REKAYASA BIOLOGIS
SUMBERDAYA HAYATI
MODIFIKASI GENETIK
PANGAN
• Manipulating and engineering genetic material in the lab
may represent the best hope for increasing agricultural
production further without destroying more natural lands.
• But many people remain uneasy about genetically
engineering crop plants and other organisms.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Genetically modified foods (GM foods, or biotech foods) are
foods derived from genetically modified organisms (GMOs),
specifically, genetically modified crops.
GMOs have had specific changes introduced into their DNA by
genetic engineering techniques.
These techniques are much more precise than mutagenesis
(mutation breeding) where an organism is exposed to radiation or
chemicals to create a non-specific but stable change.
Other techniques by which humans modify food organisms
include selective breeding; plant breeding, and animal breeding,
and somaclonal variation.
Diunduh dari:
http://en.wikipedia.org/wiki/Genetically_modified_food…… 22/12/2012
REKAYASA GENETIK
MENGGUNAKAN
DNA - REKOMBINAN
•
Genetic engineering (GE) = directly manipulating an organism’s
genetic material in the lab by adding, deleting, or changing
segments of its DNA
• Genetically modified (GM) organisms = genetically engineered
using recombinant DNA technology
• Recombinant DNA = DNA patched together from DNA of multiple
organisms (e.g., adding disease-resistance genes from one plant to
the genes of another)
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
What is transgenic food?
Transgenic food are those directly made from or processed from
the species (animals, plants and microorganisms, etc.) which can
produce substances possessing highly effective expressions, such
as polypeptide and protein, after one or several types of exogenous
genes are transferred into it through the means of genetic
engineering.
The first category----transgenic plant food
product
There are various kinds of transgenic plant foods, such as high
protein wheat used to bake breads. To reverse the situation that
wheat in the current market contains low rate of protein, protein
genes possessing highly effective expressions are transferred into
wheat, so that bread made from the wheat can be of more
nutritious value.
Diunduh dari: http://www.nobelkepu.org.cn/english/life/136898.shtml …… 22/12/2012
TRANSGENE &
BIOTEKNOLOGI
• Genes moved between organisms are transgenes,
and the organisms are transgenic.
• These efforts are one type of biotechnology, the
material application of biological science to create
products derived from organisms.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Transgenosis technology is a kind of modern
technology in molecular biology, which is used
to transfer genes from one species into another
so as to reconstruct the genetic materials of the
receiving species for the improvement of its
properties, quality of nutrition in line with the
need of human beings.
The transgenic species as immediate food and
food processed from transgenic species are
called transgenic food.
Diunduh dari:
http://www.nobelkepu.org.cn/english/life/136898.shtml…… 22/12/2012
REKAYASA GENETIK vs.
PEMULIAAN TRADISIONAL
• They are similar:
• We have been altering crop genes (by artificial
selection) for thousands of years.
• There is no fundamental difference: both
approaches modify organisms genetically.
• They are different:
• GE can mix genes of very different species.
• GE is in vitro lab work, not with whole organisms.
• GE uses novel gene combinations that didn’t come
together on their own.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Some GM foods
Golden
rice:
Enriched
with
vitamin
A.
But too
much
hype?
Ice-minus strawberries:
Frost-resistant bacteria
sprayed on.
Images alarmed public.
FlavrSavr tomato: Better
taste?
But pulled from market.
Bt crops:
Widely used
on U.S. crops.
But
ecological
concerns?
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Some GM foods
Bt sunflowers:
Insect resistant.
But could hybridize
with wild relatives to
create “superweeds”?
Roundup-Ready crops:
Resistant to Monsanto’s
herbicide. But encourages
more herbicide use?
StarLink corn: Bt corn
variety.
Genes spread to non-GM
corn; pulled from market.
Terminator
seeds: Plants
kill their own
seeds.
Farmers forced
to buy seeds
each year.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
PREVALENSI PANGAN
TRANSGENIK
• Although many early GM crops ran into bad publicity or
other problems, biotechnology is already transforming the
U.S. food supply.
• Two-thirds of U.S. soybeans, corn, and cotton are now
genetically modified strains.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Health concerns and potential food hazards
Health risks associated with genetically modified foods are
concerned with toxins, allergens, or genetic hazards. The
mechanisms of food hazards fall into three main categories
(Conner et al., 1999):
1. Inserted genes and their expression products
2. Secondary and pleiotropic effects of gene expression
3. Insertional mutagenesis resulting from gene
integration
For example, bean plants that were genetically modified to
increase cysteine and methionine content were discarded after the
discovery that the expressed protein of the transgene was highly
allergenic. (Butler et al., 1999)
Diunduh dari: http://www.nyu.edu/classes/jaeger/genetically_modified_foods.htm……
22/12/2012
ORGANISME
TRANSGENIK
1.
2.
3.
4.
5.
Are there health risks for people?
Can transgenes escape into wild plants, pollute ecosystems,
harm organisms?
Can pests evolve resistance to GM crops just as they can to
pesticides?
Can transgenes jump from crops to weeds and make them
into “superweeds”?
Can transgenes get into traditional native crop races and
ruin their integrity?
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
The potential risks accompanied by disease
resistant plants deal mostly with viral resistance.
It is possible that viral resistance can lead to the
formation of new viruses, and therefore new
diseases.
It has been reported that naturally occurring
viruses can recombine with viral fragments that
are introduced to create transgenic plants, forming
new viruses.
Additionally, there can be many variations of this
newly formed virus. (Steinbrecher, 1996)
Diunduh dari: http://www.nyu.edu/classes/jaeger/genetically_modified_foods.htm……
22/12/2012
ORGANISME
TRANSGENIK
• These questions are not fully answered yet.
• In the meantime…
Should we not
worry, because
so many U.S.
crops are already
GM and little
drastic harm is
apparent?
Or should we adopt
the precautionary
principle, the idea
that one should take
no new action until its
ramifications are
understood?
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
PRODUK-PRODUK
TRANSGENIK
• Should scientists and corporations be “tinkering with” our
food supply?
• Are biotech corporations testing their products adequately,
and is outside oversight adequate?
• Should large multinational corporations exercise power over
global agriculture and small farmers?
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
RISKS AND CONTROVERSY
With all this new technology comes question and fear.
What are the risks of "tampering with Mother Nature"?
What effects will this have on the environment?
Are there health concerns consumers should be aware of?
Is recombinant technology really beneficial?
The following section will address some major concerns
about the risks involved with genetically modified foods
and recombinant technology, touching up environmental
risks as well as health risks.
Diunduh dari: http://www.nyu.edu/classes/jaeger/genetically_modified_foods.htm …… 20/12/2012
Trade-Offs
Genetically Modified Food and Crops
Projected
Advantages
Need less fertilizer
Need less water
More resistant to insects,
plant disease, frost, and
drought
Projected
Disadvantages
Irreversible and
unpredictable genetic
and ecological effects
Harmful toxins in food
From possible plant
cell
Mutations
Faster growth
New allergens in food
Can grow in slightly salty
soils
Less spoilage
Better flavor
Less use of conventional
pesticides
Tolerate higher levels of
pesticide use
Lower nutrition
Increased evolution of
Pesticide-resistant
Insects and plant
disease
Creation of herbicideResistant weeds
Harm beneficial
insects
Higher yields
Lower genetic
diversity
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Viewpoints:
Genetically modified foods
Indra Vasil
Ignacio Chapela
“Biotech crops are
already helping to
conserve valuable
natural resources,
reduce the use of
harmful agrochemicals, produce
more nutritious foods,
and promote economic
development.”
“We should expect
fundamental alterations
in ecosystems with the
release of transgenic
crops… We are
experiencing a global
experiment without
controls.”
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
MELESTARIKAN
KEANEKA-RAGAMAN
TANAMAN
• Native cultivars of crops are important to preserve, in case
we need their genes to overcome future pests or pathogens.
• Diversity of cultivars has been rapidly disappearing from all
crops throughout the world.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Crop diversity is the variance in genetic and phenotypic
characteristics of plants used in agriculture.
Crops may vary in seed size, branching pattern, in height,
flower color, fruiting time, or flavor.
They may also vary in less obvious characteristics such
as their response to heat, cold or drought, or their ability
to resist specific diseases and pests.
It is possible to discover variation in almost every
conceivable trait, including nutritional qualities,
preparation and cooking techniques, and of course how a
crop tastes. And if a trait cannot be found in the crop
itself, it can often be found in a wild relative of the crop;
a plant that has similar species that have not been farmed
or used in agriculture, but exist in the wild.
Diunduh dari: http://en.wikipedia.org/wiki/Crop_diversity …… 22/12/2012
Seed banks preserve seeds, crop varieties
– Seed banks are living
museums of crop
diversity, saving
collections of seeds
and growing them
into plants every few
years to renew the
collection.
–
• Careful hand pollination
helps ensure plants of one
type do not interbreed with
plants of another.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Animal agriculture: Livestock
and poultry
• Consumption of meat has risen faster than
population over the past several decades.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
PERTANIAN-TERNAK
DAMPAK LINGKUNGANNYA
• Increased meat consumption has led to animals
being raised in feedlots (factory farms), huge pens
that deliver energy-rich food to animals housed at
extremely high densities.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
PERTANIAN-TERNAK
DAMPAK LINGKUNGANNYA
• Immense amount of waste produced, polluting air and water
nearby
• Intense usage of chemicals (antibiotics, steroids, hormones),
some of which persist in environment
• However, if all these animals were grazing on rangeland, how
much more natural land would be converted for agriculture?
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Diunduh dari: http://www.dpi.vic.gov.au/agriculture/about-agriculture/newsletters-andupdates/newsletters/milking-the-weather/june/seasonal-preparation ……..…… 22/12/2012
PILIHAN PANGAN =
PILIHAN ENERGI
•
• Energy is lost at each trophic level.
When we eat meat from a cow fed on grain, most of the grain’s
energy has already been spent on the cow’s metabolism.
• Eating meat is therefore very energy inefficient.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
The FOOD PYRAMID is a nutrition guide that is
shaped like a pyramid.
It is separated in parts, with each segment depicting
the suggested intake of a particular food group.
Diunduh dari: http://www.the-food-pyramid.com/healthy-diet/food-pyramid/ …..…… 22/12/2012
Grain feed input
for animal output
• Some animal food products can be produced with
less input of grain feed than others.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
LAHAN DAN AIR UNTUK
TERNAK
• Some animal food products can be produced with less input
of land and water than others.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
AQUACULTURE
• The raising of aquatic organisms for food in controlled
environments
• Provides 1/3 of world’s fish for consumption
• 220 species being farmed
• The fastest growing type of food production
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Aquaculture
The cultivation of aquatic organisms. Some of the most common
organisms that are cultivated are salmon, trout, oysters, and clams.
Diunduh dari: http://intecsciwri.wikidot.com/aquaculture …… 22/12/2012
AQUACULTURE
• Fish make up
half of
aquacultural
production.
Molluscs and
plants each
make up nearly
1/4.
• Global
aquaculture
has been
doubling about
every 7 years.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
MANFAAT AKUAKULUR
1.
