten, G. G. (1986). The complementary roles of homegardens, upland
fields, and rice fields for meeting nutritional needs in West Java. In: Traditional agriculture in
Southeast Asia. (Marten, G. G. (Ed)), Westview Press, Boulder, Colorado, 293-315.
Diunduh dari: http://www.gerrymarten.com/publicatons/agroecosystem-