2. Agriculture The term Agriculture may be defined as: the art
and science of growing plants and other crops and the raising of
animals for food, other human needs, or economic gain. It is the
science, art, or occupation concerned with cultivating land,
raising crops, and feeding, breeding, and raising livestock;
farming.
3. Agriculture & Environment Often, when speaking of the
agricultural impact on the environment, one restricts any
consideration to processes of pollution of surface and ground
waters from chemicals added to the soil during agricultural
practices. No doubt, such processes exist and may have even a
prominent importance. They are caused either by water infiltration
in soil, with the consequent possibility of nutrient and pesticide
leaching.
4. Impact of Environment on Agriculture Environment effect the
agriculture due to: Global warming Heavy rainfalls Floods Acidic
Rains Wind erosions Land sliding
5. Agricultural & Environmental Implications Developing
measures that will encourage flexibility in land use. Crop
management in relation to climate change is a key topic of global
concern. Increasing water management efficiency in order to sustain
agricultural production under changing climatic conditions.
Integrating agricultural, environmental and cultural policies to
preserve the heritage of rural environments.
6. Environmental Impacts of Agriculture When farming operations
are sustainably managed, they can help preserve and restore
critical habitats, protect watersheds, and improve soil health and
water quality. But when practiced without care, farming presents
the greatest threat to species and ecosystems.
7. Multiple Impacts Negative environmental impacts from
unsustainable farming practices include: Land conversion &
habitat loss Wasteful water consumption Soil erosion and
degradation Pollution Climate change Genetic erosion
8. Land conversion & habitat loss
9. Land conversion & habitat loss A major and growing land
use: Agriculture is a major land use. Farmland covers 38% of the
world's land area. This area is still expanding to meet demand for
food. Natural habitats converted to monocultures: Rising demand for
food and other agricultural products has seen large-scale clearing
of natural habitats to make room for intensive monocultures.
10. Land conversion & habitat loss Freshwater is also
affected: Waste water of Fields also effect to the fresh water of
river ,oceans Etc. Land lost to desertification: On top of habitat
loss due to clearing, unsustainable agricultural practices are
seeing 12 million hectares of land lost each year to
desertification.
11. Wasteful Water Consumption
12. Wasteful Water Consumption Agriculture, the greatest user
of water: Globally, the agricultural sector consumes about 70% of
the planet's accessible freshwater more than twice that of industry
(23%), and dwarfing municipal use (8%). Wasteful and unsustainable:
The main causes of wasteful water use are: 1. leaky irrigation
systems 2. wasteful field application methods 3. cultivation of
thirsty crops not suited to the environment.
13. Soil Erosion and Degradation
14. Soil Erosion and Degradation Flooding increased: Erosion
caused by deforestation can also lead to increased flooding. Arable
land destroyed: It is estimated that since 1960, one-third of the
worlds arable land has been lost through erosion and other
degradation. Waterways clogged & polluted: Soil carried off in
rain or irrigation water can lead to sedimentation of rivers, lakes
and coastal areas.
15. Pollution
16. Pollution The use of pesticides, fertilizers and other
agrochemicals has increased hugely since the 1950s. Toxic
pesticides: Pesticides often don't just kill the target pest.
Pesticides can also kill soil microorganisms. Excess nutrients:
Fertilizers are not directly toxic. However, their presence in
freshwater and marine areas alters the nutrient system.
17. Climate change
18. Climate change Agricultural practices are responsible for
around 14% of global greenhouse gas emissions Sources include:
Fertilizers Livestock Wetland rice cultivation Burning of savanna
Agricultural residues, and plugging
19. Genetic Erosion
20. Genetic Erosion Lost genetic diversity: The widespread use
of genetically uniform modern crop varieties has caused
agricultural crops to lose about 75% of their genetic diversity in
the last century. This lost genetic diversity reduces the potential
for modern crops to adapt to, or be breed for, changing conditions
and so directly threatens long-term food security.
21. Aquaculture Aquaculture is the farming of aquatic organisms
such as fish, shellfish and even plants. The term aquaculture
refers to the cultivation of both marine and freshwater species and
can range from land-based to open-ocean production.