2.
3.
4.
5.
Provides reliable protein source for people, increases food security
Can be small-scale, local, and sustainable
Reduces fishing pressure on wild stocks, and eliminates bycatch
Uses fewer fossil fuels than fishing
Can be very energy efficient
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Budidaya Ikan Lele di Gemolong Sragen
Lele merupakan jenis ikan yang digemari masyarakat, dengan rasa yang lezat,
daging empuk, duri teratur dan dapat disajikan dalam berbagai macam menu
masakan. PT. NATURAL NUSANTARA dengan prinsip K-3 (Kuantitas, Kualitas
dan Kesehatan) membantu petani lele dengan paket produk dan teknologi.
Diunduh dari: http://merubahmimpi.blogspot.com/2011/01/budidaya-ikan-lele-di-gemolongsragen.html …… 20/12/2012
DAMPAK LINGKUNGAN
AKIBAT AKUAKULTUR
1.
2.
3.
4.
5.
Density of animals leads to disease, antibiotic use, risks to food
security.
It can generate large amounts of waste.
Often animals are fed grain, which is not energy efficient.
Sometimes animals are fed fish meal from wild-caught fish.
Farmed animals may escape into the wild and interbreed with,
compete with, or spread disease to wild animals.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Aquaculture is the fastest growing food production sector in the World with
annual growth in excess of 10 percent over the last two decades. Much of this
development has occurred in Asia, which also has the greatest variety of cultured
species and systems. Asia is also perceived as the ‘home’ of aquaculture, as
aquaculture has a long history in several areas of the region and knowledge of
traditional systems is most widespread.
Diunduh dari: http://www.fao.org/docrep/006/y5098e/y5098e02.htm …… 22/12/2012
DAMPAK LINGKUNGAN
AKUAKULTUR
• Transgenic salmon (top) can compete with or spread
disease to wild salmon (bottom) when they escape
from fish farms.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Trade-Offs
Aquaculture
Advantages
Highly efficient
High yield in small
volume of water
Increased yields
through crossbreeding and genetic
engineering
Can reduce overharvesting of
conventional fisheries
Little use of fuel
Profit not tied to price
of oil
Disadvantages
Large inputs of land, feed,
And water needed
Produces large and
concentrated outputs of
waste
Destroys mangrove forests
Increased grain production
needed to feed some
species
Fish can be killed by
pesticide runoff from
nearby cropland
Dense populations
vulnerable to disease
High profits
Tanks too contaminated to
use after about 5 years
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Solutions
More Sustainable Aquaculture
• Reduce use of fishmeal as a feed to reduce depletion of
other fish
• Improve pollution management of aquaculture wastes
• Reduce escape of aquaculture species into the wild
• Restrict location of fish farms to reduce loss of
mangrove forests and other threatened areas
• Farm some aquaculture species (such as salmon and
cobia) in deeply submerged cages to protect them from
wave action and predators and allow dilution of wastes
into the ocean
• Set up a system for certifying sustainable forms of
aquaculture
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
PERTANIAN BERKELANJUTAN
•
•
Agriculture that can practiced the same way far into the future
•
Does not deplete soils faster than they form
•
Does not reduce healthy soil, clean water, and
genetic diversity essential for long-term crop and
livestock production
Low-input agriculture = small amounts of pesticides, fertilizers, water, growth
hormones, fossil fuel energy, etc.
Organic agriculture = no synthetic chemicals used. Instead, biocontrol, composting,
etc.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Components of a Sustainable Soil Management System
Diunduh dari:
http://www.fftc.agnet.org/library.php?func=view&style=&type_id=4&id=20110808172707&print=1 ……
23/12/2012
PERTANIAN
ORGANIK
•
•
Small percent of market, but is growing fast
– 1% of U.S. market, but growing 20%/yr
– 3–5% of European market, but growing 30%/yr
• Organic produce:
• Advantages for consumers: healthier; environmentally better
Disadvantages for consumers: less uniform and appealing-looking; more
expensive
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Principles in Organic Farming
Diunduh dari: http://agritech.tnau.ac.in/org_farm/orgfarm_principles.html …… 23/12/2012
PERTANIAN
ORGANIK
PRINSIP KESEHATAN
Organic Agriculture should sustain and enhance the health of
soil, plant, animal, human and planet as one and indivisible.
This principle points out that the health of individuals and
communities cannot be separated from the health of ecosystems healthy soils produce healthy crops that foster the health of
animals and people.
Health is the wholeness and integrity of living systems. It is not
simply the absence of illness, but the maintenance of physical,
mental, social and ecological well-being. Immunity, resilience
and regeneration are key characteristics of health.
The role of organic agriculture, whether in farming, processing,
distribution, or consumption, is to sustain and enhance the health
of ecosystems and organisms from the smallest in the soil to
human beings. In particular, organic agriculture is intended to
produce high quality, nutritious food that contributes to
preventive health care and well-being.
In view of this it should avoid the use of fertilizers, pesticides,
animal drugs and food additives that may have adverse health
effects.
Diunduh dari: http://agritech.tnau.ac.in/org_farm/orgfarm_principles.html …… 23/12/2012
PERTANIAN
ORGANIK
PRINSIP EKOLOGI
Organic Agriculture should be based on living ecological systems and
cycles, work with them, emulate them and help sustain them.
This principle roots organic agriculture within living ecological systems.
It states that production is to be based on ecological processes, and
recycling. Nourishment and well-being are achieved through the ecology
of the specific production environment. For example, in the case of
crops this is the living soil; for animals it is the farm ecosystem; for fish
and marine organisms, the aquatic environment.
Organic farming, pastoral and wild harvest systems should fit the cycles
and ecological balances in nature. These cycles are universal but their
operation is site-specific. Organic management must be adapted to local
conditions, ecology, culture and scale. Inputs should be reduced by
reuse, recycling and efficient management of materials and energy in
order to maintain and improve environmental quality and conserve
resources.
Organic agriculture should attain ecological balance through the design
of farming systems, establishment of habitats and maintenance of
genetic and agricultural diversity. Those who produce, process, trade, or
consume organic products should protect and benefit the common
environment including landscapes, climate, habitats, biodiversity, air and
water.
Diunduh dari: http://agritech.tnau.ac.in/org_farm/orgfarm_principles.html …… 23/12/2012
PERTANIAN
ORGANIK
PRINSIP KEADILAN
Organic Agriculture should build on relationships that ensure fairness
with regard to the common environment and life opportunities.
Fairness is characterized by equity, respect, justice and stewardship of
the shared world, both among people and in their relations to other
living beings.
This principle emphasizes that those involved in organic agriculture
should conduct human relationships in a manner that ensures fairness at
all levels and to all parties - farmers, workers, processors, distributors,
traders and consumers.
Organic agriculture should provide everyone involved with a good
quality of life, and contribute to food sovereignty and reduction of
poverty. It aims to produce a sufficient supply of good quality food and
other products.
This principle insists that animals should be provided with the
conditions and opportunities of life that accord with their physiology,
natural behavior and well-being.
Natural and environmental resources that are used for production and
consumption should be managed in a way that is socially and
ecologically just and should be held in trust for future generations.
Fairness requires systems of production, distribution and trade that are
open and equitable and account for real environmental and social costs.
Diunduh dari: http://agritech.tnau.ac.in/org_farm/orgfarm_principles.html …… 23/12/2012
PERTANIAN
ORGANIK
PRINCIPLE OF CARE
Organic Agriculture should be managed in a precautionary and
responsible manner to protect the health and well-being of current and
future generations and the environment.
Organic agriculture is a living and dynamic system that responds to
internal and external demands and conditions. Practitioners of organic
agriculture can enhance efficiency and increase productivity, but this
should not be at the risk of jeopardizing health and well-being.
Consequently, new technologies need to be assessed and existing
methods reviewed. Given the incomplete understanding of ecosystems
and agriculture, care must be taken.
This principle states that precaution and responsibility are the key
concerns in management, development and technology choices in
organic agriculture.
Science is necessary to ensure that organic agriculture is healthy, safe
and ecologically sound. However, scientific knowledge alone is not
sufficient. Practical experience, accumulated wisdom and traditional and
indigenous knowledge offer valid solutions, tested by time. Organic
agriculture should prevent significant risks by adopting appropriate
technologies and rejecting unpredictable ones, such as genetic
engineering.
Decisions should reflect the values and needs of all who might be
affected, through transparent and participatory processes.
Diunduh dari: http://agritech.tnau.ac.in/org_farm/orgfarm_principles.html …… 23/12/2012
TANTANGAN PERTANIAN MASA
DEPAN
1.
2.
3.
4.
Chemical pesticides pollute, and kill pollinators, and pests evolve
resistance.
GM crops show promise for social and environmental benefits, but
questions linger about their impacts.
Much of the world’s crop diversity has vanished.
Feedlot agriculture and aquaculture pose benefits and harm for the
environment and human health.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Pesticide Action Network (PAN) is a global network working to eliminate
the human and environmental harm caused by pesticides and to promote
biodiversity based ecological agriculture. We are dedicated to protect the
safety and health of people, and the environment from pesticide use and
genetic engineering.
Diunduh dari: http://www.thefutureoffarming.org/home.html …… 23/12/2012
TANTANGAN PERTANIAN MASA
DEPAN
1.
2.
3.
4.
5.
Organic farming remains a small portion of agriculture.
Human population continues to grow, requiring more food
production.
Soil erosion is a problem worldwide.
Salinization, waterlogging, and other soil degradation problems
are leading to desertification.
Grazing and logging, as well as cropland agriculture, contribute to
soil degradation.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
SUSTAINABLE CROP MANAGEMENT
One of the most significant challenges facing Mankind is the
adequate provision of food from sustainable and profitable
production systems within a context of high energy costs.
Diunduh dari: http://www.adas.co.uk/Home/Sustainablecropmanagement/tabid/245/Default.aspx
…… 23/12/2012
TANTANGAN PERTANIAN
MASA DEPAN
1. Biocontrol and IPM offer alternatives
to pesticides.
2. Further research and experience with
GM crops may eventually resolve
questions about impacts, and allow
us to maximize benefits while
minimizing harm.
3. More funding for seed banks can
rebuild crop diversity.
4. Ways are being developed to make
feedlot agriculture and aquaculture
safer and cleaner.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
SOLUSI PERTANIAN
MASA DEPAN
1.
2.
3.
4.
5.
Organic farming is popular and growing fast.
Green revolution advances have kept up with food demand so far.
Improved distribution and slowed population growth would help
further.
Farming strategies like no-till farming, contour farming, terracing,
etc., help control erosion.
Government laws, and government extension agents working with
farmers, have helped improve farming practices and control soil
degradation.
Better grazing and logging practices exist that have far less impact
on soils.
