Presentation on theme: "R. Shanthini 07 Jan 2012 “In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we have."— Presentation transcript:
R. Shanthini 07 Jan 2012 “In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we have been taught.” – Baba Dioum CP551 Sustainable Development
R. Shanthini 07 Jan 2012 Module 8: Use of fertilizers and pesticides, green revolution, and agricultural biotechnology in the agricultural sector, and their impact on sustainable development.
R. Shanthini 07 Jan 2012 Paddy Production in Sri Lanka 1952 - 2006 http://www.statistics.gov.lk/agriculture/Paddy%20Statistics/ TB3_NP_Annual_1952_2006.pdf Harvested area (in ‘000 hect.) doubled Production (in ‘000 Tonnes) increased 5.5 times Average Yield (kg / hect.) increased 2.6 times
R. Shanthini 07 Jan 2012 How was it possible? Fact: Average yield of paddy per area in Sri Lanka increased by a factor of 2.6 during 1952 to 2006, which keeps pace with the Sri Lanka population increase by a factor of 2.37 during 1950 to 2005. http://www.statistics.gov.lk/ and http://esa.un.org/unpp/p2k0data.asp
R. Shanthini 07 Jan 2012 What helped to increase Sri Lanka’s paddy production by a factor of 2.6 during 1952 to 2006?
R. Shanthini 07 Jan 2012 between 1960 and 2000: –world population doubled from 3 to 6 billion people –global economy increased more than sixfold to meet this demand: –food production increased 2 ½ times –water use doubled –wood harvests for pulp and paper production tripled –timber production increased by more than half http://www.millenniumassessment.org/ Take a look at the Global Agriculture Who is eating?
R. Shanthini 07 Jan 2012 Population Undernourished (% of total population) 1990s2000s High Human Development Medium Human Development2016 Low Human Development3634 High Income Middle Income Low Income World HDR2007/2008
R. Shanthini 07 Jan 2012 Population Undernourished (% of total population) 1990s2000s High Human Development Medium Human Development2016 Low Human Development3634 High Income Middle Income1411 Low Income2824 World HDR2007/2008
R. Shanthini 07 Jan 2012 HDR2007/2008 Population Undernourished (% of total population) 1990s2000s High Human Development Medium Human Development2016 Low Human Development3634 High Income Middle Income1411 Low Income2824 World2017
R. Shanthini 07 Jan 2012 http://www.who.int/mediacentre/factsheets/fs311/en/index.html Population Overweight (% of total population) World Data Table is under construction By World Health Organizations Body Mass Index (BMI) = Overweight Pre-obeseObese BMI ≥ 25.00 BMI = 25.00 - 29.99 BMI ≥ 30.00 weight (in kg) height 2 (in m 2 )
R. Shanthini 07 Jan 2012 BMI (in kg / m 2) > 30 30 to 40% 20 to 30% 10 to 20% 5 to 10% 0 to 5% No data Obese adults in population (%)
R. Shanthini 07 Jan 2012 –Food production has more than doubled since 1960 –Food production per capita has grown –Food price has fallen –Undernourished in developing countries have fallen Source: http://www.millenniumassessment.org/
R. Shanthini 07 Jan 2012 It is good to have increased the food production which might have helped reducing the number of undernourished people. The first of the Millennium Development Goals (MDGs) is to Eradicate Extreme Poverty and Hunger The seventh of the MDGs is to Ensure Environmental Sustainability How to achieve both the goals simultaneously?
R. Shanthini 07 Jan 2012 Green Revolution of the 20th century - transformed agriculture that led (in some places) to significant increases in agricultural production (between the 1940s and 1960s). - made food production to match with the global population growth. - has had major social and ecological impacts. Medieval Green Revolution or the Arab Agricultural Revolution of the 8 th century Source: http://en.wikipedia.org/wiki/Green_Revolution Green Revolution:
R. Shanthini 07 Jan 2012 President Mahinda Rajapaksa greets Prof. M.S. Swaminathan, who is considered the Father of the Indian Green Revolution. Green Revolution: Green Revolution of the 21 st century ?