22. AQUACULTURAL SYSTEMS, PRACTICES AND PROBLEMS HAVING
POTENTIAL IMPACT ON THE ENVIRONMENT Destruction of Habitat for
Aquacultural activities: The creation of ponds for marine shrimp
aquaculture has led to the destruction of thousands of hectares of
mangroves and coastal wetlands. Mangroves provide nursery grounds
for many species, including commercially important fish, and their
destruction may lead to substantial losses for commercial
fisheries.
23. Collecting wild Juveniles as Stock Aquaculture of some
species relies on juvenile fish or shellfish being caught from the
wild to supply stock, rather than using hatcheries to rear them.
Shrimp farms in many areas rely on wild caught juveniles. This has
led to over exploitation and shortages of wild stocks. The main
environmental impact of crab culture is the procurement of larvae
from wild brood stock, and the on-growing of wild crablets.
24. Depletion and Salinization of Water/land Pumping of
groundwater to supply freshwater to marine shrimp farms has
resulted in depletion and, sometimes, Salinization of local water
supplies, causing water shortages for coastal communities. There
have also been many reports of crop losses after agricultural land
has become salinized by effluent water pumped out from shrimp farms
onto land.
25. Poor research in fish diseases and abuse of medicines Novel
fish diseases cannot be treated, and diagnosis of aquatic diseases
in the third world involves undeveloped instruments and weak
technical power. Hence inability to distinguish bacterial and
nutritional diseases, which directly influence correct medication.
Once the disease comes on, the abuse of medicines is imminent.
26. Weak environment protection consciousness Though various
high-yielding aquaculture methods such as industrial fish farming,
cage fish culture, and raceway culture are developed to some
extent. Fishing and environment protection consciousness are still
deficient, and the random discharge of aquaculture waste waters
without any treatment has deteriorated the whole aquaculture
environment, and blocked the sustainable development of this
industry.
27. Residual feeds and excrements (fish waste) Feeds are the
basic material of aquaculture, and the source of main nutritional
matters. Most feeds of aquaculture are outside source foods and
given to aquatic animals directly. Large amount of residual feeds
and the excrements of aquatic animals all impact the water
environment.
28. Escaping Salmon and their threat to Wild Fish Farmed
Atlantic salmons have escaped in vast numbers and are successfully
breeding with their wild counterparts. Farmed salmon have a lower
genetic variability than wild salmon. Experiment show that the
offspring are less fit than wild salmon and a high proportion die.
Interbreeding of farmed with wild salmon could therefore drive
already vulnerable populations of wild salmon towards
extinction.
29. Environmental impacts of Aquaculture Influence on
physiochemical parameters of water: The main influence of
aquaculture on water quality is to increase the suspended
substances and the nutritional salts in waters. Cages used in
aquaculture can also reduce the dissolved oxygen in the water. The
wastes of cage aquaculture increased the total concentration of
water nutrient and increased the turbidity of the waters.
30. Influence on substrate of aquaculture facilities On the
bottom of facilities used in aquaculture, the contents of C, N and
P are higher than the contents those used for other purpose, and
the oxygen consumption is also higher. When the organic matters
accumulated on the mud bottom are too much, the physiochemical
index of the bottom will be changed, and the decomposing function
of microorganisms results into bloom, and the dissolved oxygen in
the bottom is depleted, as a result of numerous sulfates in the
water, hydrogen- sulphide (H2S) build up in the environment.
31. Influence on planktons and bottom dwellers The input of
outside-source materials and organic matters can increase the
productivity of the planktons. Feeds make the nutrient matters in
waters to gradually increase, and the phytoplankton propagated
largely at the beginning, but as time goes on and the continual
expansion of aquaculture is still on a large scale, the nutrient
matters input increases to a point the water quality deteriorates,
so the amount of phytoplankton will begin to reduce.