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
An Assets-Based Model for
Sustainability
Agricultural systems at all levels rely for their success on
the value of services flowing from the total stock of assets
that they control. Five types of capital, natural, social,
human, physical and financial, are now being addressed in
the literature :
1. Natural capital
2. Social capital
3. Human capital
4. Physical capital
5. Financial capital.
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
AN ASSETS-BASED MODEL
FOR SUSTAINABILITY
1. Natural capital produces nature’s goods and services, and comprises
food (both farmed and harvested or caught from the wild), wood and
fibre; water supply and regulation; treatment, assimilation and
decomposition of wastes; nutrient cycling and fixation; soil formation;
biological control of pests; climate regulation; wildlife habitats; storm
protection and flood control; carbon sequestration; pollination; and
recreation and leisure.
2. Social capital yields a flow of mutually beneficial collective action,
contributing to the cohesiveness of people in their societies. The social
assets comprising social capital include norms, values and attitudes that
predispose people to cooperate; relations of trust, reciprocity and
obligations; and common rules and sanctions mutually-agreed or
handed-down. These are connected and structured in networks and
groups.
3. Human capital is the total capability residing in individuals, based on
their stock of knowledge skills, health and nutrition. It is enhanced by
their access to services that provide these, such as schools, medical
services, and adult training. People’s productivity is increased by their
capacity to interact with productive technologies and with other people.
Leadership and organisational skills are particularly important in making
other resources more valuable.
4. Physical capital is the store of human-made material resources, and
comprises buildings (housing, factories), market infrastructure, irrigation
works, roads and bridges, tools and tractors, communications, and
energy and transportation systems, that make labour more productive.
5. Financial capital is accumulated claims on goods and services, built up
through financial systems that gather savings and issue credit, such as
pensions, remittances, welfare payments, grants and subsidies.
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
AN ASSETS-BASED MODEL
FOR SUSTAINABILITY
The basic premise is that sustainable systems, whether farms, firms,
communities, or economies, accumulate stocks of these five assets, thereby
increasing the per capita endowments of all forms of capital over time. But
unsustainable systems deplete or run down these various forms, spending assets
as if they were income, and so leaving less for future generations.
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
AN ASSETS-BASED MODEL
FOR SUSTAINABILITY
The assets-based model shows how farms and rural livelihoods take
inputs of various types, including renewable assets, and transform these
to produce food and other desirable outputs.
These can be processed for home consumption, transformed through
value-added processes for sale, or sold directly as raw product.
The inputs are shown as:
1. Renewable natural capital – soil, water, air, biodiversity etc;
2. Social and participatory processes – including both locally
embedded and externally-induced social capital, and partnerships
and linkages between external organisations;
3. New technologies, knowledge and skills – both regenerative (eg
legumes, natural enemies) and non-renewable (eg hybrid seeds,
machinery);
4. Non-renewable or fossil-fuel derived inputs (eg fertilizers,
pesticides, antibiotics);
5. Finance – credit, remittances, income from sales and grants.
Availability and access to these five inputs is shaped by a wide range of
contextual factors (on the far left). These include unchanging ones (at
least over the short-term), such as climate, agro-ecology, soils, culture;
and dynamic economic, social, political and legal factors shaped by
external institutions and policies.
These contextual factors are an important entry point for shaping and
influencing agricultural systems (such as national policies, markets,
trade).
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
AN ASSETS-BASED MODEL
FOR SUSTAINABILITY
The Modernisation of Agriculture
The process of agricultural modernisation during the 20th century has produced
three distinct types of agriculture: industrialised, `Green Revolution’, and all that
remains - the pre-modern, `traditional’ or `unimproved'. The first two types have
been able to respond to modern technological packages, producing highly
productive systems of agriculture.
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
AN ASSETS-BASED MODEL
FOR SUSTAINABILITY
Sustainable Agriculture
A more sustainable farming seeks to make the best use of nature’s goods and
services whilst not damaging the environment. It does this by integrating natural
processes such as nutrient cycling, nitrogen fixation, soil regeneration and natural
enemies of pests into food production processes. It also minimises the use of nonrenewable inputs (pesticides and fertilizers) that damage the environment or harm
the health of farmers and consumers. It makes better use of the knowledge and
skills of farmers, so improving their self-reliance. And it seeks to make
productive use of social capital - people’s capacities to work together to solve
common management problems, such as pest, watershed, irrigation, forest and
credit management
Diunduh dari: http://www.essex.ac.uk/ces/research/susag/WhatissusagBa1.shtm …… 23/12/2012
Sustainable Agriculture
Increase
High-yield
polyculture
Decrease
Soil erosion
Soil salinization
Organic fertilizers
Aquifer depletion
Biological pest
control
Integrated pest
management
Irrigation efficiency
Perennial crops
Overgrazing
Overfishing
Loss of
biodiversity
Loss of prime
cropland
Crop rotation
Food waste
Use of more waterefficient crops
Subsidies for unsustainable
farming and fishing
Soil conservation
Population growth
Subsidies for more
sustainable farming
and
fishing
Poverty
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
Apa yang dapat dilakukan ?
Sustainable Agriculture
Pangan minim limbah
Mengurangi konsumsi daging
Feed pets balanced grain foods instead of
meat
Use organic farming to grow some of your
food
Membeli bahan pangan organik
Komposting limbah makanan
Diunduh dari: www.instruction.greenriver.edu/.../BW_EssentialCh06Lecture.ppt …… 20/12/2012
DEGRADASI LAHAN
DEGRADASI
LAHAN
PERTANIAN
DEGRADASI LAHAN
Degradasi lahan merupakan proses menurunnya
kualitas dan kuantitas suatu lahan yang meliputi aspek
fisika tanah, kimia tanah, biologi tanah, pada suatu
bidang lahan tertentu.
Dalam praktek budidaya pertanian sendiri sering akan menimbulkan
dampak pada degradasi lahan. Dua faktor penting dalam usaha pertanian
yang potensial menimbulkan dampak pada sumberdaya lahan, yaitu
tanaman dan manusia (sosio kultural) yang menjalankan pertanian.
Faktor AKTIVITAS manusia dapat memberikan dampak positip atau
negatip pada suatu lahan, tergantung pada aktivitas pengelolaan
pertanian yang dilakukan.
Apabila dalam menjalankan pertaniannya benar maka akan berdampak
positip, namun apabila cara menjalankan pertaniannya salah maka akan
berdampak negatif.
Kegiatan budidaya pertanian yang menimbulkan dampak antara lain
meliputi kegiatan pengolahan tanah, penggunaan sarana produksi yang
tidak ramah lingkungan (pupuk dan insektisida) serta sistem budidaya
termasuk pola tanam yang mereka gunakan.
Tiga faktor penyebab degradasi tanah akibat campur tangan manusia
secara langsung, yaitu : pertanian intensif, pembukaan tambang,
deforestasi. Faktor-faktor tersebut di Indonesia pada umumnya terjadi
secara simultan, berikut adalah pembahasan dari ketiga degradasi pada
tiga bidang.
Diunduh dari: http://andikks.blogspot.com/2012/06/degradasi-lahan_05.html……… 24/12/2012
DEGRADASI LAHAN
DEGRADASI LAHAN PERTANIAN
Aktivitas budidaya pertanian dapat menyebabkan
dampak negatif pada sumberdaya lahan.
Erosi dan pencemaran tanah terjadi akibat budi daya pertanian yang
melampaui daya dukung tanah. Penggunaan bahan-bahan agrokimia
yang berlebihan dapat mencemari lingkungan dan mengganggu
kelestarian kualitas tanah. Cara-cara budi daya pertanian yang tidak
mengindahkan kaidahkaidah konservasi lahan menyebabkan kualitas
lahan menurun sejalan dengan hilangnya lapisan tanah subur akibat erosi
dan pencucian hara.
Kegiatan pembangunan yang berpotensi menimbulkan dampak terhadap
degradasi lahan antara lain kegiatan deforesterisasi, industri,
pertambangan, perumahan, dan kegiatan pertanian sendiri. Apabila
kegiatan tersebut tidak dikelola dengan baik, maka akan mengakibatkan
terjadinya degradasi lahan pertanian yang mengancam keberlanjutan
uasaha tani dan ketahanan pangan. Oleh karenanya, dalam kegiatan
pembangunan hendaknya harus dipikirkan keberlanjutannya dimasa
mendatang (sustainabilitas).
Praktek budidaya pertanian sering mengakibatkan degradasi lahan.
Kegiatan budidaya pertanian yang menimbulkan dampak negatif antara
lain meliputi kegiatan pengolahan tanah, penggunaan sarana produksi
yang tidak ramah lingkungan (pupuk dan pestisida), serta sistem
budidaya termasuk pola tanam yang tidak tepat.
Diunduh dari: http://andikks.blogspot.com/2012/06/degradasi-lahan_05.html……… 24/12/2012
DEGRADASI LAHAN
Barrow (1991) merinci faktor-faktor utama penyebab degradasi
lahan :
1)
Bahaya alami
2)
Perubahan jumlah populasi manusia
3)
Marjinalisasi tanah
4)
Kemiskinan
5)
Status kepemilikan tanah
6)
Ketidakstabilan politik dan masalah administrasi
7)
Kondisi sosial ekonomi
8)
Masalah kesehatan
9)
Praktek pertanian yang tidak tepat, dan
10) Aktifitas pertambangan dan industri.
Degradasi lahan ada tiga aspek, yaitu : aspek fisik. kimia dan
biologi.
1. Degradasi fisik terdiri dari pemadatan, pengerakan,
ketidakseimbangan air, terhalangnya aerasi, aliran permukaan,
dan erosi.
2. Degradasi kimiawi terdiri dari asidifikasi, pengurasan unsur
hara, pencucian, ketidakseimbangan unsur hara dan
keracunan, salinisasi, dan alkalinisasi.
3. Degradasi biologis meliputi penurunan karbon organik tanah,
penurunan keanekaragaman hayati tanah, dan penurunan
karbon biomas.
Diunduh dari: http://pinterdw.blogspot.com/2012/06/penyebab-degradasi-lahan.html………
24/12/2012
DEGRADASI LAHAN
TYPES OF SOIL DEGRADATION
Soil degradation is any type of problem that removes soil in an
area or makes high-quality soil become poor. Careless
agricultural practices, pollution and deforestation cause lots of
soil degradation in the world. Several types of soil degradation
exist and are a threat to natural forests and planted crops.
Read more: Types of Soil Degradation | eHow.com
http://www.ehow.com/list_6523052_types-soil-degradation.html#ixzz2FuczEfSE
SOIL EROSION
NUTRIENT LOSS
Erosion occurs when the
topsoil that many plants need to
grow gets blown or washed
away.
While some erosion is natural,
the humans often remove plants
that cover soil and, therefore,
speed up erosion.
Since topsoil takes so long to
build back up through natural
processes, erosion damage is
almost irreversible.
Nutrient loss often occurs in
conjunction with salinization.
The nutrient loss occurs through a
variety of mechanisms, including
leaching, erosion, runoff, crop uptake
and denitrification.
The crops uptake too many soil
nutrients that farmers do not always
replace.
Deforestation and careless
agricultural processes lead to soil
degradation in the form of nutrient
loss.
After soil becomes nutrient-poor,
crops and naturally occurring plants
have a hard time growing in the area.
