1. 1. Written By: Saad Arif Sair
2. 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. 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. 4. Impact of Environment on Agriculture Environment effect the agriculture due to: Global warming Heavy rainfalls Floods Acidic Rains Wind erosions Land sliding
5. 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. 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. 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. 8. Land conversion & habitat loss
9. 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. 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. 11. Wasteful Water Consumption
12. 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. 13. Soil Erosion and Degradation
14. 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. 15. Pollution
16. 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. 17. Climate change
18. 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. 19. Genetic Erosion
20. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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.