32. Escaped domestic fish and ecosystem health Another
influence of aquaculture on aquatic biology is that the escaping
fishes would impact their wild neighbours in biology. Escapees from
small-scale scenarios and unreported escape cases seem to make up a
large proportion of the escaped farmed fish. The escaping fishes in
the aquaculture may spread diseases and change the inheritance
composition of genes of wild swarm, and infect local epidemics to
wild swarms.
33. The influence on the ecological environment In the recent
years, because of the development of aquaculture, the seductive
profit of aquaculture has raised a aquatic tide in the world, most
lakes, rivers, swamps, coastal lowlands and mudflats are changed
into shrimp culture ponds and fish culture ponds. These lowlands
were mangroves, saline soils and agricultural lands, and some of
them were inhabiting, spawning and refuge places for many fishes
and shellfishes. Unreasonable development will destroy the
ecological environment of shells, and the natural resource.
34. Reduced functionality of wetlands Natural wetland functions
support a wide array of environmental goods and services that
sustain economic activities and societal systems. However,
aquaculture development can damage the functional integrity of
wetlands, disrupting the supply of environmental good and services.
Loss of the mangrove root system could decrease sediment stability,
leading to erosion, which could increase saline intrusion and the
risk of flooding inland.
35. Self-pollution Wastewater from land-based aquaculture is
routinely discharged to streams and rivers supplying other
aquaculture operations downstream, whilst waste discharged from pen
and cage farms may be conveyed to other farms by currents and
tides. Moreover, for pen and cage aquaculture facilities there is a
danger that discharged wastes that may contaminate water intended
to supply the farm.
36. High potential strategies for low impact aquaculture
Community-based management: Community-based management usually
centers on common pool resources non-exclusive resources to which
the rights of use are distributed among a number of co-owners,
generally identified by their membership to some group such as a
village or community. Include: community pastures, grazing lands
and forests, wastelands, dumping grounds and threshing areas,
village ponds, rivers and other common pool wetlands.
37. Horizontally integrated production Horizontally integrated
production has been defined as the use of unexploited resources
derived from primary aquaculture activities to facilitate the
integration of secondary aquaculture practices. Horizontal
integration has the potential to perform several important
functions, the most valuable being the assimilation of wastes,
reducing discharges to the receiving environment. Reducing waste
discharges through horizontal integration will contribute to
environmental protection and reduce the risk of negative feedback
mechanisms.
38. Resource efficient production The poor resource-base of
small-scale farms in developing countries means that unexploited
nutrient sources e.g. crop by-products, terrestrial weeds; aquatic
plants and manure represent important production enhancing inputs
to fishponds. Alternative strategies that have evolved to integrate
the production of livestock and aquaculture; manure from cattle,
buffalo, sheep, and poultry has been employed to enhance production
in aquaculture systems.
39. Sustainable seeds supplies Sustainable access to fry and
fingerlings can constitute a significant constraint to aquaculture
development. Several traditional aquaculture practices evolved
based on the collection of gravid females or seed from the wild,
however, harvest of wild seed was often unsustainable and unable to
support higher production.
40. RECOMMENDATIONS AND CONCLUSION Most aquatic wastes come
from feeds, to reduce these wastes, limit the percentage of
un-consumed feed in the culture facility. To reduce nutrient
wastes, Aquaculture effluents should be monitored and managed, to
avoid or reduce any negative environmental impacts. In feeding of
fishes, the proper feed quantity should be confirmed, this will
reduce the amount of feeds scattered and loss during feeding.
41. Contin. Using fishery chemicals correctly The chemical
dosage must the strictly controlled, and the performance and method
of fishery chemical administration must be correctly known.
Enhancing management level of aquaculture Implementing rules about
aquaculture resource development, and comprehensively utilizing the
regulations of fishery resource management.
42. Conclusion Based on the above discussion it may be
concluded that a number of promising technical, social and
institutional approaches with potential to contribute to low impact
aquaculture have been identified and to some degree tested,
however, strategies are required that promote and support their
uptake and where necessary adaptation. Awareness of promising
approaches to low impact of agriculture and aquaculture should be
promoted amongst target institutions including national and local
government authorities, extension agents, development
practitioners, educational establishments and communities that
stand to benefits.