R. Shanthini 07 Jan 2012 in India - High-yielding varieties of seeds of wheat, rice, and other grains that had been developed in Mexico and in the Philippines were introduced in India after 1965 - Use of synthetic fertilizers, irrigation and pesticide/ herbicide increased - Increased production made India self-sufficient in food grains - Famine in India, once accepted as inevitable, has not returned since the introduction of Green Revolution crops. Green Revolution: Source: http://en.wikipedia.org/wiki/Green_Revolution
R. Shanthini 07 Jan 2012 Is food production actually related to famine? Prof. Amartya Sen claimed famines such as the Bengal Famine of 1943 (about 4 million people died) were not caused by decreases in food supply, but by socioeconomic dynamics and a failure of public action. Nobel Prize in Economics (1998) Economist Peter Bowbrick has accused Sen of misrepresenting historical data, telling outright lies and being wrong on his theory of famines. Green Revolution: Source: http://en.wikipedia.org/wiki/Green_Revolution
R. Shanthini 07 Jan 2012 - introduced high-yielding varieties of seeds that are often developed elsewhere - increased the use of pesticide/herbicide which were necessary to limit the high levels of pest damage that inevitably occur in monocultures - increased the use of synthetic fertilizers - increased dependence on fossil fuels from which pesticides, herbicides and synthetic fertilizers are produced - increased the use of irrigation (which has created significant problems of arsenic contamination, salinization, waterlogging, and lowering of water tables in certain areas) - affected both agricultural and wild biodiversities Green Revolution: Source: http://en.wikipedia.org/wiki/Green_Revolution
R. Shanthini 07 Jan 2012 Socioeconomic impacts - it required the purchase of fertilisers, irrigation pumps and regular fresh supplies of seed - smaller farmers often went into debt, which in many cases result in a loss of their farmland Green Revolution: Source: http://en.wikipedia.org/wiki/Green_Revolution
R. Shanthini 07 Jan 2012 A country could go from importing food to exporting it seen by some as committing ecological and economic "suicide" Green Revolution:
R. Shanthini 07 Jan 2012 Growing crops need carbon (C), hydrogen (H), oxygen (O), energy, and other nutrients Fertilizer Use:
R. Shanthini 07 Jan 2012 Air gives C as CO 2 ; O as O 2 ; H as water vapour Water gives H Sunlight gives energy Soil gives other essential nutrients Major nutrients: Nitrogen (N) Phosphorus (P) Potassium (K) Sulphur (S) Calcium (Ca) Magnesium (Mg) Minor nutrients: Iron (Fe) Molybdenum (Mo) Boron (B) Copper (Cu) Manganese (Mn) Zinc (Zn) Chlorine (Cl) and others… Fertilizer Use:
R. Shanthini 07 Jan 2012 Fertilizers are chemicals that supply plant nutrients, mostly N, P and K. With high yielding varieties of crops, most soils are unable to supply the needed amounts of plant nutrients. Fertilizer Use: Manufacture of N-based synthetic fertilizers requires fossil fuels as raw materials.
R. Shanthini 07 Jan 2012 Source: http://www.allrefer.com/pictures/s4/p0001901-nitrogen-cycle Fertilizer Use: Nitrogen cycle
R. Shanthini 07 Jan 2012 Nitrogen fertilizer producing factory Nitrogen cycle Fertilizer Use:
R. Shanthini 07 Jan 2012 Fossil fuels Nitrogen fixations in agroecosystems Fertilizers and industrial uses Total human input Projected human input Teragrams of nitrogen per year Fertilizer Use:
R. Shanthini 07 Jan 2012 Nitrogen-based fertilizers can be washed from the fields into rivers and streams. Excessive amount of nitrogen in the water could cause algal blooms that leads to eutrophication and other harms. Fertilizer Use:
R. Shanthini 07 Jan 2012 Fertilizer run-off Eutrophication 3. Aquatic plants begin to die 4. Dead matter feeds the microbes 1.Algae grow fast, using up lots of dissolved oxygen in water. 2.Algae block sunlight Source: http://www.bbc.co.uk/gcsebitesize 5. Microbes compete for dissolved oxygen 6. Water looses dissolved oxygen 7. Fish die Fertilizer Use:
R. Shanthini 07 Jan 2012 in Taihu Lake, China Algal bloom in real life in Great Lakes, USA Fertilizer Use:
R. Shanthini 07 Jan 2012 “Red tide” of the dinoflagellate Noctiluca stretched for more than 20 miles along the southern California coast. Algal bloom in real life Fertilizer Use:
R. Shanthini 07 Jan 2012 Phaeocystis boom lead to foam formation that accumulate on nearby coastal areas in the North Sea Algal bloom in real life Fertilizer Use:
R. Shanthini 07 Jan 2012 Use of fertilizers has positive effects on the economic and the social components of sustainable development? Fertilizer Use: It has negative effect on the ecological component?
R. Shanthini 07 Jan 2012 Harmful algal blooms (HABs) could produce toxins that accumulates in shellfish that consume algae. Health of the public that consume the shellfish is at risk. Affected areas should be closed and get closed (in the west). No fishing. Fishermen are affected. Economy is affected. Algal bloom in real life Fertilizer Use: Source: http://www.whoi.edu/redtide/page.do?pid=9257# What abut the economic and the social components of SD?