Diunduh dari: http://www.ehow.com/list_6523052_types-soil-degradation.html……… 24/12/2012
DEGRADASI LAHAN
SOIL DEGRADATION
When plants (trees & shrubs) are cleared from a site, soil is exposed to
sunlight and the eroding effects of wind and water. Soil aeration is
increased and the rate of weathering increases.
Apart from erosion, the proportion of organic matter in the soil
gradually decreases, through the action of microbes in the soil which use
it as a source of energy - unless the new land use provides some
replacement.
TYPES OF SOIL DEGRADATION
A number of major soil related problems occur in Australia these
include:
1. Kehilangan kesuburan tanah
2. Erosi Tanah
3. Salinitas
4. Pemadatan Tanah
5. Pengasaman Tanah
6. Pencemaran tanah oleh bahan kimia
berbahaya.
Diunduh dari: http://www.acsgarden.com/articles/other-gardening/soil-degradation.aspx………
24/12/2012
HILANGNYA KESUBURAN TANAH
KESUBURAN TANAH
Land use, human nutrition and the carbon cycle form an intricate
set of relationships. Healthy plants use carbon dioxide, give off
oxygen and increase soil organic matter (OM), thereby enhancing
soil fertility. Practices that increase organic matter can increase
soil fertility while decreasing greenhouse gas emissions.
Diunduh dari: http://www.fertilizer101.org/science/?seq=7 ……… 24/12/2012
HILANGNYA KESUBURAN TANAH
BASIC PLANT NUTRIENT CYCLE
The basic nutrient cycle usually describes the outstanding role of soil
organic matter. Cycling of many plant nutrients, especially N, P, S, and
micronutrients, are similar to the Carbon Cycle. Plant residues, grain
green manure, farmyard manure and other substances are returned to the
soil. This organic matter pool of carbon compounds serve as food for
bacteria, fungi, and other decomposers. As organic matter is
decomposed to simpler compounds, plant nutrients are released in
available forms for root uptake and the cycle begins again. Plantavailable macronutrients such as N, P, K, Ca, Mg, S and micronutrients
are also released when soil minerals dissolve.
Diunduh dari:
http://www.tankonyvtar.hu/hu/tartalom/tamop425/0010_1A_Book_angol_02_tapanyaggazdalkodas
/ch05.html ……… 24/12/2012
HILANGNYA KESUBURAN TANAH
POTENTIAL FOR N LOSSES
Greater losses occur when soils enter the spring season with recharged subsoil
moisture, when more N is in the nitrate form, and when soils are warm. Deciding
if losses are substantial enough to warrant supplemental N application must
therefore take into consideration the following factors: (1) amount of nitrate
present, which is affected by time of N application, form of N applied, rate
applied, and use of a nitrification inhibitor; (2) when and the length of time soils
are saturated; (3) subsoil recharge, leaching rate, and drainage--water amount
moved through the soil; and (4) loss of crop yield potential from water damage.
Diunduh dari: http://www.ipm.iastate.edu/ipm/icm/2007/5-14/nitrogenloss.html ……… 24/12/2012
HILANGNYA KESUBURAN TANAH
Integrated plant nutrient components in the Nepalese
farming system
An integrated nutrient model developed quite some time ago as shown
below was a successful programme but it has not been popularized or
has not been well adopted by large number of farmers. There should be a
follow up study to see the impact on soil fertility management and to
look on how best we can promote to wider areas.
Diunduh dari: http://www.fao.org/docrep/010/ag120e/AG120E10.htm ……… 24/12/2012
HILANGNYA KESUBURAN TANAH
KEHILANGAN HARA DARI TANAH
There are several losses from soil nutrient pools caused by either unfavorable soil
conditions or improper use of fertilizers. The main characteristics of these losses
are the following:
Losses will result in a decrease in the amounts of plant available soil nutrients
Nutrient losses occur by:
1. Releases from the soil - leaving the soil-plant system
2. Transformation of soil nutrients into non-available forms (i.e. precipitation,
chemical reactions resulting insoluble forms etc.) = „internal losses”
PELEPASAN HARA DARI TANAH
1.
2.
3.
4.
5.
Crop removal by yields
Erosion losses – nutrients in soil particles removed from soil by water
Runoff – loss of dissolved nutrients moving across the soil profile
Leaching– moving dissolved nutrient forms downward into the groundwater
Gaseous losses to the atmosphere by volatilization and denitrification.
Under various cropping systems, both internal and external losses of nutrients
from soils may be rather diverse.
„INTERNAL LOSSES”
1. Transformation of soil nutrients into non-available forms (i.e.
precipitation, chemical reactions resulting insoluble forms etc.)
2. Transformation into insoluble forms – typical for P Strong fixation in
interlayer sites of clay minerals – ammonium and K+ ions
3. These forms do not leave the soil = therefore referred as „internal losses”
http://www.tankonyvtar.hu/hu/tartalom/tamop425/0010_1A_Book_angol_02_tapanyaggazdalkodas
/ch05.html
HILANGNYA KESUBURAN TANAH
What happens if we lose soil fertility, we will eventually cease to exist
as soil is alive and we require soil for almost all of the food that we
grow today around the world.
The healthy soil contains:
1. It has sufficient concentrations of nitrogen, phosphorous, and potash
(potassium) to support plant life.
2. It also has sufficient levels of the trace minerals needed for plant
nutrition, including boron, chlorine, cobalt, copper, iron, manganese,
magnesium, molybdenum, sulfur, and zinc.
Diunduh dari: http://www.examiner.com/article/permaculture-from-a-to-z-fertility-of-the-soil ………
24/12/2012
EROSI TANAH
Soil erosion is a natural process characterized by the transport or
displacement of particles (sediment) that are detached by rainfall,
flowing water, or wind. Soil erosion can be caused by the improper use
of lands for cultivation or grazing and by deforestation.
The types of soil erosion associated with agricultural activities are :
1. Splash erosion, which occurs when rain hits exposed soils.
2. Sheet and rill erosion, which mainly moves soil particles from the surface or
plough layer of the soil. Surface sediments typically contain higher pollution
potential due to richer nutrient content, the presence of chemicals from past
fertilizer and pesticide applications, and natural biological activities.
3. Rill and gully erosion, severe erosion in which trenches are cut to a depth
greater than 1 foot. Generally, trenches too deep to be crossed by farm
equipment are considered gullies (USEPA, 1994).
4. Stream and channel erosion, which occurs due to increased rates and
volumes of runoff from agricultural land uses flowing through a stream or
channel.
Diunduh dari: http://www.cep.unep.org/pubs/Techreports/tr41en/section3.html……… 24/12/2012
EROSI TANAH
Effect on soil erosion
Slope angle and length affects runoff generated when rain falls to the surface.
Examine the diagram below showing the relationship between hill slope position,
runoff, and erosion.
The amount of water on a particular hill slope segment is dependent on what falls
from precipitation and what runs into it from an upslope hill slope segment. The
hill slope has been divided into several segments and the amount of precipitation
falling on each segment is the same. As water runs down slope, the water that has
accumulated in segment A runs off adding to what falls into segment B by
precipitation. The water in B runs into C, and C into D, and so on. The amount of
water increases in the down slope direction as water is contributed of water from
upslope segments. The velocity of the water increases as well as it moves towards
the base of the slope. As a result, the amount and velocity of water, and hence
rate of erosion increases as you near the base of the slope.
Diunduh dari:
http://www.earthonlinemedia.com/ebooks/tpe_3e/soil_systems/soil__development_soil_forming_f
actors.html……… 24/12/2012
EROSI TANAH
PENGENDALIAN EROSI
Soil erosion occurs naturally when rain falls. Runoff flows to the lowest
point of the landscape. The velocity depends on the characteristics of the
soils, the slope of the land and the vegetative cover.
Erosion can be a serious environmental problem when the land is
disturbed by development, agriculture, or forestry. Surfaces like roads,
roofs, driveways and hard-packed soils will not absorb water, and the
runoff increases. Expanses of pavement like parking lots reduce the
chances for ground water recharge. Exposed soils are lost and the land
becomes less productive. Fertilizers and pesticides that may have been
applied wash away, too, causing water quality problems for people
living downstream.
Diunduh dari: http://www.ecy.wa.gov/programs/wq/wqguide/erode.html……… 24/12/2012
EROSI TANAH
EROSION EFFECTS ON SOIL WATER STORAGE, PLANT
WATER UPTAKE, AND CORN GROWTH
B. J. Andraski and B. Lowery
SSSAJ. 1992. Vol. 56 No. 6, p. 1911-1919
Levels of past erosion were based on depth to red clay (2Bt horizon): slight, 0.95
m; moderate, 0.74 m; and severe, 0.45 m. The total quantity of plant-extractable
water that could be stored in the upper 1 m of slightly eroded soil (181 mm) was
7% more than that for moderately eroded soil (169 mm) and 14% more than that
for severely eroded soil (159 mm).
For all erosion levels, water retained in the 0.5- to 1.0-m soil depth was utilized
by corn.
Erosion level had no negative effect on early-season plant growth. As plantextractable water decreased to <55 to 60% of total, evapotranspiration (ET) and
vegetative-growth rates decreased as erosion level increased. The greatest
differences in ET rates among erosion levels were observed during a 35-d period
in the drought year of 1988 when rates averaged 3.7 mm d−1 for slight erosion,
2.6 mm d−1 for moderate erosion, and 2.2 mm d−1 for severe erosion.
For the 3 yr in which plant water stress was observed, maximum plant heights for
the slight erosion level averaged 7% more than those for moderate erosion and
13% more than those for severe erosion.
Although the soil's capacity to store and supply water decreased as erosion
increased, the observed effects of erosion level on grain and stover yields, grainyield components, and harvest populations typically were not significant.
Diunduh dari: ……… 24/12/2012
EROSI TANAH
. CROPPING AND TILLAGE SYSTEMS EFFECTS ON SOIL EROSION
UNDER CLIMATE CHANGE IN OKLAHOMA
X.-C.(John) Zhang
SSSAJ. 2012. Vol. 76 No. 5, p. 1789-1797
Soil erosion under future climate change is very likely to increase because of
increases in occurrence of heavy storms.
The objective of this study is to quantify the effects of common cropping and
tillage systems on soil erosion and surface runoff during 2010 to 2039 in central
Oklahoma.
A combination of 18 cropping and tillage systems is evaluated using the Water
Erosion Prediction Project (WEPP) model for 12 climate change scenarios
projected by four global climate models (GCMs) under three emissions scenarios.
Tillage systems include conventional, reduced, delayedno tillage. Cropping
systems include continuous monocultures of winter wheat, soybean,
sorghumcotton and double crops of wheat and soybeans.
Compared with the present climate, overall t tests show that the future mean
precipitation will decrease by some 6% (>98.5% probability), daily precipitation
variance increase by 12% (>99%), and mean temperature increase by 1.36°C
(>99%).
Despite the projected precipitation declines, the overall averaged runoff and soil
loss will increase by 19.5 and 43.5% because of increased occurrence of large
storms.