R. Shanthini 07 Jan 2012 Researchers are investigating the use of natural clays in Florida’s Sarasota Bay as a potential tool to mitigate harmful algal blooms, or “red tide”. Source: http://www.whoi.edu/redtide/page.do?pid=9257# Algal bloom in real life Fertilizer Use: What abut the economic component of SD?
R. Shanthini 07 Jan 2012 Fertilizer Use: Ways to Minimize Fertilizer Impact It is not growing the same crop at the same plot of land throughout the year. Soil fertility: Different crops have different soil requirements and benefits. Changing crops from year to year minimises deficiencies and allows the soil to replenish. Soil structure: Alternating between deep-rooted and fibrous-rooted crops improves soil structure. Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp Crop rotation (or sequencing)
R. Shanthini 07 Jan 2012 Fertilizer Use: Ways to Minimize Fertilizer Impact Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp Crop rotation (or sequencing) ExamplesSoil requirementsSoil benefits Cabbage Cauliflower nitrogen-rich soil; may need liming Legumes (Pea, bean) well-drained; moisture-retentive; not nitrogen-rich Fix atmospheric nitrogen in roots for future crops Onion, Garlic Leek high organic matter; may need liming Potato Tomato high organic matter and nitrogen (potato); no lime Suppress weeds, break up soil structure Carrot Celery not freshly manuredRoot crops break up soil structure
R. Shanthini 07 Jan 2012 Fertilizer Use: Ways to Minimize Fertilizer Impact An example: Nitrogen fixing symbiotic systems such as Sesbania rostrate Azolla and free-living cyanobacteria to rice crop Source: http://www.rhs.org.uk/advice/profiles1200/crop_rotation.asp Biofertilizers
R. Shanthini 07 Jan 2012 Source: http://www.ecifm.rdg.ac.uk/pesticides.htm Pesticide Use: Fate of pesticides in the environment
R. Shanthini 07 Jan 2012 Fate of pesticide in the environment is determined by its characteristics, such as water solubility: measures how easily a pesticide may be washed off the crop, leach into the soil or move with surface runoff. soil adsorption: tendency of pesticides to be attached to soil particles half-life: pesticide persistence in the environment (or the time in days required for a pesticide to degrade in soil to one-half its original amount) http://www.agf.gov.bc.ca/pesticides/c_2.htm Pesticide Use:
R. Shanthini 07 Jan 2012 http://www.agf.gov.bc.ca/pesticides/c_2.htm Pesticide Use: Water solubility Soil adsorption Half-lifeFate of pesticide highlowLong (more than 21 days) Move into water lowvery highStrongly attached to soil
R. Shanthini 07 Jan 2012 The purpose of using pesticides / herbicides is to kill. They could kill not only pests and weeds (which they are supposed to) they could also kill and harm beneficial organisms and plants. DDT, a compound found in pesticides, had worked its way up the food chain, bioaccumulating or increasing in concentration at every level until it was enough to weaken the shells of eagle eggs. Pesticide Use:
R. Shanthini 07 Jan 2012 Crop Rotation (or Crop Sequencing) Pest and disease control: Soil pests and diseases tend to attack specific plant families, so by rotating crops the pests' life-cycles are broken and build-up is reduced. Weed control: Some crops (e.g. potatoes) can suppress weeds, minimising problems for following crops. Ways to Minimize Pesticide Impact Pesticide Use:
R. Shanthini 07 Jan 2012 Crop Rotation (or Crop Sequencing) Farmers in Matale district rotate tomato with paddy. The crop is planted in Yala (dry season) followed by paddy in the Maha (wet season) P. Solanacearum which causes bacterial wilt in tomato is unable to live under anaerobic conditions. Hence six months rotation is effective in controlling the disease. Ways to Minimize Pesticide Impact Pesticide Use: Dr. C. Kudagamage Deputy Director (Research) Horticultural Crop Research & Development Institute Gannoruwa, Peradeniya
R. Shanthini 07 Jan 2012 Integrated Pest Management (IPM) IPM doesn't rely solely on chemicals for pest control. Biological control, cultural practices, and timely chemical applications are used to obtain the necessary level of control. Pesticides are the last line of defence and are used only when pest levels are causing sufficient damage to offset the expense of the application. http://www.agf.gov.bc.ca/pesticides/c_2.htm Ways to Minimize Pesticide Impact Pesticide Use:
R. Shanthini 07 Jan 2012 http://www.agf.gov.bc.ca/pesticides/c_2.htm Ways to Minimize Pesticide Impact Pesticide Use: Native Plants Garden Planned for NO use of herbicides / pesticides Weeds removed by hand Choose plants that grow quite densely, leaving little room for weeds once they are established Tolerate many insects as part of the garden's mini- ecosystems (caterpillars bring birds to the garden!)