Soil erosion is positively related to the degree of tillage disturbances in all
cropping systems. Compared with the conventional till, reduced, delayedno
tillage substantially reduce soil erosion, showing that adoption of conservation
tillage will be effective in controlling soil erosion in the next 30 yr.
Cropping systems decrease runoff and soil loss from continuous cotton
to soybean to sorghum to wheat in all tillage systems under climate
change, indicating a preference of winter wheat for controlling runoff
and soil loss in the region.
Diunduh dari: https://www.soils.org/publications/sssaj/abstracts/76/5/1789……… 24/12/2012
DEGRADASI LAHAN
. SOIL EROSION EFFECTS ON CORN YIELDS ASSESSED BY
POTENTIAL YIELD INDEX MODEL
E. M. Craft , R. M. Cruse and G. A. Miller
SSSAJ. 1992. Vol. 56 No. 3, p. 878-883
Soil erosion alters crop production via alteration of the soil chemical and physical
environment.
The objectives of this study were to: (i) develop a Potential Yield Index (PYI)
model to index soil productivity based on simulated root growth, soil properties,
and potential nutrient and water uptake of corn (Zea mays L.) through a growing
season, (ii) utilize the PYI to estimate erosion effects on soil productivity by
simulating the removal of 15 and 30 cm of soil, and (iii) simulate the impact of
fertilizer additions to the eroded soil on the PYI.
The PYI model independently estimates P, K, and water (W) uptake by corn.
From these estimates, three separate yield indexes (PYIP, PYIK, and PYIW) are
calculated. The lowest yield index is identified as the PYI for a given soil.
The predicted PYIs for 45 soils in Iowa compared well to the 1984 10-yr average
corn yield (R2 = 0.83) and corn suitability rating (R2 = 0.73) for each soil.
Changes in the PYI were predicted for 15 and 30 cm of simulated erosion. After
15-cm soil loss, the PYI for all soils decreased, with all but three soils remaining
within 15% of the uneroded PYI. The PYI decreased further after 30-cm soil loss,
with only 12 soils remaining within 15% of the uneroded PYI.
Fertilizer additions to the plow layer of the eroded soils were then simulated. The
PYI returned to within 5% of the uneroded PYI for 38 soils with 15-cm soil loss
and for 27 soils with 30-cm soil loss.
The PYI indicated that the soil factor that most limited plant yield changed with
the soil, amount of soil loss, and plow-layer soil fertility status.
Diunduh dari: https://www.agronomy.org/publications/sssaj/abstracts/56/3/SS0560030878 ………
24/12/2012
EROSI TANAH
PERKIRAAN TINGKAT EROSI TANAH DI SUB DAS
BESAI, LAMPUNG BARAT
Asep Mulyono
Jurnal Riset Geologi dan Pertambangan, Vol 19, No 1 (2009)
Tingkat erosi tanah di sub DAS Besai telah diperkirakan sebagai dasar kuantitatif
dalam merekomendasikan upaya mempertahankan, memulihkan, meningkatkan
kesuburan dan fungsi tanah sebagai pengatur tata air.
Perkiraan tingkat erosi tanah dilakukan dengan metoda RUSLE yang dilakukan
secara spasial dengan menggunakan perangkat lunak Sistem informasi geografis
(SIG). Erosivitas, erodibilitas, kemiringan lereng, panjang lereng, sistem
penanaman dan faktor konservasi merupakan 6 parameter data yang dimasukan
dalam pendekatan RUSLE.
Tingkat konversi lahan, khususnya hutan lindung menjadi lahan pertanian dan
perkebunan, sangat pesat terjadi di Sub DAS Besai. Sub DAS Besai yang terletak
di wilayah Kecamatan Sumber Jaya, Kabupaten Lampung Barat merupakan salah
satu bagian hulu DAS Tulang Bawang Lampung. Selama rentang waktu 30 tahun
(1970 – 2000) telah terjadi penurunan tutupan lahan hutan sebesar 48 %.
Perubahan terjadi sebagai akibat tingginya aktivitas masyarakat dalam usaha tani
kopi monokultur dan tanaman semusim.
Hasil studi menunjukkan 23.62% wilayah penelitian dikategorikan dalam tingkat
erosi tanah yang normal, tingkat ringan seluas 42.98%, tingkat moderat seluas
14.57%, tingkat berat seluas 15.38% dan sangat berat seluas 3.45%. Seluas 45%
wilayah dengan tutupan lahan perkebunan kopi mengalami tingkat erosi dalam
kategori ringan sampai sangat berat pada semua rentang kelerengan dan jenis
tanah.
Perkebunan kopi sistem monokultur mengakibatkan lapisan tanah sangat mudah
tergerus oleh adanya aliran permukaan dikarenakan tidak adanya tutupan tanah di
bawah kanopi tanaman kopi tersebut.
Diunduh dari: http://www.geotek.lipi.go.id/riset/index.php/jurnal/article/view/28 ……… 25/12/2012
EROSI TANAH
EVALUASI SEDIMENT YIELD DI DAERAH ALIRAN SUNGAI
CISANGGARUNG BAGIAN HULU DALAM MEMPERKIRAKAN
SISA
UMUR WADUK DARMA
Muhammad Nursa’ban.
Hasil Penelitian Dosen muda tahun 2006, Dosen Jurusan Pendidikan Geografi
UNY.
Hasil penelitian menunjukan bahwa tingkat erosi tanah permukaan yaitu
31.558,74 ton/tahun, atau rata-rata 573,795 ton/ha/tahun, erosi total
39.448,43 ton/tahun atau 717,244 ton/ha/tahun dan erosi tanah yang
diperbolehkan yaitu 686,033 ton/tahun atau sekitar 12,473 ton/ha/tahun.
Data-data tersebut menunjukkan bahwa tingkat erosi permukaan
maupun erosi total berlangsung cukup tinggi dibandingkan dengan besar
erosi yang diperbolehkan.
Sediment Yield tahunan di Waduk Darma yaitu 32.996,419 ton/tahun
atau 14.873,660 m3.
Waduk Darma tidak dapat berfungsi lagi yaitu pada saat mencapai umur
± 84,25 tahun. Tahun 2006 Waduk Darma telah beroperasi selama 36
tahun sehingga sisa umur Waduk Darma sampai terpenuhinya
tampungan mati oleh sedimen yaitu ± 48,25 tahun atau tampungan mati
akan terisi penuh yaitu pada tahun ± 2054.
Diunduh dari: staff.uny.ac.id/..../artikel_sediment%20yield_sainte... ……… 25/12/2012
EROSI TANAH
PREDIKSI BEBAN NUTRIEN DAN SEDIMEN DAS
SUMPUR DANAU SINGKARAK MENGGUNAKAN
MODEL AGNPS
Tuahta Tarigan dan Iwan Ridwansyah.
LIMNOTEK, 2005, Vol, XII, No, 2, p. 34-40
AGNPS merupakan sebuah program model untuk mensimulasikan
kualitas air dan sedimen dari suatu catchment yang didominasi lahan
pertanian.
Model ini dikombinasikan dengan perangkat program GIS untuk
memperkirakan kemungkinan penambahan fospor ke DAS Sumpur,
Paket Program GIS (ArcView 3.1, 3D Analyst, Spatial Analyst)
digunakan untuk mempersiapkan input data model dan proses
penempatan dari hasil simulasi.
Perkiraan dari loading nutrient dari Sungai Sumpur yang masuk ke
Danau Singkarak memperlihatkan nilai 1.875 ton tahun-1 sedimen, 52,5
ton tahun-1 Total N dan 37,5 ton tahun-1 Total P dan 195 ton tahun-1
COD.
Diunduh dari: www.limnologi.lipi.go.id/.../makalah.php?... ……… 25/12/2012
EROSI TANAH
MODIFIKASI FAKTOR C-USLE DALAM MODEL ANSWERS
UNTUK MEMPREDIKSI EROSI DI DAERAH TROPIKA BASAH
(STUDI KASUS: DAS NOPU HULU, SULAWESI TENGAH)
Y. Hidayat, N. Sinukaban, H. Pawitan, dan K. Murtilaksono
Jurnal Tanah dan Iklim. Vol.26 No.4 Th. 2004
Penelitian dilakukan untuk : a) mendefinisikan nilai faktor pengelolaan tanaman
sebagai parameter input model ANSWERS, b) membangun model ANSWERS
dalam PCRaster untuk mensimulasikan perubahan penggunaan lahan dan
penerapan teknik konservasi tanah dan air, dan c) mengkaji dampak konversi
hutan terhadap aliran permukaan, erosi dan kehilangan hara.
Aliran permukaan dan erosi harian diukur pada lahan hutan primer, hutan
sekunder, lahan terbuka, jagung, kakao muda, kakao sedang, kakao dewasa, dan
tumpang sari antara kakao muda dengan jagung, pisang dan ketela pohon. Pada
outlet daerah aliran sungai debit aliran ditentukan melalui pengukuran tinggi
muka air dan kecepatan aliran, sedangkan volume sedimen diukur
melalui pengambilan sampel sedimen.
Penggunaan faktor pengelolaan tanaman parsial pada model ANSWERS dan
ANSWERS-PCRaster memberikan hasil prediksi erosi lebih baik dibandingkan
dengan menggunakan faktor pengelolaan tanaman USLE (faktor C-USLE),
khususnya pada curah hujan tinggi.
Penghutanan kembali lahan berlereng curam (> 45%) yang diikuti oleh
penerapan teras gulud pada lahan pertanian merupakan tindakan pengelolaan
terbaik dalam mengendalikan aliran permukaan dan erosi untuk menjamin
pertanian berkelanjutan dan keberlanjutan fungsi daerah aliran sungai.
Konversi hutan ke lahan pertanian telah meningkatkan aliran
permukaan, erosi dan kehilangan hara.
Diunduh dari: http://digilib.litbang.deptan.go.id/repository/repository/artikel/26/4/2004/0/1472
……… 25/12/2012
EROSI TANAH
. DEGRADASI TANAH
DI LAHAN KERING WILAYAH
BARITO KALIMANTAN TENGAH
M. A. Firmansyah, R.Y. Galingging dan Suparman (Balai Pengkajian Teknologi Pertanian
Kalimantan Tengah)
A. Krismawati (Balai Pengkajian Teknologi Pertanian Jawa Timur)
Degradasi tanah di Indonesia umumnya terjadi di lahan kering yang dipicu
oleh erosi tanah dan salah kelola tanah.
Tujuan tulisan ini untuk menunjukkan besarnya erosi yang terjadi pada berbagai
sistem usahatani eksisting antara lain: padi gogo, jagung, kacang tanah, ubi kayu,
dan karet rakyat. Lokasi penelitian dilaksanakan di Lagan (kemiringan 6%) di
Kabupaten Barito Timur dan Jingah (kemiringan 16%) di Kabupaten Barito
Utara. Hasil analisis menunjukkan bahwa Jingah mengalami erosi lebih besar
dibandingkan Lagan, hal ini disebabkan oleh tingginya faktor erosivitas hujan,
kemiringan lereng, dan teknik konservasi tanah yang buruk.
Erosi potensial di Jingah mencapai 1.497 t/ha/th sedangkan di Lagan mencapai
431 t/ha/th. Kondisi tersebut menyebabkan kedua lokasi tergolong memiliki
Indeks Bahaya Erosi (IBE) ekstrem, dengan nilai 47,4 untuk Jingah dan 11,2
untuk Lagan. Erosi aktual pada sistem usahatani di Jingah tertinggi pada karet
rakyat mencapai 954 t/ha/th (91 mm/th), begitu juga di Lagan mencapai 183
t/ha/th (14 mm/th).
Erosi aktual terendah pada sistem usahatani kacang tanah, di Jingah mencapai
505 t/ha/t (48 mm/th) dan di Lagan mencapai 97 t/ha/th (8 mm/th).
Erosi yang terjadi dikedua lokasi jauh melampaui Eosi yang piperbolehkan
(EDP) yang hanya mencapai 3 mm/th. Erosi yang terjadi berdampak terhadap
kehilangan produktivitas cukup besar di Jingah yaitu 21% pada karet rakyat, dan
terendah sebesar 2% di Lagan untuk padi gogo dan kacang tanah. Guna
mencegah erosi yang besar, maka dikedua lokasi perlu dilakukan perbaikan
terutama pada pengelolaan teknik konservasi tanah.
Diunduh dari: jatim.litbang.deptan.go.id/.../index.php?... ……… 25/12/2012
EROSI TANAH
EROSI PADA BERBAGAI PENGGUNAAN LAHAN DI
DAS CITARUM
S. Sutono, S. H. Tala’ohu, O. Sopandi, dan F. Agus
Balai Penelitian Tanah, Bogor
Prosiding Seminar Nasional Multifungsi dan Konversi Lahan Pertanian
Lahan sawah mempunyai banyak fungsi, termasuk diantaranya fungsi produksi,
dan lingkungan.
Penelitian bertujuan untuk menduga besarnya erosi pada lahan pertanian di
daerah aliran sungai Citarum serta menduga besarnya biaya pengganti
(replacement cost method/RCM) pengamanan erosi jika luas lahan sawah
berkurang. Pendugaan erosi menggunakan metode universal soil loss equation
(USLE).
Hasil penelitian menunjukkan bahwa erosi pada lahan sawah lebih rendah
dibandingkan dengan tegalan, kebun campuran, kebun teh, kebun karet, dan
hampir sama dengan tingkat erosi hutan.
Erosi paling tinggi terjadi pada lahan tegalan. Lahan sawah
erosinya berkisar antara 0,33 t/ha/tahun dan 1,45 t/ha/tahun.
Seluruh replacement cost untuk Citarum pada tahun 2000 sebesar Rp. 18,6
milyar. Jumlah ini adalah perkiraan investasi yang harus dikorbankan untuk
penanganan sedimen apabila sawah yang ada sekarang di Citarum mengalami
konversi.
Diunduh dari: balittanah.litbang.deptan.go.id/.../sutonocitarum08... ……… 25/12/2012
EROSI TANAH
NERACA AIR, EROSI TANAH DAN TRANSPOR LATERAL
HARA NPK PADA SISTEM PERSAWAHAN DI SUB DAS KALI
BABON, SEMARANG
Muhamad Kundarto 1, F. Agus 2, Azwar Maas 3, dan B. H. Sunarminto 3
Jurusan Ilmu Tanah UPN “Veteran” Yogyakarta, 2 Balai Penelitian Tanah Bogor, 3 Jurusan
Tanah UGM Yogyakarta
Prosiding Seminar Nasional Air, Erosi Tanah Konversi Lahan Pertanian
Penelitian ini bertujuan untuk mengetahui neraca air, erosi tanah, dan transpor lateral hara
NPK pada sistem persawahan. Penelitian dilaksanakan selama dua musim tanam dari
Oktober 2001 sampai Juni 2002 di sub daerah aliran sungai Kali Babon, Semarang.
Hasil penelitian pada musim ke dua menunjukkan total input air sebesar 4031,81 mm yang
berasal dari air irigasi 3530,41 mm dan air hujan 501,40 mm. Total output air sebesar
3035,13 mm terdiri atas air drainase 153,22 mm, infiltrasi/perkolasi 94,74 mm,
evapotranspirasi 85,87 mm, dan genangan 2701,30 mm. Selisih antara input dan output air
sejumlah 996,68 mm diduga merupakan total air yang menyusup secara lateral melalui
pematang (seepage dan lubang tikus/ketam) dan air yang tersimpan pada lapisan olah.
Total tanah yang tererosi dari daerah atas (upland) dan masuk ke sawah pada musim sebesar
864,1 kg dan yang keluar (lewat outlet petak no. 18) sebesar 347,5 kg. Sehingga tanah yang
mengendap di petak sawah sebesar 516,6 kg (2,05 t/ha). Pada musim kedua, total tanah
masuk ke sawah sebesar 1567,1 kg dan yang keluar dari sawah (lewat outlet petak 18)
sebesar 209,6 kg. Sehingga tanah yang mengendap di petak sawah sebesar 1357,5 kg (5,40
t/ha). Jumlah tanah yang mengendap pada musim kedua 2,5 kali lebih besar dibanding
musim pertama.
Total hara N, P, dan K dalam bentuk NH4+, NO3-PO43-, dan K+ yang
terkandung dalam air irigasi dan masuk ke sawah masing-masing sebesar:
98; 478; 29; dan 237 g/ha/musim. Sedangkan total hara NH4+, NO3-,
PO43-, dan K+ yang terkandung dalam air drainase dan keluar dari sawah
masing-masing sebesar: 10; 161; 413; dan 35 g/ha/musim.
Penambahan hara NH4+, NO3-, dan K+ pada sawah masing-masing
sebesar: 88; 317; dan 203 g/ha/musim. Hara PO43- mengalami
pengurangan sebesar 384 g/ha/musim.
Diunduh dari: balittanah.litbang.deptan.go.id/.../kundarto17.pdf……… 25/12/2012
EROSI TANAH
. APLIKASI SISTEM INFORMASI GEOGRAFIS (SIG) UNTUK
IDENTIFIKASI LAHAN KRITIS dan ARAHAN FUNGSI LAHAN
DAERAH ALIRAN SUNGAI SAMPEAN
Runi Asmaranto, Ery Suhartanto dan Bias Angga Permana
Jurusan Pengairan Fakultas Teknik Universitas Brawijaya
DAS Sampean merupakan daerah aliran sungai yang kondisi topografinya ratarata sangat curam. Kondisi tata guna lahan yang sebagian besar sawah irigasi ini
cukup memungkinkan terjadinya erosi. Apalagi tataguna lahan lainnya berupa
ladang, semak dan sawah tadah hujan yang tanamannya merupakan tanaman
berkedalaman akar rendah dan berperan besar dalam proses penyebab terjadinya
kerusakan tanah, mempercepat laju erosi dan meningkatkan volume limpasan
permukaan.
Metode yang digunakan dalam menghitung besarnya laju erosi adalah metode
MUSLE dimana metode tersebut menggunakan pendekatan dari faktor limpasan
permukaan. Pengolahan data-datanya menggunakan Sistem Informasi Geografis
(SIG) karena memudahkan dalam penganalisaan dan pengelompokan data.
Dari hasil analisa diperoleh debit limpasan permukaan yang terjadi
sebesar 247,967 m3/ dt. Total Erosivitas Limpasan Permukaan yang
terjadi adalah 48.129,73 m2/jam, hal ini memicu terjadinya laju
erosi yang rata-ratanya mencapai 43.939,94 ton/ha/thn, atau identik
dengan kehilangan tanah sebesar : 258,470 cm/thn.
Besarnya laju erosi pada DAS Sampean ini mengakibatkan tingkat bahaya erosi
sebesar 95,54% dari luas wilayahnya termasuk sangat berat. Sedangkan untuk
tingkat bahaya erosi lainnya yaitu, berat : 2,72%, sedang : 1,02%, ringan : 0,72%.
Analisa kemampuan lahan didominasi kemampuan kelas VII (75,39%), yang
merupakan daerah Pengembalaan Terbatas. Sedangkan ARLKT di DAS Sampean
terdiri dari 3 (tiga) kawasan, yaitu Kawasan lindung (10,53%), Kawasan
Penyangga (52,23%), Kawasan Budidaya Tanaman Tahunan (37,23%).
Diunduh dari: jurnalpengairan.ub.ac.id/index.php/jtp/.../103 ……… 25/12/2012
EROSI TANAH
TINGKAT EROSI PERMUKAAN PADA LAHAN PERTANIAN
JAGUNG DI DAS ALO-POHU PROVINSI GORONTALO
Fitryane Lihawa
Pusat Studi Lingkungan Universitas Negeri Gorontalo
PROSIDING KONFERENSI DAN SEMINAR NASIONAL PUSAT STUDI LINGKUNGAN HIDUP
INDONESIA KE 21. 13 – 15 SEPTEMBER 2012 DI MATARAM
Fenomena pemanfaatan lahan untuk pertanian semakin meningkat, terlebih lagi setelah
dicanangkannya Program Agropolitan di Provinsi Gorontalo. Pada Tahun 2003 luas pertanian
lahan kering adalah 1.398 ha dan Tahun 2005 meningkat hingga 30.338 ha, dan pada Tahun
2010 mencapai 150.020 ha (Citra Landsat Tahun 2003, Tahun 2005 dan BPS Tahun 2011).
Perubahan penggunaan lahan tersebut dapat mengakibatkan kerusakan DAS yang berdampak
pada rusaknya fungsi hidroorologis DAS. Salah satu DAS penyumbang sedimen terbesar ke
Danau Limboto adalah DAS Alo-Pohu.
Pengukuran erosi permukaan dilakukan dengan menggunakan sistem plot dengan bentuk
persegi panjang. Ukuran petak yaitu lebar 2 m dan panjang 5 m dan ketinggian 20 cm di atas
permukaan tanah. Untuk mengkaji pengaruh curah hujan terhadap erosi permukaan pada
lahan pertanian jagung digunakan analisis regresi.
Hasil pengukuran erosi permukaan pada lahan pertanian jagung dengan
kemiringan lereng datar (3,5%) menunjukkan bahwa tingkat erosi
permukaan sebesar 1,04 ton/ha/tahun (sangat rendah), pada lereng landai
tingkat erosi permukaan sebesar 9,88 ton/ha/tahun (sangat rendah), pada
lereng agak curam tingkat erosi permukaan sebesar 40.588 ton/ha/tahun
(rendah), dan pada lereng curam tingkat erosi permukaan sebesar 176.490
ton/ha/tahun (sedang).
Hasil pengamatan selama satu tahun menunjukkan bahwa erosi permukaan akan berkurang
seiring dengan umur pertumbuhan jagung. Hal ini disebabkan karena telah disertai dengan
tumbuhnya tanaman bawah (rumput-rumputan) pada umur jagung memasuki bulan kedua
dan ketiga.
Pengaruh curah hujan terhadap erosi permukaan pada lahan pertanian jagung lereng datar
adalah Log Y = -3,2 + 3,11 Log X; pada lereng landai Log Y = -3,02 + 2,93 Log X; pada
lereng agak curam Log Y = -2,73 + 3,74 Log X; dan pada lereng curam Log Y = 0,28 + 1,71
Log X.
Diunduh dari: repository.ung.ac.id/.../TINGKAT_EROSI_PERM... ……… 25/12/2012
EROSI TANAH
ANALISIS SPASIAL TINGKAT BAHAYA EROSI DI WILAYAH
DAS CISADANE KABUPATEN BOGOR
Tuti Herawati (Pusat Litbang Hutan dan Konservasi Alam)
Jurnal Penelitian Hutan dan Konservasi Alam. Vol. VII No. 4 : 413-424, 2010
Penelitian ini bertujuan untuk menghitung tingkat bahaya erosi di DAS Cisadane
berdasarkan rumus USLE menggunakan analisis GIS. Berdasarkan rumus yang
digunakan, maka diperlukan empat jenis peta sebagai dasar perhitungan tingkat
bahaya erosi, yaitu peta curah hujan, peta jenis tanah, kemiringan, dan peta
penutupan lahan. Pada setiap peta dilakukan klasifikasi menjadi empat atau lima
kelas berdasarkan standar tertentu. Proses overlay dilakukan untuk mendapatkan
hasil akhir berupa tingkat bahaya erosi yang dikategorikan menjadi lima kelas
yaitu sangat ringan, ringan, sedang, berat, dan sangat berat.
Hasil penelitian menunjukkan bahwa tingkat bahaya erosi di DAS
Cisadane meliputi sangat ringan hingga sangat berat dengan
persentase luas lahan berturut-turut dari yang sangat ringan hingga
sangat berat 55,85%; 15,74%; 6,33%; 0,81%; dan 0,30%. Lahan
dengan tingkat bahaya erosi sangat berat meliputi luas 316 ha dan
tingkat berat meliputi 851 ha.
Tamansari merupakan kecamatan yang memiliki luas wilayah dengan tingkat
bahaya erosi sangat berat terluas yaitu 87 ha. Beberapa kecamatan lain yang
memiliki luas lahan dengan tingkat bahaya erosi berat adalah Tenjolaya,
Caringain, Cijeruk, dan Nanggung.
Hasil penelitian ini dapat digunakan sebagai data dasar untuk membuat rencana
pengeolaan DAS yang baik.
Diunduh dari: www.forda-mof.org/index.php/content/.../788……… 25/12/2012
EROSI TANAH
PENGKAJIAN PENERAPAN TEKNIK KONSERVASI TANAH
PADA LAHAN USAHATANI BERBASIS TANAMAN SAYURAN
DI SENTRA TEMBAKAU
H. Suganda dan Ai Dariah
Pengkajian Penerapan Teknik Konservasi Tanah
BALITTANAH – LITBANG - DEPTAN.
Studi ini bertujuan untuk mendapatkan informasi tentang penerapan teknik
konservasi tanah dalam usahatani sayuran di daerah sentra tembakau, Kabupaten
Temanggung. Penelitian dilaksanakan tepatnya di tengah lokasi demontrasi plot
penerapan teknologi konservasi tanah dengan luas lahan 2,85 ha di Desa
Batursari dengan 13 orang petani kooperator, dan 2,53 ha di Desa Kledung
dengan 10 orang petani kooperator. Pengamatan berlangsung mulai musim hujan
(MH) 2006/07 sampai dengan MH 2007/08. Tanah di dua lokasi tersebut
tergolong Andisol. Teknik konservasi tanah yang diterapkan adalah cara mekanik
dengan tambahan rumput penguat teras.
Hasil penelitian menunjukkan bahwa dengan menerapkan teknik
konservasi tanah ternyata erosi pada lahan sayuran di sentra
tembakau dapat diturunkan sebanyak 38,4 % - 66,2 %, bahkan
kehilangan tanah akibat erosi dapat ditekan menjadi < 6,0 t/ha.
Rumput penguat teras (paspah) dengan luasan 1 m2, dapat
menghasilkan hijauan 3,6-4,0 kg, cukup untuk kebutuhan sehari
pakan domba yang bobotnya sekitar 20 kg.
Penerapan konservasi tanah dapat mengurangi laju kehilangan hara akibat erosi
dan mempertahankan kesuburan tanah. Petani kooperator di Desa Kledung yang
sudah menerapkan teknik konservasi tanah, lahannya relatif lebih subur
dibanding dengan lahan petani kooperator di Desa Batursari, sehingga rata-rata
pendapatannya per tahun lebih tinggi dari Rp. 3.100.000 .
Diunduh dari: balittanah.litbang.deptan.go.id/.../hsuganda_sayura...……… 25/12/2012
ANCAMAN KEKERINGAN
SAWAH KERING, WARGA SHALAT ISTISQO’
Petani Nagari Canduang Koto Laweh was-was jika musim kemarau terus
berlanjut hingga sebulan ke depan. Irigasi yang berada di nagari itu tidak lagi
mampu mengalirkan air ke lahan pertanian. Sebab debit air semakin berkurang
sejak kemarau bulan lalu. Menanggapi persoalan yang terjadi, pemerintah nagari
menganjurkan masyarakat untuk melaksanakan shalat minta hujan (istisqo’).
”Semoga hujan yang turun bisa menjadikan tanaman kami bisa kembali tumbuh
subur,” harap Wan saat berbincang dengan Padang Ekspres di salah satu warung
kopi di Jorong Tigo Alua Nagari Koto Laweh.
Diunduh dari: http://padangekspres.co.id/?news=berita&id=8183 ……… 25/12/2012
ANCAMAN KEKERINGAN
. 8.950 HEKTARE SAWAH DI LEBAK KEKERINGAN
Rabu, 8 Agustus 2012 20:20 WIB
Metrotvnews.com, Lebak:
Kekeringan sawah di Kabupaten Lebak, Provinsi Banten, hingga saat ini
mencapai 8.950 hektare akibat kemarau yang terjadi belakangan ini.
"Kekeringan ini tentu berdampak terhadap berkurangnya produksi pangan“.
Ia mengatakan pihaknya terus melakukan penyelamatan tanaman padi yang
mengalami kekeringan dengan pengoptimalan pompanisasi terpadu.
Diperkirakan dari 8.950 hektare itu dipastikan seluas 4.650 hektare bisa
diselamatkan dengan pengairan menggunakan pompanisasi terpadu. Sedangkan
4.300 hektare terancam gagal panen.
Sebagian besar areal persawahan yang terjadi kekeringan itu di daerah sawah
tadah hujan. Sawah tadah hujan itu disebabkan tidak memiliki saluran irigasi
yang memadai. Akibat kekeringan ini, petani mengalami kerugian hingga
miliaran rupiah apabila tanaman padi mereka gagal panen. Saat ini, biaya
produksi rata-rata Rp5 juta per hektare.
Diunduh dari: http://www.metrotvnews.com/read/news/2012/08/08/101462/8.950-HektareSawah-di-Lebak-Kekeringan/6……… 25/12/2012
ANCAMAN KEKERINGAN
ANTARA. 20 Juni 2011 | 14:10 WIB
450 Ha sawah di Indramayu terancam kekeringan
INDRAMAYU: Sekitar 450 hektare sawah di Desa Soge, Indramayu, Jawa Barat,
terancam gagal panen akibat kekeringan.
Pasokan air memasuki musim kemarau semakin sulit dan diperkirakan ratusan
hektare sawah akan terancam gagal panen akibat kekeringan. Dua sungai
pemasok air, yaitu kali Prawan dan Kali Persijat, debitnya semakin menurun. Jika
hujan tidak turun, diperkirakan tanaman milik petani setempat yang baru berusia
kurang dari dua bulan akan kering akibat pasokan air terhambat.
Petani kurang memperhatikan cuaca. Mereka terlalu memaksakan tanam padi,
padahal mulai memasuki kemarau. Musim tanam tahun sebelumnya pasokan air
cukup melimpah, sehingga mereka terlena diperkirakan hujan masih panjang.
Menurut dia, petani di daerah pantura Indramayu harus tanggap memperkirakan
pasokan air hujan karena lahan pertanian masih mengandalkan tadah hujan.
Lahan pertanian di sepanjang pantai pesisir utara Indramayu memasuki kemarau
setiap tahun mengalami kekeringan, sementara musim hujan sawah sering
terendam akibat banjir..
Diunduh dari: http://bisnis-jabar.com/index.php/berita/450-ha-sawah-di-indramayu-terancamkekeringan……… 25/12/2012
ANCAMAN KEKERINGAN
ANTARA. 12 September 2011 | 19:51 WIB
48.000 HEKTARE SAWAH DI KABUPATEN BEKASI
KEKERINGAN
BEKASI (bisnis-jabar.com): Dinas Pertanian Kota Bekasi, Jawa Barat, mencatat
sekitar 48.000 hektare persawahan di wilayahnya mengalami kekeringan akibat
debit air yang terus menurun selama musim kemarau.
Sumber air dari waduk Jatiluhur melalui kali Tarum Barat terus menyusut selama
musim KEMARAU. Saluran irigasi sawah di 23 kecamatan di Kabupaten Bekasi,
saat ini sudah kering seiring berkurangnya debit air tersebut. Wilayah paling
parah di bagian selatan, seperti Kecamatan Cibarusah, Cikarang Selatan, Serang
Baru, dan Kecamatan Setu.
Pompanisasi dilakukan untuk menjaga target produksi beras di Kabupaten Bekasi
sebanyak 631 ribu ton setiap kali panen tetap terjaga.
Diunduh dari: http://bisnis-jabar.com/index.php/berita/48-000-hektare-sawah-di-kabupatenbekasi-kekeringan ……… 25/12/2012
ANCAMAN KEKERINGAN
PULUHAN HEKTARE SAWAH KEKERINGAN
Puluhan hektare sawah di Dukuh Klampok, Desa Sendangsikucing, Kecamatan
Rowosari mengalami kekeringan sejak satu pekan ini. Akibat kekeringan,
tanaman padi berumur satu minggu terancam mati. Petani kesulitan mendapatkan
pasokan air dari saluran irigasi karena lokasinya jauh.
“Jika dalam jangka waktu tiga hari ke depan, pasokan air tidak ada, tanaman padi
terancam mati,” (Menurut petani Sulaemi).
Setiap musim kemarau tiba, puluhan hektare sawah di dukuhnya kekurangan air.
Selain itu, puluhan hektare sawah di perbatasan Desa Bulak- Sendang si kucing
juga kekurangan air. Pemerintah diharapkan dapat membuat saluran irigasi yang
permanen agar air dapat mengairi lahan pertanian.
Diunduh dari: http://www.beritakendal.com/2012/07/02/puluhan-hektare-sawah-kekeringan/
……… 25/12/2012
ANCAMAN KEKERINGAN
Jum'at, 07 September 2012 | 00:51 WIB
BELASAN RIBU HEKTARE SAWAH ALAMI
KEKERINGAN
TEMPO.CO, Surabaya - Kepala Bidang Produksi Tanaman Pangan Dinas Pertanian Jawa
Timur, Achmad Nurfalakhi, mengatakan 13,9 ribu hektare sawah bertanaman padi di Jawa
Timur mengalami kekeringan. Sebagai dampak akibat kekeringan sawah, sejumlah tanaman
padi mengalami puso (gagal panen).
Dinas Pertanian Jawa Timur mencatat, kekeringan paling luas terjadi di Kabupaten
Bojonegoro seluas 5.410 hektare, Lamongan 2.102 hektare, Tulungagung seluas 2.102
hektare, Trenggalek 1.470 hektare dan Ngawi 948 hektare.
Gagal panen yang dialami petani, menurut dia, terbagi dalam berbagai kriteria. Seluas
2.977,49 hektare padi mengalami gagal panen 100 persen dan 1.961 hektare gagal panen 75
persen. Selain itu, seluas 3.429 hektare mengalami kekeringan sedang (gagal panen 50
persen) dan seluas 5.588 hektare mengalami kekeringan ringan (gagal panen 25 persen).
TEMPO/Marifka Wahyu Hidayat
Diunduh dari: http://www.tempo.co/read/news/2012/09/07/179427953/Belasan-Ribu-HektareSawah-Alami-Kekeringan ……… 25/12/2012
ANCAMAN CEKAMAN AIR
American-Eurasian J. Agric. & Environ. Sci., 5 (2): 264-272, 2009
EFFECTS OF DROUGHT STRESS ON GROWTH AND YIELD OF RICE
(ORYZA SATIVA L.) CULTIVARS AND ACCUMULATION OF
PROLINE AND SOLUBLE SUGARS IN SHEATH AND BLADES OF
THEIR DIFFERENT AGES LEAVES
A. Mostajeran and V. Rahimi-Eichi
One of the main problems of rice cultivation and production is the lack of
water resources, especially during periods of low rainfall which affect the
vegetative growth rate and the amount of yield.
In this study the effect of low water supply on the number of heading per
hill, number of grain per hill, dry weight of vegetative tissues and panicle
and 1000 grain weight in three new cultivars of rice including 216, 829 and
Zayandeh-Rood were measured under submerged and non-submerged
conditions in a randomize complete block design with three replicates.
Simultaneously, the variation in proline and total sugars in sheaths and
blades of leaves at different ages was determined.
The data indicated that Zayandeh-Rood cultivar showed the lowest
reduction in shoot dry weigh and the number of tillers per hill under nonsubmerged conditions.
Furthermore, the panicle weight and the number of filled grains per spike
were higher in Zayandeh-Rood cultivar than the other cultivars. In addition,
the result of this study show that Zayandeh-Rood cultivar in which
originated from local cultivars, have higher ability in solute accumulation
such as proline and total carbohydrates than the other new lines.
Due to correlation between drought tolerance of Zayandeh-Rood
and solute accumulation, it may be suggested that the solute
accumulation is one of the mechanisms for drought tolerance in
rice.
Diunduh dari: www.idosi.org/aejaes/jaes5(2)/18.pdf ……… 25/12/2012
ANCAMAN CEKAMAN AIR
EFFECTS OF WATER STRESS ON RICE GRAIN YIELD
AND QUALITY AFTER HEADING STAGE
ZHENG Jia-guo; REN Guang-jun; LU Xian-jun; JIANG Xin-lu
Chinese Journal of Rice Science 2003, 17(3): 239-243 .
Pot experiment was conducted in 2000-2001.
Results showed that water stress reduced rice yield significantly within
25 days after 80% of full heading; the effects were very weak after 25
days due to water in soil could maintain rice physiological activity about
10 days.
The grain quality interrelated to the grain filling degree. It was better to
keep water in paddy until 25 days after 80% of full heading for rice
quality cultivation.
Diunduh dari: http://www.ricesci.cn/EN/abstract/abstract887.shtml……… 25/12/2012
ANCAMAN CEKAMAN AIR
. Ying Yong Sheng Tai Xue Bao. 2006 Jul;17(7):1201-6.
EFFECTS OF WATER STRESS DURING GRAIN-FILLING
PERIOD ON RICE GRAIN YIELD AND ITS QUALITY UNDER
DIFFERENT NITROGEN LEVELS.
Cai Y, Wang W, Zhu Z, Zhang Z, Lang Y, Zhu Q
To examine the effects of nitrogen (N) supply and water stress on rice grain yield and its
quality, a pot experiment was conducted at Yangzhou University. Three rice cultivars were
grown under two N levels (high N and normal N) from initial heading, and two water
conditions (well watering and water stress) were installed for each of the two N levels from
flowering to maturity.
The results showed that when the plants of test cultivars were grown under normal N level,
water stress markedly reduced the grain-filling percentage and grain weight, resulting in a
significant decrease of grain yield by 11.6% to approximately 14.7%. Though the headmilled rice had a slight increase, the percentage of chalkiness was significantly increased by
18.7% to approximately 33.1%, which resulted in an inferior performance in grain-apparent
quality. In contrast, when the plants were grown under high N level, water stress increased
the grain yield by 18. 8% to approximately 22.2% because of the increase of grain-filling
percentage and grain weight. As compared with well watering, water stress decreased the
percentages of chalky grain and chalkiness by 15.3% to approximately 37.2% and 13.7% to
29.9%, respectively, which improved the performance of grain-apparent quality. The
pronounced effects of N application and water treatment were observed on the RVA profile
and cooked quality. Under both two N levels, water stress decreased the peak viscosity and
breakdown (except for Yangdao 6) while increased the setback.
According to the performance in the indices of cooked quality, the palatability became poor
when subjected to water stress under normal N level, as the result of the increase of hardness
and cohesiveness. In contrast, under high N level, water stress availed the ascending of
viscosity at the early stage when rice flours were pasting, peak viscosity and breakdown were
increased, and setback was decreased, suggesting that the palpability got well.
It was concluded that mild water stress during grain-filling period
was benefit for the development of high quality grain when rice
plants were grown under high N level.
Diunduh dari: http://www.ncbi.nlm.nih.gov/pubmed/17044492……… 25/12/2012
ANCAMAN CEKAMAN AIR
BIOLOGIA PLANTARUM (PRAHA)
26 (4) : 263--266, 1984
EFFECT OF WATER STRESS AT DIFFERENT
DEVELOPMENTAL STAGES OF FIELD-GROWN RICE
AJoY K. BISWAS and M. A. CHOUDHVRI
Water-stress for 10d at different developmental stages, affected relative
water content and leaf water potential of plants. Subsequent rewatering removed
these effects.
Water stress lowered the contents of chlorophyll, protein, RNA and the activity of
catalase, while it increased free proline accumulation and activities of protease,
RNase and peroxidase. An overall improvement in biochemical parameters was
achieved as soon as the stress was withdrawn by watering and this was reflected
in subsequent developmental stages.
Water-stress at the reproductive stages induced similar
changes as in the vegetative stage but the removal of stress
could not improve these parameters to the same extent as at
the vegetative stage.
In consequence, stress applied at the vegetative stage augmented yield parameters
but when applied at the reproductive stage it significantly reduced the yield.
Diunduh dari: http://link.springer.com/content/pdf/10.1007%2FBF02902907……… 25/12/2012
ANCAMAN CEKAMAN AIR
Study of water stress effects in different growth stages on
yield and yield components of different rice (Oryza sativa L.)
cultivars
Hemmatollah Pirdashti , Zinolabedin Tahmasebi Sarvestani , Ghorbanali Nematzadeh and
A. Ismail.
Australian Agronomy Conference. 2004 12th AAC, 4th ICSC.
Water stress affects plant growth and development and ultimately, reduces grain
yield of irrigated lowland rice.
A field experiment was conducted during 2001-2003 to evaluate the effect of
water stress on the yield and yield components of four rice cultivars commonly
grown in Mazandaran province, Iran. The cultivars used were Tarom, Khazar,
Fajr and Nemat. The different water stress conditions were water stress during
vegetative, flowering and grain filling stages and well-watered was the control.
Water stress at vegetative stage significantly reduced plant height of all cultivars.
Water stress at flowering stage had a greater grain yield reduction than water
stress at other times.
The reduction of grain yield largely resulted from the reduction in
fertile panicle and filled grain percentage. Water deficit during
vegetative, flowering and grain filling stages reduced mean grain
yield by 21%, 50% and 21% on average in comparison to control
respectively.
The yield advantage of two semidwaf varieties, Fajr and Nemat, were not
maintained under drought stress.
Diunduh dari: http://www.regional.org.au/au/asa/2004/poster/1/3/3/1095_pirdashtih.htm………
25/12/2012
ANCAMAN CEKAMAN AIR
. Journal of Agricultural Biotechnology and Sustainable Development Vol. 2(6), pp. 100-107,
June 2010
EFFECT OF WATER DEFICIT AT GRAIN REPINING
STAGE ON RICE GRAIN QUALITY
M. Fofana, M. Cherif , B. Kone, K. Futakuchi and A. Audebert.
Rice production is usually reduced by water stress that can evenly occur during rice
cycle in West Africa under bimodal rainfall pattern. In order to determine the effects of
water stress on rice grain quality, experiments were conducted on upland site (on
ferralsol) at the main AfricaRice research center at M’be, 30 km North of Bouaké, Côte
d’Ivoire. The rice varieties CG14 (Oryza glaberrima), WAB56-104 (Oryza sativa), and
NERICA1 (cross WAB56-104 x CG14) were sown at 25 × 25 cm spacing during the
dry season cropping period of 2000, 2001 and 2002. Irrigation line (Boon irrigation)
was used to supply water until flowering stage. Water was then supply manually from
the milky stage of each variety to its full ripening stage. Physical (husking yield,
milling recovery, and head rice ratio), chemical (amylose and proteins contents) and
cooking parameters (cooking time, volume expansion, rice flour gelatinization
temperature, consistency and viscosity) of the harvested grains were determined in the
laboratory.
The results showed a significant difference (p < 0.05) between all the parameters in
comparison with the checks samples and stressed crop. In general, NERICA 1 showed
better physical and cooking quality traits than its parents. Rice samples from plots
subject to lower water availability during repining stage showed higher protein content
for all varieties studied. Increase in the average protein content of stressed samples
were 31, 11.8 and 13.3% times, respectively for NERICA 1, CG14 and WAB56 -104,
where (using the protein content of check plots as 100%) NERICA 1 showed higher
husking yield, total mean milling recovery and head rice ratio for samples collected on
stressed plots than the glaberrima and the sativa samples recorded on similar plots.
Finding showed that cooking properties that meet West African rice consumers’
preferences for cooked rice were more improved for NERICA 1 than its parents in
comparison with samples collected from stressed plots. It is concluded that
moisture stress at ripening stage should be further investigated as potential
indirect means of improving rice grain quality.
Diunduh dari: www.academicjournals.org/jabsd/PDF/.../Fofana%20et%20al.pdf……… 25/12/2012